RU2582470C2 - Absorbent article - Google Patents

Abstract

FIELD: hygiene.

SUBSTANCE: invention relates to an absorbent product, such as disposable diaper, particularly to an absorbent product, in which presence or absence of excrements can be detected visually. An absorbent article which comprises top sheet 1, backsheet 2 and absorbent 3, wherein indicating portion 6 whose colour visual change when coming into contact with fluid positioned between backsheet 2 and absorbent body 3, and an absorbent body 3 comprises an absorbent core 4, which comprises a fibrous material 41 and an absorbent polymer 42 and cover sheet 5 which covers outer surface of absorbent core 4, wherein cover sheet 5 has a cross-sectional view of absorbent body 3 baggy portion 51, which covers area of contact with skin side surface to not skin-contacting side of absorbent core 4 and covering mouth portion 52 connected to bag-shaped part 51 and disposed outward from it, and closing mouth portion 52 is formed so both lateral end portions 5a and 5b of cover sheet 5, arranged on skin contacting surface side of absorbent core 4 bonded in a state where they face each other and stacked, and wherein closing mouth portion 52 is disposed so as to completely cover area 61 which is indicator part 6 and closing mouth of bag-shaped part 52 and part 51 are connected.

EFFECT: presence or absence of secretions can detect visually.

22 cl, 1 tbl, 12 dwg, 2 ex

Description

FIELD OF THE INVENTION

0001 The present invention relates to an absorbent article, such as a disposable diaper, in particular to an absorbent article in which the presence or absence of secretions can be visually recognized.

BACKGROUND

0002 Absorbent articles are known, such as disposable diapers, in which an indicator part is integrated between the bottom sheet and the absorbent body, the color of which changes when it comes into contact with the released fluids to allow the color change to be distinguished from the outside. The emitted fluid typically penetrates through the absorbent core in the absorbent body and a cover sheet (also referred to as a base sheet) that covers the outer surface of the absorbent core to come into contact with the indicator portion. Thus, the indicator portion changes color to make it possible to conclude a suitable time for replacing the absorbent article. As a method related to the color change of the indicator portion, for example, Patent Literature 1 describes a diaper in which a color-changing hydrophilic composition is positioned between the bottom sheet and the portion in which the base sheet covering the absorbent core intersects and overlaps. Due to the part in which the base sheet overlaps, the composition resists leakage, and the occurrence of color erosion upon contact with urine and, therefore, the visibility of color change can be improved. In addition, a diaper is described in Patent Literature 2 in which a fluid-permeable intermediate sheet is positioned between an absorbent core and a color-changing composition. Thus, it is possible to suppress the staining of the absorbent core, which may occur when the above composition is contacted with urine.

LIST OF REFERENCES

Patent Literature

0003 Patent Literature 1: JP-A-2004-337384 (“JP-A” means Unexamined Published Japanese Patent Application)

Patent Literature 2: JP-A-2007-252659

SUMMARY OF THE INVENTION

0004 The present invention provides an absorbent article that comprises a top sheet located on a side of a skin contacting surface, a bottom sheet located on a skin contacting side of a skin contacting surface, and an absorbent body interposed between both sheets,

moreover, the indicator part, the color of which visually changes when it comes into contact with the fluid, is located between the bottom sheet and the absorbent body, and the absorbent body contains an absorbent core containing fibrous material and an absorbent polymer, and a covering sheet covers the outer surface of the absorbent core,

moreover, the covering sheet has, in the form of a cross-section of the absorbent body, a bag-shaped part that covers the area from the side of the surface in contact with the skin to the side of the surface not in contact with the skin, the absorbent core, and the mouth covering part connected to the bag-shaped part and located outward from it, and forming a mouth covering part in which both transverse end parts of the covering sheet are located on the side of the surface not in contact with the skin absorbing the heart zevins, fasten in a state facing each other and folded, and

moreover, the mouth covering part is positioned so as to completely cover the area in which the indicator part is located, and the mouth covering part and the bag-shaped part are partially connected.

0005 The present invention provides a method for producing an absorbent article, which comprises:

the step of forming an absorbent body to place the absorbent core on the raw material coating sheet, which is continuously transported, raising both transverse end parts of the raw material coating sheet and turning the end parts so that they face each other on the absorbent core, applying a hot melt adhesive to each of the facing surfaces both end parts in order to fasten both end parts in order to form a bag-like part, and folding the fastened ends eve parts so as to be along the bag-shaped part in order to form a mouth covering part in order to obtain an absorbent body, and to vertically turn the absorbent body;

the stage of forming the indicator part for applying a hot-melt composition containing a mixture of a color indicator and a pressure-sensitive adhesive component to the raw material base sheet, which is continuously transported to further cool and solidify the composition; and

a laminating step for discontinuously applying, in the transverse outward direction, the indicator part, a hot-melt adhesive to the raw material bottom sheet on which the indicator part is formed, and placing and fixing the absorbent body so as to attach the root mouth covering the mouth and the mouth closing outer side to the back mouth covering part the sheet by means of a hot-melt adhesive on the raw back sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

0006

FIG. 1. In FIG. 1 is an enlarged, partially cutaway flat view, schematically shown on the surface side not facing the skin (lower sheet side) in the unfolded state of a folding type disposable diaper, as one embodiment, in an absorbent article in accordance with the present invention.

FIG. 2. In FIG. 2 is an enlarged cross-sectional view along line II-II of FIG. 1 and a sectional view in the width direction.

FIG. 3. In FIG. 3 is a partially enlarged cross-sectional view of FIG. 2.

FIG. 4. In FIG. 4 is a partially enlarged cross-sectional view schematically showing another preferred embodiment of the opening of the mouth portion according to the embodiment.

FIG. 5. In FIG. 5 is an enlarged cross-sectional view of the cross section taken along line V-V of FIG. 1 and a longitudinal sectional view along the transverse center line C1 of the diaper 10.

FIG. 6. In FIG. 6 is a diagram schematically showing a diaper assuming a standard shape of an absorbent body in which (A) is a cross-sectional view and (B) is a longitudinal sectional view.

FIG. 7. In FIG. 7 is a cross-sectional view schematically showing a modified example of an absorbent body according to an embodiment.

FIG. 8-1. In FIG. 8-1 is a diagram schematically showing another modified example of an absorbent body according to an embodiment in which (A) is a plan view of an absorbent body and (B) is a partially enlarged cross-sectional view corresponding to FIG. 3 schematically showing the arrangement between the absorbent body in FIG. 3 (A) and indicator part.

FIG. 8-2. In FIG. 8-2 is a partially enlarged cross-sectional view corresponding to FIG. 3, which schematically shows another other modified example of an absorbent body according to an embodiment.

FIG. 9. In FIG. 9 is an explanatory drawing showing a sketch of a principle part in the form of steps for producing a folding type disposable diaper according to an embodiment with respect to a method for producing an absorbent article in accordance with the present invention.

FIG. 10. In FIG. 10 is an explanatory drawing schematically showing the steps of forming the mouth opening of the portion 52 in the absorbent body in accordance with the disposable type diaper according to the embodiment.

FIG. 11. In FIG. 11 is a schematic cross-sectional view schematically showing the shape of a diaper obtained in the examples and comparative examples.

DETAILED DESCRIPTION OF THE INVENTION

0007 The present invention relates to an absorbent article in which contact of the absorbent polymer with the indicator portion is prevented in order to make it possible to suppress unnecessary color changes while maintaining the performance of rapid color changes during urination. The present invention also relates to a method for producing an absorbent article in which a color change performance is maintained in order to appropriately allow suppression of an unnecessary color change.

0008 One preferred embodiment of an absorbent article in accordance with the present invention is explained below with reference to FIG.

An overview of the disposable diaper 10 in one embodiment is described with reference to FIG. 1 and 2. As shown in FIG. 1, the disposable diaper 10 according to one embodiment has a fluid permeable topsheet 1 located on the surface side of the skin contact, a moisture permeable and fluid permeable topsheet 2 located on the surface of the skin noncontact, and an absorbent body 3 located between two sheets. The top sheet 1 and the bottom sheet 2 have a substantially longitudinal geometric shape. The absorbent body 3 has a substantially longitudinal hourglass shape, narrowed inwardly near the longitudinal center, which has a slightly shorter longitudinal (Y direction) and transverse (X direction) length compared to the above sheets. The absorbent body 3 is positioned approximately in the center by aligning the longitudinal direction with the longitudinal direction of the upper sheet 1 and the lower sheet 2. The upper sheet 1, the lower sheet 2 and the absorbent body 3 are bonded using hot-melt adhesive or the like.

0009 As shown in FIG. 2, the absorbent body 3 is formed from the absorbent core 4 to absorb and retain the fluid and the cover sheet 5. The absorbent core 4 contains fibrous material 41 and absorbent polymer 42, which are mixed and where the fibers form clusters. A cover sheet 5 covers the outer surface of the absorbent core 4 in order to maintain its geometric shape. In addition, between the bottom sheet 2 and the absorbent body 3 are three strips of the indicator part 6 (6a, 6b and 6c) close to the transverse center of the diaper 10 from the crotch part C to the part of the front side F and the part of the back side R (see Fig. 1 and 2). The longitudinal length of the indicator part 6 is made shorter than the length of the absorbent body 3. The indicator part 6 has the function of visually changing when it comes into contact with the fluid. The indicator part 6 is placed between the bottom sheet 2 and the absorbent body 3, thereby easily bringing into contact with a fluid, such as urine, allocated to the center of the crotch part C, to allow the timely occurrence of a visual change in the indicator part 6. Urination or the like can recognize from the outside by visual change, even while the diaper 10 is worn. In the present invention, “visual change” or “color change” has a meaning that includes, upon contact with a fluid, a color change from a specific color to some other color, the color disappearing from a color state to a colorless state, and color development from colorless state to color state. The number of disposable indicator parts 6 is not limited to three stripes in one embodiment, and it can be arbitrarily set. In addition, the structure and the relationship between the arrangement of the cover sheet 5 of the absorbent body 3 and the indicator portion 6 are described in one embodiment.

