JP2021094268A - Absorbent article - Google Patents

Abstract

To provide an absorbent article that is improved in color concealment properties to the red and yellow body fluid, and thereby reducing discomfort when a wearer performs visual recognition.SOLUTION: An absorbent article includes a surface sheet arranged in a skin facing surface side, a back sheet arranged in a non-skin facing surface side, and an absorbent core arranged between the surface sheet and the back sheet. A purple second sheet is provided between the surface sheet and the absorbent core. The second sheet has water absorbing properties higher than the surface sheet and has an absorptive capacity smaller than the absorbent core. The absorbent article is configured so that the chromaticity of aP* and the chromaticity of bP* defined by a color space of L*a*b* of CIE1976 through the surface sheet may be aP*≥3 and bP*≤-2.SELECTED DRAWING: Figure 2

Description

The present invention relates to an absorbent article having improved color hiding properties for both red and yellow body fluids.

Absorbent articles such as panty liners and sanitary napkins are liquid permeable (water permeable) front sheet, liquid leak proof (waterproof) back sheet, and absorbent placed between the front and back sheets. It has a core (see, for example, Patent Documents 1 and 2).

JP-A-2018-777 Special Table 2017-500906

Absorbent articles such as panty liners and sanitary napkins may be used unintentionally or intentionally to absorb at least two of menstrual blood, vaginal discharge, and incontinence urine.
However, it has been difficult for conventional absorbent articles to conceal both red body fluids such as menstrual blood and yellow body fluids such as vaginal discharge and incontinence urine.

The present invention has been made in view of the above circumstances, and relates to an absorbent article having improved color hiding properties for both red and yellow body fluids.

The present invention has an absorbency including a front surface sheet arranged on the skin facing surface side, a back surface sheet arranged on the non-skin facing surface side, and an absorption core arranged between the front surface sheet and the back surface sheet. In the article, a purple-based second sheet is provided between the surface sheet and the absorption core, and the second sheet has higher water absorption than the surface sheet and absorbs more than the absorption core. The capacity is small, and the chromaticity a _P ^* and chromaticity b _P ^{* defined in the L *} a ^* b ^* color space of CIE1976 via the surface sheet are a _P ^* ≧ 3 and b _P ^* ≦ -2. With respect to an absorbent article configured to be.

According to the absorbent article according to the present invention, the color hiding property for red and yellow body fluids is improved, and the discomfort when the wearer visually recognizes the product can be reduced.

It is a top view of the absorbent article (panty liner) which concerns on embodiment of this invention as seen from the surface sheet side. It is sectional drawing along the line II-II of FIG. It is a top view which shows the absorbent article (panty liner) which adhered the packaging sheet to the back sheet side. It is a top view which shows the individual package body in a folded state.

Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. It should be noted that the following embodiments do not limit the invention according to each claim, and not all combinations of features described in the embodiments are essential for the means for solving the invention. ..

In the present embodiment, the "skin-facing surface" refers to the surface facing the wearer when worn, and the "non-skin-facing surface" refers to the surface opposite the skin-facing surface, that is, the side to be worn on clothing when worn. It shall refer to the aspect of. The front-back direction (longitudinal direction (X direction in FIG. 1)) refers to the direction along the long side of the absorbent article 1 corresponding to the front-back direction of the wearer, and the width direction (short direction (Y in FIG. 1)). Direction)) refers to the direction along the skin-facing surface or the non-skin-facing surface among the directions orthogonal to the longitudinal direction.

[Composition of absorbent articles]
FIG. 1 is a plan view of the panty liner 1 which is an absorbent article according to the present embodiment as viewed from the surface sheet 2 side, and FIG. 2 is a sectional view taken along line II-II of FIG. In FIG. 2, the thickness is exaggerated and thickened from the actual size for easy understanding. The absorbent article 1 according to the present embodiment shown in these figures is a panty liner used by being attached to the skin contact surface (inner surface) of clothing such as shorts.

The panty liner 1 includes a liquid-permeable (water-permeable) front sheet 2 arranged on the skin-facing surface side, a liquid-proof (waterproof) back sheet 3 arranged on the non-skin-facing surface side, and these. It is provided with an absorption core 4 arranged between both sheets 2 and 3. Further, a second sheet 5 is provided between the surface sheet 2 and the absorption core 4 (see FIG. 2). A fastening material 6 for fastening to a crotch portion such as shorts is laminated on the non-skin facing surface of the back sheet 3. When not in use, a peeling treatment sheet (not shown) is laminated on the fastening material 6.

The front surface sheet 2, the back surface sheet 3, and the second sheet 5 have the same outer shape when viewed in a plan view, and the peripheral shape thereof is the peripheral shape of the absorbent article 1. The front surface sheet 2, the back surface sheet 3, and the second sheet 5 have a shape that is vertically longer in the front-rear direction than the absorption core 4 and wider in the width direction than the absorption core 4. The front surface sheet 2, the back surface sheet 3, and the second sheet 5 extend from both ends in the front-rear direction and the width direction of the absorption core 4, respectively, and the absorption core 4 is arranged between the second sheet 5 and the back surface sheet 3. It has become.

