JP2016030178A - Disposable diapers - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disposable diaper which increases absorbency with respect to urination and fitness in wearing, is less likely to cause misunderstanding of the occurrence of urination before the urination, and can improve the impression of the diaper from a side of a surface sheet after the urination.SOLUTION: A disposable diaper 1A disclosed in this invention has an indicator 9 between a rear surface sheet 3 and an absorber 4. A surface sheet 2 is two-layered. The absorber 4 has a non-fiber stacked part 42 in an absorbent core 40. In a cross-section view, the indicator 9 is overlapped with the non-fiber stacked part 42 in a thickness direction. When the diaper 1A is measured by a color-difference meter from a side of the surface sheet 2, a color difference (Δ Evalue) between a color of the surface sheet in a position of the absorbent core 40 and a color of the surface sheet in a position overlapped with the indicator 9 is 8 or less in the state of DRY. The color difference (Δ Evalue) between a color of the surface sheet 2 in a position overlapped with the indicator 9 in the state of WET and the color of the surface sheet 2 in the position overlapped with the indicator 9 in the state of DRY is 32 or less.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a disposable diaper such as a pants-type disposable diaper.

  2. Description of the Related Art Conventionally, disposable diapers having an indicator that determines whether or not a wearer has urinated by color are known. Moreover, the disposable diaper which provided the slit penetrated to the predetermined | prescribed site | part of an absorptive core is known for the improvement of the absorptivity with respect to urination, and the improvement of the fitting property at the time of wear. For example, Patent Document 1 describes a disposable diaper in which a slit is provided in an absorbent core of an absorbent body and an indicator is disposed at a position overlapping the slit and disposed between the topsheet and the absorbent body.

  According to the disposable diaper described in Patent Document 1, since the absorbent core is provided with the slit, the absorbability for urination is improved and the fit at the time of wearing is improved.

JP 2008-55004 A

  However, since the disposable diaper described in Patent Document 1 is arranged between the top sheet and the absorbent body, the indicator is easy to be seen through the top sheet before urination, and the wearer urinates. May be. In addition, the indicator that changed color after urination was more visible through the wet surface sheet, and the impression was poor in terms of the appearance of the disposable diaper from the surface sheet after urination.

  Therefore, this invention is providing the disposable diaper which can eliminate the fault which the prior art mentioned above has.

The present invention comprises a top sheet disposed on the skin facing surface side, a back sheet disposed on the non-skin facing surface side, and a vertically long absorber disposed between both the sheets, the back sheet and the A disposable diaper in which an indicator that informs urination by color change is continuously arranged in the vertical direction between the absorbent body and the top sheet is a sheet having two layers, and the absorbent body absorbs The absorbent core includes a polymer, and the absorbent core is formed with a non-stacked fiber portion extending in the longitudinal direction, and the indicator is viewed in the thickness direction in a cross-sectional view along the lateral direction. When the disposable diaper is measured with a color difference meter from the top sheet side when the disposable diaper is measured with a color difference meter, the absorbent core excluding the indicator and the non-stacked fiber portion is removed. The surface sheet at the position of And DOO color, the indicator and the said topsheet color at the position overlapping the non-product defibrating unit is, L ^* a ^* b ^* color differences in the color system (Delta] E ^* value) is 8 or less, the disposable The color of the topsheet at a position overlapping the indicator and the non-stacked fiber portion at the time of diaper WET, and the color of the topsheet at the position overlapping the indicator and the non-stacked fiber portion at the time of DRY of the disposable diaper Provides a disposable diaper in which the color difference (ΔE ^* value) is 32 or less.

  ADVANTAGE OF THE INVENTION According to this invention, while the absorbability with respect to urination improves, the fitting property at the time of wear improves, it is hard to be mistaken for having urinated before urination, and the impression of the disposable diaper from the surface sheet side after urination can be improved.

FIG. 1 is a perspective view showing a usage state (wearing state) of a pants-type disposable diaper according to the first embodiment of the present invention. FIG. 2 is a developed plan view of a state in which the diaper shown in FIG. 1 is developed and stretched as viewed from the skin facing surface side. FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG. FIG. 4: is the expansion | deployment top view which looked at the state which expand | deployed and expanded the underpants type disposable diaper which is 2nd Embodiment of this invention from the skin opposing surface side. 5 is a cross-sectional view taken along line VV shown in FIG. FIG. 6: is the expansion | deployment top view which looked at the state which expand | deployed and expanded the underpants type disposable diaper which is 3rd Embodiment of this invention from the skin opposing surface side. 7 is a cross-sectional view taken along line VII-VII shown in FIG.

  Hereinafter, the disposable diaper of this invention is demonstrated, referring drawings based on the preferable embodiment. A disposable diaper 1A (hereinafter, also referred to as “diaper 1A”) according to the first embodiment of the present invention, as shown in FIGS. 1 to 3, is a top sheet 2 disposed on the skin facing surface side and a non-skin A back sheet 3 disposed on the opposite surface side and a vertically long absorbent body 4 disposed between the two sheets 2 and 3 are provided. Between the back sheet 3 and the absorbent body 4, urination is caused by a color change. An indicator 9 for notification is continuously arranged in the vertical direction.

Here, the “skin facing surface” is the surface of the diaper 1A or its constituent member (for example, the absorbent main body 6) that is directed toward the wearer's skin when worn, and the “non-skin facing surface” is a diaper. 1A or a component thereof is a surface directed to the side opposite to the wearer's skin side (clothing side) when worn. In the diaper 1A, the longitudinal direction (X direction) coincides with the direction along the long side of the longitudinally absorbent main body 6 that is the diaper 1A or a constituent member thereof, and the lateral direction (Y direction) is the diaper 1A or a constituent member thereof. Which coincides with the width direction of the absorbent main body 6.
The diaper 1 </ b> A is formed symmetrically with respect to a center line CL extending in the vertical direction (X direction). Hereinafter, the diaper 1A will be specifically described.

The diaper 1 </ b> A is a so-called pants-type disposable diaper, and as shown in FIGS. 1 to 3, has a top sheet 2, a back sheet 3, and an absorbent body 4 disposed between the two sheets 2 and 3. The main body 6 and the exterior body 7 which fixes the absorptive main body 6 and is located in the non-skin opposing surface side of the absorptive main body 6 are provided. Side cuffs 5 and 5 having elastic members 51 arranged in an extended state in the longitudinal direction (X direction) are provided on both side portions along the longitudinal direction (X direction) of the absorbent main body 6. When the diaper is worn, the free end portion of the side cuff 5 is erected by the contraction of the elastic member 51 to form a so-called three-dimensional gather, and the outflow of body fluid in the lateral direction (Y direction) is prevented.
The diaper 1A is divided into a ventral region A, a crotch region C, and a dorsal region B in the longitudinal direction (X direction) as shown in FIGS. The abdominal area A of the diaper 1A is a part arranged on the wearer's abdominal side when worn, the dorsal area B is a part arranged on the dorsal side of the wearer, and the crotch area C is worn It is a part arranged between the crotch of the person.
As shown in FIG. 1, a pair of side seals are formed on the diaper 1 </ b> A by joining both side edges on the ventral region A side and both side edges on the back side region B side of the exterior body 7 in the shape of a palm. Portions S and S, a waist opening WO and a pair of leg openings LO and LO are formed.

  The top sheet 2 is a sheet having two layers. That is, the surface sheet 2 is a laminated sheet of two or more layers, and as the laminated sheet, for example, an air formed by laminating a plurality of fiber webs before becoming non-woven fabric and heat-sealing each other's fibers. Examples thereof include a through nonwoven fabric or a laminated sheet in which a plurality of nonwoven fabrics are overlapped and partially joined to each other at a large number of joining portions. The top sheet 2 of the diaper 1A is an air-through nonwoven fabric obtained by superimposing two fiber webs and heat-sealing each other's fibers. The top sheet 2 of the diaper 1A is a laminated nonwoven fabric having a flat structure.

  In the surface sheet 2 of the diaper 1A, the fiber density (D1) on the skin facing surface side is higher than the fiber density (D2) on the non-skin facing surface side. The ratio (D1 / D2) of the fiber density (D1) on the skin facing surface side to the fiber density (D2) on the non-skin facing surface side is preferably 1.1 or more and 10 or less from the viewpoint of liquid absorbency, Preferably they are 1.2 or more and 5 or less. As described above, since the top sheet 2 of the diaper 1A is an air-through nonwoven fabric formed from two fiber webs, the fiber density (D1) on the skin facing surface side is the fiber density of the upper layer 21 of the two layers. The non-skin facing surface side fiber density (D2) means the fiber density of the lower layer 22 of the two layers. In the case of an air-through nonwoven fabric formed from three or more fiber webs, the fiber density (D1) on the skin facing surface side is the fiber density of the layer on the most skin facing surface side among the three or more layers. And the fiber density (D2) on the non-skin facing surface side means the fiber density of other layers excluding the layer on the most skin facing surface side. The basis weight described later is the same as the fiber density.