0010 On the side of the skin surface of the top sheet 1, a pair of side sheets 7 and 7 are arranged on both of its side parts in the longitudinal (Y direction) in the direction of each of its outer directions in the transverse (X direction). On the side of the surface not in contact with the skin of the bottom sheet 2, an outer sheet 8 formed of a nonwoven material is arranged so as to completely cover the sheet. On the outer sheet 8, outside the diaper 10, a soft texture is provided and, as a result, a pleasant feeling. The longitudinal (Y direction) length of the side sheet 7 and the outer sheet 8 approximately coincides with the longitudinal (Y direction) length of the top sheet 1 and the longitudinal (Y direction) length of the bottom sheet 2, respectively. In addition, the side sheet 7 and the outer sheet 8 extend, furthermore, in the transverse (X direction) outer direction compared to the upper sheet 1 and the lower sheet 2 in the front side part F and the rear side part R, and they are fastened using a hot melt adhesive or the like. In this way, the external geometric shape of the disposable diaper 10 shown in FIG. 1. In the form of its unfolded state in plan, the diaper 10 is formed from a part of the front side F located on the front side of the wearer while wearing, the crotch part C located on the crotch part of the wearer, and the part of the back side R located on the back side of the wearer to generally have a geometric hourglass shape in which the crotch portion C is narrowed in the transverse direction inward.

0011 An elastic element 71 is disposed in the inwardly directed end portion closer to the transverse center of the side sheet 7. The elastic element 71 is compressed while the diaper 10 is being worn, and the leakage cuff 72 is formed in the crotch portion C. In addition, the elastic elements 73 are arranged in the transverse outer direction the side sheet 7, respectively, and form the foot assembly 74. In addition, near the side of the longitudinal end portion of the diaper 10, a plurality of elastic elements 13 are arranged in the entire width direction. The expansion and contraction of the elastic elements 13, 71 and 73 allows the diaper 10 to sufficiently repeat the change in the geometric shape of the body due to the movements of the wearer or the like in order to be sufficiently consistent, thereby making it possible to effectively prevent lateral leakage of a fluid or the like. As shown in FIG. 1, a region of the front side F and a region of the rear side R of the diaper 10 are formed with the valve portion 17 on the rear side and the valve portion 18 on the front side, respectively, each of which includes a side sheet 7 and an outer sheet 8 laminated for expanding outward in the width direction . A fixing tape 19 is provided on the valve portion 17 on the rear side. The tape 19 can be attached to the tape attachment part (not shown) provided on the valve portion 18 on the front side, whereby it is possible to carry and fix the diaper in a certain position. At this point, the diaper is carefully tucked inward in the central part in the longitudinal direction and worn where the absorbent body 3 corresponds to the area from the femoral part to the lower abdomen of the wearer. Through this, the absorbent body 3 can properly absorb and retain the excreted medium. In the diaper 10 of one embodiment, it is possible to further provide a functional structural part, sheet material or the like.

0012 In the present invention, unless otherwise indicated, the surface on the side in contact with the human body is denoted as the surface of the skin side, the surface in contact with the skin or the upper surface, and the opposite surface is designated as the surface of the non-skin side, the surface not in contact with the skin or the back surface . On these two surfaces, the side closer to the surface of the skin side and the direction of expansion are designated as the side of the skin surface, the side of the surface in contact with the skin, or the side of the upper surface, and the side closer to the non-skin surface and the direction of expansion are designated as side not the skin surface, the side of the surface not in contact with the skin, or the side of the lower surface. When worn, the position on the front side of the human body is designated as the front, its edge is designated as the front edge, and the position on the back side is designated as the rear, and its edge is designated as the rear edge. The direction perpendicular to the upper surface or the rear surface of the absorbent article is denoted as the direction of the thickness, and its amount is denoted as the thickness. In addition, unless otherwise indicated, in the form of an absorbent product in plan, the direction from the front side to the back side through the crotch portion is designated as the length direction or longitudinal (Y direction), and the direction perpendicular to the length direction (longitudinal) is denoted as transverse (X direction). The longitudinal direction typically coincides with the anteroposterior direction of the body of the person wearing the diaper.

0013 Next, with reference to FIG. 3 and 4, the structure and dependence of the arrangement of the cover sheet 5 of the absorbent body 3 and the indicator portion 6 in the diaper 10 are described in detail. In addition, in FIG. 3 shows a cross-section (X direction) of only the enlarged absorbent body 3, the indicator part 6, the lower sheet 2 and the outer sheet 8.

As indicated above, three strips of the indicator part 6 are located between the bottom sheet 2 and the absorbent body 3. The indicator part 6b is located near the transverse (X direction) center line C1 of the diaper 10, and the indicator parts 6a and 6c are placed separately at equal intervals in the direction of its width from left to right. The transverse region from the end part of the indicator part 6a to the end part of the indicator part 6c is taken as the indicator region 61. The indicator part 6 is formed using a hydrophilic composition containing a color indicator that changes color, for example, due to a change in pH. As a method of placement of the indicator part 6, you can use the method applied to the product of this type. Specific examples include a method for directly applying a color-changing material such as the above composition onto a bottom sheet 2 or a covering sheet 5 of an absorbent body 3, and a method of inserting a sheet element, such as sanitary paper and a hydrophilic non-woven material, into which a color-changing material make or soak. In one embodiment, as noted below, such a color-changing material is applied to the surface (skin-contacting surface) opposite the absorbent body 3 of the lower sheet 2, from the point of view of preventing unnecessary color change of the indicator portion 6. In addition, in the present invention, the number disposable indicator parts 6 or the interval of their location is not limited to those shown in one of the embodiments, and they can be arbitrarily set, if necessary, by the use or size of the product, or things like that. The size of the indicator area 61 also change according to the situation.

0014 The diaper 10 has, in its position, a urination point p at a place slightly closer to the front side of the crotch portion C in order to receive a lot of urine. The urination point p shown in FIG. 1, indicates the position in the case of a man, and in the case of a woman, this position is slightly closer to the longitudinal center compared to it. Here, the urination point p denotes the area that first receives urine when the wearer wears the disposable diaper 10, and its periphery. Accordingly, the mouth-covering portion 52 and the indicator region 61, as described above, are preferably positioned so as to cover the transverse center line C1 above the urination point p and its periphery in the longitudinal direction.

0015 As indicated above, the absorbent body 3 is formed from an absorbent core 4 and a covering sheet 5. The absorbent core 4 is a body of mixed fiber clusters in which the absorbent polymer 42 is made to mix between the fibers of the fibrous material 41 (see FIG. 3 ) Specific examples of the geometric shape of the absorbent polymer 42 include particles, as shown in FIG. 3, as well as fibers or the like. When the absorbent polymer 42 is a particle, specific examples include, in terms of differences in geometric shape, an indefinite type, a massive type, a bale type, spherical agglomerations and a spherical type, and any one of them can be used arbitrarily. The diameter of its particles can also be set arbitrarily. The absorbent polymer 42 contains a trace amount of moisture in order to exhibit viscosity, and is stably fixed between the fibrous materials 41. In addition, in the absorbent core 4, the component ratio of the fibrous material 41 and the absorbent polymer 42 can be arbitrarily set according to use, product size or the like. .

0016 The cover sheet 5 has a length approximately equal to the longitudinal (Y direction) length of the absorbent core 4 in order to cover the transverse (X direction) opposite side surfaces from the surface side of the absorbent core 4 in contact with the skin, to further extend to the surface side, not in contact with the skin, and fasten. Thus, it is easier to maintain the geometric shape of the absorbent core 4. More specifically, in a cross-sectional view of the absorbent body 3 (X direction), the cover sheet 5 has a bag-shaped part 51 and an opening covering the mouth 52, which is located outwardly from the bag-shaped part 51. Bag-shaped part 51 is a part in contact with the outer surface of the absorbent core 4 in order to cover the core. As shown in FIG. 3, the mouth-covering portion 52 consists of right and left opposite end parts (both end parts) 5a and 5b (end parts of the bag-shaped part 51) of the cover sheet 5, as extends from the right-left transverse end of the absorbent core 4. Opposite end parts 5a and 5b of the covering sheet 5 is fastened in a state when they are facing each other from the outside of the bag-shaped part 51, in which its surfaces lying opposite to the absorbent core 4 are facing each other. The opposite end portions 5a and 5b are joined by bonding, whereby the bag-shaped portion 51 is sealed. The flat part (the flat part of the end part 5b in FIG. 3) of the cover sheet 5, fastened in a state turned to face each other of the parts, is folded along the bag-shaped part 51 so as to face the indicator part 6 and form a mouth covering part 52. In addition, the mouth-closing part 52 is connected to the bag-shaped part 51 in the closing mouth of the root part 54 (see FIG. 3). The root covering part of the mouth 54 is formed so that it is slightly lifted from the bag-shaped part 51 by turning the parts so that they face each other. In the present invention, the connection of the mouth covering portion 52 to the bag-shaped portion 51 is not limited to the case of sequential connection in the form of a continuous body of the same element, but may be in the form obtained by bonding different bodies. In addition, the connection of the mouth-covering part 52 to the bag-shaped part 51 may also be in the form of a partial fastening in a part other than the root-part closing the mouth 54.

0017 Thus, the mouth-closing portion 52 is a portion protruding outwardly from the bag-shaped portion 51 to literally seal the bag-shaped portion 51 to close the mouth. A structure is formed at the closing mouth of the part 52 in which none of the end parts 5a and 5b of the covering sheet 5 extends into the bag-shaped part 51 so that leakage of the absorbent polymer 42 is not likely to occur. Thus, leakage of the absorbent polymer 42 dispersed inside the absorbent core 4 is effectively suppressed. In addition, the bag-shaped portion 51 and the mouth covering portion 52 are formed from a continuous covering sheet 5, and its boundaries can be functionally determined based on the classification described above. "Rotating the parts so that they are facing each other" refers to folding the two surfaces of the sheet face to face, as if you put your palms together, and means lifting, at an angle, the surfaces of the two end parts 5a and 5b of the cover sheet 5, opposite the absorbent core 4 from the horizontal surface of the absorbent core 4 to enable contact with each other in a flat shape 7.