A fixing material (not shown) is provided between the front sheet 2 and the second sheet 5, between the second sheet 5 and the absorption core 4, and between the absorption core 4 and the back sheet 3, and the upper and lower members are laminated. It is joined by a fixing material. As the fixing material, a hot melt adhesive (styrene-butadiene-styrene (SBS) -based, styrene-ethylene-butadiene-styrene (SEBS) -based, olefin-based hot melt adhesive) or the like is used. By joining and crimping the outer peripheral edges of the front surface sheet 2, the back surface sheet 3 and the second sheet 5 to each other by a heat seal or the like, a joint edge portion 7 extending in a strip shape along the outer peripheral edge portion of the absorbent article 1 is formed. Has been done.

Further, a quilt embossing process is performed to integrally press the surface sheet 2 and the second sheet 5, and a grid-like quilt embossing 8 appears on the skin-facing surface of the surface sheet 2. In the panty liner 1, linear embossed lines composed of a plurality of dot-shaped pressed portions intersect to form a grid-like pattern. By this quilt embossing process, the surface sheet 2 and the second sheet 5 are integrally joined. The quilt embossing is to perform quilt pattern embossing in a dot shape by applying heat while the metal pin is pushed in. The embossing has not reached the absorption core 4.

The surface sheet 2 is a liquid permeable (water permeable) sheet and has a lower water absorption than the second sheet 5. Examples of the material constituting the surface sheet 2 include fibers containing a hydrophobic resin such as polyethylene, polypropylene, and polyester treated with a hydrophilic agent. Specifically, the surface sheet 2 is preferably an air-through non-woven fabric having a basis weight of 15 to 35 g / m ² , and is formed of, for example, an air-through non-woven fabric (basis weight 25 gsm). The surface sheet 2 has a light transmissive property that allows the color of the second sheet 5 to be seen through from the side facing the skin, and the color is preferably white, for example. The whiteness of the non-woven fabric may be improved by blending titanium oxide with the fibers of the non-woven fabric forming the surface sheet 2 to whiten the fibers.

Color of the surface sheet 2, expressed in ^{CIE-L *} a * ^{b *} color system, the lightness L _T ^* is preferably 85 or more and 100 or less, specifically 98. The chromaticity a _T ^* is preferably -2 or more and 2 or less, and specifically 0. The chromaticity b _T ^* is preferably -2 or more and 2 or less, specifically -1.
In this specification, CIE-L ^* a ^* b ^* is a color coordinate measured according to JIS Z8781-4, and specifically, it is measured by the "measurement method of brightness and chromaticity" described later. can do. Further, in the present specification, the lightness L _n ^* , the chromaticity an _n ^*, and the chromaticity b _n ^{* are the L *} values, a at the location n or the member n, respectively, when the specific location or the member is indicated by n. ^It means * value and b ^* value.

In the panty liner 1, the second sheet 5 has a higher water absorption than the surface sheet 2 and a smaller absorption capacity than the absorption core 4.
The water absorption can be evaluated by the Krem method described in "Paper and Paperboard-Water Absorption Test Method" of JIS P 8141. The Krem water absorption height of the second sheet 5 is preferably 1 mm or more higher than the Krem water absorption height of the surface sheet 2, and more preferably 5 mm or more. The Krem water absorption height of the surface sheet 2 is preferably 1 mm or more and 20 mm or less, specifically 3 mm. The Krem water absorption height of the second sheet 5 is preferably 5 mm or more and 40 mm or less, specifically 16 mm.

The second sheet 5 is preferably made of a material having higher water absorption than the surface sheet 2. As such a material, pulp, cotton fiber (cotton fiber), linen fiber (linen fiber), silk fiber (silk fiber) and the like can be used. The basis weight of the second sheet 5 is preferably larger than the basis weight of the surface sheet 2, specifically, 20 g / m ² or more and 60 g / m ² or less, and 25 g / m ² or more and 50 g / m ² or less. preferable.

The second sheet 5 has a purple color. Here, the "purple system" can be said to be a color belonging to bluish purple (PB), purple (P), and magenta (RP) in the Munsell hue circle. In the L ^* a ^* b ^* color space of CIE1976, it is preferable that the color exists in the fourth quadrant at the coordinates where ^{a *} is the X-axis and b ^{* is the Y-axis.} Specifically, the second sheet 5 according to the present embodiment has the lightness L _COLOR ^* , the chromaticity a _COLOR ^* , and the chromaticity b _COLOR ^* , for example, L _COLOR ^* <90, a _COLOR ^* > 10, b _COLOR. ^* <-10.

_{The lightness L COLOR} ^* of the second sheet 5 is preferably smaller than _{the lightness L T} ^* of the surface sheet 2 so that the shade of color can be recognized by the user through the surface sheet 2. _{The lightness L COLOR} ^* of the second sheet 5 is preferably less than 90, more preferably less than 85, from the viewpoint of color hiding property. Further, for the purpose of relieving a depressed mood, the brightness L _COLOR ^* of the second sheet 5 is preferably 40 or more, and more preferably 50 or more.
Further, the chromaticity a _COLOR ^* of the second sheet 5 is preferably larger than _{the chromaticity a T} ^* of the surface sheet 2 so that the tint of the second sheet 5 can be clearly seen from the surface sheet 2. From the viewpoint of making it difficult to feel the redness of menstrual blood and relieving a depressed mood, the chromaticity a _COLOR ^* of the second sheet 5 is preferably greater than 0, more preferably greater than 4, and greater than 10. Is more preferably less than 30, more preferably less than 25, and even more preferably less than 20.
Further, the chromaticity b _COLOR ^* of the second sheet 5 is preferably larger than _{the chromaticity b T} ^* of the surface sheet 2 so that the tint of the second sheet 5 can be clearly seen from the surface sheet 2. _{The chromaticity b COLOR} ^* of the second sheet 5 is preferably less than 0, more preferably less than -2, and more than -10 from the viewpoint of making it difficult to feel the yellowness of vaginal discharge and urine and relieving a depressed mood. Smaller is more preferable, and -30 or more is preferable, -25 or more is more preferable, and -20 or more is further preferable.