Specifically, the fiber density (D1) on the skin facing surface side is preferably 0.01 g / cm ³ or more, more preferably 0.02 g / cm ³ or more, preferably 0.1 g / cm ³ or less, preferably at 0.05 g / cm ³ or less, for example, is preferably not more than 0.01 g / cm ³ or more 0.1 g / cm ^3, is 0.02 g / cm ³ or more 0.05 g / cm ³ or less More preferably.
The basis weight of the skin facing surface side is preferably 5 g / m ² or more, more preferably 10 g / m ² or more, preferably 30 g / m ² or less, more preferably 25 g / m ² or less. For example, it is preferably 5 g / m ² or more and 30 g / m ² or less, more preferably 10 g / m ² or more and 25 g / m ² or less.

The non-skin facing side fiber density (D2) is preferably from 0.005 g / cm ³ or more, more preferably 0.01 g / cm ³ or higher, preferably 0.05 g / cm ³ or less, more preferably 0 .04g / cm ³ or less, for example, further it is preferably at most 0.005 g / cm ³ or more 0.05 g / cm ^3, it is 0.01 g / cm ³ or more 0.04 g / cm ³ or less preferable.
The basis weight of the layer on the non-skin facing surface side is preferably 5 g / m ² or more, more preferably 8 g / m ² or more, preferably 15 g / m ² or less, more preferably 13 g / m ² or less. Yes, for example, preferably 5 g / m ² or more and 15 g / m ² or less, and more preferably 8 g / m ² or more and 13 g / m ² or less.
The fiber density (D1) on the skin facing surface side, the fiber density (D2) on the non-skin facing surface side, the basis weight of the layer on the skin facing surface side, and the basis weight of the layer on the non-skin facing surface side are measured as follows. To do.

<Measuring method of fiber density and basis weight>
From the diaper 1A in a state where no load is applied, the topsheet 2 is cut into a rectangular shape of 50 mm × 100 mm (area 5000 mm ² ) to produce a measurement sample. Using an image analyzer, the cross section of the measurement sample is observed in a state where no load is applied, and the thickness of each layer is measured. Next, the layers constituting the measurement sample are separated, and the weight of each layer is determined. Then, the fiber density of each layer is calculated by dividing the weight of each layer by the volume of each layer (thickness × area of sample for measurement). Also, the weight of each layer is divided by the area of the measurement sample to calculate the basis weight of each layer. As the image analysis apparatus, for example, a scanning electron microscope (model number JCM-5100) manufactured by JEOL Ltd. can be used.

  Moreover, as for the surface sheet 2 of 1 A of diapers, the fineness of the fiber of the skin opposing surface side is low compared with the fineness of the fiber of the non-skin opposing surface side. The fineness of the fiber on the skin facing surface side is preferably 1.0 dtex or more, more preferably 1.5 dtex or more, preferably 5.0 dtex or less, more preferably 4.0 dtex or less, for example 1.0 dtex or more. It is preferably 5.0 dtex or less, and more preferably 1.5 dtex or more and 4.0 dtex or less. Further, the fineness of the fiber on the non-skin facing surface side is preferably 2.0 dtex or more, more preferably 3.0 dtex or more, preferably 10 dtex or less, more preferably 8.0 dtex or less, for example, 2.0 dtex. It is preferably 10 dtex or less, more preferably 3.0 dtex or more and 8.0 dtex or less. The fineness of the fiber on the skin facing surface side and the fineness of the fiber on the non-skin facing surface side are measured as follows.

<Measurement method of fiber fineness>
From the diaper 1A in a state where no load is applied, the topsheet 2 is cut into a rectangular shape of 50 mm × 100 mm (area 5000 mm ² ) to produce a measurement sample. Next, regarding the fineness of the fiber on the skin facing surface side, the thickness of the measurement sample is 10 cross-sectional views, and the fiber thickness is measured for 10 standard fibers at a position 10 mm apart from the skin facing surface of the measurement sample. Is measured using an electron microscope, and the fiber thickness average value Dn (μm) is calculated. Next, using a differential scanning calorimeter (DSC), a standard fiber constituent resin at a position 10 mm apart from the skin facing surface is specified, and a theoretical fiber density Pn (g / cm ³ ) is obtained. . From the obtained fiber thickness average value Dn (μm) and theoretical fiber density Pn (g / cm ³ ), the weight (g) per 10,000 m of the fiber length is calculated, and the calculated value is used for the skin. The fineness (dtex) of the fiber on the opposite surface side is taken. Regarding the fineness of the fibers on the non-skin facing surface side, the sample for measurement is viewed in cross section, and 10 standard fibers at a position 10 mm apart from the non-skin facing surface of the measurement sample are used to face the skin. It is measured in the same manner as the fineness of the fiber on the surface side.

  Moreover, the surface sheet 2 of the diaper 1A contains titanium oxide on the skin facing surface side. And in the surface sheet 2 of the diaper 1A, the content of titanium oxide on the skin facing surface side is larger than the content of titanium oxide on the non-skin facing surface side. Since the top sheet 2 of the diaper 1A is an air-through nonwoven fabric formed from two fiber webs, the content of titanium oxide on the skin facing surface side means the content of titanium oxide in the upper layer 21 of the two layers. In addition, the content of titanium oxide on the non-skin facing surface side means the content of titanium oxide in the lower layer 22 of the two layers. In the case of an air-through nonwoven fabric formed from three or more fiber webs, the content of titanium oxide on the skin facing surface side is the titanium oxide on the most skin facing surface side of the three or more layers. The content of titanium oxide on the non-skin facing side means the content of titanium oxide in other layers excluding the layer closest to the skin facing side. Specifically, the content of titanium oxide in the upper layer 21 on the skin facing surface side of the top sheet 2 of the diaper 1A is preferably 0.5% by mass or more and 15% by mass or less with respect to the total amount of the upper layer 21, and Preferably they are 1.0 mass% or more and 10 mass% or less. Further, the content of titanium oxide in the lower layer 22 on the non-skin facing surface side in the top sheet 2 of the diaper 1A is preferably 0.05% by mass or more and 1.0% by mass or less with respect to the total amount of the lower layer 22; More preferably, it is 0.1 mass% or more and 0.5 mass% or less.

  In the diaper 1 </ b> A, as shown in FIG. 3, the top sheet 2 covers the skin facing surface side of the absorbent body 4, and both end portions thereof are folded back to the non-skin facing surface side of the absorbent body 4. The non-skin facing surface side is bonded and fixed to the back sheet 3 and the side cuffs 5 by a known bonding means such as an adhesive or a seal.

  As shown in FIGS. 2 and 3, the absorbent body 4 has an absorbent core 40 containing an absorbent polymer. Specifically, in the diaper 1, the absorbent body 4 has an absorbent core 40 that is long in the longitudinal direction (X direction) and a core wrap sheet 41 that covers the absorbent core 40. The core wrap sheet 41 covers the skin facing surface and the non-skin facing surface of the absorbent core 40.

Further, as shown in FIGS. 2 and 3, the absorbent core 40 is formed with a non-stacking portion 42 extending in the longitudinal direction (X direction). Specifically, the non-stacked fiber portion 42 is formed in the lateral direction (Y direction) center portion (portion including the center line CL) in the crotch region C of the absorbent core 40, and vertically along the center line CL. It is formed in a rectangular shape that is long in the direction (X direction). Here, the non-stacked fiber portion 42 is preferably a through hole in which the material (core forming material) for forming the absorbent core 40 does not exist at all. However, the amount of the core forming material in a smaller amount than other regions is 20 g. Even if it is slightly present at about / m ² , the same effect can be obtained, so it is included in the non-stacked fiber portion. It is preferable that the width of the non-stacking portion 42 is about 3.0 mm or more and 30 mm or less.

  Moreover, in the diaper 1A, as shown in FIG.2 and FIG.3, the elasticity for raising the side part of the absorptive core 40 along the both-sides edge part extended in the vertical direction (X direction) of the absorber 4 is shown. A member 43 is arranged. The elastic member 43 of the diaper 1 </ b> A is disposed on the inner surface side or the outer surface side of the core wrap sheet 41 that covers the absorbent core 40, and is stretched along both side edges along the longitudinal direction (X direction) of the absorbent core 40. Both ends are fixed to the ventral region A and the dorsal region B.

