阅读说明：本技术 吸收性物品 (Absorbent article ) 是由 中下将志 于 2018-11-19 设计创作，主要内容包括：本发明提供吸收性物品,对于反复供给的体液也能持续发挥pH调节剂的除臭功能,并且难以产生pH调节剂的结构及配置位置的制约,可高效且充分地发挥该pH调节剂的除臭功能。本发明的吸收性物品是在与体液接触的位置包括pH调节剂(7)的吸收性物品,其中,上述pH调节剂(7)具有溶解于水而呈酸性的固体状的芯部(71)以及覆盖该芯部(71)且由在常温下为固体的油脂构成的覆盖部(72),上述覆盖部(72)具有将上述pH调节剂(7)的外部与上述芯部(71)的表面以可通液的方式连通的连通部(722)。(The invention provides an absorbent article which can continuously exert the deodorizing function of a pH regulator even for repeatedly supplied body fluid, is difficult to generate the restriction of the structure and the arrangement position of the pH regulator, and can effectively and fully exert the deodorizing function of the pH regulator. The absorbent article of the present invention is an absorbent article comprising a pH adjuster (7) at a position in contact with a body fluid, wherein the pH adjuster (7) has a solid core section (71) that is dissolved in water and is acidic, and a cover section (72) that covers the core section (71) and is made of a fat that is solid at normal temperature, and the cover section (72) has a communication section (722) that communicates the outside of the pH adjuster (7) with the surface of the core section (71) so as to allow fluid communication.)

1. An absorbent article comprising a pH adjusting agent at a position where the absorbent article is in contact with body fluid, wherein,

the pH adjuster comprises a solid core portion which is dissolved in water and is acidic, and a covering portion which covers the core portion and is composed of oil which is solid at normal temperature,

the cover portion has a communicating portion for allowing the outside of the pH adjuster to communicate with the surface of the core portion in a liquid-permeable manner.

2. The absorbent article of claim 1,

the core is dissolved in the body fluid to have a pH in the range of 3 to 5.

3. The absorbent article of claim 1 or 2,

the absorbent article has an absorbent body containing a super absorbent polymer,

the pH adjuster is configured such that a part of the core is eluted into the body fluid after at least 30 seconds from contact with the body fluid.

4. The absorbent article according to any one of claims 1 to 3,

the pH adjuster has an acidic gradual release function in which the change in pH of the body fluid from the time of contact with the body fluid to the time of 60 seconds is 0.5 or less.

5. The absorbent article according to any one of claims 1 to 4,

the covering part is formed by laminating a plurality of grease particles on the surface of the core part,

the communicating portion is formed by gaps between the plurality of fat particles.

6. The absorbent article according to any one of claims 1 to 5,

the absorbent article comprises a liquid-permeable front sheet, a liquid-impermeable back sheet, and an absorbent body disposed between the front sheet and the back sheet,

the pH adjuster is disposed at least one of the top sheet, between the top sheet and the absorbent body, and the absorbent body.

7. The absorbent article of claim 6,

the absorbent article further comprises a diffusion sheet between the topsheet and the absorbent body,

the pH adjuster is disposed at least in the diffusion sheet.

8. The absorbent article of claim 6 or 7,

the absorbent body comprises an absorbent core containing a super absorbent polymer and a core wrap sheet covering the absorbent core,

the pH adjuster is disposed at least between the absorbent core and the core wrap sheet.

Technical Field

The present invention relates to an absorbent article such as a urine absorption pad or a disposable diaper, and particularly to an absorbent article capable of reducing malodor caused by body fluid of a wearer.

Background

Absorbent articles such as urine absorbing pads and disposable diapers are generally used for a long time while contacting the skin of a wearer, and therefore, various improvements have been studied day by day to prevent the wearer from feeling strange or uncomfortable.

For example, patent document 1 discloses the following disposable absorbent article as an absorbent article for reducing or preventing rash of the wearer's skin: the absorbent article comprises (A) a liquid-impermeable back sheet, (B) a relatively hydrophobic liquid-permeable top sheet, (C) a flexible absorbent core positioned between the back sheet and the top sheet, the flexible absorbent core being composed of a hydrophilic fibrous material and particles of a hydrogel substance neutralized to a substantially water-insoluble height by a salt to produce cations and at least 50% of its acidic functional groups, and (D) 1 or more pH regulators suitable for maintaining the skin pH in the range of about 3.0 to 5.5 in the presence of feces and urine, the hydrogel particles neutralized to a substantially water-insoluble height and the pH regulators being unevenly distributed in each of the discrete zones within the absorbent article. Further, as the pH adjuster, an organic acid such as citric acid or adipic acid is exemplified. The pH adjusting agent such as citric acid exemplified here neutralizes ammonia components generated from body fluids such as urine, and therefore, it is expected to suppress skin rash and generation of malodor.

However, since a pH adjuster such as citric acid is water-soluble and easily dissolves in and diffuses in a body fluid such as urine discharged from a wearer, the pH adjuster cannot be held at a predetermined position, and there is a possibility that the function thereof cannot be sufficiently exhibited when the body fluid is repeatedly supplied.

As an absorbent article that addresses such a problem, patent document 2 discloses the following absorbent article: the fumaric acid-bearing sheet is a sheet on which fumaric acid particles having an average particle diameter of 30 [ mu ] m or less are supported and/or a sheet in which at least a part of the constituent fibers are covered with fumaric acid.

Since the absorbent article disclosed in patent document 2 does not dissolve readily, even when it comes into contact with body fluids or the like, the hardly water-soluble fumaric acid gradually dissolves in body fluids or the like, and therefore, by disposing a fumaric acid-bearing sheet on a portion of the absorbent article which can come into contact with body fluids or the like, the occurrence of rash or malodor can be suppressed for a long period of time.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 62-28402

Patent document 2: japanese patent laid-open publication No. 2014-204799

Disclosure of Invention

Problems to be solved by the invention

However, in the case where a poorly water-soluble component such as fumaric acid is used as a pH adjuster as in the absorbent article of patent document 2, there are structural constraints such as the use of a component having a predetermined size or less (for example, an average particle size of 30 μm or less) in order to sufficiently exhibit its function, and further, there are constraints on the arrangement position of the pH adjuster, and therefore, there is a possibility that the function of the pH adjuster (at least the deodorizing function) cannot be efficiently and sufficiently exhibited depending on the arrangement position.

Accordingly, an object of the present invention is to provide an absorbent article which can continuously exhibit the deodorizing function of a pH adjuster even with respect to a body fluid which is repeatedly supplied, which is less likely to cause restrictions on the structure and arrangement position of the pH adjuster, and which can efficiently and sufficiently exhibit the deodorizing function of the pH adjuster.

Means for solving the problems

One aspect (aspect 1) of the present invention is an absorbent article including a pH adjuster at a position in contact with a body fluid, wherein the pH adjuster includes a solid core portion that is dissolved in water and is acidic, and a cover portion that covers the core portion and is made of oil and fat that is solid at normal temperature, and the cover portion includes a communication portion that allows the outside of the pH adjuster and the surface of the core portion to communicate with each other so as to allow liquid to pass therethrough.

In the absorbent article of the present aspect, the pH adjuster disposed at a position in contact with the body fluid has a solid core portion that is dissolved in water and is acidic, and a covering portion that covers the core portion and is made of a fat that is solid at normal temperature, and further the covering portion has a communicating portion that allows the outside of the pH adjuster and the surface of the core portion to communicate with each other in a liquid-permeable manner, so that when the body fluid such as urine discharged from the wearer comes into contact with the pH adjuster, the body fluid reaches the core portion through the communicating portion of the covering portion and partially dissolves the core portion, and the acidic component in the core portion can be gradually eluted from the pH adjuster. In this way, in the absorbent article of the present embodiment, the pH adjuster gradually releases the acidic component each time a body fluid such as urine is supplied from the wearer, and therefore, the deodorizing function by the acidic component can be continuously exhibited over a long period of time.

In addition, in the absorbent article of the present embodiment, since the release of the acidic component of the pH adjuster is controlled by covering the covering portion of the core portion, structural constraints such as particle size and the like and constraints on the arrangement position due to the structural constraints are less likely to occur, and the deodorizing function of the pH adjuster can be efficiently and sufficiently exhibited.