As described above, the surface sheet 2 and the second sheet 5 are provided with a plurality of pressing portions that communicate with each other. As the pressing portion, there are a joining edge portion 7 on the outer peripheral edge portion of the panty liner 1 and each pressing portion forming the quilt emboss 8 existing inside the joining edge portion 7. In the panty liner 1, the squeezed portion of the outer peripheral edge portion (joint edge portion 7) of the absorbent article constitutes the quilt emboss 8 located in the inner region of the outer peripheral edge portion (joint edge portion 7). The number of the squeezed portions per unit area is larger than that. For this reason, the purple color of the second sheet 5 is easily visible from the surface sheet 2 on the outer peripheral edge portion, and the color of the body fluid discharged to the region inside the outer peripheral edge portion can be visually recognized due to the difference in shade. ing. Therefore, since it is possible for the wearer himself to confirm the diffusion state of the body fluid in the panty liner 1, it becomes easy to know when to replace the panty liner 1. From the same viewpoint, in the panty liner 1, the quilt emboss 8 is located in the inner region of the outer peripheral edge portion (joint edge portion 7) of the absorbent article than the outer peripheral edge portion (joint edge portion 7). It is preferable that the area of the squeezed portion per unit area is larger than that of the squeezed portion constituting the above.

Further, in the panty liner 1, the second sheet 5 contains an antibacterial agent. Since the water absorption of the second sheet 5 is higher than that of the surface sheet 2, the body fluid can easily come into contact with the antibacterial agent at a position away from the skin. As the antibacterial agent blended in the second sheet 5, an organic antibacterial agent or an inorganic antibacterial agent can be used, but an inorganic antibacterial agent is generally preferable because it has a wide antibacterial spectrum.
The deodorant compounded in the second sheet 5 is a substance that can directly act on the odor, that is, adsorb, neutralize, decompose, etc., and exert a deodorizing effect. In the field as well, those widely used for deodorant applications can be used. Porous deodorant granules are preferable because they have a wide deodorizing spectrum for odors.
As described above, by using a deodorant in addition to the antibacterial agent, the generation of bad odor can be further suppressed.

Known antibacterial agents can be used. When the odor-generating substance in the excrement is organic, the organic antibacterial agent can be expected to have high antibacterial and deodorant properties due to its good affinity with the odor-generating substance. Organic cationic antibacterial agents are particularly preferable from the viewpoint of affinity with organic odor-causing substances and bacteria. Cationic antibacterial agents can suppress the generation of strong putrid odors as a control of malodor production.
Examples of the cationic antibacterial agent include quaternary ammonium salts such as didecyldimethylammonium salt, alkylpyridinium salt, benzethonium salt, benzalconium salt, monoalkyltrimethylammonium salt, and dialkyldimethylammonium salt. It is preferable to contain at least one selected from. One of these cationic antibacterial agents may be used alone, or two or more thereof may be combined.

On the other hand, examples of the inorganic antibacterial agent include antibacterial metals such as silver and zinc, porous substrates such as zeolite containing the antibacterial metal, and metal oxides such as zinc oxide. In particular, it is preferable that the antibacterial metal is arranged in such a form that it can move together with the body fluid in contact with the body fluid.

Examples of the porous deodorant granules include inorganic deodorant granules and organic deodorant granules. The inorganic deodorant granules are deodorant granules mainly composed of an inorganic compound, that is, deodorant granules in which the compound serving as the skeleton of the deodorant granules is an inorganic compound. The organic deodorant granules are deodorant granules mainly composed of organic compounds, that is, deodorant granules in which the compound serving as the skeleton of the deodorant granules is an organic compound.

Preferred inorganic deodorant granules include kanclinite-like minerals, zeolites, montmorillonite, activated carbon and the like. Among these, the polar porous deodorant granules are preferable because they are suitable for deodorizing water-soluble odor-causing substances, and further, the canclinite-like mineral and zeolite have a wide deodorizing spectrum. preferable. Since activated carbon belongs to non-polarity, it is effective in deodorizing organic odorous components, and examples thereof include coconut shell coal, charcoal, bituminous coal, peat, and lignite.

Preferred organic deodorant particles include particles obtained by copolymerizing a monomer component containing a crosslinkable vinyl monomer and a vinyl monomer having a heteroaromatic ring.

The absorption core 4 contains a highly water-absorbent material. Specifically, the absorbent core 4 is arranged in a folded state by folding back an absorbent sheet (pulp) containing a super absorbent polymer (hereinafter referred to as SAP). In the absorption core 4, the absorbent sheet (pulp) of the upper layer (layer on the second sheet 5 side) and the absorbent sheet (pulp) of the lower layer (layer on the back sheet 3 side) are adhered by a fixing agent. The SAP is placed between the upper absorbent sheet and the lower absorbent sheet.

