WO2020203481A1

WO2020203481A1 - Absorbent article

Info

Publication number: WO2020203481A1
Application number: PCT/JP2020/013092
Authority: WO
Inventors: 侑也松田; 紀子清水; 井上　拓也
Original assignee: ユニ・チャーム株式会社
Priority date: 2019-03-29
Filing date: 2020-03-24
Publication date: 2020-10-08
Also published as: JP2020162996A; CN113518606B; JP6605167B1; RU2764151C1; CN113518606A

Abstract

Provided is an absorbent article (1) having an absorbent body (10), wherein the absorbent body (10) comprises: an absorbent core (11) with liquid absorption; an exterior sheet portion (13), which is disposed closer to the non-skin side than the absorbent core (11), includes a breathable film (13a) and a back sheet (13b), and has a predetermined heat flow peak value Qmax under a certain temperature condition; and a top sheet (12) which is disposed closer to the skin side than the absorbent core (11) and is configured to have a heat flow peak value Qmax which is lower than the predetermined heat flow peak value Qmax under the certain temperature condition.

Description

Absorbent article

The present invention relates to an absorbent article.

As an example of an absorbent article, a pants-type disposable diaper equipped with a collecting body is known. The absorbent body generally includes a liquid-absorbing absorbent core, a top sheet provided on the skin side of the absorbent core, and a breathable film and back sheet provided on the non-skin side of the absorbent core. have. From the viewpoint of comfort during wearing, it is desirable that each of these parts has a structure that easily maintains a transpiration effect with the wearer's body. For example, Patent Document 1 states that in an absorbent product provided with an air permeable backsheet, it is easier to maintain the natural transpiration of the wearer's skin in order to reduce overheating and sweating of the closed portion of the body. Techniques for enhancing the comfort of the wearer are disclosed.

Special Table 2018-524069

In the conventional absorbent article, after the absorbent core absorbs a liquid such as urine, the absorbent body may be cooled by the heat of vaporization when the liquid is vaporized. In particular, when wearing absorbent articles in an environment where the outside air temperature is low (for example, when wearing a diaper in winter), the temperature of the absorber is further lowered by the outside air temperature via the breathable film or back sheet. It was getting easier. In such a case, the body of the wearer may be cooled by the absorbent body whose temperature has been lowered, which may cause discomfort to the wearer.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to prevent the wearer's body from being cooled and to prevent the wearer from being discomforted. Is to provide an absorbent article with.

The main invention for achieving the above object is an absorbent article having a vertical direction and a horizontal direction intersecting each other and having an absorbent main body, wherein the absorbent main body is a liquid absorbent absorbent core. The exterior sheet portion, which is arranged on the non-skin side of the absorbent core, has a breathable film and a back sheet, and has a predetermined heat flow rate peak value Qmax under a certain temperature condition, and the skin of the absorbent core. Absorption characterized by having a topsheet arranged on the side and configured to have a heat flow peak value Qmax lower than the predetermined heat flow peak value Qmax under certain temperature conditions. It is a sex article.
Other features of the present invention will be clarified by the description in the present specification and the accompanying drawings.

According to the present invention, it is possible to provide an absorbent article having an absorbent body that suppresses the wearer's body from being cooled and does not cause discomfort to the wearer.

It is a schematic perspective view of the diaper 1. It is a top view of the diaper 1 in the expanded and extended state. It is the schematic sectional drawing in line AA shown in FIG. It is a figure explaining the heat transfer generated in the absorbent body 110 of the comparative example. It is a figure explaining the heat transfer generated in the absorbent body 10 of this embodiment. It is a table which summarized the result of having measured the Qmax value for a plurality of kinds of sheet members. It is schematic cross-sectional view which shows the surface shape of the top sheet 12 of this embodiment. It is the schematic sectional drawing which shows the modification of the absorbent body 10.

The description of this specification and the accompanying drawings will clarify at least the following matters.
It is an absorbent article having a vertical direction and a horizontal direction intersecting each other and having an absorbent main body, and the absorbent main body is formed on a liquid-absorbable absorbent core and a non-skin side of the absorbent core. An exterior sheet portion that is arranged, has a breathable film and a back sheet, and has a predetermined heat flow rate peak value Qmax under a certain temperature condition, and is arranged on the skin side of the absorbent core, and is arranged at the certain temperature condition. An absorbent article comprising a top sheet configured to have a heat flow rate peak value Qmax lower than the predetermined heat flow rate peak value Qmax.

According to such an absorbent article, heat transfer through the topsheet between the absorbent core and the wearer's skin is reduced, and even if the temperature of the absorbent core is lowered, the coldness is worn. It becomes difficult to make people feel. On the other hand, the heat transfer between the absorbent core and the outside air becomes large through the exterior sheet portion, and the moisture of the absorbent core is easily evaporated to the outside air side. Thereby, it is possible to prevent the wearer's body from being cooled and to provide an absorbent article having an absorbent body that does not cause discomfort to the wearer.

It is desirable that the top sheet, the absorbent core, and the exterior sheet portion of the absorbent body are laminated in the thickness direction at least in the crotch portion of the wearer.

According to such an absorbent article, it is possible to easily suppress heat exchange that occurs on the skin side of the wearer in the crotch where the wearer's excretion port is located. Therefore, it becomes difficult for the wearer's body to be cooled in the lower crotch, and it is possible to make it difficult for the wearer to feel uncomfortable.

The area of such an absorbent article, in which the top sheet, the absorbent core, and the exterior sheet portion are laminated in the thickness direction on the rear side of the center in the longitudinal direction of the absorbent core. Is larger than the area of the portion where the top sheet, the absorbent core, and the exterior sheet portion are laminated in the thickness direction on the front side of the center of the absorbent core in the longitudinal direction. desirable.

According to such an absorbent article, in the buttock region, which is posterior to the center in the longitudinal direction, has a large surface area, and the absorbent body is easily pressed against the wearer's body when the wearer sits down. It becomes easier to suppress the heat exchange that occurs between the skin and the absorbent core. Therefore, in the buttocks region, it is possible to make the wearer less likely to feel cold and less likely to cause discomfort.

It is desirable that the top sheet of the absorbent article is a non-woven fabric.