0018 The mouth-covering portion 52 is positioned so as to completely cover the indicator area 61, in which the three indicator parts 6 (6a, 6b, 6c) are arranged in strips. More specifically, a three-layer structure (two layers of mouth-covering parts 52 and one layer of the bag-shaped part 51) is formed by a covering sheet 5, inserted between the indicator part 6 and the absorbent core 4. Thus, the indicator part 6 can be physically separated from the absorbent polymer 42 so that to minimize opportunities for contact between them. Specific examples of contact options include those where the absorbent polymer 42 is a fluid on the non-skin surface side of the absorbent core 4 in the bag portion 51 and the absorbent polymer 42 further extends beyond the absorbent body 3 to come into direct contact with indicator part 6. In addition, specific examples may include various possibilities for contact, such as when the trace amount of moisture contained in a fluid absorbent polymer 42 penetrates from the inside of the bag-like portion 51 through the cover sheet 5 to indirectly come into contact with the indicator portion 6. As the moisture contained in the absorbent polymer 42, there is a wide range of possible types, such as moisture introduced during the formation of the absorbent core 4, and moisture absorbed from atmospheric air. As a measure of counteracting such moisture contained in the absorbent polymer 42, the mouth covering portion 52 tightly clogs the mouth of the bag-shaped portion 51 in order to limit the absorbent polymer 42. In addition, the covering mouth portion 52 can be inserted between the indicator portion 6 and the absorbent core 4. to maintain the distance between the two parts. Thus, the possibilities for direct or indirect contact between the indicator portion 6 and the absorbent polymer 42 can be effectively minimized. As a result, unnecessary color change of the indicator portion 6, which differs from that during urine output, can be effectively prevented. In this way, unnecessary color changes that can cause the user to worry about hygiene or cause a misunderstanding regarding quality can be avoided.

0019 From the point of view of suppressing the possibility of direct contact due to leakage of the absorbent polymer 42 among the above contact possibilities, the indicator part 6 is preferably positioned as far as possible from the closing mouth of the outer end 53 in the form of a tip in the mouth closing parts 52 (see FIG. 3). More specifically, the ratio (t ₄ / t ₂ ) of length (t ₄ ) from the end of the indicator portion 6a to the closing mouth of the outer end 53 with respect to the length (t ₂ ) from the transverse center line C1 of the diaper 10 to the closing mouth of the outer end 53 (= the tip of the mouth covering portion 52) is preferably in the range of 0.25 or more, and more preferably in the range of 0.40 or more. Its upper limit is preferably in the range of 0.85 or less, and more preferably in the range of 0.70 or less. Thus, the indicator portion 6 can also be prevented from leaking the absorbent polymer 42 in order to make it possible to effectively suppress the possibility of being brought into contact with it.

In addition, from the point of view of suppressing the possibility of indirect contact (the possibility of contact with penetrating moisture) between the absorbent polymer 42 and the indicator part 6 through the cover sheet 5, it is preferable to arrange in which the indicator part 6 does not come into contact with the root mouth 54 closing near the border with the bag-shaped part 51 (see Fig. 3). More specifically, the ratio (t ₅ / t ₃ ) of length (t5) from the end of the indicator portion 6c to the outer end of the closing mouth of the root portion 54 with respect to the length (t3) from the transverse center line C1 of the diaper 10 to the outer end of the closing mouth of the root portion 54 preferably in the range of 0.25 or more, and more preferably in the range of 0.40 or more. Its upper limit is preferably in the range of 0.85 or less, and more preferably in the range of 0.70 or less. Thus, it is possible to effectively suppress the possibility of penetration of a trace amount of moisture through the root opening 54 closing the mouth, in which the absorbent polymer is easily concentrated in order to come into contact with the indicator part 6.

0020 From a similar point of view, as described above, the ratio (S ₁ / t ₁ ) of the transverse (X direction) length (s ₁ ) of the indicator area 61 in which the indicator portion 6 is located with respect to the transverse (X direction) length (t ₁ ) the mouth covering portion 52 (see FIG. 3) is preferably in the range of 0.15 or more, and more preferably in the range of 0.25 or more. Its upper limit is preferably in the range of 0.75 or less, and more preferably in the range of 0.65 or less. In addition, the ratio (s ₂ / t ₂ ) of length (S2) from the transverse center (= the center of the indicator portion 6b, and the transverse center line C1 of the diaper 10) of the indicator region 61 to the end portion of the indicator portion 6a with respect to the length (t ₂ ) before the closing mouth of the outer end 53 of the closing mouth of the part 52 (see FIG. 3) is preferably in the range of 0.15 or more, and more preferably in the range of 0.25 or more. Its upper limit is preferably in the range of 0.75 or less, and more preferably in the range of 0.65 or less. In addition, the ratio (s ₃ / t ₃ ) of the length (s ₃ ) from the transverse center (= the center of the indicator portion 6b and the transverse center line C1 of the diaper 10) of the indicator region 61 to the end portion of the indicator portion 6c with respect to the length (t ₁ ) to the outer end of the closing mouth of the root portion 54 of the closing mouth of the part 52 (see FIG. 3) is preferably in the range of 0.15 or more, and more preferably in the range of 0.25 or more. Its upper limit is preferably in the range of 0.75 or less, and more preferably in the range of 0.65 or less.

0021 In addition, from the point of view of reducing the likelihood of direct contact due to polymer leakage, it is possible to use another preferred embodiment of the closing mouth portion 52 folded as shown in FIG. 4. In FIG. 4, the mouth-closing outer end 53 is additionally folded on the side of the bag-shaped part 51. In one embodiment, the mouth-closing outer end 53 is hidden so that it is not open to the side of the lower sheet 2. In addition, the mouth-closing part 52 per se is helically twisted so that to form a geometric shape that is more resistant to leakage. In addition, a five-layer structure is formed from the cover sheet 5 between the indicator portion 6 and the absorbent core 4. Thus, it is further possible to effectively suppress the likelihood of both direct contact due to leakage of the absorbent polymer 42 and indirect contact due to moisture penetration, thus making this embodiment preferred.

0022 From the point of view of suppressing the above possibilities for contact in one embodiment, the closure of the mouth 52 is not fastened to the bag-shaped part 51 at a location other than the closure of the root of the root portion 54 and is formed in a suspended state. More specifically, the region between the mouth covering portion 52 and the bag-shaped portion 51 is not fully sealed and an air gap is formed (air layer 56). In the present invention, “fully bond” means that two opposing surfaces are fully bonded without a gap, and “not fully bonded” means that the opposite surfaces described above have a gap and are not glued. In the present invention, the state in which the mouth covering portion 52 and the bag-shaped portion 51 are not fully bonded is not limited to an embodiment in which the portions are not substantially fully bonded, as in one embodiment. For example, a hot-melt adhesive can be applied spirally and in this way an alternating bond form can be obtained that has an air gap without applying a solid. Thus, the penetration of traces of moisture in the absorbent polymer 42 can be avoided in order to enable timely penetration of the excreted urine. Also, from a similar point of view, the mouth covering part 52 is preferably formed in a suspended state, without fastening to the indicator part 6. Of course, even when the mouth covering part 52 is suspended, since it differs from simple lamination of the elements, the mouth covering part 52 is connected with a bag-shaped part 51 in the closing mouth of the root part 54 and fixed on it. Thus, the combination with the indicator part 6 is unlikely to occur, thereby making possible effective protection against unnecessary color change of the indicator part 6 due to an event other than urination.

0023 In one embodiment, the mouth covering portion 52 has the structure described above, and thus an air layer 56 is formed between the covering mouth portion 52 and the bag-shaped portion 51. The intermediate air layer 56 blocks the migration of any trace amount of moisture for migration in the thickness direction by capillary forces between the fibers of the cover sheet 5 to make it difficult for moisture to penetrate to the indicator portion 6. The air layer 56 is a space formed due to the fact that the cover the mouth of the root portion 54 is slightly raised by turning the parts so that they are facing each other, and other parts of the closing mouth of the portion 52 are not fully adhered to the bag-shaped part 51. Therefore, the air layer 56 is relatively easy to maintain, regardless of the storage state before use to exhibit an effect that is difficult to achieve by simply stacking three items in a stack. Even if the mouth-covering part 52 is partially brought into contact with the bag-shaped part 51, the two-layer covering sheet 5 in the closing mouth of the part 52 serves as a double barrier to the trace amount of moisture contained in the polymer. On the other hand, when a large amount of the emitted fluid migrates, the emitted fluid can, as usual, quickly reach the indicator portion 6 in the air layer 56, which is micro-space. Thus, the main function of the indicator part 6 is to display a timely indication of when to change the diapers. As described above, the mouth-covering portion 52 in the diaper 10 exhibits an excellent effect and suppresses the penetration of the trace amount of moisture contained in the absorbent polymer 42 before use, and allows moderate penetration of the released fluid after use.

0024 In addition, in one embodiment, the opening of the mouth portion 52 is not fixed to the bag-shaped portion 51 and the indicator portion 6 in a portion other than the closing mouth of the root portion 54, and therefore is formed so as to move relatively easily. This form acts to further suppress the possibility of contact with moisture in the absorbent polymer 42 in the indicator portion 6. This item is described with reference to FIG. 5 and 6.

0025 The mouth covering portion 52 is suspended without being fastened to the bag-shaped portion 51 in the longitudinal direction (X direction), as shown in FIG. 5. Therefore, it is difficult to influence the closing mouth portion 52 by the stiffness of the thick absorbent core 4 on a wide surface other than the root mouth covering the mouth 54. As a result, even if an external force is applied to the absorbent body 3 and the absorbent core 4 is going to deform, on the closing mouth part 52 is generally difficult to influence, and the above action continues, even with the deformation of the diaper 10.

0026 In contrast, in the absorbent body 81 in the standard diaper 80, as shown in FIG. 6, the cover sheet 83 forms a fastening portion 83c in order to wrap the absorbent core 82 with partial overlaps, and combine them. More specifically, the entire bonding surface (bonding portion 83c) of both end parts 83a and 83b of the covering sheet 83 forms a portion of the bag-shaped portion 84. Therefore, the bonding portion 83C directly perceives the stiffness of the thick absorbent core 83. At this point, the diaper 10 according to one embodiment is significantly different from standard diaper 80 or the like.

