JP7599866B2 - Body fluid absorbent articles - Google Patents

Description

The present invention relates to a body fluid absorbent article.

Patent Document 1 describes a conventional body fluid absorbent article (body fluid absorbing pad in Patent Document 1). The body fluid absorbing pad described in Patent Document 1 includes a top sheet, a back sheet, and an absorbent disposed between the top sheet and the back sheet. The absorbent has the ability to absorb body fluids, and an absorbent with high body fluid absorbency, for example, is used as an SAP sheet containing superabsorbent polymer (SAP).

JP 2020-89424 A

However, because SAP sheets containing absorbent polymers are relatively hard, when an SAP sheet is layered on a top sheet, the wearer of the body fluid absorbent article feels the contact area as being hard, resulting in a poor user experience.

The present invention was made in consideration of the above circumstances, and aims to provide a bodily fluid absorbent article that maintains high absorbency while providing a good feeling of use.

One embodiment of the body fluid absorbent article according to the present invention is a body fluid absorbent article comprising a top sheet which is a surface layer that contacts the wearer's skin, a back sheet which is a back layer, and an absorbent body arranged between the top sheet and the back sheet, wherein the absorbent body is a SAP sheet containing an absorbent polymer, and further comprises a compression recovery sheet arranged between the absorbent body and the top sheet over the entire area of the absorbent body , and the compression deformation ratio of the body fluid absorbent article is 0.75 or more.

In the body fluid absorbent article, in the above aspect, it is preferable that the compression recovery sheet has a compression resilience value of 6.5% or more.

In addition, in the above-mentioned embodiment of the body fluid absorbent article, it is preferable that the compression recovery sheet is an air-through nonwoven fabric.

In addition, in the above-mentioned embodiment of the body fluid absorbent article, it is preferable that all of the dimensions between the absorbent body and the outer periphery of the body fluid absorbent article are 20 mm or less.

In addition, in the above-mentioned embodiment of the body fluid absorbent article, it is preferable that the slip start angle of the body fluid absorbent article measured by the slip start angle measurement method is 37° or more.

In addition, in the above-mentioned embodiment, it is preferable that the body fluid absorbent article absorbs 1.5 cc or more of physiological saline.

The bodily fluid absorbent article according to the above aspect of the present invention has the advantage that it provides a good feeling of use while maintaining high absorbency.

FIG. 1 is a plan view of a body fluid absorbent article according to one embodiment of the present invention. FIG. 2 is a bottom view of the above body fluid absorbent article. FIG. 3 is a cross-sectional view taken along line X1-X1 of FIG. FIG. 4 is an explanatory diagram of an SS curve used when calculating the compression resilience value. FIG. 5 is a schematic diagram of a slip start angle measuring device.

<Embodiment>
(1) Overall The body fluid absorbent article 1 according to this embodiment will be described in detail below.

The body fluid absorbent article 1 according to this embodiment is attached to the wearer's clothing (e.g., underwear) or skin to absorb body fluids. Examples of body fluids include vaginal discharge, menstrual blood, sweat, and urine. Examples of the body fluid absorbent article 1 include a vaginal discharge sheet 10 (panty liner), sanitary napkin, incontinence pad, underarm sweat pad, sweat absorption sheet, and the like. In this embodiment, as shown in FIG. 1, a vaginal discharge sheet 10 will be described as an example of the body fluid absorbent article 1. The body fluid absorbent article 1 includes a top sheet 2 that contacts the wearer's skin, a back sheet 3, an absorbent body 4, and a compression recovery sheet 5, which are laminated to form a multi-layer structure.

The body fluid absorbent article 1 is formed in a sheet shape. In this specification, one side of the body fluid absorbent article 1 that contacts the wearer's skin is defined as the "front side" and the other side as the "back side." The body fluid absorbent article 1 is laminated in the thickness direction from the front side to the back side in this order, as shown in Figure 3.

As shown in FIG. 2, the body fluid absorbent article 1 according to this embodiment has an adhesive layer 6 on the back surface of the back sheet 3. The body fluid absorbent article 1 is attached to an undergarment by the adhesive layer 6 when worn. A pressure-bonded portion 11 is formed on the outer peripheral edge of the body fluid absorbent article 1 along the entire circumference. The pressure-bonded portion 11 presses the top sheet 2, the compression recovery sheet 5, and the back sheet 3 together. The thickness of the pressure-bonded portion 11 is thinner than the other portions. Note that in this embodiment, the pressure-bonded portion 11 is not formed on the body fluid absorbent article 1 except on the outer peripheral edge.

In the body fluid absorbent article 1, all dimensions between its outer periphery (i.e., the outer periphery of the pressure-bonding portion 11) and the absorbent 4 are set to 20 mm or less. The dimension between the outer periphery of the body fluid absorbent article 1 and the absorbent 4 means the dimension between the outer periphery of the body fluid absorbent article 1 and the absorbent 4 on the normal line of the outer periphery. Even the largest dimension between the outer periphery of the body fluid absorbent article 1 and the absorbent 4 is set to 20 mm or less, so that even if body fluid moves near the outer edge, the absorbent 4 can absorb it, and the body fluid is unlikely to leak sideways and is unlikely to wrinkle. The outer periphery of the body fluid absorbent article 1 and the outer edge of the absorbent 4 may be the same in a plan view, that is, the dimension between the outer periphery of the body fluid absorbent article 1 and the absorbent 4 may be 0 mm or more.