In another aspect (aspect 2) of the present invention, in the absorbent article according to aspect 1, the core portion is dissolved in the body fluid to have a pH in a range of 3 to 5.

In the absorbent article of the present embodiment, the core portion dissolves in the body fluid and exhibits a pH in the range of 3 to 5, and therefore, the absorbent article can exhibit a predetermined deodorizing function, and also, when the body fluid after contacting the pH adjuster comes into contact with the skin of the wearer (that is, when the weakly acidic component eluted from the core portion comes into contact with the skin of the wearer), the pH of the skin can be made weakly acidic and skin inflammation such as rash is less likely to occur.

In still another aspect (aspect 3) of the present invention, in the absorbent article according to aspect 1 or 2, the absorbent article includes an absorbent body containing a super absorbent polymer, and the pH adjuster is configured such that a part of the core is eluted into the body fluid after at least 30 seconds from contact with the body fluid.

In the absorbent article of the present embodiment, since a part of the core portion of the pH adjuster is eluted as an acidic component into the body fluid after a lapse of a time (usually about 30 seconds) required for the Super Absorbent Polymer (SAP) to absorb the body fluid and swell to a certain extent or more (swell to a completely swollen 7 to 8 inclusive), the acidic component does not inhibit absorption and swelling (retention) of the SAP, and can sufficiently exhibit a predetermined deodorizing function.

In still another aspect (aspect 4) of the present invention, in the absorbent article according to any one of aspects 1 to 3, the pH adjuster has an acidic gradual release function in which a change in pH of the body fluid from contact with the body fluid to passage of 60 seconds is 0.5 or less.

In the absorbent article of the present embodiment, the pH adjuster has a predetermined gradual acidic release function and gradually releases the acidic component after coming into contact with the body fluid, and therefore, the deodorizing function by the acidic component can be more continuously exhibited.

In a further aspect (aspect 5) of the present invention, in the absorbent article according to any one of aspects 1 to 4, the covering portion is formed by stacking a plurality of fat particles on a surface of the core portion, and the communication portion is formed by gaps between the plurality of fat particles.

In the absorbent article of the present aspect, since the covering portion of the pH adjuster is formed by stacking a plurality of fat particles on the surface of the core portion, and the communicating portion is formed by the gap between the plurality of fat particles, the covering portion can cover the core portion so as not to expose the surface of the core portion to the outside, and the communicating portion capable of allowing liquid to flow can be secured, and the gradual release of the acidic component in the pH adjuster can be more reliably realized.

In still another aspect (aspect 6) of the present invention, in the absorbent article according to any one of aspects 1 to 5, the absorbent article includes a liquid-permeable front sheet, a liquid-impermeable back sheet, and an absorbent body disposed between the front sheet and the back sheet, and the pH adjuster is disposed at least one of the front sheet, between the front sheet and the absorbent body, and the absorbent body.

In the absorbent article of the present aspect, the pH adjuster is disposed at a position where it is highly likely to come into contact with the body fluid, at least one of the topsheet, the topsheet and the absorbent body, and the absorbent body. In particular, when the pH adjuster is disposed on the skin-facing surface side of the absorbent body (that is, when the pH adjuster is disposed on the topsheet and/or between the topsheet and the absorbent body), the pH adjuster can be brought into contact with the body fluid more efficiently.

In still another aspect (aspect 7) of the present invention, in the absorbent article according to aspect 6, the absorbent article further includes a diffusion sheet between the topsheet and the absorbent body, and the pH adjuster is disposed at least in the diffusion sheet.

In the absorbent article of the present embodiment, the diffusing sheet is further provided between the topsheet and the absorbent body, and the pH adjuster is disposed at least in the diffusing sheet, so that the body fluid can be brought into contact with the pH adjuster while being diffused in the planar direction by the diffusing sheet, and the deodorizing function by the pH adjuster can be more efficiently exhibited.

In addition, the absorbent article of the present embodiment has an advantage that since the surface sheet is interposed between the skin of the wearer and the pH adjuster, the pH adjuster is less likely to directly contact the skin of the wearer, and therefore, the wearer is less likely to have a feeling of strangeness, discomfort, or the like caused by the adhesion of the pH adjuster to the skin.

In still another aspect (aspect 8) of the present invention, in the absorbent article according to aspect 6 or 7, the absorbent body includes an absorbent core containing a super absorbent polymer and a core wrap sheet covering the absorbent core, and the pH adjuster is disposed at least between the absorbent core and the core wrap sheet.

In the absorbent article of the present embodiment, the pH adjuster is disposed at least between the absorbent core and the core wrap sheet, and therefore, the pH adjuster can be prevented from falling off, and the deodorizing function can be efficiently exhibited.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide an absorbent article which can continuously exhibit the deodorizing function of a pH adjuster even with respect to a body fluid which is repeatedly supplied, is less likely to cause restrictions on the structure and arrangement position of the pH adjuster, and can efficiently and sufficiently exhibit the deodorizing function of the pH adjuster.

Drawings

Fig. 1 is a plan view of a urine absorption pad 1 according to an embodiment of the present invention, as viewed in a thickness direction T from a topsheet 2 side in an unfolded state.

FIG. 2 is a sectional view of the urine absorbent pad 1 of FIG. 1 taken along the line II-II.

FIG. 3 is a sectional view of the urine absorption pad 1 of FIG. 1 taken along the line III-III.

FIG. 4 is a top view of the 2 nd absorbent layer 42 used in the urine absorbent pad 1.

FIG. 5 is a schematic sectional view of the pH adjuster 7 used in the urine absorption pad 1.

Fig. 6 is an enlarged sectional view of a main portion of the pH adjustor 7 in fig. 5 surrounded by a surrounding line IX.

Fig. 7 is an enlarged cross-sectional view of a main portion corresponding to fig. 6 of a pH adjuster in another embodiment of the present invention in which the manner of covering the pH adjuster is different.

FIG. 8 FIGS. 8(a) to (c) are plan views of the second absorption layer 2 in another embodiment of the present invention in which the arrangement of pH adjusters is different.

Detailed Description

Hereinafter, preferred embodiments of the absorbent article of the present invention will be described in detail with reference to the accompanying drawings. In the present specification, unless otherwise specified, the term "when an object (for example, a urine absorption pad (absorbent article), an absorbent body, or the like) placed on a horizontal plane in an expanded state is viewed in the thickness direction of the object from the vertically upper side" is simply referred to as "in plan view". In particular, when the object is an absorbent article, "when the absorbent article is viewed in the thickness direction from the skin surface side (i.e., topsheet side) of the wearer" is simply referred to as "in plan view".

The various directions and the like used in the present specification are as follows unless otherwise specified.

In the present specification, "longitudinal direction" means a direction in which the length of a longitudinal object (for example, an absorbent article, an absorber, or the like) is long in a plan view, "width direction" means a direction in which the length of the longitudinal object is short in a plan view (short-side direction), "and" thickness direction "means a direction perpendicular to the object placed on a horizontal plane in a developed state, and these longitudinal direction, width direction, and thickness direction are orthogonal to each other.

In the present specification, the "axis line extending in the longitudinal direction and located at the center in the width direction of the longitudinal object" is referred to as a "central axis line in the longitudinal direction" or a "central axis line extending in the longitudinal direction", and the "axis line extending in the width direction and located at the center in the longitudinal direction and extending in the width direction" is referred to as a "central axis line in the width direction" or a "central axis line extending in the width direction". In this regard, the "relatively proximal side with respect to the central axis in the width direction in the longitudinal direction of the longitudinal object" is referred to as "inner side in the longitudinal direction", and the "relatively distal side with respect to the central axis in the width direction in the longitudinal direction of the longitudinal object" is referred to as "outer side in the longitudinal direction". Similarly, "the side located relatively close to the center axis in the longitudinal direction in the width direction of the longitudinal object" is referred to as "the inner side in the width direction", and "the side located relatively far from the center axis in the longitudinal direction in the width direction of the longitudinal object" is referred to as "the outer side in the width direction".