For example, the diaper is generally doubled along the longitudinal center line C2 or tripled along the longitudinal dividing lines D1 and D2 and enclosed in a packaging bag in the form of a large number of diapers that are compressed. In this case, the bending force on the side of the skin contacting surface acts on the absorbent core 4 along the double fold line C2 or the triple fold lines D1 and D2 as a shear force to peel the fastening portion 83C (arrow directions in FIG. 5 and FIG. 6 (B)).

0027 In the standard diaper 80 shown in FIG. 6, wrapping the partially overlapping fastening part 83C may accidentally leak the absorbent polymer inside the absorbent body 3 from the peeled part of the fastening part 83C outside the absorbent body to come into direct contact with the indicator part 6. In addition, even inside the absorbent body, the fluid absorbent polymer 42 may be accidentally brought into indirect contact with the indicator portion through a cover sheet on a surface side not in contact with the skin. As indicated above, if the absorbent polymer 42 contains moisture, the indicator portion leads to the initiation of a color change even without urination or the like. This situation still easily arises with a decrease in the thickness of the fibrous material and an increase in the amount of absorbent polymer to reduce the absorbent article. If a moisture-containing absorbent polymer is brought into direct or indirect contact with the indicator portion, a spotty ultramicro-change of color occurs. As a counter measure, an increase in the laminated element or an increase in the amount of adhesive used to prevent leakage of the absorbent polymer can, on the contrary, suppress the rapid color change of the indicator portion 6 during urination.

0028 In contrast, as indicated above, the diaper 10 according to one of the options for avoiding unnecessary color change of the indicator part 6 and makes it possible to timely and quick color change when urinating in the combination of the bag-shaped part 51 and the mouth covering part 52 connected to its external part.

In addition, it is difficult to directly affect the mouth opening portion 52 by an external force acting on the absorbent core 4. Most of the mouth closing portions 52 are in a suspended state from the bag-shaped portion 51, and therefore it is difficult to block them with the absorbent core 4. As a result, it is difficult for the direct shear force to act on the fastening part between opposing surfaces 5c and 5d in the closing mouth of the part 52, and peeling is difficult. In addition, the mouth-closing part 52 is fixed on the bag-shaped part 51 in the closing mouth of the root part 54, and therefore, placement mismatch is difficult. This operation further reduces the possibility of contact between the indicator portion 6 and the absorbent polymer 42, and the above-described action also continues even when the diaper 10 is deformed during use. The action of the diaper 10 according to the embodiment includes an excellent effect, which is difficult to achieve with a standard absorbent body 81 that is susceptible to external force.

0029 Further, from the point of view of suppressing the above possibility of contact, a preferred embodiment of fastening for the closing mouth portion 52 and the indicator portion 6 is described with reference to FIG. 3.

First, the indicator portion 6 is preferably immobilized on the back sheet 2 in order to prevent the color indicator from being impregnated towards the absorbent body. If the color indicator is impregnated, for example, in the closing mouth portion 52, the distance from the absorbent polymer 42 is reduced, which increases the possibility of contact and, thus, this case is unfavorable. Therefore, the indicator portion 6 is preferably formed from a hot-melt composition containing a mixture of the color indicator described above and a pressure sensitive adhesive. The color indicator described above is immobilized on the used surface by the pressure sensitive adhesive described above, thereby making it possible to prevent infiltration into the absorbent body. Then, the hot melt composition described above is preferably laminated with an absorbent body 3 in a state deposited on the bottom sheet 2 and cured by cooling or the like. In this way, the flow properties of the above-described pressure sensitive adhesive substance per se are also suppressed, and the impregnation of the above-described color indicator on the side of the absorbent body 3 occurs with even greater difficulty. Preferred steps for forming the indicator portion 6 and a preferred component of the composition described above are described below.

0030 The end portions 5a and 5b (see FIG. 3) of the cover sheet 5 are preferably fastened as constituents of the cover mouth portion 52 as described below. The mouth-covering portion 52 should close the mouth of the bag-shaped portion 51 to prevent leakage of a trace of the moisture-containing absorbent polymer 42 to the outside even if such absorbent polymer 42 is separated from the fibrous material 41 and is fluid. Therefore, both end portions 5a and 5b are preferably tightly fastened without a gap and without peeling even under the influence of an external force before use (for example, during packaging or when the diaper 10 is put in or taken out when using it). However, on the other hand, the mouth-covering portion 52 should allow fluid, such as urine to be released, to penetrate from the absorbent core 4 in a timely manner to reach the indicator portion 6. Therefore, the end portions 5a and 5b of the covering sheet 5 are preferably fastened, for example, by adjustment the applied amount of hot-melt adhesive 52a, to the extent of preventing leakage of the absorbent polymer 42, preventing the penetration of traces of moisture in the absorbent polymer and facilitating the penetration of pain th the amount of fluid, such as urine is released. From this point of view, the bulk of the hot-melt adhesive applied between the end portions 5a and 5b of the cover sheet 5 is preferably in the range of 1.0 g / m ² or more, and more preferably in the range of 2.0 g / m ² or more. Its upper limit is preferably in the range of 10.0 g / m ² or less, and more preferably in the range of 5.0 g / m ² or less. As a bonding method using a hot-melt adhesive, the whole bonding method and striping can be applied by a contact type coating method, such as using a slotted coating device, applying an alternating pattern, such as a spiral pattern, or the like.

0031 In addition, even hot-melt adhesive 52a, which has a bulk identical to the bulk described above, allows additional strong fixation by applying adhesive 52 on surfaces 5c and 5d, opposite the end parts 5a and 5b of the covering sheet 5 (see FIG. 3 ), respectively, thereby causing tension of the mutual surfaces by means of a pressure-sensitive adhesive force. Both surface application methods are preferred in terms of both preventing polymer leakage and penetration of the fluid, as described above. In addition, hot-melt adhesive 52a applied between opposing surfaces 5c and 5d may differ in the bulk to be applied over the closing mouth of the outer end 53 and the closing mouth of the root portion 54 and the indicator contact portion 55 (see FIG. 3 and 4) between them. For example, from the point of view of preventing leakage of the absorbent polymer 42, the applied bulk at the closing mouth of the outer end 53 and that of the closing mouth of the root portion 54 can be further increased, and from the point of view of penetration of the excreted urine, the applied bulk of the indicator contact portion 55 may be less such a covering mouth of the outer end 53 and such a covering mouth of the root portion 54. Specific examples include applying an alternating coating, such as a coating with a spiral pattern m for the indicator contact portion 55, and in fact a continuous coating, such as the coating of a slotted coating device, a sprayed coating and a coating applied by irrigation, for the closing mouth of the outer end 53 and the closing mouth of the root part 54.

0032 In addition, in order to suppress the penetration of traces of moisture into the absorbent polymer 42 in order to cause a timely color change of the indicator part 6 by the penetration of the fluid through urination, the fiber density of the covering sheet 5 is preferably in the range of 0.05 g / cm ³ or more and 0.2 g / cm ³ or less and more preferably in the range of 0.1 g / cm ³ or more and 0.2 g / cm ³ or less. Correction to the lower limit or more described above allows the covering sheet 5 to be durable in order to prevent leakage during use, and adjusting to the upper limit or less allows the passage of a suitable fluid without undue delay.

0033 (Method for measuring density)

The cover sheet 5 is cut 50 mm long and 5 mm wide in order to obtain samples. The mass of each sample is then measured using an electric balance (GR-300 manufactured by A&D company, Limited, accuracy: 4 decimal places). The thickness of the sample is measured using a thickness meter with a constant pressure and the mass of the measured sample is divided by the volume of the sample (thickness × length × width) in order to calculate the density of all the material in place in each area. The measurement is performed by constant-pressure thickness meter at 0.5 g / ^cm2. The average density is obtained using the average of ten samples obtained in arbitrary parts.

0034 In addition, also the hot-melt adhesive 52a to be applied to the closing mouth portion 52 is preferably cured by cooling or the like in the preliminary step of the assembly of the elements of the diaper 10 in a manner similar to the curing of the composition of the indicator portion 6 mentioned above. More specifically, the diaper is preferably collected in a state in which the fluidity of both hot melt agents is lost. Thus, in the opening of the mouth portion 52, the gap between the fibers is filled to a certain extent by curing the hot-melt adhesive 52a, and the hot-melt composition of the indicator portion 6 becomes solid for impregnation therein. In addition, in the indicator portion 6, the hot melt composition is cured to make it difficult to penetrate even into a small space between the fibers of the mouth of the mouth 52, and the gap between the fibers is moderately maintained. As a result, the distance between the mouth covering portion 52 and the indicator portion 6 is maintained, and the possibility of contact with a trace amount of moisture can be effectively suppressed.

0035 In addition, specific examples of embodiments of fastening elements to suppress the above possibility of contact due to leakage of the absorbent polymer 42 include an embodiment of fastening the bag-shaped portion 51 near the closing mouth of the root portion 54 with the absorbent core 4 using hot-melt adhesive 44 (see FIG. . 3). In one embodiment, the connecting portion to the mouth-closing portion 52 in the bag-shaped portion 51 is additionally forcibly sealed to enable additional effective prevention of leakage of the absorbent polymer 42, and such an embodiment is preferred. Furthermore, according to an embodiment, the absorbent polymer 42 is difficult to concentrate in the closing mouth of the root portion 54 in order to suppress the occurrence of moisture penetration, and therefore such an embodiment is preferred.

0036 Similarly, the mouth-closing outer end 53 and the mouth-closing root portion 54 of the mouth-closing part 52 are preferably bonded to the bottom sheet 2 using hot-melt adhesive 21 longitudinally in the form of a strip. Thus, leakage of the absorbent polymer 42 and the penetration of moisture into the absorbent polymer 42 can further be effectively suppressed. On the other hand, although the indicator contact part 55 of the closing mouth portion 52 and the indicator part 6 are not fastened, the mouth closing outer end 53 and the mouth closing root part 54 are fixed on the back sheet 2. Therefore, the location relationship between the indicator contact part 55 and the indicator part 6 difficult to break, and from the point of view of preventing unnecessary color changes of the indicator part 6, such an embodiment is preferred. In this case, even if the part of the mouth covering part 52 is fastened to the bottom sheet 2, the mouth covering part 52 is combined with the flexible bottom sheet 2, since it differs from the thick absorbent core 4, also in suspension, on the bag-shaped part 51, and the rigidity of the absorbent core 4 difficult to perceive, and therefore such a case is preferred. In addition, although not shown, a plurality of strips of hot-melt adhesive can be intermittently applied across the outside of the hot-melt adhesive 21 in parallel with this in order to bond the bag-like portion 51 to the bottom sheet 2.