The initial thickness of the body fluid absorbent article 1 according to this embodiment is not particularly limited, but if the initial thickness is too thick, the user will feel uncomfortable due to stiffness, while if it is too thin, the resilience will be low and the article will be prone to twisting and slipping, making it difficult for the wearer to use it for long periods of time. Therefore, the initial thickness of the body fluid absorbent article 1 is preferably 0.5 mm or more and 7.5 mm or less. The "initial thickness" here refers to the thickness of the body fluid absorbent article 1 before it absorbs body fluids and is not under any load.

The amount of physiological saline absorbed by the body fluid absorbent article 1 is preferably 1.5 cc or more, more preferably 1.7 cc or more, and even more preferably 2 cc or more.

(2) Top sheet The top sheet 2 is a surface layer that comes into contact with the wearer's skin. The top sheet 2 is configured to allow bodily fluids to pass through in the thickness direction. Therefore, the top sheet 2 comes into contact with the wearer's skin, and when bodily fluids are discharged from the wearer, the bodily fluids pass through the top sheet 2 in the thickness direction and are transferred to the compression recovery sheet 5 and the absorbent body 4. In short, the top sheet 2 is liquid permeable.

The top sheet 2 is not particularly limited as long as it has liquid permeability, and examples thereof include woven fabrics, knitted fabrics, nonwoven fabrics, felts, etc., among which nonwoven fabrics are preferred from the viewpoints of pleasant feel, low irritation to the skin, and high absorbency. The nonwoven fabric constituting the top sheet 2 can be manufactured by, for example, a wet papermaking method, a dry papermaking method, a spunbond method, a meltblowing method, a latex resin bond method, a solvent bond method, a stitch bond method, a needle punch method, a spunlace method, a thermal bond method, an air-through method, an air-laid method, etc., among which the spunlace method, the thermal bond method, the air-through method, the air-laid method, the needle punch method, and the spunbond method are preferred, as these methods have a good texture and do not use adhesives or solvents, making it possible to increase safety to the skin. From the viewpoint of pleasant feel to the skin, nonwoven fabrics manufactured by the spunlace method (spunlace nonwoven fabrics) are preferred.

The material constituting the top sheet 2 is not particularly limited, and examples thereof include synthetic fibers such as polyester fibers, polyamide fibers, acrylic fibers, polypropylene fibers, polyethylene/polyester composite fibers, and polyethylene/polypropylene composite fibers; natural fibers such as cotton, silk, pulp, wool, and hemp; semi-synthetic fibers such as rayon fibers and acetate fibers; and fibers made by mixing various fibers (blended fibers, mixed fibers). Among these, natural fibers are preferred from the viewpoint of pleasant feel and low irritation to the skin, and cotton is particularly preferred. Furthermore, the top sheet 2 is not limited to being a single layer, and may be composed of a laminate consisting of multiple layers.

(3) Backsheet The backsheet 3 is a back surface layer, and prevents the body fluid absorbed by the absorbent 4 from penetrating to the back surface side. The backsheet 3 is liquid-impermeable. The backsheet 3 is not particularly limited as long as it is liquid-impermeable, and examples thereof include films, liquid-impermeable nonwoven fabrics such as SMS, and sheets in which a resin film is laminated on a spunbonded nonwoven fabric or a point-bonded nonwoven fabric. Examples of liquid-impermeable films include films made of polyethylene, polypropylene, polyester, nylon, polyvinyl alcohol, cellophane, vinyl chloride, etc., or multilayer films thereof.

(4) Absorbent Body The absorbent body 4 is disposed between the top sheet 2 and the back sheet 3 as shown in FIG. 3, and absorbs and retains body fluids. The absorbent body 4 is a superabsorbent polymer (SAP) sheet 40 containing SAP. The SAP sheet 40 here means a sheet-like member having SAP. The SAP sheet 40 according to this embodiment is made of a nonwoven fabric in which SAP is dispersed (for example, a nonwoven fabric produced by an airlaid method (i.e., an airlaid nonwoven fabric)).

However, the SAP sheet may be constructed in a sheet form by using a nonwoven fabric with SAP dispersed therein as an absorbent layer, sandwiching this between a support sheet and a covering sheet and laminating them. In this case, it may be constructed, for example, as follows:

The support sheet is a sheet facing the back sheet 3, and supports the absorbent layer having SAP. The covering sheet is a sheet that covers the SAP sheet 40 from the front side, and has liquid permeability. Examples of the covering sheet include paper and tissue paper made of cellulosic fibers. Examples of the cellulosic fibers include wood pulp such as softwood or hardwood; recycled paper pulp; non-wood pulp such as hemp or cotton; chemically synthesized pulp; and cellulose fibers derived from cotton. Synthetic fibers such as polyester fibers, polyamide fibers, acrylic fibers, polypropylene fibers, polyethylene/polyester composite fibers, and polyethylene/polypropylene composite fibers may also be included. The covering sheet may also be embossed.

The SAP sheet 40 may be rectangular in plan view, or may have an outer edge that fits along the outer edges of the top sheet 2 and the back sheet 3. In this embodiment, the SAP sheet 40 has an outer edge that fits along the outer edges of the top sheet 2 and the back sheet 3, and as described above in "(1) Overall configuration," the distance between the outer edge of the absorbent article 1 and the absorbent body 4 is set to 20 mm or less.