In the present specification, the term "one side which becomes a relatively close side to the abdomen of the wearer when the absorbent article is worn in the longitudinal direction of the absorbent article" is referred to as "front side of the absorbent article", and the term "the other side which becomes a relatively far side to the abdomen of the wearer when the absorbent article is worn in the longitudinal direction of the absorbent article (i.e., a relatively close side to the back of the wearer)" is referred to as "rear side of the absorbent article".

In the present specification, unless otherwise specified, in the thickness direction of the absorbent article, "the side located relatively close to the skin surface of the wearer when the absorbent article is worn" is referred to as "the skin-facing surface side", and "the side located relatively far from the skin surface of the wearer when the absorbent article is worn" is referred to as "the non-skin-facing surface side". Here, the term "worn" refers to a period (wearing period) during which the absorbent article is maintained from the time when the absorbent article is worn by the wearer (i.e., the time when the usable state is established).

Fig. 1 is a plan view of a urine absorption pad 1 according to an embodiment of the present invention, as viewed in a thickness direction T from a front sheet 2 side in an unfolded state, and fig. 2 and 3 are sectional views taken along lines II-II and III-III of the urine absorption pad 1 in fig. 1, respectively. Further, FIG. 4 is a plan view of the 2 nd absorbent layer 42 used in the urine absorption pad 1. Fig. 5 is a schematic sectional view of the pH adjuster 7 used in the urine absorption pad 1, and fig. 6 is an enlarged schematic sectional view of a main portion of the pH adjuster 7 in fig. 5 surrounded by a surrounding line IX.

As shown in fig. 1, the urine absorption pad 1 according to one embodiment of the present invention has a vertically long outer shape including a longitudinal direction L and a width direction W, more specifically, a substantially central portion in the longitudinal direction L (i.e., a central region a described later) in a plan view_CCorresponding portion) is tapered toward the inner side in the width direction W to have a substantially hourglass shape.

In the present invention, the outer shape of the absorbent article is not limited to such a configuration, and any outer shape (for example, a rectangle, an ellipse, a gourd-shape, or the like) according to various applications can be adopted as long as the outer shape is a long shape in which the length dimension in the longitudinal direction L is larger than the width dimension in the width direction W.

As shown in fig. 1, the urine absorption pad 1 of the present embodiment includes: a front region A corresponding to the wearer's abdomen when worn_F(ii) a When worn, with the back of the wearer orPosterior area A corresponding to buttocks_B(ii) a And a central region A located between the two regions and corresponding to the crotch of the wearer when worn_C. In the present specification, as shown in fig. 1, the side of the diaper 1 which is relatively close to the abdomen of the wearer when worn is referred to as the front side D in the longitudinal direction L thereof_FThe relatively proximal side with respect to the back or hip of the wearer when worn is referred to as the rear side D_B。

As shown in fig. 2 and 3, the urine absorption pad 1 includes the following components as main components in the thickness direction T: a liquid-permeable top sheet 2 positioned on the skin-facing surface side of the urine absorbent pad 1; a back sheet 3 positioned on the non-skin-facing surface side of the urine absorbent pad 1; an absorbent body 4 having liquid-absorbing properties disposed between the two sheets; and a pair of side sheets 5, 5 positioned on the skin-facing surface side of the top sheet 2 at both ends in the width direction W of the urine absorption pad 1.

The pair of side panels 5, 5 are erected by contraction of an elastic member (not shown) such as a rubber thread provided in the vicinity of each end on the inner side in the width direction W when the urine pad 1 is worn, and form a leakage-proof wall portion for preventing leakage of body fluid such as urine.

Further, as shown in fig. 2 and 3, the absorbent body 4 is composed of two absorbent layers, i.e., a 1 st absorbent layer 41 located on the skin-facing surface side in the thickness direction T and a 2 nd absorbent layer 42 located on the non-skin-facing surface side. In the present embodiment, the 1 st absorbent layer 41 is made of an absorbent material containing a Super Absorbent Polymer (SAP) and hydrophilic fibers, and is joined to the hydrophilic sheet 6 disposed at a position on the skin-facing surface side thereof by an arbitrary joining means (not shown) such as a hot-melt adhesive agent to maintain the shape thereof, while the 2 nd absorbent layer 42 maintains the shape thereof by covering the absorbent core 421 containing the SAP as an absorbent material and hydrophilic fibers with a hydrophilic core wrap sheet 422.

Further, as shown in fig. 2 to 4, the urine absorbent pad 1 of the present embodiment includes a pH adjuster 7 at a position in contact with a body fluid such as urine discharged from the wearer (in the present embodiment, a position between the absorbent core 421 of the 2 nd absorbent layer 42 and the core wrap sheet 422), and the pH adjuster 7 has a solid core portion 71 dissolved in water and having acidity, and a cover portion 72 covering the core portion 71 and made of a fat or oil that is solid at normal temperature, as shown in fig. 5 and 6, and the cover portion 72 has a communication portion 722 for allowing the outside of the pH adjuster 7 to communicate with the surface of the core portion 71 so as to be liquid-permeable.

In this way, in the urine absorption pad 1 of the present embodiment, the pH adjuster 7 disposed at the position in contact with the body fluid has the core portion 71 in a solid state dissolved in water and rendered acidic, the cover portion 72 covering the core portion 71 and made of the oil or fat solid at normal temperature, and the communication portion 722 allowing the cover portion 72 to communicate the outside of the pH adjuster 7 with the surface of the core portion 71 so as to allow fluid communication, so that the body fluid B such as urine discharged from the wearer_FBody fluid B upon contact with pH adjuster 7_FAs shown in fig. 6, the acidic component in the core portion 71 can be gradually eluted from the pH adjuster 7 by reaching the core portion 71 through the communication portion 722 of the cover portion 72 and locally dissolving the core portion 71. Thus, the urine absorption pad 1 is configured to supply body fluid B such as urine from the wearer every time_FSince the pH adjuster 7 gradually releases the acidic component, the deodorizing function by the acidic component can be continuously exhibited for a long period of time.

Further, since the urine absorption pad 1 controls the release of the acidic component of the pH adjuster 7 by covering the cover portion 72 of the core portion 71, it is difficult to cause structural restrictions such as particle size and restrictions on the arrangement position due to the structural restrictions, and the deodorizing function of the pH adjuster 7 can be efficiently and sufficiently exhibited.

Further, in the urine absorbent pad 1 of the present embodiment, since the pH adjuster 7 is disposed between the absorbent core 421 of the 2 nd absorbent layer 42 and the core wrap sheet 422, there is an advantage that the deodorizing function can be efficiently exhibited while suppressing the falling-off of the pH adjuster 7.

In the absorbent article of the present invention, the position of the pH adjuster is not limited to the position described in the above embodiment as long as it is a position that comes into contact with body fluid as described later, and the pH adjuster may be disposed at any position in consideration of a desired deodorizing function, absorption performance, and the like.

Hereinafter, the various members constituting the absorbent article of the present invention will be described in more detail with reference to the urine absorption pad 1 according to the above-described embodiment.

[ surface sheet ]

In the urine absorption pad 1 according to the above-described embodiment, the top sheet 2 has an outer shape of a vertically long substantially rectangular shape that is long in the longitudinal direction L, extending from the front side end portion to the rear side end portion in the longitudinal direction L of the urine absorption pad 1 in a plan view, and extending from the vicinity of one side end portion to the vicinity of the other side end portion in the width direction W of the urine absorption pad 1, as shown in fig. 1 to 3. As shown in fig. 1 to 3, the top sheet 2 is disposed at a position facing the skin-facing surface side in the thickness direction T of the urine absorbing pad 1, forms a contact surface capable of coming into contact with the skin surface of the wearer, and is composed of a liquid-permeable sheet member that functions to allow body fluid such as urine discharged from the wearer to pass through the non-skin-facing surface side.

In the absorbent article of the present invention, the configuration of the outer shape of the topsheet is not limited to the configuration described above, and if the surface of the skin-facing surface side of the absorbent body can be covered so as not to be exposed at least in the central region, the configuration can be adopted in any outer shape and size according to various applications and the like.