0037 In addition, in the diaper 10, as an aid to the action of the opening of the mouth portion 52, the diaper 10 may have an absorbent core 4, as shown in FIG. 7, 8-1 and 8-2.

In the absorbent body shown in FIG. 7, the absorbent core 4 is formed from a layer 45 of a mixture of fibrous material 41 and an absorbent polymer 42, and a filter layer 46 consisting of only fibrous material. The one-component layer 46 is disposed on the side of the surface not in contact with the skin. Thus, the absorbent polymer 42 is difficult to peel off in place between the side of the non-skin surface of the absorbent core 4 and the bag-like portion 51 (covering sheet). Thus, the aforementioned action of the closing mouth of the part 52 can further be effectively enhanced. In addition, although not shown, the formation of a three-layer structure, in which a layer consisting of only absorbent polymer 42, is vertically inserted between layers consisting of only fibrous material, also allows you to enhance the above effect of the covering mouth portion 52, and, therefore, such a structure is preferred.

0038 Absorbent 3 shown in FIG. 8-1 has an absorbent core 4 in which two strips of slotted portions 43 and 43 are formed in the longitudinal direction (Y direction) in the part corresponding to the crotch portion C (see FIG. 8-1 (A)). The slit portion 43 penetrates from the non-cutaneous surface side to the skin surface side of the absorbent core 4. In the diaper with the absorbent body 3, as shown in FIG. 8-1 (B), the amount of absorbent polymer 42 located in the crotch portion C is reduced in order to suppress unnecessary color changes in the part in which the color change is most likely to occur during urination. In addition, the diaper has excellent fluid permeability during urination in the slit portion 43 of the crotch portion C, and the color of the indicator portion 6 is timely changed. From a similar point of view, as a modified example of the absorbent body 3, the absorbent body 3 can also be formed in one of the embodiments of the presence, without penetrating the slit 43, of a portion of the absorbent material of a thin form on the side of the skin surface, as shown in FIG. 8-2. The case of the absorbent shown in FIG. 8-2 is also preferred in view of the efficient flow of fluid on the side of the skin contact surface within the absorbent body in order to make it possible to effectively suppress the remainder of the fluid and the backflow of the fluid.

0039 The following describes a method for producing an absorbent article in accordance with the present invention based on a method for producing a folding type disposable diaper 10 according to one embodiment, with reference to FIG. 9 and 10.

First, the step of forming the absorbent body 201 is described. The absorbent core 4 is obtained using a drum 91 to form clusters of fibers and a channel 92. In particular, a suction fan (not shown) is started inside the drum 91 to form clusters of fibers, a suction force is generated in the concave portion for the cluster (not shown) on the outer surface of the drum 91 to form clusters of fibers, and an air stream flowing to the peripheral surface of the drum 91 to form clusters of fibers is generated channel 92. Subsequently, the fibrous material 41 is introduced from its inlet 93 into the channel 92 so as to disperse the material and simultaneously the absorbent polymer 42 is introduced from its inlet 94. The fibrous material 41 and the absorbent polymer 42 are dispersed in the direction of the outer surface of the rotary drum 91 to form clusters of fibers, and deposition on the concave portion for clusters. In this way, an absorbent core 41 is formed. Subsequently, the absorbent core 4 on the outer surface of the drum 91 is released onto the raw material covering sheet 59, which is continuously fed to the vacuum conveyor 96, to form clusters of fibers.

0040 Subsequently, both ends (both ends in CD (transverse direction)) of the raw material cover sheet 59 are lifted and rotated so that they face each other. This point is described with reference to FIG. 10. In FIG. 10 is a cross-sectional view of an absorbent core 4 and a raw material covering sheet 59. FIG. 10 (a) shows the state before the absorbent core 4 is coated with the raw material cover sheet 59. In this state, both ends 59a and 59b of the raw material cover sheet 59 are raised over the absorbent core 4 in order to cover the side surfaces and the upper surface (the surface serving as the side the non-skin surface of the absorbent body) of the absorbent core 4. Then, the left-right ends 59a and 59b of the raw material covering sheet 59 are aligned in the form of raised ends with respect to the absorbent core 4 ( m. FIG. 10 (b)). Sometimes, the transverse length of the raw material cover sheet 59 is made longer than the peripheral length in the cross section of the absorbent core 4, and therefore an extra length is generated at the end parts 59a and 59b of the working roll 59 of the raw material cover sheet. Subsequently, the additional long parts of the raw material cover sheet 59 are rotated so that they face each other in the form of raised parts relative to the absorbent core 4, a hot melt or the like is applied to both surfaces of the end parts 59a and 59b, and both surfaces are fastened and combined (fastening the part at this stage is designated as part 58, rotated so as to face each other). Thus, a bag-shaped part 51 is formed which has a closed mouth (see FIG. 10 (c)). Subsequently, part 58 is folded at the base point 57 of the bend, and thus, a mouth covering part 52 is formed along the bag-shaped part 51 (see FIG. 10 (d)).

0041 At the stage of forming the absorbent body 201 according to one of the embodiments, both end parts 59a and 59b of the raw material covering sheet 59 are lifted and combined, and therefore, the bag-shaped part 51 can be forced clogged. In addition, the lift makes it possible to force the application of hot-melt adhesive or the like on both end parts 59a and 59b. More specifically, with the continuous formation of the absorbent body, the lifting avoids risk, for example, fluctuation of the elements and misalignment during continuous transport on the conveyor 96, so as to align sufficiently along the raw material covering sheet 59 and the absorbent core 4, which is continuously transported, thereby making it possible to force the clogging of the absorbent core 4. As a treatment tool for raising, an upward folding fold can be used -governing.

In addition, an important point in the formation of the closing mouth of the part 52 is to provide the closing mouth of the part 52 with a width and an arrangement that sufficiently enables coating of the indicator area 61 in a subsequent step (lamination step 203 (see FIG. 9)) to accommodate the absorbent body 3 on the back sheet 2. This moment can be achieved by adjusting the bend base point 57 and the length (q) of the part 58, turned so as to face each other, and it can be easily controlled by raising general processing. Thus, the mouth-covering portion 52 can completely cover the indicator area 61, while avoiding the mouth-closing outer end 53 and the root-mouth covering the mouth 54. Then, as shown in FIG. 3, this formation makes it possible to achieve equal width from right to left (t ₂ = t ₃ ) from the transverse center line C1 (= center line of the diaper 10) of the absorbent body 3. In addition, in the subsequent lamination step 203, the transverse center line of the absorbent body 3 is adjusted so that it coincides with the transverse center line (= the center line of the diaper 10) of the raw material bottom sheet 29, thereby making it possible to achieve a preferred ratio with the transverse length (s ₁ , s ₂ , s ₃ ) of the indicator portion, as described above. Therefore, the bend base point 57 is positioned in a position deviated from the transverse center of the absorbent core 4. In addition, to make it possible to rotate the parts so that they are facing each other, with the required length at the end parts 59a and 59b, even if the base point 57 fold offset, use the raw material covering sheet 59, which has a sufficient width. In addition, when forming the opening of the mouth portion 52, the absorbent core 4 can be placed close to the transverse center of the raw material cover sheet 59 so as to cut off the excess end part of the raw material cover sheet 59 while turning the parts so that they face each other. Alternatively, bearing in mind the base point 57 of the bend, the absorbent core 4 can be placed in a position offset from the transverse center of the working roll 59 of the covering sheet in order to form a covering mouth 52.

0042 In addition, in the step of forming the absorbent body 201, the absorbent body 3 is obtained by applying, in random order, a curing step using a coolant 95, hot-melt adhesive or the like applied during the formation of the closing mouth portion 52, the cutting step of the raw material coating sheet 59 to a predetermined length (length in MD (machine direction)) and a pressing step (not shown). The resulting absorbent body 3 is vertically inverted and transferred to conveyor 97. Curing of the hot-melt adhesive at this point in time makes it possible, in the lamination step 203, as a subsequent step, suppressing the impregnation of the composition of the indicator part 6 in order to suppress the above possibility of contact with the indicator part 6 due to moisture penetration and, therefore, such curing is preferred. Specific examples of coolant 95 include air blasting (blown air) (similar to coolant 99 indicated above).

0043 The following describes the stage 202 of the formation of the indicator part. First, the raw material bottom sheet 29 is continuously transported from the working roll 29a of the lower sheet obtained by winding the long raw material bottom sheet 29, and using the indicator coating means 98, the indicator composition is applied in the vicinity of the transverse (CD) center of the raw material bottom sheet 29. B in one embodiment, the indicator composition is formed from a hot-melt composition containing a mixture of a color indicator and pressure-sensitive adhesive material, and an appar can be used at a slotted coating apparatus, a spray coating apparatus, an irrigation coating apparatus, or the like. Subsequently, a cooling medium 99 is used to cure the applied hot-melt composition and thus form an indicator part 6. Curing the hot-melt adhesive suppresses, at the lamination step 203, as a subsequent step, impregnation of the hot-melt composition into the mouth covering part 52 in order to make it possible to suppress the above possibility of contact with the indicator part 6 due to moisture penetration, and therefore, such curing is preferred solid. In addition, the step of forming the indicator portion 202 and the step of forming the absorbent body 201 are essentially applied separately. As long as the hot melt means in the closing mouth portion 52 and the indicator portion 6 is sufficiently cured before the lamination step 203 as a subsequent step, the order is not limited, and both steps can be used in parallel.