  Moreover, in the diaper 1A, the core wrap sheet 41 is fixed by the adhesive between the skin facing surface of the absorbent core 40 and the non-skin facing surface of the absorbent core 40. The adhesive is not coated and not fixed. Specifically, an adhesive is applied to the skin facing surface of the absorbent core 40 excluding the non-stacked fiber portion 42 and the non-skin facing surface of the absorbent core 40 excluding the non-stacked fiber portion 42, The core wrap sheet 41 is fixed at the coating portion. However, no adhesive is applied to the non-stacked fiber portion 42, and in the non-stacked fiber portion 42, the core wrap sheet 41 on the skin facing surface side of the absorbent core 40, and the absorbent core 40. The core wrap sheet 41 on the non-skin facing surface side is not fixed, and a space is easily formed in the non-stacking portion 42.

  Moreover, in diaper 1A, as shown in FIG. 3, the surface sheet 2 and the absorber 4 are being fixed with the adhesive agent 8, and the adhesive agent 8 is thickness direction seeing in cross section along a horizontal direction. The non-stacked fiber portion 42 is arranged outward in the lateral direction (Y direction) from both side edges along the longitudinal direction (X direction). Specifically, the adhesive 8 is applied to the skin facing surface of the absorbent body 4 corresponding to the skin facing surface of the absorbent core 40 excluding the non-stacked fiber portion 42, and the absorption corresponding to the non-stacked fiber portion 42. The adhesive is not applied to the skin facing portion of the body 4. Therefore, the skin facing surface of the absorbent body 4 corresponding to the skin facing surface of the absorbent core 40 excluding the non-stacked fiber portion 42 and the non-skin facing surface of the topsheet 2 are fixed via the adhesive 8. The part of the skin-facing surface of the absorbent body 4 corresponding to the non-stacking portion 42 and the non-skin-facing surface of the topsheet 2 are not fixed via the adhesive 8, and a space is formed in the non-stacking portion 42. It is easy to be done.

  As shown in FIG. 3, the diaper 1 has a cross-sectional view along the lateral direction (Y direction), and the indicator 9 overlaps the non-stacked portion 42 in the thickness direction. Specifically, as shown in FIG. 3, the indicator 9 is arranged at the center in the horizontal direction (Y direction) in the horizontal direction (Y direction), and is arranged within the range of the width of the non-stacking portion 42. The non-stacked fiber portion 42 is overlapped. As shown in FIG. 2, the indicator 9 is formed along the non-stacking portion 42 in the longitudinal direction (X direction), and the end portion and the back-side region of the non-stacking portion 42 on the ventral region A side. It extends beyond each end on the B side. The indicator 9 in the diaper 1 </ b> A is disposed between the core wrap sheet 41 of the absorbent body 4 and the back sheet 3, and is disposed on the skin facing surface of the back sheet 3. The change in the color of the indicator 9 is visible from the outside through the back sheet 3 and the exterior body 7.

  More specifically, the indicator 9 of the diaper 1 </ b> A is two elongated linear objects arranged in parallel symmetrically with respect to the center line CL, and each of these two elongated linear indicators 9 has a vertical direction. In the (X direction), it extends linearly from the crotch region C to the ventral region A and the dorsal region B. The indicator 9 of the diaper 1A is arranged in a straight line in the vertical direction (X direction) from the crotch region C to the ventral region A and the dorsal region B. It may be distribute | arranged only over the range of the vertical direction (X direction), and may be distribute | arranged over the full length of the vertical direction (X direction) of the absorptive core 40. FIG.

  Moreover, in the diaper 1A, as shown in FIG.2 and FIG.3, it fixes to the side cuff 5 provided in the side part along the vertical direction (X direction) of the absorptive main body 6 in the expansion | extension state in the free end vicinity. In addition to the elastic member 51, a cuff intermediate elastic member 52 fixed in an extended state in the longitudinal direction (X direction) is disposed between the fixed end and the free end of the side cuff 5. In the diaper 1A, as shown in FIG. 3, as a side cuff 5, a sheet of a belt-like sheet having a predetermined width is folded in two along its longitudinal direction (X direction), so that the opposite layers are hot. A two-layered sheet joined by a melt-type adhesive or a partial heat seal or ultrasonic seal is used. The elastic member 51 and the cuff intermediate elastic member 52 described above extend between the two-layered sheets. It is fixed in the state.

  The absorbent main body 6 configured as described above is bonded to the central portion of the outer package 5 such that the longitudinal direction (X direction) coincides with the longitudinal direction (X direction) of the diaper 1A in the expanded and expanded state. It is joined by the agent. Thus, the exterior body 5 is arranged and bonded and fixed to the non-skin facing surface side of the back sheet 3 constituting the absorbent main body 6 in the thickness direction of the diaper 1A.

As shown in FIGS. 2 and 3, in the diaper 1 </ b> A, the exterior body 7 includes two exterior body forming sheets 71 and 72, and each part fixed in an extended state between the two sheets 71 and 72. The elastic member. That is, between the two exterior body forming sheets 71 and 72, a waist elastic member 73 that forms a waist gather at the periphery of the waist opening WO, and a leg that forms a leg gather at the periphery of the leg opening LO Waist elastic forming a waistline gather in a state where it is divided into left and right parts in a waist elastic part 74 and a waistline part D (region from a position 20 mm downward from the peripheral edge of the waist opening WO to the upper end of the leg opening LO) Each of the members 75 is bonded and fixed by an arbitrary bonding means such as a hot-melt adhesive in an extended state.
The exterior body forming sheets 71 and 72 are, in the longitudinal direction (X direction), one or both of these two sheets are folded at the peripheral edge of the waist opening WO, and the folded portions are It is fixed to the skin facing surface side of the absorbent main body 6 at the front and rear ends of the absorbent main body 6.

The diaper 1A configured as described above has a surface at the position of the absorbent core 40 excluding the indicator 9 and the non-stacking portion 42 when the disposable diaper is DRY when measured with a color difference meter from the surface sheet 2 side. The color difference (ΔE ^* value) in the L ^* a ^* b ^* color system is 8 or less between the color of the sheet 2 and the color of the topsheet 2 at the position overlapping the indicator 9 and the non-stacked portion 42. That is, the color difference (ΔE ^* value) at the time of DRY of the disposable diaper is the L ^* a of the topsheet 2 at the position of the absorbent core 40 excluding the indicator 9 and the non-stacked fiber portion 42 at the time of DRY of the disposable diaper. ^* b ^* means the color expressed by color system, a difference between the color represented by the indicator 9 and Hiseki defibrating unit topsheet 2 at 42 overlaps the position L ^* a ^* b ^* color system.

And when measuring with the color difference meter from the surface sheet 2 side, the color of the surface sheet 2 at the position overlapping the indicator 9 and the non-stacking portion 42 at the time of WET of the disposable diaper, and the indicator 9 at the time of DRY of the disposable diaper The color difference (ΔE ^* value) of the color of the topsheet 2 at the position overlapping the stacking portion 42 is 32 or less. That is, the color difference (ΔE ^* value) at the time of DRY of the disposable diaper is the L ^* a ^* b ^* color system of the surface sheet 2 at the position overlapping the indicator 9 and the non-stacked fiber part 42 at the time of WET of the disposable diaper. And the color represented by the L ^* a ^* b ^* color system of the topsheet 2 at a position overlapping the indicator 9 and the non-stacked fiber portion 42 at the time of DRY of the disposable diaper.

As the color difference meter, a simple spectral color difference meter NF333 (trade name) manufactured by Nippon Denshoku Industries Co., Ltd. can be used. In the “L ^* a ^* b ^* color system” defined in JIS-Z-8729, L ^* indicates brightness, a ^* , b ^* indicate the direction of color, a ^* indicates a substantially red direction, − a ^* indicates an approximately green direction, b ^* indicates an approximately yellow direction, and -b ^* indicates an approximately blue direction. ΔE ^* is a value obtained by the following formula (1).

ΔE ^* = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2 (1)

Here, ΔL ^* , Δa ^* , and Δb ^* are differences in L ^* value, a ^* value, and b ^* value between two colors, respectively. For example, ΔL ^* is calculated by ΔL ^* = L ^* _2- L ^* ₁ .
In the measurement method using the simplified spectral color difference meter NF333, a ND110 sensor of φ4 mm is attached in a stapler type, an O-ring (small) is used at the tip of the sensor, a light source C / 2, and a viewing angle of 2 °. Measure with The sample at the time of measurement is a state where the disposable diaper is unfolded and stretched, and the tip of the sensor is brought into contact with the topsheet 2 from the topsheet 2 side so that no gap is generated between the topsheet 2 and the tip of the sensor. Press to measure. The measurement is performed 5 times, and the average is taken as the measured value.