According to such an absorbent article, the fibers constituting the non-woven fabric are entangled with each other to form a large number of voids between the fibers, so that the voids inside the non-woven fabric easily hinder the transfer of heat in the thickness direction. Become. Therefore, the heat insulating performance of the top sheet is enhanced, and the wearer's body can be made difficult to cool.

It is desirable that the thickness of the top sheet of the absorbent article is larger than the thickness of the exterior sheet portion.

According to such an absorbent article, heat is less likely to pass in the thickness direction in the top sheet as compared with the exterior sheet portion, so that the heat is passed between the absorbent core and the wearer's body through the top sheet. Less heat transfer. This makes it difficult for the wearer's body to cool down.

In such an absorbent article, the top sheet has a convex portion protruding on one side in the thickness direction and a concave portion provided between two adjacent convex portions in the left-right direction. , Is desirable.

According to such an absorbent article, the area of the portion where the top sheet and the wearer's body come into contact with each other can be reduced by providing the surface of the top sheet with irregularities. As a result, the heat insulating performance of the top sheet is improved, and the wearer's body can be made difficult to cool.

It is desirable that the convex portion of the absorbent article has a narrower width in the left-right direction toward the skin side in the thickness direction.

According to such an absorbent article, the contact area with the wearer's skin becomes smaller and the heat insulating performance of the top sheet is improved as compared with the case where the width of the convex portion is not narrowed. In addition, the space formed between the convex portions adjacent to each other in the left-right direction suppresses the transfer of heat, making it easier to exert a higher heat insulating effect. This makes it difficult for the wearer to feel the cold.

It is desirable that the absorbent article is provided with a second sheet between the top sheet and the absorbent core.

According to such an absorbent article, the provision of the second sheet makes it easier to suppress the transfer of heat between the collecting core and the wearer's body on the skin side of the absorbent core. This makes it difficult for the wearer to feel the cold.

In such an absorbent article, the absorbent core has a constricted portion having a narrowed width in the left-right direction between one side end portion and the other side end portion in the longitudinal direction in the extended state. , Is desirable.

According to such an absorbent article, the surface area of the absorbent core is smaller than that in the case where the width of the absorbent core is constant. Therefore, when the absorbent article is worn, the contact area between the wearer's body and the absorbent core is reduced, and heat transfer between the absorbent core and the wearer's skin can be reduced. This makes it difficult for the wearer to feel cold.

It is desirable that the absorbent core has a high density portion in which the density of the absorbent core is higher than the density around the absorbent core.

According to such an absorbent article, the absorbent core is less likely to come into contact with the wearer's body in the area where the high density portion is provided. Therefore, the contact area with the wearer's skin is smaller than that in the case where the high-density portion is not provided, and the heat transfer between the absorbent core and the wearer's skin can be reduced. This makes it difficult for the wearer to feel cold.

It is desirable that the absorbent core has a low basis weight region in which the basis weight of the absorbent core is lower than the basis weight around the absorbent core.

According to such an absorbent article, in the portion where the low basis weight region is provided, the absorbent core is less likely to be pressed against the wearer's body when the absorbent article is worn. Therefore, the contact area with the wearer's skin is smaller than that in the case where the low basis weight region is not provided, and heat transfer between the absorbent core and the wearer's skin can be reduced. This makes it difficult for the wearer to feel cold.

=== Embodiment ===
As the absorbent article according to the present embodiment, a pants-type disposable diaper 1 (hereinafter, also simply referred to as “diaper 1”) will be described as an example. However, the absorbent article is not limited to the pants-type disposable diaper, and may be sanitary shorts, panty liners, or the like.

<Structure of pants-type disposable diaper 1>
FIG. 1 is a schematic perspective view of a pants-type disposable diaper 1. FIG. 2 is a plan view of the unfolded and stretched diaper 1. FIG. 3 is a schematic cross-sectional view taken along the line AA shown in FIG.

The diaper 1 has a vertical direction, a horizontal direction, and a front-rear direction that intersect with each other in the pants-shaped state shown in FIG. 1, and a waist circumference opening BH and a pair of leg circumference openings LH are formed. In the vertical direction, the waist opening BH side is the upper side and the inseam side is the lower side. Further, as shown in the cross-sectional view of FIG. 3, the direction in which the materials constituting the diaper 1 are laminated is referred to as the thickness direction, and the side in the thickness direction in contact with the wearer's body (skin) is referred to as the skin side. The side that does not come into contact with the wearer's body (skin) is called the non-skin side.

Further, the "extended state" of the diaper 1 means the entire diaper 1 (the entire product) by extending each elastic member (for example, the leg circumference elastic member 17 and the filamentous

elastic members

23, 33, etc., which will be described later) included in the diaper 1. ) Is stretched without wrinkles, specifically, the dimensions of each member (for example, the absorbent main body 10 and the

belt portions

20, 30 described later) constituting the diaper 1 match the dimensions of the member alone. It refers to a state in which it is stretched to a size close to that.

The diaper 1 has an absorbent main body 10, a front belt portion 20, and a rear belt portion 30, which are three members having a rectangular shape in a plan view. The front belt portion 20 (ventral waist circumference) is a portion that is applied to the wearer's ventral side when the diaper 1 is worn, and the rear belt portion 30 (dorsal waist circumference) is the wearer when the diaper 1 is worn. It is the part that is applied to the dorsal part of the diaper.

In the unfolded diaper 1 shown in FIG. 2, the front belt portion 20 and the rear belt portion 30 are arranged so that their longitudinal directions are along the left-right direction (width direction in FIG. 2) of the diaper 1. Then, the front end portion of the absorbent body 10 in the longitudinal direction is arranged at the center of the front belt portion 20 in the left-right direction, and the longitudinal end portion of the absorbent body 10 is arranged at the center of the rear belt portion 30 in the left-right direction. The rear end is located.

In the unfolded diaper 1 shown in FIG. 2, the absorbent main body 10 is folded in half at a predetermined position FL in the longitudinal direction so that the longitudinal direction of the absorbent main body 10 is along the vertical direction of the diaper 1, and the front belt portion 20 And the rear belt portion 30 are joined at both ends in the left-right direction by using a joining means such as heat welding or ultrasonic welding to form a pair of side joining regions 2. As a result, the diaper 1 is in a pants-type state (see FIG. 1) having a waist circumference opening BH and a pair of leg circumference openings LH. The predetermined position FL is the lower end in the vertical direction and the center in the front-rear direction in the pants-type diaper 1.