The liquid-permeable sheet-like member usable as the top sheet is not particularly limited as long as it has various properties (for example, liquid permeability (liquid discharge property), texture, flexibility, strength, and the like) usable as the top sheet of the absorbent article, and for example, the following can be used: nonwoven fabrics such as spun-bonded nonwoven fabrics, hot air nonwoven fabrics, spunlace nonwoven fabrics, and point-bonded nonwoven fabrics formed of hydrophilic fibers; a nonwoven fabric obtained by hydrophilizing the surface of a nonwoven fabric formed of hydrophobic fibers such as thermoplastic resin fibers; and an optional sheet-like member such as a resin film having a plurality of openings. When a nonwoven fabric is used as the top sheet, the type of the constituent fibers is not particularly limited, and examples thereof include: cellulose-based fibers; and any hydrophilic fibers such as hydrophilized thermoplastic resin fibers (e.g., olefin resin fibers, polyester resin fibers, etc.). These fibers may be used alone, or two or more kinds of fibers may be used in combination.

Further, the structure of the sheet-like member usable as the surface sheet is not particularly limited, and any structure such as a porous structure having a plurality of openings, an uneven structure having a plurality of projections and recesses (for example, an uneven structure having a plurality of hollow projections and recesses and having a wave-shaped cross section, a furrow structure having a plurality of solid projections and recesses, or the like) may be employed in addition to the flat sheet-like structure having no openings, unevenness, or the like.

The weight and thickness of the sheet-like member (nonwoven fabric or the like) that can be used as the top sheet are not particularly limited as long as the effects of the present invention are not impaired, and any weight and thickness can be used according to the desired liquid permeability, skin touch, flexibility, strength, and the like.

In the absorbent article of the present invention, the top sheet may be joined to a part of the surface of the pair of side sheets located on the skin-facing surface side, at least a part of the surface of the skin-facing surface side or the surface of the non-skin-facing surface side of the absorbent body, and/or a part of the surface of the back sheet on the skin-facing surface side. The joining means is not particularly limited, and any means such as a hot-melt adhesive or heat fusion may be used.

[ Back sheet ]

In the urine absorption pad 1 according to the above-described embodiment, as shown in fig. 1 to 3, the back sheet 3 extends from the front side end portion to the rear side end portion in the longitudinal direction L of the urine absorption pad 1 and from one side end portion to the other side end portion in the width direction W of the urine absorption pad 1 in a plan view, and has a substantially hourglass shape in which a substantially central portion in the longitudinal direction L is narrowed inward in the width direction W similarly to the outer shape of the urine absorption pad 1. As shown in fig. 2 and 3, the back sheet 3 is arranged at a position opposite to the non-skin-facing surface side in the thickness direction T of the urine absorption pad 1, prevents the permeation of body fluid such as urine discharged from the wearer, and is formed of a liquid-impermeable sheet member that functions so that the body fluid does not leak to the outside of the urine absorption pad 1.

In the absorbent article of the present invention, the configuration of the back sheet is not limited to the above configuration, and any configuration having an external shape and dimensions according to various applications and the like may be employed as long as the back sheet can cover the entire surface of the absorbent body on the side other than the skin-facing surface.

The liquid-impermeable sheet member usable as the back sheet is not particularly limited as long as it has various properties (for example, liquid-impermeability (leakage-preventing property), strength, and the like) usable as the back sheet of the absorbent article, and for example, the following can be used: nonwoven fabrics such as spun bond nonwoven fabrics, point bond nonwoven fabrics, melt blown nonwoven fabrics, SMS nonwoven fabrics, and hot air nonwoven fabrics formed of hydrophobic fibers such as thermoplastic resin fibers; a resin film made of a hydrophobic thermoplastic resin such as polyethylene or polypropylene, which may or may not have a plurality of openings; an optional sheet-like member such as a laminate sheet in which a nonwoven fabric is bonded to a resin film. When a nonwoven fabric is used as the back sheet, the type of the constituent fibers (hydrophobic fibers) is not particularly limited, and examples thereof include: polyolefin resin fibers such as polyethylene and polypropylene; polyester resin fibers such as polyethylene terephthalate; and composite fibers such as core-sheath fibers and side-by-side fibers. These fibers may be used alone, or two or more kinds of fibers may be used in combination.

Further, the structure of the sheet member usable as the back sheet is not particularly limited, and any structure may be employed other than a flat sheet structure having no openings, irregularities, or the like, such as a porous structure having a plurality of openings, an irregular structure having a plurality of projections and recesses (for example, an irregular structure having a plurality of hollow projections and recesses and having a wave-shaped cross section), or the like.

The sheet member usable as the back sheet is not particularly limited as long as the effect of the present invention is not impaired, and any sheet member having a weight or thickness per unit area corresponding to desired liquid impermeability, strength, air permeability, and the like can be used.

In the absorbent article of the present invention, a liquid impermeable leakproof sheet may be further provided at a position between the back sheet and the absorbent body. The leakproof sheet is not particularly limited as long as it has a predetermined liquid impermeability (leakproof property), and for example, a resin film made of any thermoplastic resin such as polyethylene or polypropylene can be used.

The provision of such a leakage-preventing sheet is not a necessary constituent condition for the absorbent article of the present invention, but if the absorbent article is provided with such a leakage-preventing sheet, leakage of body fluid such as urine can be more effectively suppressed.

In the absorbent article of the present invention, the back sheet may be joined to a part of the surface of the pair of side sheets on the side other than the skin-facing surface, a part of the surface of the top sheet on the side other than the skin-facing surface, and/or at least a part of the surface of the absorbent body on the side other than the skin-facing surface. The joining means is not particularly limited, and any means such as a hot-melt adhesive or heat fusion may be used.

[ side square pieces ]

In the urine absorption pad 1 according to the above-described embodiment, the pair of side sheets 5 and 5 are each formed of a pair of belt-like sheet members extending from the front side end portion to the rear side end portion in the longitudinal direction L of the urine absorption pad 1at both end portions in the width direction W of the urine absorption pad 1 in a plan view, as shown in fig. 1 to 3. As shown in fig. 1 to 3, the pair of side sheets 5 and 5 are disposed at positions on the skin-facing surface side of the top sheet 2 in the thickness direction T of the urine absorption pad 1, and have an outer end in the width direction W joined to the surface on the skin-facing surface side of the back sheet 3 to form a fixed end, and an inner end in the width direction W not joined to any component such as the top sheet 2 to form a free end.

Further, the pair of side pieces 5 and 5 are provided with elastic members (not shown) such as rubber threads for causing the pair of side pieces 5 and 5 to contract in the longitudinal direction L and raising inner side end portions (free end portions) in the width direction W along the longitudinal direction L in the vicinity of the inner side end portions in the width direction W, respectively. By contraction of the elastic member, the inner side end portions (free end portions) in the width direction W of the pair of side pieces 5, 5 stand up to form a leakage preventing wall portion for preventing leakage of bodily fluid such as urine.

The tape-like sheet member usable as the side sheet is not particularly limited as long as it has various characteristics (for example, liquid impermeability (leakage resistance), texture, flexibility, strength, and the like) usable as the side sheet of the absorbent article, and any sheet member such as a nonwoven fabric made of hydrophobic fibers, a resin film made of a hydrophobic thermoplastic resin, a laminate sheet made of a resin film and a nonwoven fabric bonded thereto, and the like, which are similar to the above-described back sheet, can be used.

The shape, size, weight per unit area, thickness, and the like of the belt-like sheet member usable as the side sheet are not particularly limited as long as a predetermined leakage-preventing wall portion can be formed, and any shape, size, weight per unit area, thickness, and the like can be adopted according to the desired leakage-preventing property, skin touch, flexibility, strength, and the like.

Although the provision of such side panels is not a necessary constituent condition in the absorbent article of the present invention, the provision of such side panels in the absorbent article can more effectively suppress leakage of body fluid such as urine (in particular, leakage in the width direction of the absorbent article).

[ absorbent body ]

In the urine absorbent pad 1 according to the above-described embodiment, the absorbent member 4 is positioned from the front region a of the urine absorbent pad 1 in the longitudinal direction L in the plan view as shown in fig. 1 to 3_F(more specifically, the vicinity of the front end in the longitudinal direction L) to the rear region A_B(more specifically, the vicinity of the rear end in the longitudinal direction L) and extends from the vicinity of one end to the vicinity of the other end in the width direction W of the urine absorbent pad 1, and as a whole, has a central region A which is long in the longitudinal direction L and is parallel to the longitudinal direction L_CThe corresponding portion is tapered and narrowed inward in the width direction W to have a substantially hourglass shape.