0044 The following describes the lamination stage 203 for placing the absorbent body 3 on the raw material bottom sheet 29 to be bonded. First, on the raw material bottom sheet 29, on which the indicator portion 6 is formed, a hot-melt adhesive for bonding to the absorbent body 3 is applied along the longitudinal direction (MD direction, using the hot-melt adhesive applying means 100). The hot-melt adhesive is intermittently applied in the transverse outward direction in the form of a plurality of strips without overlapping with the indicator part 6 to go parallel to it. Sometimes, the hot-melt adhesive is preferably positioned at least in positions in contact with the mouth opening of the outer end 53 and the mouth covering the root portion 54 of the absorbent body 3. Thus, the above possibility of contacting the absorbent polymer 42 with the indicator part 6 can be further effectively suppressed. Then, before the hot-melt adhesive is cured, the absorbent body 3 is placed and fastened. Occasionally, the absorbent body 3 is positioned to allow the transverse center line of the absorbent body 3 to coincide with the transverse center line of the raw material bottom sheet 29, and in order to cover the indicator portion 6 with the mouth covering portion 52.

0045 Then, on the above-described laminate of the bottom sheet 2 and the absorbent body 3, the necessary elements are laminated and attached, such as the top sheet 1, the side sheet 7, the outer sheet 8 and the elastic elements 13, 71 and 73, to cut the resulting material to the desired size and geometric form, thereby obtaining a diaper 10. In addition, lamination, bonding and cutting of each element can be carried out by applying the method applied to the method of obtaining this type of product and in accordance with the usual stage.

0046 Preferred materials forming the elements that form the diaper 10 in one embodiment are described below.

As the materials forming the absorbent body 3, those that are typically used for the absorbent article can be used. For example, as the fibrous material 41 forming the absorbent core 4, it is possible to use hydrophilic natural fibers, synthetic fibers (preferably subjected to hydrophilizing treatment), and so on, for example, fibrous material. Although the bulk is not particularly limited, it is preferably 150 g / m ² or more and 500 g / m ² or less. As the absorbent polymer 42, various types of polymeric materials, typically used for products of this type, can be used. The absorbent polymer 42 is preferably a superabsorbent macromolecular compound that can absorb and retain water or physiological saline that is 20 or more times its own weight. In addition, as the covering sheet 5, for example, thin paper (sanitary paper), such as hydrophilic sanitary paper, non-woven fabrics formed from hydrophilic fibers such as cotton and rayon, non-woven fabrics formed from fibers can be used from synthetic resins that have been hydrophilized (composite non-woven materials such as SMS, SMMS and SSMS).

0047 As a color indicator to be incorporated into a hydrophilic composition forming indicator part 6, an indicator that changes color at pH 3 or more and 7 or less is preferred, and specific examples thereof include bromophenol blue, methyl orange, alizarin S, bromocresol green, methyl red and bromocresol purple, but not limited to this. Specific examples of its particularly preferred color indicators include bromophenol blue, bromocresol green, and bromocresol purple. These color indicators are embedded in it preferably in the range of 0.01% by mass or more and 50% by mass or less, more preferably in the range of 0.01% by mass or more and 40% by mass or less, even more preferably in the range 0.01% by mass or more and 1% by mass or less and most preferably in the range of 0.01% by mass or more and 0.5% by mass or less based on the total amount of the hydrophilic composition. If the amount of the color indicator is less than 0.01% by weight, the color is dull even after a color change is caused, and sometimes it is difficult to visually recognize from the outside. If the amount exceeds 50% by weight, the color before the color change of the hydrophilic composition is too deep, the appearance is poor and the cost sometimes also increases, and therefore, the amount is preferably adjusted within the range described above.

In addition, as a pressure-sensitive adhesive material mixed with a color indicator, specific examples include a hydrophilic polymer that functions as an adhesive. Specific examples of the hydrophilic polymer include polyethylene glycol (PEG), polypropylene glycol (PPG), polyvinyl alcohol (PVA), polyamide and a vinyl pyrrolidone homopolymer. The number average molecular weight of these hydrophilic polymers is preferably in the range of 1000 to 50,000, and particularly preferably in the range of 2000 to 20,000 due to forced immobilization. A hot-melt composition containing a mixture of pressure-sensitive adhesive material and a color indicator is applied as a component, thereby immobilizing the color indicator on the back sheet 2 accordingly.

0048 In addition, in the diaper 10 of one embodiment, the hydrophilic composition forming the indicator portion 6 may include a wet indicator composition described below. Thus, self-staining, color removal, color spots or the like can be prevented by absorbing moisture or the like. In particular, the hot melt composition described above contains: 0.1% by mass or more and 5% by mass or less of a pH indicator (a) that is substantially colorless at pH 7 to develop color in the acidic region; 20% by weight or more and 90% by weight or less of a glycerol ester of a fatty acid (b), which has a surface-active effect; 20% by mass or more and 35% by mass or less of polyalkylene glycol (c); 0% by mass or more and 70% by mass or less of a polymer (d) that has a carboxyl group; and 0.1% by mass or more and 5% by mass or less of acidic material (e) other than (b) and (d). In more detail, the hot-melt composition can be formed using the component and using the application method, as described in paragraphs [0014] to [0039] in JP-A-2009-247409.

0049 In addition, from the point of view of avoiding discoloration due to a fluid other than urinary excretion, such as traces of moisture, in the hydrophilic composition, the acidic compound described in JP-B-3558828 can be incorporated in which the acidic compound makes it possible maintaining the pH of the hydrophilic composition, and also keeping the pH below 4 by pure contact of the hydrophilic composition with water, or a water-soluble compound that is alkaline if the compound is dissolved in moisture can be embedded in the bottom sheet 2. The hydrophilic composition described above may contain an antioxidant, an ultraviolet absorber or the like, in addition to the above component. The components are preferably contained in the range of 0.5% by mass or more and 5% by mass or less and more preferably in the range of 0.5% by mass or more and 3% by mass or less, based on the total amount of the hydrophilic composition.

0050 As materials forming the top sheet 1, the bottom sheet 2 and the side sheet 7, you can use those that are usually used for an absorbent product.

As the top sheet 1, for example, a hydrophilic non-woven material is preferred, and as a hydrophilic non-woven material, non-woven materials called breathable non-woven material, dot bonded non-woven fabric, melt non-woven fabric, hydro-woven non-woven fabric and three-dimensional non-woven fabric can preferably be used. in which its fibers are polypropylene monofilaments, connected fibers of polypropylene and polyethylene and connected fibers of polyethylene terephthalate and polyethylene, which was subjected to a hydrophilizing treatment, and can be preferably used those in which the bulk of 15 g / m ² or more and 50 g / m ² or less. Specific examples of the nonwoven fabric described above or its constituent fibers can be used alone or in combination of two or more types thereof. In addition, in the crotch region of the top sheet 1, the hydrophilic film with holes and the hydrophilic non-woven material may partially overlap on the surface side in contact with the skin of the top sheet 1.

0051 The materials forming the bottom sheet 2 are not particularly limited as long as it has a water-repellent property and is moisture permeable. An example is a porous film obtained by mixing a melt of a hydrophobic thermoplastic resin and a small inorganic filler containing calcium carbonate or the like, or an organic polymer that is not compatible and the like, in order to form a film and stretch the film on one axis or two axes. Examples of thermoplastic resins may include polyolefins. Examples of polyolefins may include high and low density polyethylenes, linear low density polyethylenes, polypropylene, polybutene, and the like, and can be used alone or by mixing.

0052 It is preferable to use, for example, a water-repellent nonwoven material for the side sheet 7, and in particular, melt nonwoven fabric, meltblown nonwoven fabric (SM), spunbond-meltblown-spunbond non-woven fabric (SMS), and etc. In addition, as the elastic elements 71 and 72 located in the side sheet 7, and the elastic element 13 forming the assembly at the waist, you can use the usual elastic element used for products of this type. Examples of such elastic materials include synthetic rubbers such as styrene-butadiene, butadiene, isoprene and neoprene, natural rubber, EVA, elastic polyolefins and polyurethane. Forms of elastic elements preferably include a thread or string (flat rubber) with a rectangular, square, round or polygonal cross-section or multifilament yarn.

0053 As described above, the absorbent article of the present invention exhibits an excellent effect of preventing contact between the absorbent polymer and the indicator portion in order to make it possible to suppress unnecessary color changes while maintaining the performance of rapid color changes during urination. The method for producing an absorbent article of the present invention exhibits an excellent effect of producing an absorbent article to accordingly make it possible to suppress an unnecessary color change while maintaining the color change performance.

0054 In the absorbent article of the present invention, the position and limits (= the limits of the indicator region 61) in plan view of the indicator part 6 can be arbitrarily determined as long as forced contact with the fluid and visibility of the color change are ensured. The geometric shape, size and number of each indicator part 6 can also be arbitrarily selected based on the above point of view, and the device of the closing mouth part 52 can be set in accordance with the device of the indicator part 6. In addition, the geometric shape of the absorbent body 3 is not particularly limited, and the surface may be in the form of a block or a slot may be provided in it. The absorbent article of the present invention is not limited to a folding type disposable diaper according to one embodiment, may be a pants type disposable diaper, a urine pad, a sanitary nappy, a panty liner and a moderate incontinence pad.

0055 With respect to the above embodiments, the present invention further discloses absorbent articles and methods for its preparation are described below.

<1> An absorbent article that contains a top sheet located on the side of the surface in contact with the skin, a bottom sheet located on the side of the surface not in contact with the skin, and an absorbent body located between both sheets,

moreover, the indicator part, the color of which visually changes when it comes in contact with the fluid, is placed between the bottom sheet and the absorbent body, and the absorbent body contains an absorbent core that contains fibrous material and an absorbent polymer, and a covering sheet that covers the outer surface of the absorbent core,

moreover, the covering sheet has, in the form of a cross-section of the absorbent body, a bag-shaped part that covers the area from the side of the surface in contact with the skin to the side of the surface not in contact with the skin, the absorbent core, and the mouth covering part connected to the bag-shaped part and located outward from it, and forming a mouth covering part in which both transverse end parts of the covering sheet are located on the side of the surface not in contact with the skin absorbing the heart zevins, fasten in a state in which they are turned so that they are facing each other and are folded, and

moreover, the mouth covering part is positioned so as to completely cover the area in which the indicator part is located, and the mouth covering part and the bag-shaped part are partially connected.

0056 <2> An absorbent article according to the above <1>, wherein the mouth covering part is connected to the bag-shaped part in the root mouth covering mouth.

<3> An absorbent article according to the above <1> or <2> in which the mouth covering portion is not fastened to the indicator portion.

