JP7803752B2 - sanitary products - Google Patents

Description

The present invention relates to hygiene products.

Conventionally, sanitary products have been known in which a skin care liquid is applied to the surface that comes into contact with the wearer's skin (see, for example, Patent Documents 1 to 4).

Japanese Patent Application Laid-Open No. 2004-255164 Japanese Patent Application Laid-Open No. 2015-171649 Japanese Patent Application Laid-Open No. 2021-84906 Japanese Patent Application Laid-Open No. 2021-186662

However, with conventional sanitary products, when medicinal liquid is applied to the contact surface, the liquid passes through the gaps in the fibers, making it difficult for the liquid to adhere to the contact surface. This poses the problem of reducing the skin care effect of the medicinal liquid.

The present invention was developed in response to the above-mentioned problems, and aims to provide a sanitary product that can fix a skin care liquid to the surface that comes into contact with the wearer's skin, thereby improving the skin care effect of the liquid.

In order to achieve the above object, the present invention provides a sanitary product to be worn by a wearer, comprising a sheet material having a contact surface that comes into contact with the wearer's skin, the sheet material including at least one of first fibers that are hydrophobic synthetic fibers containing a hydrophilic resin inside, and second fibers that have a surface area-enhancing structure on the fiber surface and contain either modified cross-section fibers, crimped fibers, or heat-shrinkable fibers, and a hydrophilic skin care medicinal solution is applied to the contact surface, forming a medicinal solution layer on the surface of the contact surface .

As a result, the sanitary product of the present invention allows the skin care medicinal solution to adhere to the surface that comes into contact with the wearer's skin, improving the skin care effect of the medicinal solution.

FIG. 1 is a perspective view showing a sanitary product according to a first embodiment. 1 is an explanatory diagram showing a cross section of a sanitary product according to a first embodiment of the present invention; 1A is an explanatory diagram showing a first example of a modified cross-section fiber, and FIG. 1B is an explanatory diagram showing a second example of a modified cross-section fiber. FIG. 2 is an explanatory diagram showing an example of crimped fibers. FIG. 2 is an explanatory diagram showing an example of a heat-shrinkable fiber. 1 is an explanatory diagram showing the fiber surfaces of various fibers. FIG. FIG. 2 is a schematic diagram showing a compression pattern of heat embossing in the sanitary product of Example 1. FIG. 2 is a schematic diagram showing a first example of an adhesive application pattern in the sanitary product of Example 1. FIG. 10 is a schematic diagram showing a second example of an adhesive application pattern in the sanitary product of Example 1.

A mode for implementing the sanitary product of the present invention will be described based on Example 1 shown in the drawings. The sanitary product of the present invention is applicable to absorbent articles capable of absorbing the wearer's bodily fluids, such as sanitary napkins, panty liners, incontinence pads, medical pads, and disposable diapers. The sanitary product of the present invention may also be applied to masks that cover the wearer's nose and mouth and block droplets. Example 1 describes the sanitary product 1 applied to a sanitary napkin that is attached to underwear and used to absorb bodily fluids (menstrual blood and vaginal discharge).

As shown in Figure 1, the sanitary product 1 of Example 1 comprises a top sheet 10 (surface material), an absorbent member 20, and a back sheet 30.

The topsheet 10 is a thin film member that is liquid-permeable and allows bodily fluids to pass through quickly. The topsheet 10 has a contact surface 10a that comes into contact with the wearer's skin S when the sanitary product 1 is in use.

The absorbent member 20 is placed between the topsheet 10 and the backsheet 30 and absorbs bodily fluids that have permeated the topsheet 10. The absorbent member 20 is formed by laminating materials such as cotton-like pulp, absorbent paper, and superabsorbent polymers. The superabsorbent polymers have the ability to quickly absorb 50 to 100 times their own weight in liquid and retain the absorbed liquid by gelling.

The back sheet 30 is a liquid-impermeable thin film that prevents leakage of bodily fluids. The absorbent member 20 is laminated on the back sheet 30, which covers the back side of the absorbent member 20 and comes into contact with the underwear P when the sanitary product 1 is in use. The periphery of the back sheet 30 is joined to the periphery of the top sheet 10 by an adhesive such as hot melt or by an adhesive method such as heat sealing. Furthermore, the outer surface 30a of the back sheet 30 that comes into contact with the underwear P is provided with an anti-slip adhesive (not shown) to secure the sanitary product 1 to the underwear P.

As shown in Figure 2, the topsheet 10 of Example 1 is composed of a first sheet 11 (sheet material) and a second sheet 12 (second sheet material) superimposed on the first sheet 11, forming a so-called two-layer structure.