  The above-mentioned “DRY disposable diaper” means the diaper 1A before use. Moreover, the above-mentioned “at the time of WETY of the disposable diaper” is a state in which 200 ml of physiological saline is injected from the surface sheet 2 side to the diaper 1A in an unfolded and stretched state, and after 5 minutes have passed since the injection. It means diaper 1A.

The material for forming each part of the diaper 1A will be described.
As the back sheet 3, the absorber 4 and the side cuffs 5 constituting the absorbent main body 6, various kinds of materials conventionally used for absorbent articles such as pants-type disposable diapers can be used without particular limitation. . For example, as the back sheet 3, a moisture-permeable resin film or the like can be used. The absorbent core 40 of the absorbent body 4 can be made of absorbent polymer particles and fiber material, and the core wrap sheet 41 can be tissue paper or the like. Incidentally, the basis weight of the absorbent core 40 is the degree 200 g / ^{m 2} or more 700 g / ^{m 2} or less. Further, the thickness of the absorbent core 40 is in a state where no load is applied. It is about 1 mm or more and 30 mm or less. Further, as the side cuff 5, a water-repellent single layer or multilayer nonwoven fabric or the like can be used.

  As the two exterior body forming sheets 71 and 72 constituting the exterior body 7, a single layer nonwoven fabric composed of a spunbond nonwoven fabric, an air-through nonwoven fabric, a heat roll nonwoven fabric, a spunlace nonwoven fabric, a melt blown nonwoven fabric, etc., or two or more layers A laminated nonwoven fabric or the like can be used. Different sheet materials may be used for the two exterior body forming sheets 71 and 72.

  Examples of the elastic member (elastic member 43, elastic member 51, cuff intermediate elastic member 52, waist elastic member 73, leg elastic member 74, waist elastic member 75, etc.) include styrene-butadiene, butadiene, isoprene, neoprene, and the like. Synthetic rubber, natural rubber, EVA, stretchable polyolefin, polyurethane and the like. As a form of the elastic member, a cross-sectionally rectangular, square, circular, elliptical or polygonal thread shape (thread rubber or the like), a string shape (flat rubber etc.), or a multifilament type thread shape or the like It can be preferably used.

  As the adhesive 8, the adhesive that fixes each member, and the adhesive that fixes the exterior body 7 and the absorbent main body 6, various hot-melt adhesives conventionally used for absorbent articles such as pants-type disposable diapers An agent or the like can be used without particular limitation.

  The side seal portion S is formed by overlapping the both end portions of the exterior body 7 on the side of the ventral region A and the both end portions of the exterior body 7 on the back side region B, and subjecting the portions to heat embossing. . Further, as a process for forming the side seal portion S, an ultrasonic seal, a laser, or the like may be employed instead of the heat embossing process.

The indicator 9 is composed of, for example, a hot melt composition, and the hot melt composition can be used without particular limitation as long as it is normally used for absorbent articles such as disposable diapers. The basis weight of the indicator 9 is about 5 g / m ² or more and 50 g / m ² or less.

The effect at the time of using the diaper 1A mentioned above is demonstrated.
As shown in FIGS. 2 and 3, the diaper 1 </ b> A is formed with the non-stacked fiber portion 42 extending in the longitudinal direction (X direction) on the absorbent core 40, thereby improving the absorbability with respect to urination while wearing the diaper. The fit when wearing a diaper is improved. In particular, in the diaper 1 </ b> A, the elastic member 43 is arranged in an extended state along both side edges along the longitudinal direction (X direction) of the absorbent core 40, so that the side portion of the absorbent core 40 during wearing of the diaper It is easy to start up and the fit at the time of wearing is further improved.

Moreover, the diaper 1A is a sheet | seat which the surface sheet 2 has two layers as shown in FIG.2, FIG.3, and the indicator 9 is distribute | arranged between the core wrap sheet | seat 41 and the back surface sheet 3 of the absorber 4. In addition, when viewed in a cross-section along the lateral direction (Y direction), the non-stacked portion 42 overlaps in the thickness direction. And when it measures with a color difference meter from the surface sheet 2 side, at the time of DRY of a disposable diaper, the position of the absorptive core 40 except the indicator 9 and the unstacked fiber part 42, and the indicator 9 and the unstacked fiber part 42 overlap. The color difference (ΔE ^* value) of the color of the surface sheet 2 at the position is 8 or less. Therefore, it is difficult for the indicator 9 to be seen through the top sheet 2 before urination and to be mistaken for urination. Furthermore, the indicator 9 is arranged between the core wrap sheet 41 and the back sheet 3 of the absorber 4, and when measured with a color difference meter from the top sheet 2 side, the indicator 9 and the The color difference (ΔE ^* value) of the color of the topsheet 2 before and after use at a position overlapping the non-stacked fiber portion 42 is 32 or less. Therefore, the color change of the indicator 9 is easily visible from the outside through the back sheet 3 and the exterior body 7, but the indicator 9 that has changed color after urination is difficult to be seen through the top sheet 2, The impression of the disposable diaper from the surface sheet side after urination can be improved.

  Further, in the diaper 1A, the fiber density (D1) on the skin facing surface side is higher than the fiber density (D2) on the non-skin facing surface side. Therefore, while improving the absorbability of the urination to the absorptive core 40 in which the non-stacking fiber part 42 was formed, the indicator 9 which discolored after urination permeate | transmits the surface sheet 2, and it becomes difficult to be visually recognized further. The impression of the disposable diaper from the rear surface sheet side can be further improved. In particular, in the diaper 1A, the fineness of the fibers on the skin facing surface side is lower than the fineness of the fibers on the non-skin facing surface side. Therefore, the indicator 9 that has changed color after urination is more difficult to be seen through the top sheet 2 and the impression of the disposable diaper from the top sheet side after urination can be further improved.

  Moreover, the diaper 1A contains titanium oxide on the skin facing surface side, and the content of titanium oxide on the skin facing surface side is larger than the content of titanium oxide on the non-skin facing surface side. Therefore, the indicator 9 that has changed color after urination is more difficult to be seen through the top sheet 2 and the impression of the disposable diaper from the top sheet side after urination can be further improved.

  Moreover, as for the diaper 1A, as shown in FIG. 3, the adhesive 8 which fixes the surface sheet 2 and the absorber 4 is a horizontal direction (from the both-side edges along the vertical direction (X direction) of the non-stacking part 42 ( (Y direction) It is arranged on the outside, and the skin facing surface of the absorbent body 4 corresponding to the skin facing surface of the absorbent core 40 excluding the non-stacking portion 42 and the non-skin facing surface of the topsheet 2 are adhesives. 8 is fixed through the adhesive 8, and the part of the skin facing surface of the absorbent body 4 corresponding to the non-stacking portion 42 and the non-skin facing surface of the topsheet 2 are not fixed through the adhesive 8. Therefore, when a force pulling the top sheet 2 is generated during wearing, a space is easily formed in the non-stacked fiber portion 42, and the absorbability with respect to urination while wearing a diaper is further improved, and the indicator 9 discolored after urination is displayed on the top sheet. It is more difficult to see through 2 and the impression of the disposable diaper from the surface sheet side after urination can be further improved. In particular, in the diaper 1A, the adhesive that fixes the core wrap sheet 41 and the absorbent core 40 is not applied to the non-stacked fiber portion 42, and the non-stacked fiber portion 42 has an absorbent property. The core wrap sheet 41 on the skin facing surface side of the core 40 and the core wrap sheet 41 on the non-skin facing surface side of the absorbent core 40 are not fixed, and a space is easily formed in the non-stacking portion 42. Yes. For this reason, the above-described effect is further exhibited. In the diaper 1 </ b> A, an elastic member 51 and a cuff intermediate elastic member 52 that are fixed in a stretched state in the longitudinal direction (X direction) are disposed on the pair of side cuffs 5, 5. Since the elastic member 43 fixed in an extended state in the longitudinal direction (X direction) is arranged at the edge, the side portion of the absorbent core 40 is easily lifted, and a space is easily formed in the non-stacked portion 42. Thus, the above-described effect is further exhibited.

  Next, the disposable diaper 1B of the second embodiment of the present invention (hereinafter also referred to as “diaper 1B”) and the disposable diaper 1C of the third embodiment of the present invention (hereinafter also referred to as “diaper 1C”) will be described. To do. About the diapers 1B and 1C, a different point from the diaper 1A of 1st Embodiment is mainly demonstrated, the same code | symbol is attached | subjected about the same point, and description is abbreviate | omitted. The description regarding the diaper 1A is appropriately applied to points that are not particularly mentioned. Moreover, about the effect of diapers 1B and 1C, a different point from the effect of diaper 1A is demonstrated, The point which is not demonstrated especially is the same as the effect of diaper 1A, and description of the effect of diaper 1A is applied suitably.