<4> An absorbent article according to any one of the above from <1> to <3>, wherein the closing mouth portion is fastened to the bottom sheet in the outer end portion of the covering mouth portion and the root portion of the covering mouth portion.

<5> An absorbent article according to any one of the above from <1> to <4>, wherein the bag-shaped portion near the root portion of the mouth covering portion is fastened to the absorbent core.

<6> An absorbent article according to any one of the above from <1> to <5>, in which the place between the mouth covering part and the bag-shaped part is in a state of alternating bonding, which has a gap due to the spiral application of hot-melt adhesive.

<7> An absorbent article according to any one of the above from <1> to <6>, in which the absorbent core has a filter layer not containing an absorbent polymer, and a layer of a mixture of fibrous material and an absorbent polymer that is disposed on its surface side, in contact with skin.

<8> An absorbent article according to any one of the above from <1> to <7>, wherein the indicator portion contains a hydrophilic composition that contains a color indicator that changes color due to a change in pH.

<9> An absorbent article according to any one of the above from <1> to <8>, in which the indicator portion contains a hot-melt composition that contains a mixture of a color indicator that changes color due to a change in pH, and a pressure sensitive adhesive material, and the indicator portion is cured to prevent the hot melt composition from entering the coating sheet.

<10> An absorbent article according to any one of the above from <1> to <9>, wherein a ratio t ₄ / t _{2 of} length t ₄ from the end of the indicator portion to the closing mouth of the outer end with respect to the length t ₂ from the transverse central the line of the absorbent article to the closing mouth of the outer end is in the range of 0.25 or more and 0.85 or less, and preferably in the range of 0.40 or more and 0.70 or less.

<11> An absorbent article according to any one of the above from <1> to <10>, wherein the ratio s ₁ / t _{1 of the} transverse length s _{1 of the} indicator region in which the indicator portion is positioned with respect to the transverse cover length t ₁ the mouth of the part is in the range of 0.15 or more and 0.75 or less and preferably in the range of 0.25 or more and 0.65 or less, and the ratio s ₂ / t _{2 of} length s ₂ from the transverse center of the indicator area to the end part indicator part with respect to the length t ₂ from the transverse center of the indicator area to the closing mouth of the outer end of the closing mouth of the part is in the range of 0.15 or more and 0.75 or less, and preferably in the range of 0.25 or more and 0.65 or less.

<12> An absorbent article according to any one of the above from <1> to <11>, in which both transverse end portions of the coating sheet are bonded by applying a hot-melt contact means, and the bulk of the hot-melt adhesive applied is in the range of 1.0 g / m ² or more and 10.0 g / m ² or less, and preferably in the range of 2.0 g / m ² or more and 5.0 g / m ² or less.

<13> An absorbent article according to any one of the above from <1> to <12>, in which the fiber density of the coating sheet is in the range of 0.05 g / cm ³ or more and 0.2 g / cm ³ or less and preferably in the range of 0.1 g / cm ³ or more and 0.2 g / cm ³ or less.

<14> An absorbent article according to any one of the above from <1> to <13>, in which the indicator portion comprises a hydrophilic composition comprising a color indicator that changes color due to a change in pH, and a color indicator contained in the hydrophilic composition, represents any one of bromophenol blue, methyl orange, alizarin S, bromocresol green, methyl red and bromocresol violet, which change color at a pH in the range of 3 or more and 7 or less.

<15> An absorbent article according to any one of the above from <1> to <14>, in which the indicator portion contains a hydrophilic composition that contains a color indicator that changes color due to a change in pH, the color indicator is in the range of 0.01 % by mass or more and 50% by mass or less, preferably in the range of 0.01% by mass or more and 40% by mass or less, and most preferably in the range of 0.01% by mass or more and 0.5% by mass mass or less, based on the total amount of the hydrophilic composition.

<16> An absorbent article according to any one of the above from <1> to <15>, in which the indicator portion contains a composition that contains: 0.1% by weight or more and 5% by weight or less than a pH indicator (a ), which is essentially colorless at pH 7 to develop color in the acid range; 20% by weight or more and 90% by weight or less of a glycerol ester of a fatty acid (b), which has a surface-active effect; 20% by mass or more and 35% by mass or less of polyalkylene glycol (c); 0% by mass or more and 70% by mass or less of a polymer (d) that has a carboxyl group; and 0.1% by mass or more and 5% by mass or less of an acidic substance (e) other than (b) and (d).

<17> An absorbent article according to any one of the above from <1> to <16>, in which the top sheet is a hydrophilic non-woven material and contains one type individually or a combination of two or more types selected from breathable non-woven material, non-woven material with point bonding, melt nonwoven fabric, hydrowoven nonwoven fabric and three-dimensional nonwoven fabric, nonwoven fabric fibers contain one type separately or a combination of two or more types selected from fittings fibers of polypropylene conjugate fiber of polypropylene and polyethylene conjugate fibers of polyethylene terephthalate and polyethylene, etc., which are subjected to a hydrophilizing treatment, and the bulk of the fibers in the sheet is in the range of 15 g / m ² or more and 50 g / m ² or less.

<18> An absorbent article according to any one of the above <1> to <17>, wherein the bottom sheet comprises a porous film obtained by mixing a melt of a hydrophobic thermoplastic resin and small particles of an inorganic filler that contains calcium carbonate or organic macromolecules that do not have compatibility, in order to form a film, and stretching the film along one axis or two axes, and the thermoplastic resin is a polyolefin.

<19> An absorbent article according to any one of the above <1> to <18>, in which the absorbent core has a gap portion in an area corresponding to the crotch portion of the article, and the gap portion is positioned so as to overlap with the indicator portion in the direction thickness.

<20> An absorbent article according to any one of the above from <1> to <19>,

in which the absorbent product is a disposable diaper that contains:

the front part located on the front side of the wearer; the crotch portion located on the crotch portion of the wearer; and a rear portion located on the rear side of the wearer, the product generally having a geometric hourglass shape, in which the crotch portion is narrowed in the transverse direction inward.

<21> A method for producing an absorbent article according to any one of the above from <1> to <20>, which includes:

the step of forming an absorbent body to place the absorbent core on the raw material covering sheet, which is continuously transported, raising both transverse end parts of the raw material covering sheet and turning the end parts so that they face each other, on the absorbent core, applying a hot-melt adhesive to each of the facing surfaces of both end parts in order to fasten both end parts in order to form a bag-like part, and bending the fastened ends piece so as to extend along the bag portion to form a portion covering the mouth, to receive an absorbent body, and vertical turning of the absorbent body;

the stage of forming the indicator part for applying a hot-melt composition containing a mixture of a color indicator and a pressure-sensitive adhesive component to the raw material base sheet, which is continuously transported, in order to further cool and cure the composition; and

a laminating step for discontinuously applying, in the transverse outward direction, the indicator part, a hot-melt adhesive to the raw material lower sheet on which the indicator part is formed, and placing and fixing the absorbent body to fasten the root mouth covering the mouth and the mouth closing outer side of the mouth covering part with the lower sheet by hot-melt adhesive on the raw back sheet.

<22> A method for producing an absorbent article according to paragraph <21> above, in which both end parts of the coating sheet are rotated so that they face each other and fastened at the stage of formation of the absorbent body, and then the applied hot-melt adhesive is cooled and cured before vertical turning of the absorbent body.

EXAMPLES

{0057} The present invention is described in more detail based on the following examples, but they are not intended to limit the invention. Furthermore, in a schematic cross-sectional view shown in FIG. 11, (a) and (b) schematically show the shape of the diaper in the examples, and (c) and (d) schematically show the shape of the diaper in the comparative examples.

0058 (Example 1)

A disposable diaper (sample 1) was obtained, which has a cross-sectional structure schematically shown in FIG. 11 (a). In sample 1, the mouth-covering part and the bag-shaped part were not fastened, but the mouth-closing part and the indicator part were fastened.

For top sheet 1, a sheet having the structure of a two-layer concave-convex top sheet was used in a disposable diaper sample. As the upper layer and the lower layer of the upper sheet, respectively, a fluid-permeable breathable non-woven material having a bulk of 18 g / m ^{2 was used} , as was obtained using fibers with a shell-core structure of polyethylene terephthalate / polyethylene. For the top layer, a material was used on which a concave-convex was provided by applying embossing to a breathable non-woven material. The bulk of the top layer after providing a concave-convex was 23.5 g / m ² .

For backsheet 2 used a material in which a material obtained by laminating, using a hot melt, a nonwoven material which has a structure «spunbond / melt-blown / spunbond » (SMS) using polypropylene resin, which has a basis weight of 15 g / m ² for a liquid impermeable and moisture permeable film of polyethylene resin (compounded with calcium carbonate), which has a bulk of 20 g / m ² .

For absorbent 3, an absorbent core that has a total basis weight of 490 g / m ² was formed from a homogeneous mixture of cellulose wool having 200 g / m ² and an absorbent polymer having 290 g / m ² was used as the material in which the absorbent polymer water molecules held for aggregate fibers.

0059 (Example 2)

A disposable diaper sample 2 was prepared in a manner that is similar to the sample in example 1, except that the mouth covering portion and the indicator portion were not glued (see FIG. 11 (b)).

0060 (Comparative Example 1)

A disposable diaper sample 3 was prepared in a manner that is similar to sample 1 in Example 1, except that the mouth covering portion and the indicator portion were positioned without partial overlap (see FIG. 11 (c)).

0061 (Comparative example 2)

A sample of the disposable diaper 4 was prepared in a manner that is similar to sample 1 in Example 1, except that the mouth-covering part and the bag-shaped part were completely attached to the contact surface (see FIG. 11 (d)).

0062 (Rating)

For each sample of a disposable diaper made as described above, the state of change of the indicator before use and after use, and the time to change were evaluated. In Table 1, “before use” refers to the condition before wearing the diaper, and “after use” refers to the condition after urinating after the diaper has been used.

The specific test conditions and test method are detailed below.

A diaper sample was experimentally obtained and then placed in a perforated packaging bag and stored for two months in an air-conditioned room having a temperature of 40 ° C. and a humidity of 80%. After storage, the temperature was returned to room temperature and then a measurement was carried out.

1. Change indicator before use

Visually assessed the degree of color change of the indicator.