In the absorbent article of the present invention, the outer shape of the absorber is not limited to the embodiment of the present invention, and any outer shape (for example, a rectangle, an ellipse, a gourd-shaped shape, or the like) can be adopted according to various applications as long as the absorbent article has a long configuration in which at least the longitudinal length is longer than or equal to the longitudinal length of the central region of the absorbent article.

In the urine absorption pad 1 of the present embodiment, the absorbent member 4 is disposed at a position between the front sheet 2 and the back sheet 3 in the thickness direction T as shown in fig. 2 and 3, and is composed of 2 layers of absorbent layers that function to absorb and retain body fluid such as urine of a wearer who has passed through the front sheet 2, that is, a 1 st absorbent layer 41 located on the skin-facing surface side in a facing manner and a 2 nd absorbent layer 42 located on the non-skin-facing surface side in a facing manner.

Among the 2-layered absorbent layers constituting the absorbent body 4, the 1 st absorbent layer 41 has, as shown in fig. 1, an outline shape substantially similar to that of the absorbent body 4 in plan view, i.e., extends from the vicinity of the front end portion to the vicinity of the rear end portion in the longitudinal direction L of the urine absorbent pad 1 in the longitudinal direction L, extends from the vicinity of one end portion to the vicinity of the other end portion in the width direction W of the urine absorbent pad 1 in the longitudinal direction L, and has, as a whole, a central region a which is long in the longitudinal direction L and is parallel to the longitudinal direction L_CThe corresponding portion has a substantially hourglass shape which is narrowed inward in the width direction W, while the 2 nd absorbent layer 42 extends in the longitudinal direction L from near the front end portion in the longitudinal direction L of the urine absorbent pad 1 (more specifically, a portion located forward of the front end portion of the 1 st absorbent layer 41) to near the rear end portion (more specifically, a portion located rearward of the rear end portion of the 1 st absorbent layer 41) in a plan view as shown in fig. 1 and 4, and both end portions in the width direction W are located inward in the width direction of the width direction W of the 1 st absorbent layer 41 in the width direction W (more specifically, both end portions in the width direction W are substantially overlapped with both end portions in the width direction W of the narrowed portion of the 1 st absorbent layer 41 in the thickness direction T), the overall shape is a substantially rectangular shape elongated in the longitudinal direction L. If relatively arranged at a position other than the skin-facing surface sideWhen the 2 nd absorbent layer 42 has such an outer shape, the step difference at the end portions in the width direction W of the 1 st absorbent layer 41 and the 2 nd absorbent layer 42 can be made less likely to be felt by the wearer.

Therefore, in the present embodiment, as shown in fig. 1, the 1 st absorbent layer 41 forms the outline shape of both end portions in the width direction W in a plan view of the absorbent body 4, and the 2 nd absorbent layer 42 forms the outline shape of both end portions in the longitudinal direction L in a plan view of the absorbent body 4.

In the absorbent article of the present invention, the absorbent body does not need to be constituted by such 2-layer absorbent layers, and the absorbent body may have a single-layer structure constituted by 1-layer absorbent layers or a multilayer structure constituted by 3 or more absorbent layers. The outer shape of one or more of the absorbent layers constituting the absorbent body is not particularly limited as long as it has various characteristics (e.g., liquid absorption properties, liquid retention properties, flexibility, etc.) that can function as an absorbent body of an absorbent article, and any outer shape (e.g., oval, gourd-shaped, square, circular, etc.) can be adopted in accordance with various uses, in addition to the substantially hourglass or rectangular shape of the above-described embodiment.

In the urine absorption pad 1 according to the above-described embodiment, as shown in fig. 2 and 3, the 1 st absorbent layer 41 is made of an absorbent material including a Super Absorbent Polymer (SAP) and hydrophilic fibers, and is partially covered with the hydrophilic sheet 6 joined to the surface on the skin-facing surface side thereof, thereby retaining the shape thereof, while the 2 nd absorbent layer 42 is covered with the hydrophilic core wrap sheet 422 via the absorbent core 421 including the SAP as the absorbent material and the hydrophilic fibers, thereby retaining the shape thereof. As shown in fig. 2 to 4, the 2 nd absorbent layer 42 is disposed such that the core wrap sheet 422 covers the absorbent core 421 from the non-skin-facing surface side, and further, on the skin-facing surface side of the absorbent core 421, one side end portion 422E in the width direction W of the core wrap sheet 422 is provided₁The near portion and the other end 422E₂The core wrap sheet 422 covers the entirety of the absorbent core 421 in such a manner that the vicinities are partially overlapped. Although the constitution of the 2 nd absorbent layer in this way is not essential in the absorbent article of the present inventionHowever, if the second absorbent layer 2 is formed in this way, there is an advantage that the absorbent material contained in the absorbent core and the pH adjuster described later can be less likely to fall off.

The hydrophilic sheet 6 and the core wrap sheet 422 are each formed of a hydrophilic sheet-like member such as a tissue.

In the absorbent article of the present invention, the absorbent material constituting the absorbent layer of the absorbent body is not particularly limited as long as it can absorb and retain body fluid such as urine, and any absorbent material known in the art can be used. Examples of such an absorbent material include hydrophilic fibers and super absorbent polymers, and more specifically, include: pulverizing cellulose fiber such as paper pulp, cotton, rayon, and acetate; granules composed of a Super Absorbent Polymer (SAP) such as a sodium acrylate polymer; mixtures thereof in any combination, and the like.

In the case where the absorbent body is constituted by a plurality of absorbent layers as in the above-described embodiment, the same absorbent material or a combination thereof may be used for all the absorbent layers, or different absorbent materials or a combination thereof may be used for each absorbent layer. Therefore, in the case where the absorbent body is constituted by the 2-layer absorbent layers of the 1 st absorbent layer and the 2 nd absorbent layer as in the above-described embodiment, SAP alone may be used as the absorbent material of the 1 st absorbent layer, and a combination of SAP and hydrophilic fibers may be used as the absorbent material of the 2 nd absorbent layer.

In the absorbent article of the present invention, when the absorbent layer constituting the absorbent body can retain its shape by means other than the hydrophilic sheet or the core wrap sheet as in the above-described embodiments or only by the absorbent material, the hydrophilic sheet or the core wrap sheet as in the above-described embodiments may not be provided.

Further, in the urine absorption pad 1 according to the above-described embodiment, as shown in fig. 1 and 2, the 1 st absorbent layer 41 includes the through-hole 41S which penetrates the 1 st absorbent layer 41 in the thickness direction T, is positioned at the center in the width direction W in a plan view, and is formed from the front region a of the urine absorption pad 1 in the longitudinal direction L_FRear ofThe side portions extend to the central region A_CThe front side portion of (1). The through-holes 41S are provided so as to correspond to the positions of the excretory opening of the wearer who excretes body fluid such as urine, and can promote absorption of body fluid such as urine immediately after excretion in the thickness direction T of the absorbent body 4, and therefore, more excellent absorption performance (particularly, absorption rate, liquid transfer property, and the like) can be exhibited, and as a result, generation of malodor can be suppressed.

In the urine absorbent pad 1 of the present embodiment, the through-holes are formed only in the 1 st absorbent layer 41 and not in the 2 nd absorbent layer 42, but in the absorbent article of the present invention, similar through-holes may be formed in the 2 nd absorbent layer. In the case where the 2 nd absorbing layer forms the through-holes, it is preferable that the through-holes of the 1 st absorbing layer have a smaller size and shape (area in plan view) than the through-holes of the 1 st absorbing layer in plan view at positions overlapping in the thickness direction. When the through-holes of the 2 nd absorbent layer are formed in this manner, the through-holes of the 1 st absorbent layer and the through-holes of the 2 nd absorbent layer communicate with each other in the thickness direction, and as a whole, the through-holes having an opening area gradually narrowed in the thickness direction of the absorbent body can be formed.