(Absorbable body 10)
As shown in FIG. 3, the absorbent body 10 has an absorbent core 11, a liquid-permeable top sheet 12 arranged on the skin side of the absorbent core 11, and a non-skin side of the absorbent core 11. It is provided with an exterior sheet portion 13 that is arranged and forms the exterior of the absorbent main body 10. Further, a pair of leakage-proof wall portions 50 are provided on both sides of the absorbent core 11 in the left-right direction.

The absorbent core 11 is a portion that absorbs and retains excrement liquid such as urine, and is formed by molding liquid absorbent fibers such as pulp containing a highly absorbent polymer (SAP) into a predetermined shape. As shown in FIG. 3, the outer peripheral surface of the absorbent core 11 is covered with the core wrap sheet 11a. The core wrap sheet 11a is formed of, for example, tissue paper. However, the core wrap sheet 11a does not necessarily have to be provided.

The absorbent core 11 of the present embodiment has a one-sided end portion between an end portion 11ef on one side (front side) in the longitudinal direction and an end portion 11eb on the other side (rear side) in the elongated state as shown in FIG. It has a constricted portion 11c whose length (width) W11 in the left-right direction (width direction) is shorter than that of 11ef and the other end portion 11eb, and has a substantially hourglass-shaped plan view as shown in FIG. It has a shape. The constricted portion 11c is a portion sandwiched between the wearer's legs (inguinal region) when the diaper 1 is worn, and the length of the portion in the left-right direction is short (narrow width), so that the portion is absorbent. The core 11 is easier to fit in the wearer's crotch.

Further, a low basis weight region (not shown in FIG. 2) may be provided at a predetermined position of the absorbent core 11. The low basis weight region is a region in which the basis weight (weight per unit area) of the absorbent core 11 is lower than its surroundings. Since the absorbent core 11 has low rigidity in the portion where such a low basis weight region is provided, the low basis weight region becomes the starting point of bending of the absorbent core 11 when the diaper 1 is worn. For example, when a low basis weight region is provided along the longitudinal direction of the absorbent core 11, the absorbent core 11 is likely to be bent and deformed in the width direction along the unevenness of the wearer's body. This makes it easier for the absorbent body 10 to fit the wearer's body.

The top sheet 12 is a liquid-permeable sheet member arranged on the skin side of the absorbent core 11 and is formed of a flat-sized nonwoven fabric (for example, an air-through nonwoven fabric or a spunbonded nonwoven fabric) larger than the absorbent core 11. To. In the example of FIG. 3, both ends of the top sheet 12 in the left-right direction are arranged so as to be folded into the non-skin side of the absorbent core 11, and the top sheet 12 is configured to wrap the absorbent core 11 from the skin side. .. However, it is not always necessary that both ends of the top sheet 12 in the left-right direction are folded into the non-skin side of the absorbent core 11.

The exterior sheet portion 13 is a sheet member arranged on the non-skin side of the absorbent core 11, and is a flat-sized sheet member larger than the absorbent core 11. The exterior sheet portion 13 is composed of, for example, a breathable film 13a which is a liquid-impermeable and breathable film such as polyethylene or polypropylene, and a back sheet 13b such as a non-woven fabric which covers the breathable film 13a from the non-skin side. It is a two-layered sheet member.

Side seats 14 are provided at both ends of the exterior seat portion 13 in the left-right direction. In the left-right direction, the side sheet 14 extends outward from the exterior sheet portion 13 and is folded inward with the predetermined positions 10es and 10es as folding positions to form the side flap SF of the diaper 1.

As shown in FIG. 1, the side flap SF is provided so as to project outward in the left-right direction along the leg circumference opening LH. In the present embodiment, a plurality of elastic members around the

legs

17, 17 ... Such as rubber threads are extended in the vertical direction (longitudinal direction) between the

side sheets

14, 14 folded in the thickness direction. Is fixed at a predetermined interval in the left-right direction (width direction) (see FIGS. 2 and 3). As a result, elasticity is imparted to the side flap SF along the vertical direction (longitudinal direction of the absorbent body 10). That is, elasticity is imparted along the leg circumference opening LH. Therefore, when the diaper 1 is worn, the side flap SF is likely to fit on the surface along the leg stretch of the wearer, and it is easy to prevent excrement and the like from leaking from the leg circumference opening LH.

Further, leakage-proof wall portions 50 are provided on both sides of the absorbent core 11 in the left-right direction. When the diaper 1 is worn, the leak-proof wall portion 50 stands up from both sides of the absorbent core 11 in the left-right direction toward the wearer's skin side, so that excrement leaks to the outside of the absorbent body 10 (lateral leakage). Suppress doing.

The leak-proof wall portion 50 of the present embodiment has a leak-proof wall sheet 51 and a plurality of leak-proof wall elastic members 52. The leak-proof wall sheet 51 is a flexible rectangular sheet member, and is made of, for example, a non-woven fabric. The leak-proof wall sheet 51 is bent inward in the left-right direction on the outside of the outer end 11es of the absorbent core 11 in the left-right direction, and the bent one end 50t is from the absorbent core 11. On the skin side, the bent other end 50b is arranged on the non-skin side of the absorbent core 11.

A state in which a plurality of leak-proof wall

elastic members

52, 52 ... Extend in the vertical direction (longitudinal direction) at an end portion 50t on one side of the leak-proof wall sheet 51 which is arranged on the skin side of the absorbent core 11. It is provided in. When the diaper 1 is worn, the end portion 50t of the leak-proof wall portion 50 stands up on the wearer's skin side based on the elasticity developed by the leak-proof wall elastic member 52. On the other hand, the end portion 50b on the other side of the leak-proof wall sheet 51, which is arranged on the non-skin side of the absorbent core 11, is joined in a state of being sandwiched between the absorbent core 11 and the exterior sheet portion 13. It is fixed and serves as an upright base when the leak-proof wall 50 stands up.

(Belts 20, 30)
The front belt portion 20 and the rear belt portion 30 have inner layer sheets 21 and 31, outer layer sheets 22 and 32 laminated on the inner layer sheets 21 and 31, and a plurality of filamentous

elastic members

23 and 33, respectively.