While the SAP sheet 40 has high absorbency, it is relatively hard and has poor flexibility. Therefore, the use of the SAP sheet 40 may impair the pleasant feel of the body fluid absorbent article 1 against the skin. In this embodiment, however, a flexible compression recovery sheet 5 is disposed between the SAP sheet 40 (absorbent body 4) and the top sheet 2.

(5) Compression-recovery sheet The compression-recovery sheet 5 is a flexible sheet disposed between the absorbent body 4 and the top sheet 2. The compression-recovery sheet 5 preferably has a compression resilience value (RC value) of 6.5% or more, more preferably 13% or more, and even more preferably 21% or more.

Here, the compression resilience value (RC value) is a value indicating compression recovery, and the closer the value is to 100%, the higher the compression recovery. The compression resilience value can be calculated using values measured using a compression tester (KES-G5 manufactured by Kato Tech Co., Ltd.). Using the compression tester, the load (gf/cm ² ) and the indentation amount (mm) are measured when the compression recovery sheet 5 is compressed and when the compression recovery sheet 5 is unloaded at a load of 2000 g/cm ² and a speed of 0.10 cm/sec. The relationship between the load (gf/cm ² ) and the indentation amount (mm) is displayed as an SS curve, and the ratio of the total force W2 during recovery to the total force W1 during compression is calculated as a percentage, which is the compression resilience value.

Specifically, as shown in Fig. 4, the SS curve has the load (gf/ ^cm2 ) when the compression recovery sheet 5 is pressed on the vertical axis, and the pressing distance (mm) which is the deformation amount of the compression recovery sheet 5 on the horizontal axis. The total force W1 during compression is defined as W1 = (area of portion A1) + (area of portion B1), and the total force W2 during recovery is defined as W2 = (area of portion B1), and the compression resilience value RC is calculated using the formula RC = (W2/W1) x 100.

When the compression resilience value of the compression recovery sheet 5 is 6.5% or more, the body fluid absorbent article 1 has high compression recovery, so that it can maintain contact with the wearer's skin at an appropriate pressure, and by using the SAP sheet 40, even if the body fluid absorbent article 1 becomes somewhat hard, the feel against the skin can be improved.

As the compression recovery sheet 5, for example, a fiber structure composed of woven fabric, knitted fabric, nonwoven fabric, pulp products, etc., or a foam such as urethane sponge is used. As the compression recovery sheet 5, for example, an aggregate (for example, nonwoven fabric) composed of natural fibers or synthetic fibers is used. Examples of natural fibers include cotton, silk, pulp, wool, and hemp. Examples of synthetic fibers include nylon fibers, polyethylene fibers, polyester fibers, polyamide fibers, acrylic fibers, polyvinyl alcohol fibers, polypropylene fibers, polyethylene terephthalate fibers, ethylene vinyl acetate fibers, and urethane fibers. Semi-synthetic fibers such as rayon fibers, acetate fibers, and cupra, as well as blends and mixed fibers of various fibers, may also be used. These may be used alone or in combination of two or more types.

Nonwoven fabrics can be manufactured by methods such as the wet papermaking method, dry papermaking method, spunbond method, meltblowing method, latex resin bond method, solvent bond method, stitch bond method, needle punch method, spunlace method, thermal bond method, air-through method, and airlaid method. Among these, nonwoven fabrics manufactured by the air-through method (sometimes called air-through nonwoven fabrics) are preferred from the viewpoint of high flexibility.

The thickness dimension of the compression recovery sheet 5 is preferably 2.0 mm or more and 7.3 mm or less, and more preferably 3.0 mm or more and 7.0 mm or less. The compression recovery sheet 5 is preferably weakly hydrophilic.

The compression recovery sheet 5 according to the present embodiment is an air-through nonwoven fabric made of synthetic fibers of PET and PET/PE (core: PET sheath: PE core-sheath structure). The basis weight of the compression recovery sheet 5 is preferably 20 g/m ² or more, more preferably 40 g/m ² or more, and even more preferably 60 g/m ² or more. If the basis weight of the compression recovery sheet 5 is less than 20 g/m ² , the wearer will not feel fluffy and the texture will tend to be poor. If the basis weight is 40 g/m ² or more, the wearer who wears the body fluid absorbent article 1 will tend to feel fluffy. If the basis weight is 60 g/m ² or more, the wearer who wears the body fluid absorbent article 1 will be able to feel a sufficient fluffy texture. The term "fluffy" refers to a soft and gentle texture when worn.

In addition to flexibility, the compression recovery sheet 5 can also have the function of absorbing bodily fluids, but even if it exceeds a certain thickness under certain load conditions, its absorbency does not improve. For example, the thickness at which the compression recovery sheet 5 can be expected to improve its absorbency of bodily fluids is up to 2.5 mm under a load of 0.5 g/ ^cm2 , and if the thickness is 2.5 mm or more under a load of 0.5 g/ ^cm2 , its absorbency of bodily fluids does not improve, but its flexibility improves.

(6) Adhesive layer The adhesive layer 6 is provided by applying an adhesive to the back sheet 3, etc. The adhesive used in the adhesive layer 6 is not particularly limited as long as it can attach the body fluid absorbent article 1 to underwear, etc., and examples thereof include adhesives such as water-soluble adhesives (e.g., acrylic water-soluble adhesives) and non-water-soluble adhesives (e.g., rubber-based hot melt, olefin-based hot melt, etc.). Among them, non-water-soluble adhesives are preferred because they have superior adhesive strength to underwear compared to other adhesives, and rubber-based hot melts are more preferred. The adhesive layer 6 may be provided so as to cover the entire surface of the back sheet 3, or may be provided partially in the length direction of the back sheet 3. In the body fluid absorbent article 1 according to this embodiment, as shown in FIG. 2, the adhesive layer 6 is partially provided in stripes formed at regular intervals in the length direction of the back sheet 3.