Since the formation of such through-holes in the absorbent body is not an essential constituent condition in the absorbent article of the present invention, such through-holes may not be formed in the absorbent body.

In the absorbent article of the present invention, the weight per unit area, the thickness, and the like of the absorbent layer constituting the absorbent body are not particularly limited as long as the effects of the present invention are not impaired, and any weight per unit area, thickness, and the like can be adopted according to the desired absorption performance, flexibility, and the like.

In the urine absorbent pad 1 according to the above-described embodiment, as shown in fig. 2 to 4, the region (i.e., the pH adjuster disposition region a) of the 2 nd absorbent layer 42 between the absorbent core 421 and the core wrap sheet 422 in the front half of the 2 nd absorbent layer 42 in a plan view (i.e., the pH adjuster disposition region a)₇) Neutralizing or suppressing substances causing offensive odor such as ammonia or amines contained in or generated from components contained in a body fluid such as urineA pH adjusting agent 7 for controlling the growth of bacteria causing the generation of the odor-causing substance (i.e., having a deodorizing function).

Hereinafter, the pH adjuster used in the absorbent article of the present invention will be described in more detail with reference to the urine absorption pad 1 according to the above-described embodiment.

[ pH adjusting agent ]

In the urine absorption pad 1 according to the above-described embodiment, the pH adjuster 7 has, as shown in fig. 5 and 6, a solid core portion 71 that is dissolved in water and is acidic, and a covering portion 72 that covers the core portion 71 and is made of a fat that is solid at normal temperature, and the covering portion 72 has a communication portion 722 that allows the outside of the pH adjuster 7 to communicate with the surface of the core portion 71 so as to allow liquid communication.

In the present specification, "normal temperature" means 20 ℃.

When the pH adjuster 7 is so configured that it is disposed at a position where it comes into contact with the body fluid of the wearer, the body fluid B such as urine discharged from the wearer_FBody fluid B upon contact with pH adjuster 7_FAs shown in fig. 6, the acidic component in the core portion 71 can be gradually eluted from the pH adjuster 7 by reaching the core portion 71 through the communication portion 722 of the cover portion 72 and locally dissolving the core portion 71. Thus, the urine absorption pad 1 is configured to supply body fluid B such as urine from the wearer every time the body fluid B is supplied from the wearer_FIn this case, the pH adjuster 7 gradually releases the acidic component, and thus can continuously exhibit the deodorizing function (i.e., a function of neutralizing the odor-causing substance such as ammonia or amines contained in or generated from the components contained in the body fluid such as urine, or suppressing the growth of bacteria causing the generation of the odor-causing substance) obtained by the acidic component for a long period of time.

In addition, the urine absorption pad 1 does not pass through the body fluid B_FThe cover part 72 made of fat and oil eluted from the core part 71 controls the release of the acidic component (specifically, body fluid B)_FThe chance of contact with the core portion 71, the elution amount of the acidic component from the core portion 71, and the like), it is difficult for structural restrictions such as particle size and the like, and restrictions on the arrangement position due to the structural restrictions, and the deodorizing function of the pH adjuster 7 can be efficiently and sufficiently exhibited.

Further, in the urine absorption pad 1 of the present embodiment, the covering portion 72 of the pH adjuster 7 is formed by stacking a plurality of grease particles 721 on the surface of the core portion 71 as shown in fig. 6, and the communication portion 722 is formed by the gaps between the plurality of grease particles 721. When the covering portion 72 and the communicating portion 722 of the pH adjuster 7 are formed in this manner, the surface of the core portion 71 is covered so as not to be exposed to the outside, and the communicating portion 722 through which liquid can pass is secured, whereby the above-described gradual release of the acidic component in the pH adjuster 7 can be more reliably achieved.

In the absorbent article of the present invention, the form of the covering portion (including the communicating portion) of the pH adjuster is not particularly limited as long as the effect of the present invention is not hindered, and the covering portion may be formed by, for example, a covering layer made of fat or oil covering the entire surface of the core portion and one or more cracks or openings (communicating portions) formed in the covering layer.

Here, fig. 7 is an enlarged cross-sectional view of a main portion corresponding to fig. 6 of a pH adjustor in another embodiment of the present invention in which the manner of covering the pH adjustor is different. In this other embodiment, the configuration other than the configuration different from the above-described embodiment is basically the same as that of the above-described embodiment, and therefore, the description thereof is omitted.

In this other embodiment, as shown in fig. 7, the coating portion 73 of the pH adjuster is formed by a grease coating layer 731 that covers the entire surface of the core portion 71 and is formed of grease that is solid at normal temperature, and a communication portion that is formed of a plurality of cracks 732 formed in the grease coating layer 731. Even if the cover 73 of the pH adjuster is configured as described above, the pH adjuster is applied to the body fluid B such as urine discharged from the wearer_FBody fluid B upon contact with a pH adjusting agent_FSince the core portion 71 is locally dissolved by reaching the core portion 71 through the crack 732 (communicating portion) formed in the fat coating layer 731 as shown in fig. 7, the acidic component in the core portion 71 can be gradually eluted from the pH adjuster, and the urine absorbent pad provided with the pH adjuster can supply body fluid B such as urine from the wearer every time the body fluid B is supplied from the wearer_FIn this case, the pH adjuster can gradually release the acidic component, and the deodorizing function by the acidic component can be continuously exhibited for a long period of time.

(core part)

In the absorbent article of the present invention, any acidic compound may be used as long as the core portion of the pH adjuster is in a solid state that is dissolved in water and is acidic, and examples of such acidic compounds include organic acids such as citric acid, adipic acid, azelaic acid, malic acid, tartaric acid, gluconic acid, glutamic acid, levulinic acid, glycolic acid, succinic acid, fumaric acid, pimelic acid, suberic acid, sebacic acid, lactic acid, 2-hydroxybutyric acid, mandelic acid, ascorbic acid, methyl α -hydroxyoctanoate, hydroxyoctanoic acid, salicylic acid, β -hydroxybutyric acid, hyoscyate, troxocaic acid, sorbic acid, benzoic acid, benzilic acid, and nonanol benzoic acid; inorganic acids such as phosphoric acid and boric acid. Among them, in view of having both of a neutralizing action for neutralizing an odor causing substance such as ammonia or amines contained in a body fluid such as urine or generated from a component contained in the body fluid and an antibacterial action for suppressing bacterial growth which causes the generation of the odor causing substance, it is preferable to use an organic acid such as citric acid or adipic acid, and further, it is particularly preferable to use citric acid in view of making the skin of a wearer weakly acidic and making it difficult to cause skin inflammation such as macula.

In the present specification, the term "acidic after dissolving in water" means that the aqueous solution has water solubility at room temperature (20 ℃) and standard atmospheric pressure (1atm) and has a pH in the range of 1 to 5. Here, the pH of the aqueous solution can be measured by bringing a pH test paper into contact with the aqueous solution to be measured.

In the present specification, the term "solid" means a solid state at normal temperature and normal atmospheric pressure.

The mass ratio of the core portion in the pH adjuster is not particularly limited as long as the effect of the present invention is not hindered, but when the particle mass of the pH adjuster is 100 mass%, the mass ratio is usually in the range of 20 to 99 mass%, preferably in the range of 50 to 99 mass%, and more preferably in the range of 75 to 95 mass%.

In the absorbent article of the present invention, when the body fluid that has been brought into contact with the pH adjuster (i.e., the body fluid in which the core portion has been dissolved) does not come into contact with the skin of the wearer depending on the position of the arrangement of the pH adjuster, a substance that exhibits a pH of less than 3 when dissolved in the body fluid (i.e., a substance that exhibits strong acidity) may be used as the core portion of the pH adjuster, but a substance that exhibits a pH in the range of 3 to 5 when dissolved in the body fluid (i.e., a substance that exhibits weak acidity) is preferably used as the core portion of the pH adjuster. When the core portion of the pH adjuster is dissolved in the body fluid to have a pH in the range of 3 to 5, a predetermined deodorizing function is exhibited, and when the body fluid after contact with the pH adjuster comes into contact with the skin of the wearer (that is, when the weakly acidic component eluted from the core portion comes into contact with the skin of the wearer), the pH of the skin becomes weakly acidic and skin inflammation such as rash is less likely to occur.