The outer layer sheets 22 and 32 are arranged on the non-skin side of the inner layer sheets 21 and 31. The inner layer sheets 21 and 31 and the outer layer sheets 22 and 32 are arranged on the non-skin side of the absorbent body 10. The inner layer sheets 21 and 31 and the outer layer sheets 22 and 32 alone are non-stretchable sheets that do not substantially have elasticity in the left-right direction of the diaper 1. As the inner layer sheets 21 and 31 and the outer layer sheets 22 and 32, SMS non-woven fabric (spunbond, meltblown, spunbond non-woven fabric), spunbond non-woven fabric, air-through non-woven fabric, plastic sheet, perforated plastic sheet and their laminated sheets are used. Can be done.

The plurality of filamentous

elastic members

23 and 33 are arranged side by side in the vertical direction between the inner layer sheets 21 and 31 and the outer layer sheets 22 and 32, and are fixed in a state of being extended in the horizontal direction. Therefore, the front belt portion 20 and the rear belt portion 30 expand and contract in the left-right direction to fit the wearer's waist circumference. Examples of the filamentous

elastic members

23 and 33 include filamentous elastic members such as rubber and spandex.

<About the temperature drop of the absorbent body>
Next, the mechanism of the temperature drop of the absorbent body that occurs when wearing a diaper (absorbent article) will be described. FIG. 4 is a diagram illustrating heat transfer generated in the absorbent main body 110 of the comparative example. In FIG. 4, as a comparative example, the state of heat transfer occurring between the wearer's skin side and the non-skin side of the conventional absorbent body 110 is schematically shown.

The absorbent main body 110 of the comparative example includes an absorbent core 111, a top sheet 112 arranged on the skin side of the absorbent core 111, and an exterior sheet portion 113 arranged on the non-skin side of the absorbent core 111. It has. Further, the exterior sheet portion 113 has a two-layer structure in which the breathable film 113a and the back sheet 113b are laminated in the thickness direction. The basic functions and configurations of each part of the absorbent main body 110 of the comparative example are substantially the same as those of the absorbent main body 10 of the present embodiment. Further, for convenience of explanation, the leak-proof wall portion and the side flap are omitted in FIG.

Further, in FIG. 4, the temperature of the absorbent body 110 on the skin side is set to 38 ° C., assuming a temperature close to the wearer's body temperature. On the other hand, the temperature on the non-skin side of the absorbent main body 110 is set to 15 ° C. assuming the outside air temperature in winter (specifically, the temperature in the space between clothes such as trousers and diaper 1). Then, under such temperature conditions, the transfer of heat generated between the absorbent main body 110 and its skin side or non-skin side will be examined.

In the present specification, "heat flow rate peak value Qmax (W / cm ² )" is used as an index indicating the amount of heat transfer. The heat flow rate peak value Qmax (hereinafter, also simply referred to as "Qmax value") stores a predetermined heat on a hot plate having a constant area and a constant mass, and immediately after this comes into contact with the sample surface, the stored heat amount is a sample on the low temperature side. It represents the peak value of the heat flow rate when moving to. That is, the Qmax value is a value simulating the amount of heat (body temperature, etc.) taken away by the sample when wearing clothes, and the larger the Qmax value, the larger the body temperature taken away when wearing clothes, and the higher the feeling of cold contact. That is, the larger the Qmax value, the larger the amount of heat transfer, and the easier it is for the wearer to feel cold.

Conventionally, in the absorbent main body 110 as in the comparative example, since the top sheet 112 and the back sheet 113b are formed of the same non-woven fabric (for example, air-through non-woven fabric or spunbonded non-woven fabric), both under the same temperature condition. Qmax values are almost the same. That is, the top sheet 112 and the back sheet 113b have the same heat transfer characteristics.

The exterior sheet portion 113 of the absorbent main body 110 has a two-layer structure of a back sheet 113b and a breathable film 113a, but the breathable film 113a has good breathability and has an influence on heat transfer. Is small. That is, it can be considered that the Qmax value of the exterior sheet portion 113 (back sheet 113b and the breathable film 113a) and the Qmax value of the back sheet 113b alone are substantially the same. Therefore, in the absorbent main body 110 of the comparative example, the Qmax value (Qm112) of the top sheet 112 and the Qmax value (Qm113) of the exterior sheet portion 113 are substantially the same value (Qm112 = Qm113).

Immediately after the absorbent core 111 absorbs excrement such as urine in such an absorbent main body 110, the temperature of the absorbent core 111 becomes a temperature close to the wearer's body temperature (38 ° C.). Then, when the water (for example, urine) absorbed by the absorbent core 111 evaporates to the outside (skin side and non-skin side) as water vapor, the heat of vaporization is taken away, so that the absorbent core 111 has the passage of time. The temperature gradually decreases. In particular, in the case of FIG. 4, since the outside air temperature (15 ° C.) on the non-skin side is low, heat exchange is likely to occur between the absorbent core 111 and the outside air via the exterior sheet portion 113, and the temperature of the absorbent core 111 is high. Is likely to decrease.

As a result, the temperature of the absorbent core 111 after a long period of time drops to near the outside air temperature (15 ° C.). Then, heat exchange occurs between the absorbent core 111 whose temperature has decreased and the wearer's skin via the top sheet 112, and heat is easily transferred from the wearer's skin to the absorbent core 111 side.

In this way, when the diaper is worn for a long time, the absorbent core 111 may remove heat from the wearer's body and cool the wearer's body. In particular, when the outside temperature is low in winter and the wearer wears the diaper for a long time without changing the diaper when going out or going to bed, the wearer's body tends to be cooled and causes discomfort.

<About the absorbent body 10 of this embodiment>
On the other hand, in the diaper 1 of the present embodiment, the Qmax value is appropriately adjusted between the top sheet 12 of the absorbent body 10 and the exterior sheet portion 13, so that the diaper 1 can be worn for a long time under a low outside air temperature. Even when it is worn, the wearer's body is not easily cooled. FIG. 5 is a diagram illustrating heat transfer generated in the absorbent main body 10 of the present embodiment.

In the absorbent body 10 of the present embodiment, the Qmax value (Qm12) of the top sheet 12 under a certain temperature condition is smaller than the Qmax value (Qm13) of the exterior sheet portion 13 under the same temperature condition. 12 is configured (Qm13> Qm12). That is, the top sheet 12 has a structure in which heat transfer in the thickness direction is less likely to occur as compared with the exterior sheet portion 13. In other words, the top sheet 12 has higher heat insulating performance than the exterior sheet portion 13. The specific configuration of the top sheet 12 will be described later.