(7) Compressive deformation rate In the bodily fluid absorbent article 1 having the above-mentioned configuration, the compression recovery sheet 5 is disposed between the absorbent body 4 and the top sheet 2, and therefore the compressive deformation rate T is set to an appropriate value, improving the wearer's comfort. The compressive deformation rate T is an index showing the ease with which the bodily fluid absorbent article 1 deforms under a compressive load.

The compressive deformation rate T is expressed as T = (T1 - T2) / T1, where T1 is the thickness (mm) of the absorbent article 1 when a load of 0.5 gf/ ^cm2 is applied from the top sheet 2 side along the thickness direction of the absorbent article 1. Also, T2 is the thickness (mm) of the absorbent article 1 when a load of 2000 gf/ ^cm2 is applied from the top sheet 2 side along the thickness direction of the absorbent article 1.

In the body fluid absorbent article 1 according to this embodiment, the compression deformation rate T is preferably 0.75 or more, more preferably 0.79 or more, even more preferably 0.81 or more, and even more preferably 0.85 or more. If the compression deformation rate T is less than 0.75, the wearer will feel the article is stiff and the comfort of use will be poor.

The compression deformation rate T can be calculated using values measured using a compression tester (KES-G5, manufactured by Kato Tech Co., Ltd.). First, the absorbent article 1 is placed on a horizontal measurement table with the top sheet 2 side facing up, and a rectangular frame-shaped weight (outer dimensions L 8 cm × W 6 cm, inner dimensions L 6 cm × W 4 cm) is placed on the absorbent article 1. Next, the absorbent article 1 is compressed at a speed of 0.10 cm/sec toward a portion of the absorbent article 1 located within the frame of the weight (here, the center portion) using a sensor of the tester. Then, the thickness T1 (mm) of the absorbent article 1 when the load compressing the absorbent article 1 is 0.5 gf/cm ² is measured, and the thickness T2 (mm) of the absorbent article 1 when the load compressing the absorbent article 1 is 60 gf/cm ² is measured using the sensor. Then, the compression deformation rate T can be calculated using the formula T = (T1 - T2) / T1.

The target portion of the body fluid absorbent article 1 that is compressed by the sensor of the testing machine when calculating this compression deformation rate T may be any portion other than the pressure-bonded portion 11, but it is preferable to measure in the area (sometimes called the "liquid-permeable area") that faces the area through which the wearer's body fluids are discharged when worn. The liquid-permeable area here refers to the center of the body fluid absorbent article 1. For example, in the vaginal discharge sheet 10 according to this embodiment, it is sufficient that the compression deformation rate T in at least the liquid-permeable area is 0.75 or more. However, it is more preferable that the compression deformation rate T in all portions excluding the pressure-bonded portion 11 is 0.75 or more.

(8) Static Friction Coefficient The static friction coefficient of the surface of the top sheet 2, which is the surface layer of the bodily fluid absorbent article 1, is set as follows, so that the top sheet 2 is less likely to slip against the skin when in contact with the skin, and irritation caused by rubbing against the skin can be reduced. In other words, the static friction coefficient can affect the gentleness of the feel on the wearer's skin. In this embodiment, the static friction coefficient is set so that the slip start angle measured by the following slip start angle measurement method is α = 37° or more.

(Method of measuring the start of slippage angle)
A slippage start angle measuring device 7 (ball tack adhesion measuring device, manufactured by YOSHIMITSU SEIKI) as shown in Fig. 5 is used. In the slippage start angle measuring device 7, the absorbent article 1 is attached so that the back sheet 3 faces the inclined surface 72 of an inclined plate 71 whose angle with respect to the horizontal plane is variable. A vinyl chloride sheet 73 (product name: Unisandee EB435-1, manufactured by Hikari Co., Ltd.) having a thickness of 0.5 mm is cut into a rectangle of 6 cm x 3 cm, and artificial leather 74 of Thoroughbred 602 manufactured by Kyowa Life Techno Co., Ltd., similarly cut into a rectangle of 6 cm x 3 cm, is attached to the vinyl chloride sheet 73 using double-sided tape to create a plate 75. This is placed on the body fluid absorbent article 1 so that the artificial leather 74 faces the top sheet 2.

The inclined plate 71 of the slip start angle measuring device 7 is moved from a horizontal state (i.e., the angle α between the horizontal plane and the inclined surface 72 = 0°) so that the angle α between the horizontal plane and the inclined surface 72 increases at a speed of 0.1°/sec. Then, the angle α between the horizontal plane and the inclined surface 72 when the plate body 75 starts to slip is defined as the slip start angle.

From the viewpoint of softness to the touch, it is preferable that the bodily fluid absorbent article 1 has a slip start angle of α = 37° or more, and more preferably a slip start angle of α = 40° or more. However, in the bodily fluid absorbent article 1 according to this embodiment, if emphasis is placed on softness, the slip start angle may be less than α = 37°.

＜Effects＞
As described above, the bodily fluid absorbent article 1 according to this embodiment has the compression recovery sheet 5 between the absorbent body 4 and the top sheet 2, and has a compression deformation rate T of 0.75 or more, so that the wearer is likely to feel a fluffy feeling when wearing the article, and is likely to obtain a good feeling of use. In addition, since the SAP sheet is used in the absorbent body, high absorbency can be obtained. Therefore, the bodily fluid absorbent article 1 according to this embodiment is likely to obtain a good feeling of use while maintaining high absorbency.