  In the diaper 1 </ b> B of the second embodiment, as shown in FIGS. 4 and 5, a liquid-permeable sublayer 10 wider than the unstacked portion 42 is provided between the topsheet 2 and the absorbent body 4. I have. As shown in FIG. 5, the diaper 1 </ b> B is viewed in cross section along the lateral direction (Y direction), and the sublayer 10 overlaps with the non-stacking portion 42 and the indicator 9 in the thickness direction. Specifically, a liquid-permeable sublayer 10 that is separate from the topsheet 2 is disposed between the topsheet 2 and the absorber 4. The sublayer 10 is a rectangular sheet that is long in the vertical direction (X direction). In the vertical direction (X direction), the sublayer 10 is longer than the length of the non-stacked portion 42 of the absorbent core 40, and The sheet is shorter than the length. In addition, the sublayer 10 is a sheet that is wider than the non-stacking portion 42 and narrower than the width of the absorbent core 40 in the lateral direction (Y direction).

In the diaper 1B, the fiber density (D3) of the sublayer 10 is lower than the fiber density (D1) on the skin facing surface side and the fiber density (D2) on the non-skin facing surface side of the topsheet 2. Yes. In other words, in the diaper 1B, the fiber density (D1) on the skin facing surface side of the topsheet 2, the fiber density (D2) on the non-skin facing surface side of the topsheet 2, and the fiber density (D3) of the sublayer 10 Among them, the fiber density (D1) on the skin facing surface side is the highest, and the fiber density (D3) of the sublayer 10 is the lowest. The ratio (D1 / D3) of the fiber density (D1) on the skin facing surface side to the fiber density (D3) of the sublayer 10 is preferably 1.05 or more and 10 or less from the viewpoint of improving liquid diffusibility. Preferably they are 1.1 or more and 5.0 or less. Specifically, the fiber density (D3) of the sublayer 10 is preferably 0.01 g / cm ³ or more, more preferably 0.02 g / cm ³ or more, preferably 0.1 g / cm ³ or less, more preferably. it is a 0.05 g / cm ³ or less, for example, is preferably not more than 0.01 g / cm ³ or more 0.1 g / cm ^3, or less 0.02 g / cm ³ or more 0.05 g / cm ³ Is more preferable. Further, the basis weight of the sublayer 10 is preferably 20 g / m ² or more, more preferably 30 g / m ² or more, preferably 100 g / m ² or less, more preferably 80 g / m ² or less. It is preferably 20 g / m ² or more and 100 g / m ² or less, and more preferably 30 g / m ² or more and 80 g / m ² or less. The fiber density (D3) and basis weight of the sublayer 10 are measured as follows.

<Measurement method of sublayer fiber density and basis weight>
From the diaper 1A in a state where no load is applied, the sublayer 10 is cut into a 50 mm × 100 mm (area 5000 mm ² ) rectangular shape to produce a measurement sample. Using an image analyzer, the cross section of the measurement sample is observed in a state where no load is applied, and the thickness of each layer is measured. Next, the weight of the measurement sample is obtained. Then, the fiber density of the measurement sample is calculated by dividing the weight of the measurement sample by the volume of the measurement sample (thickness × area of the measurement sample). Further, the basis weight of each layer is calculated by dividing the weight of the measurement sample by the area of the measurement sample.

  Moreover, the fineness of the sublayer 10 in the diaper 1B is higher than the fineness of the fibers on the skin facing surface side of the topsheet 2 and the fineness of the fibers on the non-skin facing surface side. In other words, in the diaper 1B, among the fineness of the fiber on the skin facing surface side of the top sheet 2), the fineness of the fiber on the non-skin facing surface side of the top sheet 2, and the fineness of the fiber of the sublayer 10 The fineness of the fiber on the surface side is the lowest, and the fineness of the fiber of the sublayer 10 is the highest. The fineness of the fibers of the sublayer 10 is preferably 3 dtex or more, more preferably 5 dtex or more, preferably 12 dtex or less, more preferably 10 dtex or less, for example, 3 dtex or more and 12 dtex from the viewpoint of increasing the nonwoven fabric thickness and rigidity. Or less, more preferably 5 dtex or more and 10 dtex or less. The fineness of the fibers of the sublayer 10 is measured as follows.

<Measurement method of sub-layer fiber fineness>
From the diaper 1A in a state where no load is applied, the sublayer 10 is cut into a 50 mm × 100 mm (area 5000 mm ² ) rectangular shape to produce a measurement sample. Next, the measurement sample is viewed in cross-section, and the fiber thickness is measured using an electron microscope for standard fibers at 10 positions of the measurement sample, and the average fiber thickness value Dn (μm ) Is calculated. Next, using a differential scanning calorimeter (DSC), a standard fiber constituent resin at the 10 positions is specified, and a theoretical fiber density Pn (g / cm ³ ) is obtained. From the obtained fiber thickness average value Dn (μm) and theoretical fiber density Pn (g / cm ³ ), the weight per 10,000 m of fiber length (g) is calculated, and this calculated value is sub The fiber fineness (dtex) of the layer is used.

  Moreover, in the diaper 1B, the content of titanium oxide on the skin facing surface side of the topsheet 2 is larger than the content of titanium oxide on the non-skin facing surface side and the content of titanium oxide in the sublayer 10. Yes. The content of titanium oxide in the sublayer 10 is preferably 0.05% by mass or more and 1.0% by mass or less with respect to the total amount of the sublayer 10 from the viewpoint of decreasing the rigidity of the fiber when contained in a large amount. More preferably, it is 0.1 mass% or more and 0.5 mass% or less.

The diaper 1B configured as described above has a surface at the position of the absorbent core 40 excluding the indicator 9 and the non-stacked fiber portion 42 when the disposable diaper is DRY when measured with a color difference meter from the surface sheet 2 side. The color difference (ΔE ^* value) in the L ^* a ^* b ^* color system is 8 or less between the color of the sheet 2 and the color of the surface sheet 2 at the position overlapping the indicator 9 and the non-stacking portion 42, 5 or less is preferable. And when measuring with the color difference meter from the surface sheet 2 side, the color of the surface sheet 2 at the position overlapping the indicator 9 and the non-stacking portion 42 at the time of WET of the disposable diaper, and the indicator 9 at the time of DRY of the disposable diaper The color difference (ΔE ^* value) of the color of the topsheet 2 at a position overlapping the stacking portion 42 is 32 or less, and preferably 27 or less.

  In the diaper 1B of 2nd Embodiment, as shown in FIG. 5, since the sublayer 10 mentioned above is distribute | arranged, the absorptivity with respect to the urination during diaper wear improves further. Moreover, the indicator 9 is difficult to be seen through the top sheet 2 and the sublayer 10 before urination, and is difficult to be mistaken for having urinated. And the indicator 9 discolored after urination is difficult to be seen through the top sheet 2 and the sublayer 10, and the impression of the disposable diaper from the top sheet side after urination can be improved.

  Next, in the diaper 1 </ b> C of the third embodiment, as shown in FIGS. 6 and 7, the topsheet 2 overlaps two non-woven fabrics of an upper non-woven fabric 23 and a lower non-woven fabric 24 to form a large number of joints 25. Are laminated sheets that are partially bonded to each other, and are laminated nonwoven fabrics having an uneven structure. As shown in FIG. 7, the upper-layer nonwoven fabric 23 protrudes toward the wearer's skin side at portions other than the joint portion 25, and forms a large number of convex portions 231 that are hollow inside. The convex portions 231 and the joint portions 25 are arranged alternately and in multiple rows in the vertical direction (X direction) and the horizontal direction (Y direction). The upper layer nonwoven fabric 23 and the lower layer nonwoven fabric 24 are made of a nonwoven fabric that does not substantially expand and contract. The convex portion 231 is a flat rectangular parallelepiped or truncated quadrangular pyramid with rounded ridge lines as a whole, while the joint portion 25 is rectangular. The convex portion 231 of the laminated nonwoven fabric having a concavo-convex structure has a length in the longitudinal direction (X direction) of about 2 mm to 5 mm, a length in the lateral direction (Y direction) of about 2 mm to 5 mm, and a height of It is preferable that it is about 0.5 mm or more and 3.0 mm or less. In the top sheet 2 of the diaper 1 </ b> C, the upper layer nonwoven fabric 23 is disposed only in a region that covers the skin facing surface of the absorbent body 4. And while the lower layer nonwoven fabric 24 coat | covers the skin opposing surface side of the absorber 4, the both-sides edge part is return | folded by the non-skin opposing surface side of the absorber 4, and the non-skin opposing surface side of the absorber 4 Is also coated. A laminated nonwoven fabric having such a concavo-convex structure is formed by forming the upper layer nonwoven fabric 23 into a concavo-convex shape by a method such as inserting it between concavo-convex rolls meshing with each other, and then overlaying the upper layer nonwoven fabric 24 on the lower layer nonwoven fabric 24. The two nonwoven fabrics can be partially joined by heat fusion or the like.