Similar to that described in FIG. 4, in the absorbent body 10 of FIG. 5, immediately after the absorbent core 11 absorbs excrement such as urine, the temperature of the absorbent core 11 becomes the body temperature of the wearer. The temperature will be close (38 ° C). Then, the water such as urine absorbed by the absorbent core 11 evaporates to the outside of the absorbent core 11 as water vapor. At this time, since the top sheet 12 of the present embodiment has higher heat insulating properties than the exterior sheet portion 13, evaporation from the absorbent core 11 to the skin side via the top sheet 12 is unlikely to occur, and the exterior sheet portion Evaporation from the absorbent core 11 to the non-skin side is likely to occur via 13.

In this case, on the non-skin side of the absorbent body 10, the temperature of the absorbent core 11 tends to decrease due to heat exchange between the absorbent core 11 and the outside air. On the other hand, on the skin side of the absorbent body 10, it is difficult for heat exchange between the absorbent core 11 and the wearer's skin, and even if the temperature of the absorbent core 11 drops, the effect of the temperature drop affects the wearer. It is hard to convey to the skin. That is, it is difficult for the wearer to feel the coldness of the absorbent body 10. Further, since the evaporation of water from the absorbent core 11 to the non-skin side (outside air side) is not restricted, it is possible to prevent the absorbent body 10 from being stuffed with water when the diaper 1 is worn. .. As a result, it is possible to realize the absorbent main body 10 which is hard to cool the wearer's body and is hard to cause discomfort when worn.

The Qmax value can be measured using, for example, Servo Lab KES-F7 (manufactured by Kato Tech Co., Ltd.) as follows. First, in a state where the sheet member to be measured (top sheet 12, exterior sheet portion 13, hereinafter also referred to as "sample") and the absorbent core 11 are overlapped, 300 ml of artificial urine is dropped and allowed to stand for 30 minutes. The absorbent core 11 is allowed to absorb artificial urine. Then, the absorbent core 11 and the sample are cooled in an incubator until the temperature becomes 15 ° C. or lower. As described above, 15 ° C. is a temperature assuming an external temperature of the diaper 1 in winter. Then, after warming the sensor portion of Servo Lab KES-F7 to about 40 ° C. (assuming that the human skin is 38 ° C.), the sample and the absorbent core are attached to the sensor portion so that the sample and the sensor portion are in contact with each other. Put 11 on it. Further, a weight of 200 g is placed on the absorbent core 11 so that the pressure applied by the weight of the baby when wearing the diaper 1 (body pressure: assumed to be 0.35 g / mm ² ) is applied. Under such a load condition, the Qmax value when the internal temperature of the absorbent core 11 becomes 15 ° C. is measured.

FIG. 6 is a table summarizing the results of measuring the Qmax values for a plurality of types of seat members. FIG. 6 shows the results of measuring the Qmax value of four types of sheet members (samples) in addition to the top sheet 12 and the exterior sheet portion 13 of the present embodiment based on the above-mentioned measurement method as a comparative example. ing. Also. In the table of FIG. 6, in addition to the Qmax value, the thickness, basis weight, surface shape, and cold feeling evaluation of each sheet member (sample) are shown.

“Thickness (μm)” represents the average thickness of each sample. For the thickness measurement, for example, a dial thickness gauge ID-C1012C manufactured by Mitutoyo Co., Ltd. or an equivalent one is used, and the contact area is set to 20 cm ² and the contact pressure is set to ³ gf / cm ^2. The target site may be pressurized for measurement, visually compared, or a cross section of a sample cut in the longitudinal direction may be used for comparison. Then, the average thickness measured at a plurality of locations for each sample is calculated. "Basis weight (g / m ² )" represents the weight per unit area of a sample. For example, by cutting each sample into a predetermined shape and size and measuring the weight with an electronic balance or the like. calculate. The "surface shape" indicates whether the surface of each sample has a planar shape or an uneven shape.

In addition, the "cold feeling evaluation" represents an evaluation as to whether or not the user feels cold when touching the surface of the sample. Specifically, a test was conducted in which a predetermined number of users (for example, 20 people) touched the surface of the sample (and absorbent core) in which artificial urine was absorbed, and the total number of users who did not feel cold was 8 When it exceeded the percentage, the cold feeling evaluation was evaluated as 〇, and in other cases, it was evaluated as x. As described above, it is desirable that the top sheet 12 that comes into direct contact with the wearer's skin when the diaper 1 is worn does not make the wearer feel cold. Therefore, if the seat member having a cold feeling evaluation of ◯ is used as the top sheet 12, it is possible to make the wearer less likely to feel uncomfortable.

As shown in FIG. 6, the Qmax values of the top sheet 12 and the exterior sheet portion 13 in the diaper 1 of the present embodiment are Qm12 = 0.169 (W / cm ² ) and Qm13 = 0.31 (W / cm, respectively). ² ). That is, the Qmax value of the top sheet 12 is smaller than the Qmax value of the exterior sheet portion 13 (Qm12 <Qm13). Therefore, as described with reference to FIG. 5, the heat transfer between the absorbent core 11 and the wearer's skin is reduced, and even if the temperature of the absorbent core 11 is lowered, the heat is cooled. It becomes difficult for the wearer to feel the temperature. On the other hand, the heat transfer between the absorbent core 11 and the outside air becomes large through the exterior sheet portion 13, and the moisture such as urine absorbed by the absorbent core 11 is easily evaporated to the non-skin side (outside air). This makes the absorbent body 10 less stuffy.

Further, as shown in FIG. 6, since the cold feeling evaluation of the top sheet 12 is 〇, in the absorbent main body 10 of the present embodiment, the top sheet 12 itself is hard to make the wearer feel cold. It has become. Since it is difficult to feel the coldness of the sheet member as the amount of heat transfer of the sheet member is smaller, the lower the Qmax value of the sheet member, the higher the evaluation of coldness should be. With reference to the Qmax values for each of the top sheet 12, the exterior sheet portion 13 and Comparative Examples 1 to 4 in FIG. 6, when the Qmax value is larger than 0.23 (W / cm ² ) (exterior sheet portion 13, In Comparative Examples 2 and 3), the cold feeling evaluation was x. On the other hand, when the Qmax value is smaller than 0.21 (W / cm ² ) (top sheet 12 and Comparative Examples 1 and 4), the cold feeling evaluation is 〇. Therefore, it is desirable that the sheet member used as the top sheet 12 is configured so that the Qmax value is at least 0.21 (W / cm ² ) or less.