Examples of SAP include a hydrogel material obtained by polymerizing a water-soluble ethylenically unsaturated monomer containing acrylic acid or acrylate as a main component and optionally adding a cross-linking agent. In addition, polyethylene oxide, polyvinylpyrrolidone, crosslinked products of sulfonated polystyrene and polyvinylpyridine, starch-poly (meth) acrylonitrile graft copolymer saponified product, starch-poly (meth) acrylic acid graft copolymer, starch-poly ( Meta) Examples thereof include a hydrolyzate of an acrylic ester graft copolymer. These super absorbent polymers may be used alone or in combination of two or more. As the superabsorbent polymer material, a material capable of absorbing and retaining pure water 20 times or more, particularly 50 times or more of its own weight, and gelling is preferable.
As the shape of the superabsorbent polymer material, various materials used for the absorbent sheet can be used without particular limitation. For example, spherical, granular, fibrous, bale-shaped, lump-shaped and the like can be mentioned.

The specific embodiment of the absorption core 4 is not limited to the above, and those generally used for the absorption core of the absorbent article can be adopted. The absorbent core 4 is preferably in the form of a sheet, and examples thereof include a pulp sheet, an absorbent sheet containing pulp and a superabsorbent polymer, and an absorbent sheet in which a superabsorbent polymer is sandwiched between sheets such as non-woven fabric.

The back sheet 3 is a liquid-proof (waterproof) sheet, and a sheet generally used for the back sheet of an absorbent article can be adopted. The back sheet 3 may also be colored purple like the second sheet 5.

Since such a panty liner 1 has a second sheet 5 colored in purple, the chromaticity a _P ^* and the chromaticity b of the panty liner 1 via the surface sheet 2 before absorbing the body fluid. _P ^* is configured such that _{a P} ^* ≧ 3 and b _P ^{* ≦ -2.} Here, the "chromaticity of the panty liner 1 via the surface sheet 2" refers to the chromaticity of the panty liner 1 in a state where the panty liner 1 is visually recognized from the surface sheet 2 side.

_{Specifically, the chromaticity a P} ^* of the panty liner 1 via the surface sheet 2 is preferably 3 or more, more preferably 6 or more, and 10 or more from the viewpoint of shielding the body fluid. It is more preferable to have.

_{Further, the chromaticity b P} ^* of the panty liner 1 via the surface sheet 2 is preferably -2 or less, more preferably -6 or less, and more preferably -10 or less, from the viewpoint of shielding the body fluid. It is more preferable to have.

Incidentally, panty liner 1 chromaticity through the topsheet 2 is a _P ^* ≧ 3 and b _P ^* ≦ -2, for ^{_{example, L T * = 98, a}} T * = -0.05, b T * = This can be achieved by combining the surface sheet 2 of 1 with _{the second sheet 5 of L COLOR} ^* <86, a _COLOR ^* > 4, b _COLOR ^{* <-2.}

[Absorption of body fluids by absorbent articles, etc.]
In the panty liner 1 according to the present embodiment, the second sheet 5 has higher water absorption than the surface sheet 2, and the second sheet 5 and the surface sheet 2 are integrally joined by embossing, so that the surface sheet 2 The body fluid excreted in the water quickly permeates the second sheet 5 and becomes difficult to diffuse on the surface sheet 2.

The second sheet 5 has a smaller absorption capacity than the absorption core 4, whereas the absorption core 4 has a larger absorption capacity. Therefore, of the body fluid diffused by the second sheet 5, the portion that cannot be completely absorbed by the second sheet 5 is absorbed. We will move to core 4. In particular, when the absorption core 4 contains SAP, the absorption capacity can be further increased, so that the transfer and retention of the body fluid to the absorption core 4 is good.

In this way, the second sheet 5 plays a role of drawing in the body fluid excreted in the surface sheet 2 and temporarily stocking it, and quickly permeating the absorption core 4 located on the non-skin facing surface side thereof, and the absorption core 4 Plays a role of drawing in and holding body fluid from the second sheet 5.

Therefore, most of the excreted body fluid is drawn into and held by the absorption core 4 having a large absorption capacity via the second sheet 5 having a higher water absorption than the surface sheet 2, so that the body fluid remaining on the surface sheet 2 is extremely small. Further, since the second sheet 5 diffuses the body fluid and delivers it to the absorption core 4, the amount of the body fluid remaining on the second sheet 5 is small. As a result, the color of the body fluid in the second sheet 5 is unlikely to become dark, and when viewed from the surface sheet 2 side, the color shielding property against the body fluid absorbed in the second sheet 5 is improved. At this time, the color of the second sheet 5 that has absorbed the body fluid is determined by the contrast between the purple color of the second sheet 5 and the color of the body fluid. The "color hiding property" refers to a property that makes the color of the absorbed body fluid less noticeable as compared with the non-diffusion region of the body fluid even if the absorbent article absorbs the colored body fluid.

As described above, since the panty liner 1 has the second sheet 5 colored in purple, the chromaticity a _P ^* and the chromaticity b _P ^{* of} the absorbent article 1 via the surface sheet 2 are It is configured so that a _P ^* ≧ 3 and b _P ^{* ≦ -2.} Therefore, even if the panty liner 1 absorbs a red body fluid such as menstrual blood or a yellow body fluid such as a pantyliner or incontinence urine, the color hiding property for the color of the body fluid is improved.