The first sheet 11 is placed on the front side (skin S side) of the top sheet 10 and has a contact surface 10a that comes into contact with the skin S. A skin care medicinal solution 40 (see Figure 2) is applied to the contact surface 10a, and a medicinal solution layer is formed on the surface of the contact surface 10a. Here, the medicinal solution 40 is evenly applied to almost the entire surface of the contact surface 10a.

The medicinal solution 40 contains ingredients such as glycerin, hyaluronic acid, and shea butter. The skin care effects of the medicinal solution 40 include moisturizing the skin S, reducing friction between the sanitary product 1 and the skin S, and improving the barrier function of the skin S. The medicinal solution 40 is applied to the contact surface 10a of the first sheet 11 by, for example, a non-contact application method such as spray application, or a contact application method such as printing (transfer).

The second sheet 12 is laminated to the non-contact surface 10b of the first sheet 11, which is located opposite the contact surface 10a. In other words, the second sheet 12 is positioned on the back side of the topsheet 10 (the absorbent member 20 side).

The first sheet 11 and the second sheet 12 are each formed from a nonwoven fabric containing at least one of first fibers containing a hydrophilic resin and second fibers having a surface area-enhancing structure on the fiber surface.

Here, the first fiber is formed by kneading a hydrophilic resin into the interior of a hydrophobic synthetic fiber. Because the first fiber contains the hydrophilic resin, it absorbs moisture from the air and forms a water film on the surface of the hydrophobic synthetic fiber. Furthermore, the first fiber can diffuse electricity with the water film formed by the hydrophilic resin, thereby reducing the generation of static electricity. The hydrophilic resin may be incorporated into the first fiber by being attached to the surface of the hydrophobic synthetic fiber by spraying, coating, or the like.

The "surface area-enhancing structure" of the second fiber is a structure that increases (enlarges) the surface area compared to a fiber with a smooth fiber surface and a circular cross-sectional contour, such as irregularities, undulations, crimps, or scales formed on the fiber surface. The second fiber has a surface area-enhancing structure, which results in an irregular cross-sectional contour. Specifically, the second fiber may be a modified cross-section fiber, a crimped fiber, a heat-shrinkable fiber, or a natural fiber. Modified cross-section fibers are synthetic fibers with a non-circular cross-section (e.g., triangular, star-shaped, Y-shaped, hollow, or flower-shaped), as shown in Figures 3(a) and 3(b). Crimped fibers are fibers that are not straight but are crimped and deformed, as shown in Figure 4. Crimped fibers may be natural fibers that exhibit crimping, such as wool, or synthetic fibers that have been given crimping properties through false twisting (woolly processing). Heat-shrinkable fibers are synthetic fibers that are not linear but have shrunk due to heat processing, as shown in Figure 5. Natural fibers are primarily made from natural materials and are broadly classified into "plant fibers" and "animal fibers." Examples of "plant fibers" include flax (Sample 1 shown in Figure 6) and cotton (Sample 2). Examples of "animal fibers" include silk (Sample 3 shown in Figure 6) and wool (Lincoln: Sample 4, Merino: Sample 5). Fibers such as Samples 1 to 5 have unevenness, undulations, crimps, and scales on the fiber surface compared to common synthetic fibers such as Sample 6 (polyester) shown in Figure 6, resulting in second fibers with an increased surface area. Note that the second fibers may also be fibers that have both the characteristics of a non-circular cross-section fiber, such as a non-circular crimped fiber, and the characteristics of a crimped fiber.

Furthermore, the first and second fibers contained in the first and second sheets 11 and 12 are both set to have a single yarn fineness of 2 dtex (decitex) or less. Because the single yarn fineness is 2 dtex or less, the first and second fibers are finer than typical clothing fibers, which have a single yarn fineness of approximately 3.33 dtex (3 denier).

The first sheet 11 and the second sheet 12 are preferably formed by thermal bonding, spunbonding, meltblowing, or the like. The weight per unit area of the first sheet 11 and the second sheet 12 is preferably approximately 10 to 40 gsm. Furthermore, the first sheet 11 and the second sheet 12 may be formed from the same material or different materials.

In Example 1, the first sheet 11 is bonded to the second sheet 12 by thermal embossing, and the first sheet 11 and the second sheet 12 are joined together. In Example 1, the thermal embossing is evenly applied to the entire surface of the first sheet 11, and a thermal embossed bonded pattern 41 is formed over the entire surface of the first sheet 11. The "bonded pattern" refers to a region where the fibers are compressed and depressed by the heat and pressure of the thermal embossing.

As shown in Figure 7, the crimped pattern 41 has a circular shape with a diameter r of 1 mm or more and 5 mm or less in plan view. Furthermore, the spacing W between adjacent crimped patterns 41 is set to 5 mm or less.