Next, the relationship between the configuration of the seat member and the Qmax value will be described. It has been explained that the smaller the Qmax value, the higher the heat insulating property of the seat member, but a difference in the configuration of the seat member can be considered as a factor affecting the heat insulating performance of the seat member. One example of such a factor is the "thickness" of the seat member. For example, when the sheet member is a non-woven fabric as in the present embodiment, the thicker the sheet member, the higher the heat insulating performance. In general, a non-woven fabric is formed by entwining fibers with each other, and therefore has a structure having a large number of voids between the entangled fibers. Therefore, the thicker the non-woven fabric, the thicker the air layer due to the voids inside the non-woven fabric, and the more easily the heat transfer in the thickness direction is hindered. That is, the thicker the non-woven fabric, the higher the heat insulating performance and the smaller the Qmax value.

With reference to Comparative Example 1 and Comparative Example 2 in FIG. 6, both have the same basis weight and surface shape. On the other hand, the thickness of Comparative Example 1 is 1125 μm, whereas the thickness of Comparative Example 2 is 675 μm, which are significantly different. In such a configuration, the Qmax value of Comparative Example 1 is 0.163, and the cold feeling evaluation is 〇. On the other hand, the Qmax value of Comparative Example 2 is 0.23, and the cold feeling evaluation is ×. Therefore, it can be seen that the "thickness" of the sheet member has a great influence on the difference between the two Qmax values, and the larger (thicker) the thickness, the smaller the Qmax value, indicating good heat insulation performance.

Actually, also in the diaper 1 of the present embodiment, the thickness of the top sheet 12 is 1350 μm, whereas the thickness of the exterior sheet portion 13 is 250 μm, and the thicker top sheet 12 has a higher Qmax value. It's getting smaller. As described above, in the diaper 1, it is desirable that the thickness of the top sheet 12 is larger than the thickness of the exterior sheet portion 13. As a result, the amount of heat exchanged between the absorbent core 11 and the wearer's body via the top sheet 12 is reduced, and it becomes easier to realize the diaper 1 (absorbent body 10) that does not easily cool the wearer's body.

In addition, the surface shape of the sheet member can be mentioned as a factor that affects the heat insulating performance of the sheet member. For example, when the surface shape of the seat member is flat, the seat member easily comes into close contact with the wearer's body, and the contact area between the seat member and the wearer's body becomes large. In this case, heat tends to be transferred between the seat member and the wearer's body, and the amount of heat exchange may increase. On the other hand, when the surface of the seat member is uneven in the thickness direction, the contact area with the wearer's body is smaller than when the surface of the seat member is flat. That is, it becomes difficult for the seat member to come into contact with the wearer's body in the concave portion of the unevenness, and it becomes difficult for the surface of the seat member to come into close contact with the wearer's body. Therefore, it becomes difficult for heat to transfer between the seat member and the wearer's body, and the amount of heat exchange can be reduced. Further, since a space (gap) is formed between the recess of the seat member and the wearer's body, the heat transfer is easily suppressed by the space. By making the surface shape of the sheet member uneven in this way, the Qmax value can be reduced and the heat insulating performance can be improved.

Referring to Comparative Example 2 and Comparative Example 3 in FIG. 6, both have the same basis weight and a small difference in thickness. On the other hand, the surface shape of Comparative Example 2 is uneven, whereas the surface shape of Comparative Example 3 is flat. In such a configuration, the Qmax value of Comparative Example 2 is 0.23, whereas the Qmax value of Comparative Example 3 is 0.392, and the Qmax value is greatly increased. Therefore, it can be seen that the "surface shape" of the sheet member has a great influence on the difference between the two Qmax values, and that the surface has irregularities, so that the Qmax value becomes smaller than when the surface is flat.

In the present embodiment, the surface of the top sheet 12 is uneven, whereas the surface of the exterior sheet 13 is flat, and the top sheet 12 has a smaller Qmax value than the exterior sheet 13. It has become. Therefore, in the diaper 1, it is desirable that at least the surface of the top sheet 12 is provided with irregularities in the thickness direction. As a result, the amount of heat exchanged between the absorbent core 11 and the wearer's body via the top sheet 12 becomes smaller, and it becomes easier to realize the diaper 1 (absorbent body 10) that does not easily cool the wearer's body. ..

FIG. 7 is a schematic cross-sectional view showing the surface shape of the top sheet 12 of the present embodiment. As shown in FIG. 7, a plurality of convex portions 121 projecting on one side (skin side) in the thickness direction are provided on the surface of the top sheet 12 side by side in the left-right direction (width direction). .. Further, a concave portion 122 is provided between the two

convex portions

121 and 121 adjacent to each other in the width direction, and the convex portion 121 and the concave portion 122 are continuously formed along the longitudinal direction of the top sheet 12. Has been done. That is, on the surface of the top sheet 12, striped irregularities extending in the longitudinal direction are formed by the convex portions 121 and the concave portions 122. As a result, the contact area between the top sheet 12 and the wearer's body is reduced, and the heat insulating performance of the top sheet 12 is improved.

Further, each of the convex portions 121 has a substantially parabolic shape as shown in FIG. 7, and the length in the left-right direction (width direction) increases toward one side (skin side) in the thickness direction. (Width) W121 is smaller. In other words, the width W121 on one side (skin side) in the thickness direction is smaller than the width W121 on the other side (non-skin side) in the thickness direction. Therefore, as compared with the case where the width W121 is constant in the thickness direction (when the width is not narrowed), the contact area with the wearer's skin becomes smaller, and the heat insulating performance of the top sheet 12 is improved. Further, since the space S121 formed between the

convex portions

121 and 121 adjacent to each other in the left-right direction becomes larger on the skin side in the thickness direction, the heat transfer is suppressed by the space S121, and a higher heat insulating effect is obtained. It becomes easier to demonstrate. This makes it difficult for the wearer to feel the cold.