This is because when the red body fluid is absorbed, the red component becomes stronger and ^{the value of chromaticity a *} becomes higher after absorption than before absorption, but the absorbent article via the surface sheet 2 before absorption. Since the chromaticity a _P ^{* of} 1 is high in the first place and the ^{amount of change in the chromaticity a *} before and after absorption is small, the concealing property for the red component is high. Therefore, when menstrual blood, which is a red body fluid, is absorbed, the color difference between the menstrual blood diffusion region and the menstrual blood non-diffusion region is small, and the color hiding property for menstrual blood is high.

Further, when the yellow body fluid is absorbed, the yellow component becomes stronger and ^{the value of chromaticity b *} becomes higher after absorption than before absorption, but the absorbent article 1 via the surface sheet 2 before absorption 1 The chromaticity b _P ^* is low in the first place, and ^{even if the value of the chromaticity b *} increases after absorption, the value itself is small, so that the hiding property against the yellow component is high. Therefore, when vaginal discharge or incontinence urine, which is a yellow body fluid, is absorbed, the color hiding property for such a yellow body fluid is high.

Specifically, in the red liquid injection test using the red liquid imitating the red body liquid, the panty liner 1 has a chromaticity a _P ^* before the red liquid injection and after the red liquid injection via the surface sheet 2. The difference a _PR ^* -a _P ^{* in} chromaticity a _PR ^* is configured such that 0 <a _PR ^* -a _P ^{* <12.} From the viewpoint of recognizing the excretion of menstrual blood, this difference a _PR ^* -a _P ^* is preferably greater than 0, more preferably greater than 3, more preferably greater than 5, and incompatible with menstrual blood. From the viewpoint of not giving a pleasant sensation, it is preferably less than 12, more preferably less than 10, and even more preferably less than 8.

The red liquid injection test can be carried out by the following method. That is, _{0.5 g of a red liquid having a brightness L R} ^* of 82, a chromaticity a _R ^* of 25, and a chromaticity b _R ^* of -1 is injected into the surface sheet 2 side of the panty liner 1 for 30 seconds. _{Later, the chromaticity a P} ^* of the panty liner 1 via the surface sheet 2 is measured using a color difference meter. By such a red liquid injection test, the chromaticity a _PR ^* after the red liquid injection can be measured.

Further, in the panty liner 1, in the yellow liquid injection test using the yellow liquid imitating the yellow body fluid, the chromaticity b _PY ^* after the yellow liquid injection via the surface sheet 2 is b _PY ^* <10. It is configured as follows. The chromaticity b _PY ^* is preferably less than 8, more preferably less than 6, further preferably less than 5, from the viewpoint of not causing discomfort to vaginal discharge or incontinence urine. From the viewpoint of recognizing the excretion of vaginal discharge and incontinence urine, it is preferably greater than 0, more preferably greater than 1, and even more preferably greater than 3.

The yellow liquid injection test is carried out by the following method. That is, _{0.5 g of a yellow liquid having a brightness L Y} ^* of 98, a chromaticity a _Y ^* of -7, and a chromaticity b _Y ^* of 28 is injected into the surface sheet 2 side of the panty liner 1 for 30 seconds. Later, the chromaticity of the absorbent article 1 via the surface sheet 2 is measured using a color difference meter. By such a yellow liquid injection test, the chromaticity b _PY ^* after the yellow liquid injection can be measured.

Further, in the above-mentioned red liquid injection test, the panty liner 1 has a difference L _P ^* -L _PR ^* _{between the lightness L P} ^* before the liquid injection and the lightness L _PR ^{* after the liquid injection via the surface sheet 2.} It is configured so that L _P ^* -L _PR ^{* <12.} This difference L _P ^* -L _PR ^* is preferably less than 12, preferably less than 11, more preferably less than 10.5, and more preferably less than 10.5, from the viewpoint of making it less likely to cause discomfort to menstrual blood. From the viewpoint of making blood excretion recognizable, it is preferably greater than 0, more preferably greater than 1, more preferably greater than 3, and the lightness L _PR ^* after liquid injection is the red liquid described above. It can be measured by the color difference meter used in the injection test.

Further, in the above-mentioned yellow liquid injection test, the panty liner 1 has a difference L _P ^* -L _PY ^* _{between the lightness L P} ^* before the liquid injection and the lightness L _PY ^{* after the liquid injection via the surface sheet 2.} It is configured so that L _P ^* -L _PY ^{* <4.} This difference L _P ^* -L _PY ^* is preferably less than 4, more preferably less than 3.5, and more preferably less than vaginal discharge or incontinence urine, from the viewpoint of making it less likely to cause discomfort to vaginal discharge or incontinence urine. From the viewpoint of making the excretion of urine recognizable, it is preferably larger than 0, and more preferably larger than 1. _{The brightness L PY} ^* after the liquid injection can be measured by the color difference meter used in the above-mentioned yellow liquid injection test.

As described above, the color of the body fluid in the second sheet 5 is difficult to darken, and the color hiding property against the red body fluid such as menstrual blood and the yellow body fluid such as cages and incontinence urine is high, so that the body fluid is absorbed. The discomfort when visually recognizing the panty liner 1 is reduced. In this way, the color hiding property for the absorbed body fluid is high and the discomfort is reduced, so that the panty liner is not discarded even though it can still be used. In addition, it becomes easy to dispose of used panty liners even in places other than home.