Furthermore, as shown in Figure 2, the topsheet 10 of Example 1 is adhered to the absorbent member 20 via adhesive 42, which is uniformly applied between the topsheet 10 and the absorbent member 20. Here, the adhesive 42 is applied by a curtain spray method in which the adhesive is discharged in a linear (fibrous) form from a single tiny outlet, or, as shown schematically in Figure 8, in a linear form (a curtain-like form of a predetermined width overall) from multiple tiny outlets aligned in a certain direction. The application pattern T of the adhesive 42 by the curtain spray method exhibits randomly oriented fibrous form in plan view, as shown enlarged in Figure 8.

The adhesive 42 may be applied by a slot coating method, in which the adhesive 42 is dispensed from a narrow, elongated outlet formed in a certain direction and applied in a strip of a predetermined width, as shown schematically in Figure 9. Slot coating methods include a method in which the adhesive 42 is applied on a roll R (see Figure 9) and a method in which the adhesive 42 is applied using tension between rolls (not shown). Either method allows the adhesive 42 to be applied continuously or intermittently, as shown enlarged in Figure 9.

Next, the effects of the sanitary product 1 of Example 1 will be explained.

In the sanitary product 1 of Example 1, the top sheet 10, which faces the wearer when worn, is provided with a first sheet 11 having a contact surface 10a that comes into contact with the wearer's skin S. A skin care solution 40 is applied to the contact surface 10a of the first sheet 11. Furthermore, the first sheet 11 is formed from a nonwoven fabric that includes at least one of first fibers containing a hydrophilic resin and second fibers having a surface area-enhancing structure on the fiber surface.

The hydrophilic resin contained in the first fibers allows a water film to form on the fiber surface. Therefore, when the first sheet 11 includes the first fibers, the first sheet 11 can form a water film of the medicinal solution 40 on the contact surface 10a using the first fibers, thereby fixing the medicinal solution 40 to the contact surface 10a. As a result, the sanitary product 1 of Example 1 can improve the skin care effect of the medicinal solution 40 and reduce skin stress when wearing the sanitary product 1.

Furthermore, the second fibers have a surface area-increasing structure on their fiber surfaces. Therefore, when the first sheet 11 includes the second fibers, the first sheet 11 can increase the area onto which the chemical solution 40 is applied compared to sheet materials formed from fibers with smooth fiber surfaces, such as general synthetic fibers. This allows the first sheet 11 to increase the amount of chemical solution applied and the amount of chemical solution 40 that settles on the contact surface 10a. Furthermore, the chemical solution 40 is more likely to become entangled in the surface area-increasing structure, and the second fibers have a higher ability to retain the chemical solution 40 than fibers with smooth fiber surfaces. As a result, the first sheet 11 including the second fibers can settle the chemical solution 40 on the contact surface 10a. Therefore, the sanitary product 1 of Example 1 can improve the skin care effect of the chemical solution 40 even when the first sheet 11 includes the second fibers.

Furthermore, in the sanitary product 1 of Example 1, the single yarn fineness of the first and second fibers contained in the first sheet 11 is set to 2 dtex or less. Therefore, the sanitary product 1 of Example 1 can increase the density of the fiber structure of the first sheet 11. This makes it difficult for the chemical solution 40 to pass through the first sheet 11, and the sanitary product 1 can keep the chemical solution 40 on the contact surface 10a.

In the sanitary product 1 of Example 1, the second sheet 12 is laminated on the non-contact surface 10b of the first sheet 11, giving the top sheet 10 a two-layer structure. The second sheet 12 is formed from a nonwoven fabric containing at least one of first fibers containing a hydrophilic resin and second fibers having a surface area-enhancing structure on the fiber surface. This allows the sanitary product 1 to inhibit the passage of the chemical solution 40 through both the first sheet 11 and the second sheet 12, improving the retention of the chemical solution 40 on the contact surface 10a.

In addition, in the sanitary product 1 of Example 1, the single yarn fineness of the first fiber and the second fiber contained in the second sheet 12 is also set to 2 dtex or less. This allows the sanitary product 1 of Example 1 to increase the density of the fiber structure of the second sheet 12, making it more difficult for the chemical solution 40 to pass through the second sheet 12. As a result, the sanitary product 1 of Example 1 can further improve the fixation performance of the chemical solution 40 on the contact surface 10a.

In addition, in the sanitary product 1 of Example 1, the first sheet 11 is bonded to the second sheet 12 by thermal embossing. Here, the bonded pattern 41 formed by thermal embossing melts the top sheet 10 and creates a depression in the contact surface 10a. Therefore, the chemical solution 40 applied to the contact surface 10a tends to accumulate inside the bonded pattern 41 (the depression in the contact surface 10a).