  In the top sheet 2 of the diaper 1C, the fiber density (D4) of the upper nonwoven fabric 23 is lower than the fiber density (D5) of the lower nonwoven fabric 24. The ratio (D4 / D5) of the fiber density (D4) of the upper layer nonwoven fabric 23 to the fiber density (D5) of the lower layer nonwoven fabric 24 is preferably 1.1 or more and 10 or less, from the viewpoint of cushioning properties and softness improvement. Preferably they are 1.2 or more and 5 or less. In the diaper 1C, the fiber density (D4) of the upper layer nonwoven fabric 23 is lower than the fiber density (D5) of the lower layer nonwoven fabric 24, but the fiber density (D4) of the upper layer nonwoven fabric 23 is the fiber density of the lower layer nonwoven fabric. It may be higher than (D5).

Specifically, the fiber density of the upper layer nonwoven fabric 23 (D4) is preferably 0.005 g / cm ³ or more, more preferably 0.01 g / cm ³ or higher, preferably 0.05 g / cm ³ or less, more preferably it is a 0.04 g / cm ³ or less, for example, is preferably not more than 0.005 g / cm ³ or more 0.05 g / cm ^3, it is 0.01 g / cm ³ or more 0.04 g / cm ³ or less Is more preferable.
The basis weight of the upper non-woven fabric 23 is preferably 10 g / m ² or more, more preferably 15 g / m ² or more, preferably 50 g / m ² or less, more preferably 30 g / m ² or less. It is preferably 10 g / m ² or more and 50 g / m ² or less, and more preferably 15 g / m ² or more and 30 g / m ² or less.

The fiber density (D5) of the lower layer nonwoven fabric 24 is preferably 0.01 g / cm ³ or more, more preferably 0.02 g / cm ³ or more, preferably 0.1 g / cm ³ or less, more preferably 0.05 g. / cm ³ or less, for example, is preferably not more than 0.01 g / cm ³ or more 0.1 g / cm ^3, more preferably not more than 0.02 g / cm ³ or more 0.05 g / cm ^3.
The basis weight of the lower layer nonwoven fabric 24 is preferably 10 g / m ² or more, more preferably 15 g / m ² or more, preferably 50 g / m ² or less, more preferably 30 g / m ² or less. It is preferably 10 g / m ² or more and 50 g / m ² or less, and more preferably 15 g / m ² or more and 30 g / m ² or less. The fiber density (D4) and basis weight of the upper layer nonwoven fabric 23 and the fiber density (D5) and basis weight of the lower layer nonwoven fabric 24 are measured by the fiber density and basis weight measurement methods described above.

  Further, in the surface sheet 2 of the diaper 1 </ b> C, the fineness of the fibers of the upper nonwoven fabric 23 is lower than the fineness of the fibers of the lower nonwoven fabric 24. The fineness of the fibers of the upper non-woven fabric 23 is preferably 1.0 dtex or more, more preferably 1.5 dtex or more, preferably 6.0 dtex or less, more preferably 5.0 dtex or less, for example 1.0 dtex or more and 6 It is preferably 0.0 dtex or less, and more preferably 1.5 dtex or more and 5.0 dtex or less. The fineness of the fibers of the lower layer nonwoven fabric 24 is preferably 1.5 dtex or more, more preferably 2.0 dtex or more, preferably 5.0 dtex or less, more preferably 3.0 dtex or less, for example, 1.5 dtex. It is preferably 5.0 dtex or less, and more preferably 2.0 dtex or more and 3.0 dtex or less. The fineness of the fibers of the upper nonwoven fabric 23 and the fineness of the fibers of the lower nonwoven fabric 24 are measured as follows.

<The measuring method of the fineness of the fiber in the surface sheet 2 of diaper 1C>
From the diaper 1A in a state where no load is applied, the topsheet 2 is cut into a rectangular shape of 50 mm × 100 mm (area 5000 mm ² ) to produce a measurement sample. Next, regarding the fineness of the fibers of the upper layer nonwoven fabric 23, the upper layer nonwoven fabric 23 in the measurement sample is viewed in cross-section, and the fiber thickness is measured using an electron microscope for 10 standard fibers, and the fiber thickness is measured. An average value Dn (μm) is calculated. Next, using a differential scanning calorimeter (DSC), the constituent resin of standard fibers of the upper nonwoven fabric 23 is specified, and the theoretical fiber density Pn (g / cm ³ ) is obtained. From the obtained fiber thickness average value Dn (μm) and theoretical fiber density Pn (g / cm ³ ), the weight per 10,000 m of fiber length (g) is calculated, and this calculated value is used as the upper layer. The fineness (dtex) of the fibers of the nonwoven fabric 23 is used. The fineness of the fibers of the lower layer nonwoven fabric 24 is measured in the same manner as the fineness of the fibers on the skin facing surface side with respect to 10 standard fibers as a cross-sectional view of the lower layer nonwoven fabric 24 in the measurement sample.

  Further, in the topsheet 2 of the diaper 1C, the upper nonwoven fabric 23 and the lower nonwoven fabric 24 contain titanium oxide, and the content is preferably 0.5% by mass or more with respect to the total amount of each nonwoven fabric 23, 24. It is 15 mass% or less, More preferably, it is 1.0 mass% or more and 10 mass% or less.

The diaper 1C configured as described above has a surface at the position of the absorbent core 40 excluding the indicator 9 and the non-stacking portion 42 when the disposable diaper is DRY when measured with a color difference meter from the surface sheet 2 side. The color difference (ΔE ^* value) in the L ^* a ^* b ^* color system is 8 or less between the color of the sheet 2 and the color of the surface sheet 2 at the position overlapping the indicator 9 and the non-stacking portion 42, It is preferably 6 or less, more preferably 4 or less, and particularly preferably 3.3 or less. And when measuring with the color difference meter from the surface sheet 2 side, the color of the surface sheet 2 at the position overlapping the indicator 9 and the non-stacking portion 42 at the time of WET of the disposable diaper, and the indicator 9 at the time of DRY of the disposable diaper The color difference (ΔE ^* value) of the color of the topsheet 2 at the position overlapping the stacking section 42 is 32 or less, preferably 26 or less, and more preferably 25 or less.

  As the diaper 1C of 3rd Embodiment is shown in FIG. 7, since the inside mentioned above is provided with the surface sheet 2 of the uneven structure provided with many convex parts 231 of a cavity, the absorptivity with respect to the urination during diaper wear is Further improvement. In addition, the indicator 9 is difficult to be seen through the surface sheet 2 having the concavo-convex structure before urination, and is difficult to be mistaken for having urinated. And the indicator 9 discolored after urination is difficult to be seen through the topsheet 2 having the concavo-convex structure, and the impression of the disposable diaper from the topsheet side after urination can be improved.

  The disposable diaper of this invention is not restrict | limited at all to the disposable diaper 1A-1C of the above-mentioned 1st-3rd embodiment, It can change suitably. Moreover, each component in the disposable diaper 1A-1C of the above-mentioned 1st-3rd embodiment can be implemented suitably combining in the range which does not impair the meaning of this invention.

  For example, in the diapers 1A and 1B described above, the fiber density (D1) on the skin facing surface side is higher than the fiber density (D2) on the non-skin facing surface side. It may be the same as the density (D2) or may be low. Similarly, in the diaper 1C, the fiber density (D4) of the upper nonwoven fabric 23 is higher than the fiber density (D5) of the lower nonwoven fabric 24, but may be the same as the fiber density (D5) of the lower nonwoven fabric 24. It may be low.

  Moreover, in the above-mentioned diaper 1A, the content of titanium oxide on the skin facing surface side is larger than the content of titanium oxide on the non-skin facing surface side. It may be the same as the content or low. Moreover, in the above-mentioned diaper 1B, the content of titanium oxide on the skin facing surface side of the topsheet 2, the content of titanium oxide on the non-skin facing surface side, and the content of titanium oxide in the sublayer 10 are the most. Although the content of titanium oxide on the skin facing surface side is increased, the content of titanium oxide on the non-skin facing surface side may be the highest, and the content of titanium oxide in the sublayer 10 is the highest. It may be. In the diaper 1 </ b> C described above, the content of titanium oxide in the upper nonwoven fabric 23 may be the same as or lower than the content of titanium oxide in the lower nonwoven fabric 24. Further, the content of titanium oxide in the lower layer nonwoven fabric 24 may be the same as or lower than the content of titanium oxide in the upper layer nonwoven fabric 23.