2. Change indicator after use

After the injection of 300 ml of water into the diaper, a certain degree of indicator color change was confirmed and the time during was also evaluated.

0063 The results of the above test are presented in table 1. The contents of the ratings "A", "B" and "C" in table 1 are described below.

1. Change indicator before use

A: no changes are observed.

B: partially modified part is observed.

C: color changed.

2. Change indicator after use

A: The color changes by spraying water.

B: partially unchanged portion is observed.

C: most parts are not changed.

3. Time until the indicator changes

A: change occurs within 1 minute.

B: the change partially occurs within 1 minute.

C: one minute or more elapses before the change.

0064

Table 1 Example 1 Example 2 Comparative Example 1 Reference Example 2 Sample one 2 3 four Reference FIG. 4 (a) 4 (b) 4 (c) 4 (d) Change indicator before use A A FROM A Indicator change after use A A A B ~ c Time until indicator changes after use A A A B ~ c

0065 As can be seen from the results presented in table 1, the disposable diapers in examples 1 and 2 did not change the indicator part before use. More specifically, the indicator portion is found to have high resistance to contact with the absorbent polymer per se or a trace amount of moisture contained therein. In addition, the indicator portion is found to show excellent color change after use. In contrast, in the disposable diaper in comparative example 1, it is found that the indicator portion forms contact with the absorbent polymer per se or the trace amount of moisture contained therein before use. In addition, in the disposable diaper in comparative example 2, the change does not occur prior to use, but the change of the indicator part through allocation is difficult to perceive and this leads to difficulties in assessing the optimal replacement time. As described above, it is found that the structure of the present invention makes it possible, in an absorbent having a mouth covering portion, to appropriately suppress the possibility of contact with the polymer or a trace amount of moisture in it before use, in order to sufficiently fulfill the main function of initiating an optimal replacement of the indicator part from - due to urine during use.

DESCRIPTION OF SYMBOLS

0066

1 top sheet

2 bottom sheet

3 Absorbent body

4 Absorbent core

41 Fibrous material

42 Absorbent polymer

5 Cover sheet

51 Sack part

52 Closing mouth

53 Outer closure of mouth

54 Root blocking mouth

55 Indicator contact part

56 air layer

6, 6a, 6b, 6c Indicator part

61 Indicator Area

7 side sheet

8 External sheet

10 Disposable Diaper

Claims (22)

1. An absorbent product that contains a top sheet located on the side of the surface in contact with the skin, a bottom sheet located on the side of the surface not in contact with the skin, and an absorbent body located between the two sheets,
moreover, the indicator part, the color of which visually changes when it comes in contact with the fluid, is located between the bottom sheet and the absorbent body, and the absorbent body contains an absorbent core that contains fibrous material and an absorbent polymer, and a covering sheet that covers the outer surface of the absorbent core,
moreover, the covering sheet has, in the form of a cross section of the absorbent body, a bag-shaped part that covers the area from the side of the surface in contact with the skin to the side of the surface not in contact with the skin, the absorbent core, and the mouth covering part connected to the bag-shaped part and located outward from it, and the mouth covering part is formed so that both transverse end parts of the covering sheet located on the side of the surface not in contact with the skin absorbing sulfur dtsoviny fastened in a state in which they are turned so that they are facing each other and are folded, and
wherein the mouth-covering part is positioned so as to completely cover the region in which the indicator part is located, and the mouth-closing part and the bag-shaped part are partially connected. 2. The absorbent product according to claim 1, in which the covering mouth is connected to the bag-shaped part in the closing mouth of the root part. 3. An absorbent article according to claim 1 or 2, wherein the mouth covering portion is not bonded to the indicator portion. 4. The absorbent product according to claim 1 or 2, in which the mouth covering part is bonded to the bottom sheet in the outer end part of the mouth covering part and the root part of the mouth covering part. 5. The absorbent product according to claim 1 or 2, in which the bag-shaped part near the root part of the part covering the mouth is bonded to the absorbent core. 6. The absorbent product according to claim 1 or 2, in which the place between the covering mouth part and the bag-shaped part is in a state of alternating fastening, which has a gap due to the spiral application of hot-melt adhesive. 7. The absorbent product according to claim 1 or 2, in which the absorbent core has a filter layer that does not contain an absorbent polymer, and a layer of a mixture of fibrous material and an absorbent polymer, which is located on its side of the surface in contact with the skin. 8. An absorbent product according to claim 1 or 2, in which the indicator part contains a hydrophilic composition, which contains a color indicator that changes color due to a change in pH. 9. The absorbent product according to claim 1 or 2, in which the indicator part contains a hot-melt composition, which contains a mixture of a color indicator that changes color due to a change in pH, and pressure-sensitive adhesive material, and the indicator part is cured to prevent penetration of the applied hot melt composition in a covering sheet. 10. The absorbent product according to claim 1 or 2, in which the ratio t ₄ / t ₂ length t ₄ from the end of the indicator part to the closing mouth of the outer end relative to the length t ₂ from the transverse center line of the absorbent product to the closing mouth of the outer end is in a range of 0.25 or more and 0.85 or less. 11. The absorbent product according to claim 1 or 2, in which the ratio s ₁ / t _{1 of the} transverse length s _{1 of the} indicator region in which the indicator part is located, in relation to the transverse length t _{1 of} the mouth covering part is in the range of 0.15 or more and 0.75 or less, and a ratio s ₂ / t _{2 of} length s ₂ from the transverse center of the indicator region to the end of the indicator part with respect to the length t ₂ from the transverse center of the indicator region to the covering mouth of the outer end of the covering mouth is in the range 0 15 or more and 0.75 or IU it bigger. 12. The absorbent product according to claim 1 or 2, in which both the transverse end parts of the coating sheet are bonded by applying a hot-melt contact means, and the bulk of the hot-melt adhesive applied is in the range of 1.0 g / m ² or more and 10.0 g / m ² or less. 13. An absorbent product according to claim 1 or 2, in which the density of the fibers of the coating sheet is in the range of 0.05 g / cm ³ or more and 0.2 g / cm ³ or less. 14. An absorbent product according to claim 1 or 2, in which the indicator part contains a hydrophilic composition containing a color indicator that changes color due to a change in pH, and the color indicator contained in the hydrophilic composition is any one of bromophenol blue, methyl orange, alizarin S, bromocresol green, methyl red and bromocresol purple, which change color at a pH in the range of 3 or more and 7 or less. 15. The absorbent product according to claim 1 or 2, in which the indicator part contains a hydrophilic composition, which contains a color indicator that changes color due to changes in pH, the color indicator is contained in the range of 0.01% by mass or more and 50% by mass or less, preferably in the range of 0.01% by mass or more and 40% by mass or less, and most preferably in the range of 0.01% by mass or more and 0.5% by mass or less, based on the total amount of the hydrophilic composition . 16. An absorbent product according to claim 1 or 2, in which the indicator part contains a composition that contains 0.1% by weight or more and 5% by weight or less of a pH indicator (a), which is essentially colorless at pH 7, to develop color in the acid range; 20% by weight or more and 90% by weight or less of a glycerol ester of a fatty acid (b), which has a surface-active effect; 20% by mass or more and 35% by mass or less of polyalkylene glycol (c); 0% by mass or more and 70% by mass or less of a polymer (d) that has a carboxyl group; and 0.1% by mass or more and 5% by mass or less of an acidic substance (e) other than (b) and (d). 17. An absorbent product according to claim 1 or 2, in which the top sheet is a hydrophilic non-woven material and contains one type individually or a combination of two or more types selected from breathable non-woven material, spot bonded non-woven fabric, melt-woven fabric, hydro-woven nonwoven fabric and three-dimensional nonwoven fabric, nonwoven fabric fibers contain one type separately or a combination of two or more types selected from individual polypropylene fibers connected by windows of polypropylene and polyethylene, connected fibers of polyethylene terephthalate and polyethylene, and so on, which are subjected to hydrophilizing treatment, and the bulk of the fiber in the sheet is in the range of 15 g / m ² or more and 50 g / m ² or less. 18. An absorbent product according to claim 1 or 2, in which the bottom sheet contains a porous film obtained by mixing a melt of a hydrophobic thermoplastic resin and small particles of an inorganic filler that contains calcium carbonate or organic macromolecules that are not compatible in order to form a film and stretching the film along one axis or two axes, and the thermoplastic resin is a polyolefin. 19. The absorbent product according to claim 1 or 2, in which the absorbent core has a gap part in an area corresponding to the crotch part of the product, and a gap part located so as to overlap with the indicator part in the thickness direction. 20. The absorbent product according to claim 1 or 2, in which the absorbent product is a disposable diaper that contains a front part located on the front side of the wearer; the crotch portion located on the crotch portion of the wearer; and a rear portion located on the rear side of the wearer, the product generally having a geometric hourglass shape, in which the crotch portion is narrowed in the transverse direction inward. 21. A method of obtaining an absorbent product according to any one of paragraphs. from 1 to 20, which includes the following stages, in which:
an absorbent body is formed to place the absorbent core on the raw material coating sheet, which is continuously transported, raise both transverse end parts of the raw material coating sheet and rotate the end parts so that they face each other, on the absorbent core, a hot-melt adhesive is applied to each of the facing surfaces both end parts in order to fasten both end parts in order to form a bag-like part, and bend together the end parts so that believing them along part of the bag to form a covering of the mouth to obtain an absorbent body, and
vertically invert the absorbent body,
forming an indicator part for applying a hot-melt composition containing a mixture of a color indicator and a pressure-sensitive adhesive component to the raw material base sheet, which is continuously transported, in order to further cool and cure the composition; and
laminated for intermittent application, in the transverse outward direction of the indicator part, of hot-melt adhesive to the raw material lower sheet on which the indicator part is formed, and the absorbent body is placed and fixed so as to fasten the root mouth covering the mouth and the mouth closing outer side of the mouth covering part with the lower sheet by hot-melt adhesive on the raw back sheet. 22. The method of producing an absorbent product according to claim 21, in which both end parts of the covering sheet are rotated so that they are facing each other, and fastened at the stage of formation of the absorbent body, and then the applied hot-melt adhesive is cooled and cured before vertical turning of the absorbent body .

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