In contrast, the pressure-bonded pattern 41 in Example 1 has a circular shape with a diameter r of 1 mm or more and 5 mm or less in plan view. Furthermore, the spacing W between adjacent pressure-bonded patterns 41 is set to 5 mm or less. Therefore, the sanitary product 1 can form many relatively fine pressure-bonded patterns 41 on the contact surface 10a, and by storing a large amount of chemical solution 40 within the pressure-bonded patterns 41, the adhesion performance of the chemical solution 40 on the contact surface 10a can be improved.

Furthermore, the sanitary product 1 of Example 1 comprises a topsheet 10 having a first sheet 11 and facing the wearer, and an absorbent member 20 positioned on the non-skin side of the topsheet 10 to absorb the wearer's bodily fluids. The topsheet 10 is adhered to the absorbent member 20 via adhesive 42 uniformly applied between the topsheet 10 and the absorbent member 20.

As a result, in the sanitary product 1, the adhesive 42 prevents the chemical solution 40 from passing through the top sheet 10, allowing the chemical solution 40 to adhere to the contact surface 10a. This allows the sanitary product 1 to improve the adhesion performance of the chemical solution 40 to the top sheet 10.

The sanitary product 1 of the present invention has been described above based on Example 1, but the specific configuration is not limited to Example 1, and design changes and additions are permitted as long as they do not deviate from the gist of the invention as defined in each claim.

In the sanitary product 1 of Example 1, the bonding pattern 41 that bonds the first sheet 11 to the second sheet 12 has a circular shape in a planar view. However, the shape of the bonding pattern 41 is not limited to a circular shape. The bonding pattern 41 may, for example, be rectangular in a planar view, with the length of each side set to 1 mm or more and 5 mm or less. In other words, the bonding pattern 41 may have a rectangular shape with the length of each side set to 1 mm or more and 5 mm or less in a planar view. Even in this case, the sanitary product 1 can improve the adhesion performance of the chemical solution 40 on the contact surface 10a by storing a large amount of chemical solution 40 in the bonding pattern 41.

Furthermore, the sanitary product 1 may have a mixture of circular and rectangular pressure-bonded patterns 41 in a planar view. Even in this case, by setting the diameter r and the length of each side to 1 mm or more and 5 mm or less, and setting the spacing W between adjacent pressure-bonded patterns 41 to 5 mm or less, a large amount of chemical solution 40 can be stored in the pressure-bonded patterns 41, improving the fixing performance of the chemical solution 40.

In the sanitary product 1 of Example 1, the first sheet 11 constituting the top sheet 10 is bonded to the second sheet 12 by heat embossing. However, the first sheet 11 may also be bonded to the second sheet 12 via an adhesive uniformly applied between the first sheet 11 and the second sheet 12. In this case, the adhesive applied between the first sheet 11 and the second sheet 12 can prevent the passage of the chemical solution 40 applied to the contact surface 10a, thereby improving the adhesion of the chemical solution 40 to the top sheet 10.

In addition, in the sanitary product 1 of Example 1, an example was shown in which the topsheet 10 has a two-layer structure composed of a first sheet 11 and a second sheet 12. However, the configuration of the topsheet 10 is not limited to this. The topsheet 10 only needs to include at least the first sheet 11 having a contact surface 10a that comes into contact with the wearer's skin S, and may have a single-layer structure. Furthermore, the topsheet 10 may have a three-layer or more structure in which an additional sheet material is laminated on the second sheet 12. In other words, the second sheet 12 does not need to be provided, or may be multiple sheet materials.

In addition, the sanitary product 1 in Example 1 is shown as being applied to a sanitary napkin (absorbent article) in which an absorbent member 20 capable of absorbing the wearer's bodily fluids is covered with a topsheet 10. However, the sanitary product 1 may also be one that does not have an absorbent member 20, such as a mask.

In addition, in the sanitary product 1 of Example 1, the medicinal liquid 40 is evenly applied to almost the entire surface of the contact surface 10a that comes into contact with the wearer's skin S. However, the medicinal liquid 40 may be applied to any part of the contact surface 10a, or the amount applied may vary in parts. Furthermore, multiple different types of medicinal liquid 40 may be applied to the contact surface 10a.

1. Sanitary goods 10. Surface sheet (surface material)
10a: Contact surface 10b: Non-contact surface 11: First sheet (sheet material)
12 Second sheet (second sheet material)
20 Absorbent member 30 Back sheet 40 Chemical solution 41 Compression pattern 42 Adhesive

Claims (1)

A hygiene product to be worn by a wearer,
a sheet material having a contact surface that contacts the wearer's skin,
The sheet material comprises at least one of a first fiber containing a hydrophilic resin inside a hydrophobic synthetic fiber and a second fiber having a surface area increasing structure on the fiber surface and containing either a modified cross-section fiber, a crimped fiber, or a heat-shrinkable fiber, and a hydrophilic skin care liquid medicine is applied to the contact surface , forming a liquid medicine layer on the surface of the contact surface .