In addition, the compression recovery sheet 5 has a compression resilience value of 6.5% or more, so it can maintain contact with the skin at an appropriate contact pressure, providing a high level of comfort. In addition, its high resilience makes it less likely to wrinkle.

In addition, when the compression recovery sheet is an air-through nonwoven fabric, it is easy to achieve a fluffy feel and has high compression recovery, making it easy to achieve a high level of comfort when used.

In addition, since the dimensions between the absorbent body 4 and the outer periphery of the body fluid absorbent article 1 are all 20 mm or less, the body fluids are less likely to leak, and the body fluid absorbent article 1 has high absorbency. In addition, since the dimensions between the absorbent body 4 and the outer periphery are 20 mm or less, there is no difference in compression rate between the part where the absorbent body 4 is located and the entire body fluid absorbent article 1, and wrinkling is less likely to occur.

In addition, the slippage start angle of the body fluid absorbent article is set to α = 37° or more, so that when worn, the skin and the top sheet 2 are less likely to rub against each other, reducing irritation to the skin caused by friction and improving the comfort of use.

<Modification>
The above embodiment is merely one of various embodiments of the present invention. The embodiment can be modified in various ways depending on the design, etc., as long as the object of the present invention can be achieved. Modifications of the embodiment are listed below. The modifications described below can be applied in appropriate combination.

In the above embodiment, an example of the body fluid absorbent article 1 has been described as the panty liners 10, but the thickness and size of the body fluid absorbent article 1 are not particularly limited and can be set appropriately depending on the part of the body where it is worn. The shape of the body fluid absorbent article 1 is also not particularly limited. The body fluid absorbent article 1 according to this embodiment is formed in a roughly gourd shape when viewed from above, but can be formed in various other shapes, such as a rectangular shape, a square shape, a circle shape, an oval shape, an oval shape, a polygonal shape, etc., depending on the part of the body where it is worn.

In the bodily fluid absorbent article 1 according to the above embodiment, the pressure-bonding portion 11 is provided on the outer periphery of the bodily fluid absorbent article 1, but in the present invention, the pressure-bonding portion 11 may be provided around the entire circumference of the outer periphery, away from the outer periphery.

In the bodily fluid absorbent article 1 according to the above embodiment, the surface of the top sheet 2 (excluding the pressure-bonded portion 11) does not have unevenness formed by embossing or the like, but unevenness may be formed by embossing or the like.

In the bodily fluid absorbent article 1 according to the above embodiment, the top sheet 2, compression recovery sheet 5, and back sheet 3 are bonded together with adhesive and are fixed to each other by the pressure-bonding parts 11. However, the present invention is not limited to this, and the top sheet 2, compression recovery sheet 5, absorbent body 4, and back sheet 3 may be bonded together only by adhesive. Examples of adhesives include water-soluble adhesives (e.g., acrylic water-soluble adhesives), water-insoluble adhesives (e.g., rubber-based hot melt, olefin-based hot melt), etc. The bodily fluid absorbent article 1 may be constructed by fixing only at the pressure-bonding parts 11 without bonding with adhesive.

In the body fluid absorbent article 1 according to the above embodiment, the pressure-bonded portion 11 is formed by pressing the top sheet 2, the compression recovery sheet 5, and the back sheet 3, but the present invention is not limited to this. The pressure-bonded portion 11 may be formed, for example, by pressing the top sheet 2, the compression recovery sheet 5, the absorbent body 4, and the back sheet 3, by pressing only the top sheet 2 and the back sheet 3, by pressing the top sheet 2, the compression recovery sheet 5, and the back sheet 3, or by pressing the top sheet 2, the compression recovery sheet 5, and the back sheet 3, or by pressing the top sheet 2, the absorbent body 4, and the back sheet 3.

The bodily fluid absorbent article 1 according to the above embodiment has a four-layer structure consisting of a top sheet 2, a compression recovery sheet 5, an absorbent body 4, and a back sheet 3, but the present invention is not limited to this. In the bodily fluid absorbent article 1 according to the present invention, for example, a sheet (liquid diffusion sheet) that has a liquid permeability effect, a liquid diffusion effect, or suppresses the return of bodily fluids to the top sheet 2 may be provided between the top sheet 2 and the compression recovery sheet 5. The liquid diffusion sheet may also be provided between the compression recovery sheet 5 and the absorbent body 4. A hydrophilic spunbond is preferably used as the liquid diffusion sheet.

<Example>
The present invention will be described in more detail below with reference to examples, although the absorbent article according to the present invention is not limited to the following examples.

(1) Example 1
The bodily fluid absorbent article according to Example 1 had a top sheet, a compression recovery sheet and an absorbent body configured as follows, and a back sheet made of a polyethylene film. Then, a test was carried out using the bodily fluid absorbent article according to Example 1.
Top sheet: A nonwoven fabric made of cotton by the spunlace method was used. The basis weight was 30 g/ ^m2 .
Compression recovery sheet: A nonwoven fabric made by mixing PET/PE (core: PET sheath: PE core-sheath structure) and PET using the air-through method was used. The basis weight was 60 g/ ^m2 .
Absorbent body: SAP, pulp and PP/PE (core-sheath structure of core: PP sheath: PE) were defibrated and mixed by airlaid method, and accumulated to form a mass of 150 g/ ^m2 . The surface of the nonwoven fabric was not embossed. The shape of the absorbent body was made to follow the outer edge of the top sheet, and the distance between the outer edge of the body fluid absorbent article and the absorbent body was 1.2 cm at the longitudinal end and 0.5 cm at the lateral end.