Here, in the present specification, the pH when dissolved in a body fluid refers to the pH of a solution when a physiological saline solution is used as a simulated body fluid and dissolved in the physiological saline solution. The absorbent article of the present invention is intended to absorb various body fluids such as urine, sweat, blood, saliva, etc., and the saline concentration (0.9 w/v% sodium chloride) of physiological saline having a tonicity approximately equal to that of such human body fluids is used as a substitute for real-time body fluids, and is not limited to the field, and is used in various fields such as research, analysis, and test. In the present specification, the pH of the body fluid (physiological saline) can be measured by bringing a pH test paper into contact with the physiological saline, as in the case of the pH measurement of the aqueous solution described above.

(covering section)

In the absorbent article of the present invention, any fat or oil can be used as long as it is solid at ordinary temperature and can cover the core portion, and examples of such fat or oil include hardened oils, higher alcohols, higher fatty acids, vegetable or animal fats, waxes, polyethylene glycols, and the like. Examples of hardened oils include hardened rapeseed oil, hardened castor oil, hardened soybean oil, and the like, examples of higher alcohols include stearyl alcohol, cetyl alcohol, and the like, and examples of plant-based or animal fats include lard, beef tallow, chicken tallow, whale tallow, tuna oil, sardine oil, mackerel oil, saury oil, bonito oil, milk fat, butter, palm oil, perilla oil, cocoa butter, peanut oil, coconut oil, evening primrose oil, borage oil, jojoba oil, and the like. As the coating portion of the pH adjuster, it is also preferable to use a highly hardened oil having a melting point of 50 ℃ or higher (that is, an oil product obtained by hydrogenating rapeseed oil, soybean oil, corn oil, palm oil, or the like to have an iodine value of 10 or less), and among these, it is particularly preferable to use a highly hardened oil of rapeseed oil containing erucic acid in a range of 20% to 60% in constituent fatty acids.

The amount of the coating portion (i.e., the mass ratio of the coating portion in the pH adjuster) is not particularly limited as long as the effect of the present invention is not impaired, and is usually in the range of 1 to 80 mass%, preferably in the range of 1 to 50 mass%, and more preferably in the range of 5 to 25 mass% when the particle mass of the pH adjuster is 100 mass%.

The means for forming the covering portion, that is, the means for covering the surface of the core portion with the fat is not particularly limited, and for example, a plurality of fat particles for forming the covering portion may be adhered to the surface of the solid (for example, granular, powdery, etc.) core portion by any spraying means or mixing means under heating or non-heating conditions (such a method may be hereinafter referred to as "granular adhesion method") to form the covering portion composed of the fat, or the fat for forming the covering portion may be heated to a melting point or higher to form a molten liquid, which is adhered to the solid core portion by spraying or dripping, and then cooled and dried (such a method may be hereinafter referred to as "liquid adhesion method") to form the covering portion composed of the fat.

(communicating part)

In the absorbent article of the present invention, the communicating portion formed in the covering portion of the pH adjuster is not particularly limited as long as the outside of the pH adjuster and the surface of the core portion are in fluid communication (i.e., in a manner allowing body fluid to pass therethrough), and may be formed of, for example, gaps between a plurality of fat particles, one or a plurality of cracks or openings formed in the fat covering layer as in the above-described embodiment. The number, size, area, and the like of such gaps, cracks, openings, and the like (hereinafter, sometimes referred to as "gaps and the like") are not particularly limited as long as the effects of the present invention are not hindered, and the gaps and the like can be formed in any manner according to the desired deodorization function (more specifically, the gradual release property of the core portion and the like).

The means for forming the communicating portion is not particularly limited, and for example, when the particle adhesion method is used as the means for forming the covering portion, the communicating portion may be formed by a gap between a plurality of fat particles, and when the liquid adhesion method is used as the means for forming the covering portion, the communicating portion may be formed by a crack of the fat covering layer generated by adjusting a cooling and drying condition after a melted liquid of the fat is adhered to the solid core portion, or by an opening or a notch formed by mechanical means such as punching or cutting after the covering portion (fat covering layer) made of the fat is formed on the surface of the solid core portion.

In the absorbent article of the present invention, the particle size (average particle size) of the pH adjustor is not particularly limited as long as the effect of the present invention is not hindered, and is, for example, in the range of 50 to 1500. mu.m, preferably in the range of 100 to 1200. mu.m, and more preferably in the range of 300 to 1000. mu.m. When the particle size of the pH adjuster is 50 μm or more, the pH adjuster disposed in the absorbent article is less likely to fall off, and when the particle size of the pH adjuster is 1500 μm or less, the amount of the acidic component eluted from the core portion is easily controlled to an appropriate level, and further, when the pH adjuster is disposed in a position such that it contacts the skin of the wearer, the feeling of the particles of the pH adjuster is less likely to be felt by the wearer, and there is an advantage that a good wearing feeling is easily maintained. The particle size (average particle size) of the pH adjuster can be measured by a sieving method.

Further, in the absorbent article of the present invention, when the absorbent article has an absorbent body containing a Super Absorbent Polymer (SAP), it is preferable that a part of the core is eluted into a body fluid after a lapse of at least 30 seconds from the time when the pH adjuster comes into contact with the body fluid. After the lapse of a time (usually about 30 seconds) required for the SAP to swell to a certain extent or more (to swell to about 7 to 8 which are completely swollen) by absorbing the body fluid, the pH adjuster dissolves a part of the core of the pH adjuster as an acidic component into the body fluid, and therefore, the acidic component does not inhibit the absorption and swelling (retention) of the SAP and can sufficiently exhibit a predetermined deodorizing function.

The pH adjuster having a delayed dissolution start time in the core portion can be easily obtained by adjusting the number, size, area, and the like of the gaps between the plurality of fat particles, the one or more cracks or openings formed in the fat covering layer, and the like formed in the communicating portion of the covering layer so that the core portion is difficult to dissolve, or by using a substance having low solubility in water as the acidic compound forming the core portion.

The start time of elution of the core portion can be obtained by measuring the pH of a solution obtained by dissolving a pH adjuster to be measured in a simulated body fluid (physiological saline). Specifically, 50g of physiological saline was first measured as a simulated body fluid in a 100ml beaker, and the pH of the physiological saline in the beaker was measured using a pH meter (for example, a pH meter manufactured by Toyo DKK Co., Ltd.). Further, while continuing the measurement of pH, 0.25g of the pH adjuster to be measured was added to the beaker, and the pH measured by the pH meter was recorded at regular intervals (for example, at intervals of 10 seconds). The measurement of pH was terminated when the change in pH disappeared. The time when the measured pH decreased by 0.1 or more was defined as the dissolution start time of the core portion.

In the absorbent article of the present invention, it is preferable that the pH adjuster has an acidic gradual release function in which the change in pH of the body fluid from contact with the body fluid to 60 seconds is 0.5 or less. When the pH adjuster has such a predetermined gradual acidic release function, the acidic component is gradually released from the time of contact with the body fluid, and thus the deodorizing function by the acidic component can be more continuously exhibited.

The pH adjuster having such an acidic gradual release function can be easily obtained by adjusting the number, size, area, and the like of the gaps between the plurality of fat particles, one or more cracks or openings formed in the fat covering layer, and the like formed in the communicating portion of the covering layer so that the core portion is gradually eluted, or by using a substance having low solubility to water as the acidic compound forming the core portion.

The amount of change in pH of the body fluid from the time of contact with the pH adjuster can be obtained by measuring the pH of a solution in which the pH adjuster to be measured is dissolved in a simulated body fluid (physiological saline) as in the case of the start timing of elution of the core portion described above.

(location of pH adjuster)

In the urine absorbent pad 1 according to the above-described embodiment, since the pH adjuster 7 is disposed between the absorbent core 421 and the core wrap sheet 422 of the 2 nd absorbent layer 42, the pH adjuster 7 can be easily prevented from falling off, and the deodorizing function can be efficiently exhibited.