In the top sheet 12 of the present embodiment, the distance G121 of the

convex portions

121 and 121 in the left-right direction (width direction) is 1.5 mm to 2.0 mm. The height H121 of the convex portion 121 (distance between the apex of the convex portion 121 and the bottom point of the concave portion 122 in the thickness direction) is 0.8 mm to 1.2 mm. As a result, sufficient heat insulation performance can be maintained. Further, the shape of the convex portion 121 is not limited to a substantially parabolic shape as shown in FIG. 7, and may be a semicircle, a cone, a trapezoid, or the like, and the width W121 becomes narrower toward the skin side in the thickness direction. If there is, the above-mentioned effect can be obtained.

Another factor that affects the heat insulating performance (Qmax value) of the sheet member is the size of the basis weight of the sheet member. This is because the larger the basis weight of the sheet member, the larger the amount of fibers per unit area, and thus the heat transfer inside the sheet member is likely to be hindered. Therefore, it is desirable that the basis weight of the top sheet 12 is larger than that of the exterior sheet portion 13. In the present embodiment, as shown in FIG. 6, the basis weight of the top sheet 12 is 30 (g / m ² ), whereas the basis weight of the exterior sheet portion 13 is 15 (g / m ² ). The top sheet 12 has a larger basis weight than the exterior sheet portion 13. Therefore, it is possible to make the wearer less likely to feel the cold.

Further, in order to improve the heat insulating performance of the sheet member, it is preferable to increase the fiber diameter to increase the rigidity of the non-woven fabric so that it is easy to prevent the non-woven fabric from being crushed by external pressure or the like. As a result, the voids between the fibers are not easily crushed inside the non-woven fabric, and the air layer is easily maintained, so that the heat insulating performance of the sheet member can be improved. Further, the fibers constituting the non-woven fabric may be hollow tubular fibers. In this case, since the air layer is formed inside the fiber, the heat insulating performance of the sheet member can be improved.

Further, the top sheet 12 may have a structure in which a hydrophobic fiber layer and a hydrophilic fiber layer (for example, a cellulosic fiber layer) are laminated. For example, cellulosic fibers are unevenly distributed and exposed on one surface of the top sheet 12 in the thickness direction, and hydrophobic fibers are unevenly distributed on the other surface. By doing so, of the one side surface and the other side surface, the skin side surface (preferably the side surface opposite to the surface where the cellulosic fibers are unevenly distributed) comes into contact with the body fluid and becomes wet. Even if it touches the wearer's skin at that time, it is difficult to give the wearer a cold, chilly and unpleasant sensation.
The layer is referred to as a "hydrophobic fiber layer".

Further, in order to further enhance the heat insulating performance of the absorbent main body 10 on the skin side, the absorbent main body 10 may be deformed as follows. FIG. 8 is a schematic cross-sectional view showing a modified example of the absorbent body 10. In the absorbent body 10 of the modified example, a second sheet 15 is provided between the top sheet 12 and the absorbent core 11 in the thickness direction. The second sheet 15 is a sheet member having liquid permeability and breathability, and is formed of, for example, a non-woven fabric such as an air-through non-woven fabric. The configuration other than the second sheet 15 is the same as the configuration of the absorbent main body 10 described with reference to FIG.

As shown in FIG. 8, by stacking the second sheet 15 between the absorbent core 11 and the top sheet 12, the heat transfer between the absorbent core 11 and the wearer's body is more likely to be suppressed. .. That is, the heat insulating performance of the sheet member on the skin side of the absorbent core 11 can be further enhanced. As a result, when the diaper 1 is worn, the wearer can hardly feel the coldness.

In the absorbent body 10 of the present embodiment, the top sheet 12 and the exterior sheet portion extend from the end portion 11ef on one side (front side) of the absorbent core 11 to the end portion 11eb on the other side (rear side) in the longitudinal direction. 13 is provided. In other words, the top sheet 12, the absorbent core 11, and the exterior sheet portion 13 are laminated in the thickness direction in all regions of the absorbent core 11 in the longitudinal direction. As a result, it is possible to make the wearer less likely to feel cold in the entire longitudinal direction of the absorbent core 11.

However, the absorbent body 10 does not necessarily have the above-described configuration in the entire longitudinal direction of the absorbent core 11, and each member is laminated in the thickness direction in a part of the longitudinal direction. It may be in a state of being. In that case, it is desirable that the top sheet 12, the absorbent core 11, and the exterior sheet portion 13 are laminated in the thickness direction at least in the lower part of the wearer's crotch. Since the lower crotch is a portion where the excretion opening such as the wearer's vagina is located, it is possible to prevent the wearer from causing discomfort by keeping the wearer's body cool in the crotch. The crotch portion of the absorbent body 10 is a region having a predetermined width in the front-rear direction from the central position CL in the longitudinal direction of the absorbent core 11, and the constricted portion 11c of the absorbent core 11 is formed in the longitudinal direction of FIG. It is a region that overlaps with the formed region.

Further, in the absorbent body 10, the area of the portion where the top sheet 12, the absorbent core 11 and the exterior sheet portion 13 are laminated in the thickness direction is behind the central position CL in the longitudinal direction of the absorbent core 11. Is desirable to be larger than the front side of the central position CL. The area behind the central position CL is the area that comes into contact with the wearer's buttocks when the diaper 1 is worn. Therefore, since each part is laminated on the buttocks having a large surface area, it is possible to make it difficult to feel the coldness in a wide range of the wearer's body. Further, the area on the buttocks side is also an area in which the absorbent body 10 is easily pressed against the wearing body due to the weight applied when the wearer sits while wearing the diaper 1. Therefore, by making it difficult to feel the coldness in the area, it is difficult to give the wearer discomfort.

<About the configuration of the absorbent core 11>
In order to prevent the wearer from feeling the coldness of the absorbent body 10 when wearing the diaper 1, the method of reducing the Qmax of the top sheet 12 has been described, but the absorbent core 11 can also be configured as follows. , It is possible to make it difficult to feel the coldness of the absorbent body 10.