  Moreover, in the diaper 1A-1C mentioned above, as shown in FIG.3, FIG.5, FIG.7, the adhesive agent 8 which fixes the surface sheet 2 and the absorber 4 is the vertical direction (X Is disposed outward in the lateral direction (Y direction) from both side edges along the direction), but may be disposed over the entire skin-facing surface of the absorbent body 4. Moreover, although the adhesive agent which fixes the core wrap sheet | seat 41 and the absorptive core 40 is not applied to the part of the non-stacking fiber part 42, it may be applied also to the part of the non-stacking fiber part 42. .

  Moreover, in the above-mentioned diaper 1C, as shown in FIGS. 6 and 7, the topsheet 2 is a laminated nonwoven fabric having a concavo-convex structure formed from two nonwoven fabrics, an upper nonwoven fabric 23 and a lower nonwoven fabric 24. A laminate of an upper fiber layer containing shrinkable fibers and a lower fiber layer containing fibers that are not heat-shrinkable or fibers that are not heat-shrinkable at the shrinkage start temperature of the heat-shrinkable fibers is partially formed at a number of joints. It may be a laminated nonwoven fabric having a concavo-convex structure in which the upper fiber layer contracts and protrudes between the joints to form a large number of convex parts. Since a large number of convex portions can be formed by partially bonding the laminate and then shrinking the upper fiber layer by hot air treatment, the convex portions have a solid shape.

  Moreover, in the diaper 1A-1C mentioned above, as shown in FIG. 1, the exterior body 5 is a pants-type disposable diaper having a continuous shape such as an hourglass shape extending over the ventral region A, the crotch region C, and the dorsal region B. However, the exterior body 5 may be a split-type pants-type disposable diaper that is divided as a separate member into an abdominal exterior body, a back exterior body, and a crotch exterior body. Moreover, the disposable diaper of this invention can be used suitably for a deployment-type disposable diaper etc. other than a pants-type disposable diaper, for example. The disposable diaper may be a disposable diaper for infants or adults.

  The following disposable diaper is further disclosed regarding the embodiment mentioned above.

<1>
A surface sheet disposed on the skin facing surface side, a back sheet disposed on the non-skin facing surface side, and a vertically long absorbent body disposed between both sheets, the back sheet and the absorber In the meantime, disposable diapers in which indicators that indicate urination due to color changes are arranged continuously in the vertical direction,
The top sheet is a sheet having two layers,
The absorbent body has an absorbent core containing an absorbent polymer, and the absorbent core is formed with a non-stacked fiber portion extending in the longitudinal direction,
In cross-sectional view along the horizontal direction, the indicator is overlapped with the non-stacked portion in the thickness direction in the thickness direction,
When the disposable diaper is measured with a color difference meter from the top sheet side, when the disposable diaper is DRY, the color of the top sheet at the position of the absorbent core excluding the indicator and the non-stacked portion, The color of the topsheet at the position overlapping the indicator and the non-stacked fiber portion is a color difference (ΔE ^* value) of 8 or less in the L ^* a ^* b ^* color system, and the disposable diaper at the time of WET The color of the topsheet at a position overlapping the indicator and the non-stacked fiber portion and the color of the topsheet at the position overlapping the indicator and the non-stacked fiber portion at the time of DRY of the disposable diaper are the color difference ( A disposable diaper having a ΔE ^* value of 32 or less.

<2>
The disposable diaper according to <1>, wherein the topsheet is a laminated nonwoven fabric having an uneven structure or a laminated nonwoven fabric having a flat structure.
<3>
The said surface sheet is a disposable diaper as described in said <1> or <2> in which the fiber density of the skin opposing surface side is high compared with the fiber density of the non-skin opposing surface side.
<4>
The surface sheet has a ratio (D1 / D2) of the fiber density (D1) on the skin facing surface side to the fiber density (D2) on the non-skin facing surface side of 1.1 to 10 and preferably 1.2 to 5 The disposable diaper according to <3>, which is the following.
<5>
The fiber density (D1) on the skin facing surface side of the surface sheet is 0.01 g / cm ³ or more, preferably 0.02 g / cm ³ or more, 0.1 g / cm ³ or less, preferably 0.05 g / cm. The disposable diaper according to <1> to <4>, which is cm ³ or less.
<6>
Fiber density of the non-skin facing side of the topsheet (D2) is, 0.005 g / cm ³ or higher, preferably 0.01 g / cm ³ or more, 0.05 g / cm ³ or less, preferably 0.04g The disposable diaper according to any one of <1> to <5>, which is / cm ³ or less.
<7>
The top sheet and the absorber are fixed with an adhesive,
In cross-sectional view along the lateral direction, the adhesive is arranged in the thickness direction in the laterally outward direction from both side edges along the longitudinal direction of the non-stacked portion. The disposable diaper according to any one of 3>.
<8>
The absorbent body has a core wrap sheet covering the absorbent core and the absorbent core,
Adhesive is not applied to the non-stacked fiber portion of the absorbent core. In the non-stacked fiber portion, the core wrap sheet on the skin facing surface side of the absorbent core, and the absorbent core The disposable diaper according to any one of <1> to <7>, wherein the core wrap sheet on the non-skin facing surface side is not fixed.
<9>
The said surface sheet is a disposable diaper any one of said <1>-<8> which contains the titanium oxide in the skin opposing surface side.
<10>
The content of titanium oxide on the skin facing surface side of the surface sheet is 0.5% by mass or more and 15% by mass or less, preferably 1.0% by mass or more and 10% by mass with respect to the total amount of the surface sheet on the skin facing surface side. The disposable diaper according to <9>, wherein the disposable diaper is not more than% by mass.
<11>
The said surface sheet is a disposable diaper as described in said <9> or <10> in which content of the titanium oxide of the skin opposing surface side is large compared with content of the titanium oxide of the non-skin opposing surface side.

<12>
The surface sheet is a laminated nonwoven fabric having a flat structure,
The content of titanium oxide on the non-skin facing surface side of the surface sheet is 0.05% by mass or more and 1.0% by mass or less, preferably 0.1% with respect to the total amount of the non-skin facing surface side of the surface sheet. The disposable diaper according to any one of <8> to <11>, wherein the disposable diaper is not less than 0.5% by mass and not more than 0.5% by mass.
<13>
Between the top sheet and the absorbent body, comprising a liquid-permeable sublayer wider than the non-stacked portion,
The disposable diaper according to any one of <1> to <12>, wherein the sublayer overlaps with the non-stacked fiber portion and the indicator in a thickness direction when viewed in cross-section along a lateral direction. .
<14>
The fiber density (D3) of the sublayer is lower than the fiber density (D1) on the skin facing surface side and the fiber density (D2) on the non-skin facing surface side of the top sheet <13>. Disposable diapers described in 1.
<15>
Of the fiber density (D1) on the skin facing surface side of the surface sheet, the fiber density (D2) on the non-skin facing surface side of the surface sheet, and the fiber density (D3) of the sublayer, The disposable diaper according to <13> or <14>, wherein the fiber density (D1) is the highest, and the fiber density (D3) of the sublayer is the lowest.
<16>
The ratio (D1 / D3) of the fiber density (D1) on the skin facing surface side of the top sheet to the fiber density (D3) of the sublayer is 1.05 or more and 10 or less, preferably 1.1 or more and 5. The disposable diaper according to any one of <13> to <15>, which is 0 or less.
<17>
Fiber density of the sublayer (D3) is, 0.01 g / cm ³ or more, preferably 0.02 g / cm ³ or more, 0.1 g / cm ³ or less, is preferably 0.05 g / cm ³ or less The disposable diaper according to any one of <13> to <16>.
<18>
Any one of the above items <13> to <17>, wherein the sublayer has a basis weight of 20 g / m ² or more, preferably 30 g / m ² or more, and 100 g / m ² or less, preferably 80 g / m ² or less. The disposable diaper according to 1.
<19>
The disposable diaper according to any one of <13> to <18>, wherein the fineness of the fibers of the sublayer is 3 dtex or more, more preferably 5 dtex or more, preferably 12 dtex or less, more preferably 10 dtex or less.