When the body fluid is absorbed by the absorption core 4, the liquid diffusion region in which the body fluid is absorbed has a lower brightness than the liquid non-diffusion region in which the body fluid is not absorbed. Therefore, the distinction between the two regions should be visually recognized. Can be done. Therefore, the appropriate replacement time of the panty liner 1 can be known from the size of the liquid diffusion area, and the panty liner 1 should be used until the appropriate replacement time without discarding it before the appropriate replacement time. Can be done.

Further, in the panty liner 1, since the absorption core 4 is smaller than the second sheet 5, when the body fluid is diffused to the outside of the absorption core 4, the appearance of the body fluid is shaded in the existing region of the absorption core 4 and the outside thereof. Can be done. Further, the shade of purple emphasized by the squeezed portion of the outer peripheral edge portion of the panty liner 1 can be obtained. Therefore, although the visibility of the body fluid is small, the diffusion state of the body fluid is easily visible to the wearer who is conscious of the state of the body fluid, which is useful for determining the replacement time.

The absorption core 4 is preferably white from the viewpoint of shielding the body fluid. In particular, when the absorption core 4 is smaller than the second sheet 5, color contrast is likely to occur in the region where the absorption core 4 exists and the region outside the absorption core 4, which is useful for determining the replacement time.

When the back sheet 3 is colored purple like the second sheet 5, the panty liner 1 that has absorbed the red or yellow body fluid has a color shielding effect on the absorbed body fluid even when viewed from the back sheet 3 side. Obtainable.

Specific examples of the absorbent article of the present invention include various absorbent articles used for absorbing body fluid excreted from the human body, such as a sanitary napkin and an incontinence pad, in addition to the panty liner.

As described above, the absorbent articles according to the present embodiment include the front surface sheet 2 arranged on the skin facing surface side, the back surface sheet 3 arranged on the non-skin facing surface side, and the front surface sheet 2 and the back surface sheet 3. It is an absorbent article having an absorption core 4 arranged between them, and a purple-based second sheet 5 is provided between the surface sheet 2 and the absorption core 4, and the second sheet 5 is the surface sheet 2. It has higher water absorption than, and has a smaller absorption capacity than the absorption core 4, and has _{chromaticity a P} ^* and chromaticity b _P ^{defined in the L *} a ^* b ^* color space of CIE1976 via the surface sheet 2. ^* Is configured such that _{a P} ^* ≧ 3 and b _P ^{* ≦ -2.}

With such a configuration, the color hiding property for red and yellow body fluids is improved, and the discomfort when the wearer visually recognizes the body fluid can be reduced.

Further, as shown in FIG. 3, the absorbent article 1 of the present invention is folded with the front surface sheet 2 inside by adopting a configuration in which the packaging sheet 9 is adhered to the back sheet 3 side of the absorbent article 1. The individual package 10 as shown in FIG. 4 can be formed by accommodating (packaging) the absorbent article 1 by the packaging sheet 9. The packaging sheet 9 has a rectangular shape that is vertically long in the front-rear direction and wide in the width direction with respect to the absorbent article 1, and is provided with the adhesive tape 11. In the folded state as shown in FIG. 4, both ends of the packaging sheet 9 in the front-rear direction are fixed by the adhesive tape 11 to maintain the folded individual packaging body 10.

The panty liner 1 can have a so-called tri-fold structure by two fold lines L1 and L2 located on both end sides in the front-rear direction. The panty liner 1 has a constricted portion N whose length in the width direction becomes shorter from both ends in the front-rear direction toward the center, and a region of both ends that is wider than the constricted portion N forms the constricted portion N. The structure is folded so as to cover it. With such an individual packaging structure, when the used panty liner 1 is discarded, the purple color derived from the second sheet 5 overlaps with the surface sheet 2 in the central portion, and the excretory part in which a large amount of body fluid is absorbed is absorbed. The body fluid in the central part facing the body fluid becomes difficult to see, and it is possible to relieve embarrassing feelings at the time of disposal. Further, since both widthwise edges of both ends in the front-rear direction cover the outside of the constriction N, even if the body fluid leaks from both widthwise edges of the constriction N at the time of disposal, the body fluid is reabsorbed from both ends. At the same time, the color of the body fluid can be shielded by purple, so that the above-mentioned effect is further enhanced.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples, and changes within the scope of the present invention are included in the scope of the present invention.

[Examples 1 and 2 and Comparative Examples 1 to 4]
In Examples 1, 2, and Comparative Examples 1 to 4, as shown in FIGS. 1 and 3, a panty liner (absorption) in which a front surface sheet, a second sheet, an absorption core, and a back surface sheet are laminated in this order. It is common in that it is a sex article). The panty liner of Example 1 is a second sheet colored purple, the panty liner of Example 2 is a second sheet colored light purple, and the panty liner of Comparative Example 1 is a second sheet. The panty liner of Comparative Example 2 is white, the second sheet is colored blue, the panty liner of Comparative Example 3 is the second sheet colored green, and the panty of Comparative Example 4 is used. The liner is a liner in which the absorption core is colored purple while the second sheet is white.