In the tests, the compression deformation rate and compression resilience value were calculated. In addition, a sensory test for fluffiness ("Fluffiness" in the table), twist deformation rate, static friction coefficient, sensory test for texture ("Gentleness" in the table), and absorption capacity were also performed.

The compression deformation ratio was measured and calculated using the same method as described in "(7) Compression deformation ratio" in the above embodiment.

The compression resilience value was measured and calculated using the same method as described in "(5) Compression recovery sheet" in the above embodiment.

A sensory test for the fluffy feel was conducted as follows. Thirty people wore the body fluid absorbent article and rated it as follows: If 20 or more wearers felt it was soft and gentle to the touch (i.e., fluffy), it was rated as "◎". If 15 or more wearers felt it was fluffy, it was rated as "◯". If 14 or fewer wearers felt it was fluffy, it was rated as "X".

The twist deformation rate was measured as follows. The leg width of the doll capable of reproducing walking movements was set to 75 mm, the angle between the legs was set to 30°, and the bodily fluid absorbent article was attached so that 1/3 of the length of the article was located forward from the center seam of the shorts to be worn by the doll, and the shorts were then worn by the doll. The bodily fluid absorbent article attached to the shorts was photographed together with another article of known size, and this was used as the photograph before walking.

The doll's legs were then moved 100 steps at 60 steps/min. After that, the shorts with the bodily fluid absorbent article attached were carefully removed from the doll and a photograph was taken of the doll together with other items of known size to obtain the post-walking photograph. Using the image analysis software ImageJ, the area of the bodily fluid absorbent article before and after walking was calculated from the pre-walking and post-walking photographs. The ratio of the area of the bodily fluid absorbent article after walking to the area before walking was determined as the twist deformation rate.

The static friction coefficient was measured using the method described in (8) Static friction coefficient (Method for measuring the starting angle of sliding) above.

A sensory test for texture was conducted as follows. Thirty people wore the body fluid absorbent article and rated it as follows: If 20 or more wearers felt it was gentle on the skin, it was rated as "◎" If 15 or more wearers felt it was gentle on the skin, it was rated as "〇" If 14 or fewer wearers felt it was gentle on the skin, it was rated as "×".

The amount of absorption was measured as follows. A bodily fluid absorbent article was attached onto the filter paper, and physiological saline was dropped onto the center of the surface of the bodily fluid absorbent article. After one minute, a 0.5 mm thick polyvinyl chloride sheet (product name: Unisandee EB435-1, manufactured by Hikari Co., Ltd.) was placed on top, and a weight with a base area of 10 cm x 10 cm and a weight of 3.5 kg was placed on the polyvinyl chloride sheet. At this time, the load applied to the filter paper was 35 g/ ^m2 . It was left in this state for one minute. Thereafter, it was confirmed whether physiological saline had seeped out onto the filter paper, and the maximum amount of physiological saline that did not seep out was taken as the amount of absorption. The results are shown in Table 1 below.

(2) Example 2
The bodily fluid absorbent article according to Example 2 was constructed as follows: the top sheet, the compression recovery sheet, and the absorbent body, and the back sheet was made of a polyethylene film. Tests were then carried out using the bodily fluid absorbent article according to Example 2.
Top sheet: A nonwoven fabric made of cotton by the spunlace method was used. The basis weight was 30 g/ ^m2 .
Compression recovery sheet: A nonwoven fabric made by mixing PET/PE and PET using the air-through method was used. The basis weight was 60 g/ ^m2 .
Absorbent body: SAP, pulp and PP/PE were defibrated and mixed by the airlaid method, and then accumulated to form a mass of 150 g/ ^m2 . The surface of the nonwoven fabric was not embossed. The shape of the absorbent body was a rectangle measuring 3.5 cm x 11.5 cm. The distance between the outer edge of the body fluid absorbent article and the absorbent body was 3.5 cm for the longitudinal ends and 2.2 cm for the lateral ends.

The compression deformation rate and compression resilience value were calculated as part of the test. In addition, a sensory test was conducted on the softness, twist deformation rate, static friction coefficient, and texture, as well as tests on the absorption capacity. The results are shown in Table 1 below.

(3) Example 3
The bodily fluid absorbent article according to Example 3 was constructed as follows: the top sheet, the compression recovery sheet, and the absorbent body, and the back sheet was constructed of a polyethylene film. Then, a test was carried out using the bodily fluid absorbent article according to Example 3.
Top sheet: A nonwoven fabric made of polypropylene by the spunbond method was used. The basis weight was 18 g/ ^m2 .
Compression recovery sheet: A nonwoven fabric made by mixing PET/PE and PET using the air-through method was used. The basis weight was 60 g/ ^m2 .
Absorbent body: SAP, pulp and PP/PE were defibrated and mixed by the airlaid method, and then accumulated to form a mass of 150 g/ ^m2 . The surface of the nonwoven fabric was not embossed. The shape of the absorbent body was a rectangle measuring 3.5 cm x 11.5 cm. The distance between the outer edge of the body fluid absorbent article and the absorbent body was 3.5 cm for the longitudinal ends and 2.2 cm for the lateral ends.