However, in the absorbent article of the present invention, the position where the pH adjuster is disposed is not limited to the position as in the above-described embodiment, and the pH adjuster may be disposed at any position in consideration of the desired deodorizing function, absorption performance, and the like. Among them, the pH adjuster is preferably disposed at least one of the top sheet, between the top sheet and the absorbent body, and the absorbent body. If the pH adjuster is disposed at such a position that is highly likely to come into contact with the body fluid, the pH adjuster can be brought into contact with the body fluid efficiently, and thus the deodorizing function can be exerted more reliably. In particular, when the pH adjuster is disposed on the skin-facing surface side of the absorbent body (that is, when the pH adjuster is disposed on at least one of the topsheet and the space between the topsheet and the absorbent body), the pH adjuster can be brought into contact with the body fluid more efficiently.

In the present specification, the term "pH adjuster" disposed in the topsheet means at least one of a surface of the topsheet on the skin-facing surface side, a surface on the non-skin-facing surface side, and an interior of the topsheet. The same applies to the case where the pH adjuster is disposed in the absorbent body or in a diffusion sheet described later.

In the absorbent article of the present invention, a diffusion sheet may be further provided between the topsheet and the absorbent body, and the pH adjuster may be disposed at least in the diffusion sheet. When the pH adjuster is disposed in such a diffusing sheet, the body fluid can be diffused in the planar direction by the diffusing sheet and simultaneously brought into contact with the pH adjuster, and therefore the deodorizing function by the pH adjuster can be more effectively exhibited. Further, since the surface sheet is interposed between the skin of the wearer and the pH adjuster, the pH adjuster is less likely to directly contact the skin of the wearer, and therefore, there is an advantage that it is less likely that the wearer feels a strange or uncomfortable feeling due to the adhesion of the pH adjuster to the skin.

In addition, when the pH adjuster is disposed in a sheet member such as a nonwoven fabric having a low fiber density, the pH adjuster may be fixed by a fixing means such as a binder from the viewpoint of preventing the pH adjuster from falling off.

Further, in the urine absorbent pad 1 according to the above-described embodiment, the pH adjuster 7 is disposed in a region (i.e., the pH adjuster disposition region a) of the front half of the 2 nd absorbent layer 42 in plan view as shown in fig. 4₇) However, in the absorbent article of the present invention, the arrangement region of the pH adjuster in a plan view is not limited to this embodiment as long as the pH adjuster is in contact with the body fluid, and the pH adjuster may be arranged in any arrangement region in a plan view.

Here, fig. 8(a) to (c) are plan views of the 2 nd absorbing layer in still another embodiment of the present invention in which the arrangement of the pH adjuster is different.

FIG. 8(a) shows a 2 nd absorbing layer 42a in a further embodiment of the present invention, in which a pH adjuster is disposed in a region A_7aA partial region which is a front half region of the 2 nd absorption layer 42a in plan view, and the pH adjustor arrangement region A_7aIs disposed at a position overlapping the through-hole 41S of the 1 st absorbent layer 41 described above in the thickness direction T (i.e., a position corresponding to the position of the excretory opening of the wearer). If the pH regulator is disposed in the region A_7aConfigured in this manner, all of the pH adjusters 7a are easily brought into contact with the body fluid discharged from the wearer, and thus, canThe deodorizing function obtained by the pH adjuster 7a can be more efficiently exhibited.

The pH adjuster may be disposed over the entire surface of the absorbent layer constituting the absorbent body in a plan view, or may be partially disposed in a band-like region extending in the width direction in the vicinity of the front side end and/or the vicinity of the rear side end in the longitudinal direction. When the pH adjuster is disposed as described above, the possibility of the pH adjuster coming into contact with the body fluid discharged from the wearer becomes higher, and therefore, the deodorizing function obtained by the pH adjuster can be more reliably exhibited, and when the pH adjuster is disposed as described later, the time for which the pH adjuster is continuously in contact with the skin of the wearer is long, and the core portion of the pH adjuster is eluted into the sweat discharged from the wearer in the vicinity of the front side end portion and/or the vicinity of the rear side end portion in the longitudinal direction in which stuffiness is likely to occur due to the sweat of the wearer, and the deodorizing function described above can be more effectively exhibited.

The number or area of the pH adjuster disposition region is not particularly limited as long as the effect or absorption performance of the present invention is not hindered, and the pH adjuster disposition region may be disposed in any number or area. The shape of the pH adjuster disposition region in plan view is not limited to the rectangular shape shown in fig. 4 and 8(a), and the planar shape of the pH adjuster disposition region may be, for example, a circular shape, an elliptical shape, or other geometric shapes.

In addition, in the 2 nd absorption layer 42b in still another embodiment of the present invention shown in FIG. 8(b), the pH adjuster disposition region A is_7bThe central portion in the width direction W and both end portions in the width direction W in a plan view are each formed by a 3-stripe region extending from a front side end portion to a rear side end portion in the longitudinal direction L. If the pH regulator is disposed in the region A_7bFormed in this way, the pH adjustor arrangement regions A adjacent in the width direction W_7bThe region between the absorbent layers can absorb body fluid such as urine discharged from the wearer and promote diffusion in the longitudinal direction L, and therefore, the body fluid can be absorbed from a wide region in the longitudinal direction L of the 2 nd absorbent layer 42b, and the pH adjuster 7b can be brought into contact with the body fluid in a wide region in the longitudinal direction L. This enables the device to more efficiently exhibitAbsorption performance by the absorber and deodorizing function by the pH adjuster.

Further, if the pH adjuster is disposed in the region A_7bWith such a configuration, the pH adjuster 7b can be contacted with the body fluid which is repeatedly supplied and diffused in the width direction W step by step, and there is an advantage that the deodorizing function by the pH adjuster 7b can be continuously exhibited for a longer period of time.

When the pH adjuster arrangement region is formed by such a band-shaped region, the number of the band-shaped regions is not limited to the above 3, and may be 1, 2, or 4 or more, for example. The band-shaped pH adjuster disposition region may be disposed only in a band-shaped region extending in the longitudinal direction at the center in the width direction, or may be disposed only in a band-shaped region extending in the width direction at the center in the longitudinal direction.

Furthermore, in the 2 nd absorbing layer 42c in still another embodiment of the present invention shown in FIG. 8(c), the pH adjuster disposition region A is_7cThe region in the front half of the 2 nd absorbent layer 42c in plan view is formed as a double oval region having a major axis in the longitudinal direction L, and the double oval pH adjuster disposition region a_7cThe center of the inner elliptical region (i.e., the center of the major and minor axes of the ellipse) is arranged at a position overlapping the through-hole 41S of the 1 st absorbent layer 41 in the thickness direction T (i.e., a position corresponding to the position of the excretory opening of the wearer). If the pH regulator is disposed in the region A_7cFormed in such a manner that when the pH adjustor arrangement region A is reached_7cThe body fluid in the center of the inner oval region of (2) can be repeatedly supplied and can be gradually brought into contact with the pH adjuster 7c when diffused in the longitudinal direction L and the width direction W, and therefore, the deodorizing function by the pH adjuster 7c can be continuously and effectively exhibited for a longer period of time.

When the pH adjuster disposition region is formed by such a ring-shaped region, the number of the ring-shaped regions is not limited to the double number (2), and may be, for example, one (1) or three (3) or more. The shape of the annular region in plan view is not limited to the above-described elliptical shape, and may be any annular shape such as a circular shape or a rectangular shape.

In the absorbent article of the present invention, a means for controlling the flow of body fluid (for example, diffusion flow in the planar direction, permeation flow in the thickness direction, or the like) in the openings, the low basis weight portions, the compressed portions, or the like may be employed to improve the contact efficiency between the pH adjuster and the body fluid.

The present invention can be applied to various absorbent articles such as disposable diapers for adults or infants, light incontinence pads, panty liners, sanitary napkins, sweat pads, and breast pads, in addition to the urine absorbent pads of the above-described embodiments. The absorbent article of the present invention is not limited to the above-described embodiments or the examples described below, and may be appropriately combined, substituted, or modified without departing from the object and the concept of the present invention. In the present specification, the ordinal numbers "1 st", "2 nd", etc. are elements for distinguishing items to which the ordinal numbers are assigned, and do not refer to the order, priority, importance, etc. of the items.