For the panty liners of each Example and Comparative Example, the brightness L ^* , chromaticity a ^* and b ^* before injecting the test solution were measured. Next, a cylindrical syringe having a diameter of 1 mm was brought into contact with the surface sheet, and 0.5 g of the red test solution or the yellow test solution was injected at once. After 30 seconds, the brightness L ^* , chromaticity a ^* and b ^* were measured. The methods for measuring the lightness L ^* and the chromaticity a ^* and b ^{* are as follows.}

[Measurement method of lightness and chromaticity]
It can be obtained by measuring the reflected light of the sheet using a handy type spectrocolor difference meter NF333 (trade name) manufactured by Nippon Denshoku Kogyo Co., Ltd. under the measurement conditions of the light source C and the viewing angle of 2 °. At this time, the measurement is performed using a white plate having an ^{L * value of 95 or more as the background plate.}

[Test solution]
The red liquid and the yellow liquid, which are the test liquids to be injected into Examples 1 and 2 and Comparative Examples 1 to 4, are as follows.

The red liquid was prepared by mixing glycerin (51% by mass) and Red No. 2 (0.01% by mass) in ion-exchanged water. The red liquid having a viscosity of 8 cP had a lightness L ^* of 82, a chromaticity a ^* of 25, and a chromaticity b ^* of -1.

The yellow liquid was prepared by mixing glycerin (51% by mass) and Yellow No. 4 (0.01% by mass) in ion-exchanged water. The viscosity is 8 cP. The lightness L ^* of this yellow liquid is 98, the chromaticity a ^* is -7, and the chromaticity b ^* is 28.

The viscosity of the test solution (red solution and yellow solution) prepared as described above was 20 mL of the test solution at 25 ° C. using a Viscometer (TOKI SANGYO, TVB-10M type viscometer, rotary: using L / Adp). The measurement was carried out under the condition of 30 rpm. The color difference was measured at 25 ° C. using a spectrophotometer SE-2000, a spectrophotometer SE-2000, in which 14 mL of the test solution was placed in a square cell (10 × 36 × 45 mm).

Table 1 is a characteristic table showing the results of the red liquid injection test, and Table 2 is a characteristic table showing the results of the yellow liquid injection test.

The following was found from the red liquid injection test.
(A) Focusing on the difference in chromaticity of red-green system before and after injection of red liquid a _PR ^* -a _P ^* , the values of Comparative Examples 1, 2 and 3 (13.54, 14.41, 17.39). On the other hand, the values of Examples 1 and 2 (6.52, 9.27) are small. Therefore, in Examples 1 and 2, when menstrual blood, which is a red body fluid, is absorbed, the color difference between the menstrual blood diffusion region and the menstrual blood non-diffusion region is small, and the color shielding property against menstrual blood is high.
Further, in the red liquid injection test, the difference L _P ^* -L _PR ^* _{between the lightness L P} ^* before the liquid injection and the lightness L _PR ^* after the liquid injection was 10.35 in Example 1 and 10 in Example 2. , Examples 1 and 2 both have L _P ^* -L _PR ^* <12, and the brightness is reduced after the injection of the red liquid. Therefore, the color hiding property is improved in combination with the high color hiding property for the red body fluid.
(B) In Comparative Example 4, although the purple color of the absorption core can be seen from the surface sheet side, the color shielding property is low because the white second sheet exists between the surface sheet and the absorption core.

In addition, the following can be seen from the yellow injection test.
_{(C) Focusing on the chromaticity b PY} ^* via the surface sheet after injecting the yellow liquid, the values of Examples 1 and 2 (12.22, 12.60) are compared with the values of Comparative Examples 1 and 3 (11.22, 12.60). 4.11, 9.54) is small. As described above, in Examples 1 and 2, since _{the value of the chromaticity b PY} ^* itself after injecting the yellow liquid is small, the color shielding property against the yellow body fluid (the cage and incontinence urine) is high.
Further, in the yellow liquid injection test, the difference between _{the lightness L P} ^* before the liquid injection and the lightness L _PY ^* _{after the liquid injection L P} ^* −L _PY ^* was 3.48 in Example 1 and 3.7 in Example 2. In both Examples 1 and 2, L _P ^* −L _PY ^* <4, and the brightness is reduced after the injection of the yellow liquid, so that the color hiding property is improved in combination with the high color hiding property for the yellow body fluid. ..
Since the chromaticity b _PY ^* of Comparative Example 2 is as small as 7.10, the color shielding property against yellow body fluid is high, but the color shielding property against red color is low as shown in (a) above.
(D) In Comparative Example 4, although the purple color of the absorption core can be seen from the surface sheet side, the color shielding property is low because the white second sheet exists between the surface sheet and the absorption core.

From the results of the red liquid injection test and the yellow liquid injection test described above, Examples 1 and 2 were applied to both red body fluids such as menstrual blood and yellow body fluids such as cages and incontinence urine. , It was found that the color hiding property was high.

[Measurement method of absorption capacity and liquid diffusion area in liquid injection test]
The method for measuring the absorption capacity and the method for measuring the liquid diffusion area of the second sheet and the absorption core in the liquid injection test described above will be described as a reference.

The method for measuring the absorption capacity is as follows. That is, the initial weight g (W1) was measured with respect to a test piece (absorbent article) of 0.1 × 0.1 m (S). This test piece was immersed in the above-mentioned sufficient amount of red test solution for 5 minutes. Then, the test piece was centrifuged at 1650 rpm for 10 minutes with a centrifuge (Kokusan Co., Ltd., upper discharge type centrifuge H-130E special). The weight g (W2) of the test piece after centrifugal dehydration was measured, and the absorption capacity g / m ² (C = W2-W1 / S) was determined.
As a result, it was possible to measure that the absorption capacity C of the second sheet was 7.2 (g / m ² ) and the absorption capacity C of the absorption core was 398 (g / m ^2).