The compression deformation rate and compression resilience value were calculated as part of the test. In addition, a sensory test was conducted on the softness, twist deformation rate, static friction coefficient, and texture, as well as tests on the absorption capacity. The results are shown in Table 1 below.

(4) Example 4
The bodily fluid absorbent article according to Example 4 was constructed as follows: the top sheet, the compression recovery sheet, and the absorbent body, and the back sheet was constructed of a polyethylene film. Then, a test was carried out using the bodily fluid absorbent article according to Example 4.
Top sheet: A nonwoven fabric made of cotton by the spunlace method was used. The basis weight was 30 g/ ^m2 .
Compression recovery sheet: A nonwoven fabric made by mixing PET/PE and PET using the air-through method was used. The basis weight was 40 g/ ^m2 .
Absorbent body: SAP, pulp and PP/PE were defibrated and mixed by the airlaid method, and then accumulated to form a mass of 150 g/ ^m2 . The surface of the nonwoven fabric was not embossed. The shape of the absorbent body was a rectangle measuring 3.5 cm x 11.5 cm. The distance between the outer edge of the body fluid absorbent article and the absorbent body was 3.5 cm for the longitudinal ends and 2.2 cm for the lateral ends.

The compression deformation rate and compression resilience value were calculated as part of the test. In addition, a sensory test was conducted on the softness, twist deformation rate, static friction coefficient, and texture, as well as tests on the absorption capacity. The results are shown in Table 1 below.

(5) Example 5
The bodily fluid absorbent article according to Example 5 had the following configurations of the top sheet, compression recovery sheet and absorbent body, and the back sheet was made of a polyethylene film. Tests were then conducted using the bodily fluid absorbent article according to Example 5.
Top sheet: A nonwoven fabric made of cotton by the spunlace method was used. The basis weight was 30 g/ ^m2 .
Compression recovery sheet: A nonwoven fabric made by mixing PET/PE and PET using the air-through method was used. The basis weight was 20 g/ ^m2 .
Absorbent body: SAP, pulp and PP/PE were defibrated and mixed by the airlaid method, and then accumulated to form a mass of 150 g/ ^m2 . The surface of the nonwoven fabric was not embossed. The shape of the absorbent body was a rectangle measuring 3.5 cm x 11.5 cm. The distance between the outer edge of the body fluid absorbent article and the absorbent body was 3.5 cm for the longitudinal ends and 2.2 cm for the lateral ends.

The compression deformation rate and compression resilience value were calculated as part of the test. In addition, a sensory test was conducted on the softness, twist deformation rate, static friction coefficient, and texture, as well as tests on the absorption capacity. The results are shown in Table 1 below.

(6) Comparative Example 1
The bodily fluid absorbent article according to Comparative Example 1 had a top sheet and an absorbent body configured as follows, and a back sheet configured of a polyethylene film. Tests were then conducted using the bodily fluid absorbent article according to Comparative Example 1. Note that the bodily fluid absorbent article according to Comparative Example 1 did not include a compression recovery sheet.
Top sheet: A nonwoven fabric made of cotton by the spunlace method was used. The basis weight was 30 g/ ^m2 .
Absorbent body: SAP, pulp and PP/PE were defibrated and mixed by the airlaid method, and then accumulated to form a mass of 150 g/ ^m2 . The surface of the nonwoven fabric was not embossed. The shape of the absorbent body was a rectangle measuring 3.5 cm x 11.5 cm. The distance between the outer edge of the body fluid absorbent article and the absorbent body was 3.5 cm for the longitudinal ends and 2.2 cm for the lateral ends.

The compression deformation rate and compression resilience value were calculated as part of the test. In addition, a sensory test was conducted on the softness, twist deformation rate, static friction number, sensory test on the feel on the skin, and tests on the absorption amount were also conducted. The results are shown in Table 1 below.

(7) Comparative Example 2
The body fluid absorbent article according to Comparative Example 2 had a top sheet and a compression recovery sheet configured as follows, and a back sheet configured from a polyethylene film. Tests were then conducted using the body fluid absorbent article according to Comparative Example 2. The body fluid absorbent article according to Comparative Example 2 did not include an absorbent body.
Top sheet: A nonwoven fabric made of cotton by the spunlace method was used. The basis weight was 30 g/ ^m2 .
Compression recovery sheet: A nonwoven fabric made by mixing PET/PE and PET using the air-through method was used. The basis weight was 40 g/ ^m2 .

The compression deformation rate and compression resilience value were calculated as part of the test. In addition, a sensory test was conducted on the softness, twist deformation rate, static friction coefficient, and texture, as well as tests on the absorption capacity. The results are shown in Table 1 below.

(8) Comparative Example 3
The bodily fluid absorbent article according to Comparative Example 3 was constructed as follows: the top sheet, the compression recovery sheet, and the absorbent body, and the back sheet was constructed of a polyethylene film. Tests were then carried out using the bodily fluid absorbent article according to Comparative Example 3.
Top sheet: A nonwoven fabric made of cotton by the spunlace method was used. The basis weight was 30 g/ ^m2 .
Compression recovery sheet: A nonwoven fabric made of polypropylene by the spunbond method was used. The basis weight was 18 g/ ^m2 .
Absorbent body: SAP, pulp and PP/PE (core-sheath structure of core: PP sheath: PE) were defibrated and mixed by the airlaid method, and accumulated to form a mass of 150 g/ ^m2 . The surface of the nonwoven fabric was not embossed. The shape of the absorbent body was a rectangle of 3.5 cm x 11.5 cm. The distance between the outer periphery of the body fluid absorbent article and the absorbent body was 3.5 cm for the longitudinal ends and 2.2 cm for the lateral ends.