As described above, the absorbent core 11 of the present embodiment has a constricted portion 11c in which the length (width) W11 in the left-right direction (width direction) is narrowed (see FIG. 2). By having the constricted portion 11c having such a narrow width, the absorbent core 11 is less likely to hinder the movement of the wearer's legs in the crotch portion of the wearer, and fits between the wearer's groin portions. It will be easier. Further, the surface area of the absorbent core 11 is reduced by having the constricted portion 11c as compared with the case where the width of the absorbent core 11 is constant (that is, the absorbent core 11 is rectangular). Therefore, when the diaper 1 is worn, the contact area between the wearer's body and the absorbent core 11 (absorbent body 10) is reduced, and heat transfer between the absorbent core 11 and the wearer's skin is reduced. be able to. This makes it difficult for the wearer to feel the coldness of the absorbent body 10.

Further, a high-density portion (not shown) in which a predetermined region of the absorbent core 11 is pressed in the thickness direction (for example, embossing) so that the density of the absorbent core 11 is higher than the density around the absorbent core 11 is formed. It may be provided. Since the absorbent core 11 is squeezed in the thickness direction in the region where the high-density portion is provided, it is difficult to come into contact with the wearer's body. That is, the absorbent core 11 has a smaller contact area with the wearer's skin than in the case where the high-density portion is not provided. Therefore, as in the above case, the heat transfer between the wearer's body and the absorbent core 11 is reduced, and it is possible to make it difficult for the wearer to feel the coldness of the absorbent body 10. Further, if a plurality of such high-density portions are provided over the entire absorbent core 11, the liquid absorbent fibers such as pulp are less likely to disperse, and the shape of the absorbent core 11 is stably maintained. It will be easier. Therefore, it is possible to improve the absorption performance of the absorbent body 10.

Further, the absorbent core 11 may be provided with a low basis weight area in which the basis weight (weight per unit area) is lower than the basis weight around the absorbent core 11. In the portion where such a low basis weight region is formed, when the diaper 1 is worn, the absorbent core 11 is less likely to be pressed against the wearer's body as compared with other portions. That is, when the diaper 1 is worn, the contact area between the absorbent core 11 and the wearer's body becomes smaller. Therefore, heat transfer between the wearer's body and the absorbent core 11 is reduced, making it difficult for the wearer to feel the coldness of the absorbent body 10.

=== Other embodiments ===
Although the embodiments of the present invention have been described above, the above-described embodiments are for facilitating the understanding of the present invention, and are not for limiting the interpretation of the present invention. Further, it is needless to say that the present invention can be changed or improved without departing from the spirit thereof, and the present invention includes an equivalent thereof.

In the above-described embodiment, as an example of the absorbent article, a diaper in which the front belt portion 20 and the rear belt portion 30 are separated and are separate members is illustrated, but between the front belt portion 20 and the rear belt portion 30. A diaper may be a diaper in which a lower crotch is provided and the front belt portion 20 and the rear belt portion 30 are formed by a continuous member.

1 Diaper (pants type absorbent article),
2 side joint area,
10 Absorbent body, 10es predetermined position,
11 Absorbent core,
11es end (outer end), 11ef end (ventral side), 11eb end (dorsal side),
11a core wrap sheet, 11c constriction,
12 top sheet,
121 convex part, 122 concave part,
13 Exterior sheet,
13a temper film, 13b backsheet,
14 side seats,
15 second sheet,
17 Leg elastic member,
20 Front belt (ventral waist circumference),
21 inner layer sheet, 22 outer layer sheet, 23 thread-like elastic member,
30 Rear belt part (dorsal waist circumference part),
31 inner layer sheet, 32 outer layer sheet, 33 thread-like elastic member,
50 leak-proof wall, 50t end, 50b end,
51 Leak-proof wall sheet, 52 Leak-proof wall elastic member,
110 Absorbent body (comparative example),
111 Absorbent core,
112 top sheet,
113 exterior sheet, 113a vapor film, 113b back sheet,
BH waist opening,
LH leg opening,
FL predetermined position, CL center position (absorbent core),
SF side flap,

Claims

It has a vertical direction and a horizontal direction that intersect each other,
An absorbent article having an absorbent body
The absorbent body
With a liquid-absorbing absorbent core,
An exterior sheet portion that is arranged on the non-skin side of the absorbent core, has a breathable film and a back sheet, and has a predetermined heat flow rate peak value Qmax under a certain temperature condition.
A top sheet arranged closer to the skin than the absorbent core and configured to have a heat flow peak value Qmax lower than the predetermined heat flow peak value Qmax under certain temperature conditions.
An absorbent article characterized by having.
The absorbent article according to claim 1.
The absorbent body is an absorbent article in which the top sheet, the absorbent core, and the exterior sheet portion are laminated in the thickness direction at least in the crotch portion of the wearer.
The absorbent article according to claim 2.
The area of the portion where the top sheet, the absorbent core, and the exterior sheet portion are laminated in the thickness direction on the rear side of the center in the longitudinal direction of the absorbent core is determined.
It is characterized in that, on the front side of the center of the absorbent core in the longitudinal direction, the area of the top sheet, the absorbent core, and the exterior sheet portion is larger than the area of the portion where the top sheet, the absorbent core, and the exterior sheet portion are laminated in the thickness direction. Absorbent article.
The absorbent article according to any one of claims 1 to 3.
An absorbent article, characterized in that the top sheet is a non-woven fabric.
The absorbent article according to any one of claims 1 to 4.
An absorbent article characterized in that the thickness of the top sheet is larger than the thickness of the exterior sheet portion.
The absorbent article according to any one of claims 1 to 5.
The top sheet is characterized by having a convex portion protruding to one side in the thickness direction and a concave portion provided between two adjacent convex portions in the left-right direction. Goods.
The absorbent article according to claim 6.
The convex portion is an absorbent article characterized in that the width in the left-right direction becomes narrower toward the skin side in the thickness direction.
The absorbent article according to any one of claims 1 to 7.
An absorbent article characterized in that a second sheet is provided between the top sheet and the absorbent core.
The absorbent article according to any one of claims 1 to 8.
The absorbent core is characterized by having a constricted portion having a narrowed width in the left-right direction between one side end portion in the longitudinal direction and the other side end portion in the extended state. Goods.
The absorbent article according to any one of claims 1 to 9.
The absorbent core is an absorbent article characterized in that the absorbent core has a high density portion having a density higher than the density around the absorbent core.
The absorbent article according to any one of claims 1 to 10.
The absorbent core is an absorbent article characterized in that the absorbent core has a low basis weight region in which the basis weight of the absorbent core is lower than the basis weight around the absorbent core.