The method for measuring the liquid diffusion area of the second sheet and the absorption core is as follows. That is, the first weight is placed on the entire surface of the product (absorbent article) ^{so as to be 5 g / cm 2,} and the above-mentioned test solutions 0 are used by using a liquid injection plate having a surface in contact with the product having a diameter of 1 mm. 5.5 g was injected into the product all at once. After standing for 1 minute, remove the first mass and the liquid injection plate, placed in the product central portion short side of the filter paper 60 × 80 mm is set to be in the product width direction, the so that 3 g / cm ² 2 Weight was placed on the product. After allowing to stand for 10 seconds, the second weight was removed, each diffusion area was copied onto an OHP sheet, and the diffusion area was determined by capturing as an image with a scanner (Canon Co., Ltd., CanonScan 8800F).
As a result, it was possible to measure that the diffusion area of the red liquid was 9.9 cm ² and the diffusion area of the yellow liquid was 10.7 cm ^{2 for both the second sheet and the absorption core.}

1 Absorbent article (panty liner)
2 Front sheet 3 Back sheet 4 Absorption core 5 Second sheet 6 Fastener 7 Joint edge 8 Quilt embossed 9 Packaging sheet 10 wrapping body 11 Adhesive tape N Constriction

Claims (10)

An absorbent article comprising a front surface sheet arranged on the skin facing surface side, a back surface sheet arranged on the non-skin facing surface side, and an absorbing core arranged between the front surface sheet and the back surface sheet. ,
A purple-based second sheet is provided between the surface sheet and the absorption core.
The second sheet has higher water absorption than the surface sheet and has a smaller absorption capacity than the absorption core.
So that the chromaticity a _P ^* and the chromaticity b _P ^{* defined in the L *} a ^* b ^* color space of CIE1976 via the surface sheet are a _P ^* ≧ 3 and b _P ^* ≦ -2. Absorbent article made up. The surface sheet is white so that the color of the second sheet can be seen through.
The lightness L _COLOR ^* of the second sheet is smaller than the lightness L _T ^{* of the} _{surface sheet, and the chromaticity a COLOR} ^* and b _COLOR ^* _{of the second sheet are the chromaticity a T} ^* and b of the surface sheet, respectively. The absorbent article according to claim 1, which is larger than _T ^*. The surface sheet and the second sheet are provided with a plurality of pressing portions that communicate with each other.
The absorbent article according to claim 1 or 2, wherein the outer peripheral edge portion of the absorbent article has a larger number of the squeezed portions per unit area than the region inside the outer peripheral edge portion. The absorbent core contains a highly absorbent material and is smaller than the second sheet.
The absorbent article according to any one of claims 1 to 3. The absorbent article according to any one of claims 1 to 4, wherein the embossing that integrally presses the surface sheet and the second sheet is arranged in a grid pattern, and the embossing does not reach the absorption core. .. The second sheet is
In a red liquid injection test in which a red liquid having a brightness L ^* of 82, a chromaticity a ^* of 25, and a chromaticity b ^* of -1 was injected into the absorbent article from the surface facing the skin of the surface sheet, the red liquid was injected through the surface sheet. , The difference a _PR ^* -a _P ^* _{between the chromaticity a P} ^* before the injection of the red liquid _{and the chromaticity a PR} ^* after the injection of the red liquid is 0 <a _PR ^* -a _P ^* <12, and
In a yellow liquid injection test in which a yellow liquid having a brightness L ^* of 98, a chromaticity a ^* of -7, and a chromaticity b ^* of 28 was injected into the absorbent article from the surface facing the skin of the surface sheet, the yellow liquid was injected through the surface sheet. The absorbent article according to any one of claims 1 to 5, wherein _{the chromaticity b PY} ^* after injection of the yellow liquid is b _PY ^{* <10.} In the red liquid injection test, the difference L _P ^* -L _PR ^* _{between the lightness L P} ^* before the liquid injection and the lightness L _PR ^* after the liquid injection is L _P ^* -L _PR ^* <12 via the surface sheet. The absorbent article according to claim 6, which is configured to be. In the yellow liquid injection test, the difference between _{the lightness L P} ^* before the liquid injection and the lightness L _PY ^* _{after the liquid injection L P} ^* −L _PY ^* is L _P ^* −L _PY ^* <4 via the surface sheet. The absorbent article according to claim 6 or 7, which is configured to be. The brightness L _COLOR ^* of the _{second sheet is L COLOR} ^* <90.
The chromaticity a _COLOR ^* and the chromaticity b _COLOR ^* of the second sheet are set to any one of claims 1 to 8 configured so that _{a COLOR} ^* > 10 and b _COLOR ^{* <-10.} The absorbent article described. An individual package in which the absorbent article according to any one of claims 1 to 9 is contained in a packaging sheet.
The outer circumference of the absorbent article along the front-rear direction has a constricted portion in the central portion in the front-rear direction, which is narrower in the width direction than both ends in the front-rear direction.
Absorbent, which is folded back so that both ends are on the center side, the surface sheet is on the inside, and the constricted portion is covered by the both ends, and is housed in the packaging sheet. Individual wrapping of goods.

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