The compression deformation rate and compression resilience value were calculated as part of the test. In addition, a sensory test was conducted on the softness, twist deformation rate, static friction coefficient, and texture, as well as tests on the absorption capacity. The results are shown in Table 1 below.

(9) Comparative Example 4
The bodily fluid absorbent article according to Comparative Example 4 was constructed as follows: the top sheet, the compression recovery sheet, and the absorbent body, and the back sheet was constructed of a polyethylene film. Tests were then carried out using the bodily fluid absorbent article according to Comparative Example 4.
Top sheet: A nonwoven fabric made of cotton by the spunlace method was used. The basis weight was 30 g/ ^m2 .
Compression recovery sheet: A nonwoven fabric made of polypropylene by the spunbond method was used. The basis weight was 18 g/ ^m2 .
Absorbent body: SAP, pulp and dish paper were used, the basis weight was 150 g/ ^m2 , and the entire surface was embossed. The shape of the absorbent body was a rectangle of 3.5 cm x 11.5 cm. The distance between the outer edge of the body fluid absorbent article and the absorbent body was 3.5 cm at the longitudinal end and 2.2 cm at the lateral end.

As the test, the compression deformation rate and compression resilience value were calculated. In addition, a sensory test for the softness, the twist deformation rate, the static friction coefficient, the sensory test for the feel on the skin, and the absorption amount were also tested. The results are shown in Table 1 below.

As shown in Table 1, Examples 1-5 and Comparative Examples 1-4 demonstrate that a compressive deformation ratio of 0.73 or less makes it difficult to obtain a fluffy feel, while a compressive deformation ratio of 0.75 or more for the absorbent article is effective in obtaining a fluffy feel.

Comparing Comparative Example 2 and Comparative Example 3, the compression resilience value was 13.9 in Comparative Example 2 and 6.02 in Comparative Example 3, but the twist deformation rate was 80% in Comparative Example 2 and 76% in Comparative Example 3. Therefore, it was found that if the compression resilience value is 6.02 or less, the material is prone to twisting.

Comparing Example 1 and Example 2-5, the dimension from the end of the SAP sheet to the outer edge of the body fluid absorbent article was 20 mm or less in Example 1, whereas it was greater than 20 mm in all cases in Examples 2-5. The absorption amount was 2 cc in Example 1, whereas it was 1.8 cc in Example 2-5. Therefore, it was demonstrated that if the dimension between the absorbent body and the outer edge of the body fluid absorbent article is 20 mm or less, the absorption amount can be increased. In addition, the twist deformation rate was 95% in Example 1, whereas it was 89% or less in Example 2-5. Therefore, it was demonstrated that if the dimension between the absorbent body and the outer edge of the body fluid absorbent article is 20 mm or less, twisting is less likely to occur.

Comparing Example 3 with Examples 1 and 2, the sliding start angle was 35° in Example 3, while it was 40° in Examples 1 and 2, and the gentleness to the skin was rated as "good" in Example 3, while it was rated as "good" in Examples 1 and 2. It is believed that this result was obtained because the frictional force of the top sheet affects the ability of the top sheet to conform to the skin that is in contact with it. Therefore, it was found that when the sliding start angle is 35° or less, the gentleness to the skin is somewhat compromised.

Comparing Example 4 and Comparative Example 2, Example 4, which has an absorbent body (SAP sheet), has a compression deformation rate of 0.81, whereas Comparative Example 2, which does not have an absorbent body, has a compression deformation rate of 0.47. The only difference between Example 4 and Comparative Example 2 is the presence or absence of an absorbent body. This shows that by overlapping the absorbent body (SAP sheet) and the compression recovery sheet, the compression deformation rate and fluffiness are improved compared to the case of only the compression recovery sheet.

Reference Signs List 1 Body fluid absorbent article 2 Top sheet 3 Back sheet 4 Absorbent body 40 SAP sheet 5 Compression recovery sheet 71 Inclined plate 72 Inclined surface 73 Acrylic plate 74 Artificial leather T Compression deformation rate

Claims (6)

a top sheet which is a surface layer in contact with the wearer's skin and is made of natural fibers, preferably cotton ;
A back sheet which is a back surface layer;
an absorbent body disposed between the top sheet and the back sheet;
A body fluid absorbent article comprising:
The absorbent body is an SAP sheet containing an absorbent polymer,
The device further includes a compression recovery sheet disposed between the absorbent body and the top sheet over the entire area of the absorbent body,
The compressive deformation ratio of the body fluid absorbent article is 0.75 or more.
Body fluid absorbing articles. The compression recovery sheet has a compression resilience value of 6.5% or more.
The body fluid absorbent article according to claim 1. The compression recovery sheet is an air-through nonwoven fabric.
The body fluid absorbent article according to claim 1 or 2. The distance between the absorbent body and the outer peripheral edge of the body fluid absorbent article is 20 mm or less.
The body fluid absorbent article according to any one of claims 1 to 3. The slip start angle of the body fluid absorbent article measured by a slip start angle measuring method is 37° or more.
The body fluid absorbent article according to any one of claims 1 to 4. The amount of physiological saline absorbed is 1.5 cc or more.
The body fluid absorbent article according to any one of claims 1 to 5.

Images