<20>
The sublayer contains titanium oxide;
The content of titanium oxide on the skin facing surface side of the surface sheet is greater than the content of titanium oxide on the non-skin facing surface side of the surface sheet and the content of titanium oxide in the sublayer < The disposable diaper according to any one of 8> to <19>.
<21>
The sublayer contains titanium oxide;
The titanium oxide content of the sublayer is 0.05% by mass or more and 1.0% by mass or less, preferably 0.1% by mass or more and 0.5% by mass or less, based on the total amount of the sublayer. The disposable diaper according to any one of 13> to <20>.
<22>
The surface sheet color at the position of the absorbent core excluding the indicator and the non-stacked fiber portion and the color of the surface sheet at a position overlapping the indicator and the non-stacked fiber portion are L ^* a ^* b ^*. The disposable diaper according to any one of <1> to <21>, wherein the color difference (ΔE ^* value) in the color system is 8 or less, preferably 5 or less.
<23>
At the time of WET of the disposable diaper, the color of the surface sheet at a position overlapping with the indicator and the non-stacked fiber portion, and the position at the position of overlapping the indicator and the non-stacked fiber portion at the time of DRY of the disposable diaper The disposable diaper according to any one of <1> to <22>, wherein the color of the topsheet is a color difference (ΔE ^* value) of 32 or less, preferably 27 or less.
<24>
The basis weight on the skin facing surface side of the surface sheet is 5 g / m ² or more, preferably 10 g / m ² or more, 30 g / m ² or less, preferably 25 g / m ² or less <1> to < The disposable diaper according to any one of 23>.
<25>
The basis weight on the non-skin facing surface side of the surface sheet is 5 g / m ² or more, preferably 8 g / m ² or more, 15 g / m ² or less, preferably 13 g / m ² or less <1> to The disposable diaper according to any one of <24>.
<26>
The disposable according to any one of <1> to <25>, wherein the fineness of the fibers on the skin facing surface side of the surface sheet is lower than the fineness of the fibers on the non-skin facing surface side of the surface sheet. Diapers.
<27>
The fineness of the fiber on the skin facing surface side of the top sheet is 1.0 dtex or more, preferably 1.5 dtex or more, 5.0 dtex or less, preferably 4.0 dtex or less. <1> to <26> The disposable diaper according to any one of the above.
<28>
The surface sheet is a laminated nonwoven fabric having a flat structure,
Any one of the above items <2> to <27>, wherein the fineness of the fiber on the non-skin facing surface side of the surface sheet is 2.0 dtex or more, preferably 3.0 dtex or more, 10 dtex or less, preferably 8.0 dtex or less. The disposable diaper according to claim 1.

<29>
The <1> to <28, wherein the indicator is disposed in the lateral direction center of the disposable diaper in the lateral direction, is disposed within the range of the width of the non-stacked fiber portion, and overlaps the non-stacked fiber portion. > The disposable diaper of any one of>.
<30>
The indicator is formed in the longitudinal direction along the non-stacking portion, and extends beyond the ventral region side end and the dorsal region side end of the non-stacking portion. The disposable diaper according to any one of <1> to <29>.
<31>
The absorbent body has a core wrap sheet covering the absorbent core and the absorbent core,
The indicator is disposed between the core wrap sheet of the absorber and the back sheet, and any one of <1> to <30> disposed on the skin facing surface of the back sheet. The disposable diaper described.
<32>
The indicator is two elongated lines arranged symmetrically in parallel with a center line CL extending in the longitudinal direction of the disposable diaper, and each of the two elongated linear indicators is in the longitudinal direction. The disposable diaper according to any one of <1> to <31>, wherein the disposable diaper is arranged linearly from the crotch region to the ventral region and the dorsal region.
<33>
The surface sheet has an upper layer nonwoven fabric and a lower layer nonwoven fabric,
Fiber density of the upper layer nonwoven fabric (D4) is, 0.005 g / cm ³ or higher, preferably 0.01 g / cm ³ or more, 0.05 g / cm ³ or less, is preferably 0.04 g / cm ³ or less The disposable diaper according to <2> or <3>.
<34>
The disposable diaper according to <33>, wherein the upper layer nonwoven fabric has a basis weight of 10 g / m ² or more, preferably 15 g / m ² or more, and 50 g / m ² or less, preferably 30 g / m ² or less.
<35>
Fiber density of the lower layer nonwoven fabric (D5) is, 0.01 g / cm ³ or more, preferably 0.02 g / cm ³ or more, 0.1 g / cm ³ or less, is preferably 0.05 g / cm ³ or less The disposable diaper according to <33> or <34>.
<36>
Any of the above <33> to <35>, wherein the basis weight of the lower layer nonwoven fabric is 10 g / m ² or more, preferably 15 g / m ² or more, 50 g / m ² or less, preferably 30 g / m ² or less. The disposable diaper according to 1.
<37>
The surface sheet is a laminated nonwoven fabric with a concavo-convex structure,
The fineness of the fibers of the upper layer nonwoven fabric is 1.0 dtex or more, preferably 1.5 dtex or more, 6.0 dtex or less, preferably 5.0 dtex or less, according to any one of the above items <33> to <36>. Disposable diapers.
<38>
The surface sheet is a laminated nonwoven fabric with a concavo-convex structure,
The fineness of the fibers of the lower layer nonwoven fabric is 1.5 dtex or more, preferably 2.0 dtex or more, 5.0 dtex or less, preferably 3.0 dtex or less, according to any one of <33> to <37>. Disposable diapers.
<39>
The surface sheet is a laminated nonwoven fabric with a concavo-convex structure,
The color of the topsheet at the position of the absorbent core excluding the indicator and the non-stacked fiber portion and the color of the topsheet at the position overlapping the indicator and the non-stacked fiber portion are L ^* a ^*. The disposable diaper according to any one of <1> to <38>, wherein the color difference (ΔE ^* value) in the b ^* color system is 6 or less, preferably 4 or less, and more preferably 3.3 or less.
<40>
The color of the surface sheet at the position overlapping the indicator and the non-stacked fiber part when the disposable diaper is wet, and the surface at the position overlapping the indicator and the non-stacked fiber part when the disposable diaper is DRY The disposable diaper according to any one of <1> to <39>, wherein the color of the sheet is a color difference (ΔE ^* value) of 26 or less, preferably 25 or less.

  Hereinafter, the disposable diaper of this invention is demonstrated still in detail by an Example. However, the scope of the present invention is not limited by the examples.

<Example 1>
A pants-type disposable diaper having the same basic configuration as the diaper 1 </ b> A shown in FIGS. 1 to 3 was produced and used as a sample of Example 1. As the top sheet, a two-layer air-through nonwoven fabric formed by superposing the upper fiber web on the skin facing surface side and the lower fiber web on the non-skin facing surface side was used. Fiber density of the upper layer is 0.038 g / cm ^3, the lower the fiber density of 0.020 g / cm ^3. Further, the basis weight of the upper layer was 15 g / m ² , and the basis weight of the lower layer was 10 g / m ² . Further, the fineness of the upper layer fiber was 2.0 dtex, and the fineness of the lower layer fiber was 5.6 dtex. Furthermore, the content of the upper layer titanium oxide was 3.0% by mass, and the content of the lower layer titanium oxide was 0.3% by mass or less. Further, the absorbent core had a basis weight of 550 g / m ² and a thickness of 10 mm. The width of the non-stacked portion formed in the absorbent core was 20 mm. The basis weight of the indicator was 25 g / m ² .

<Example 2>
A pants-type disposable diaper having the same basic configuration as the diaper 1 </ b> B shown in FIGS. 4 to 5 was produced and used as a sample of Example 2. Specifically, in the sample of Example 1, a sublayer was disposed between the top sheet and the absorber to prepare the sample of Example 2. The sublayer has a fiber density of 0.035 g / cm ³ , a basis weight of 40 g / m ² , a fiber fineness of 7.8 dtex, and a titanium oxide content of 0.3 mass. % Or less.

<Example 3>
A pants-type disposable diaper having the same basic configuration as the diaper 1 </ b> C shown in FIGS. 6 to 7 was prepared and used as a sample of Example 3. Specifically, in the sample of Example 1, the topsheet was replaced with a laminated nonwoven fabric having a concavo-convex structure formed by superposing two nonwoven fabrics of an upper layer nonwoven fabric and a lower layer nonwoven fabric, and the rest was the same as in Example 1. Thus, a sample of Example 3 was produced. Fiber density of the upper layer nonwoven fabric is 0.022 g / cm ^3, the fiber density of the lower layer nonwoven fabric was 0.026 g / cm ^3. The basis weight of the upper layer nonwoven fabric was 18 g / m ² , and the basis weight of the lower layer nonwoven fabric was 18 g / m ² . Further, the fineness of the fibers of the upper non-woven fabric was 2.2 dtex, and the fineness of the fibers of the lower non-woven fabric was 4.4 dtex. Furthermore, the content of titanium oxide in the upper layer nonwoven fabric was 3.0% by mass, and the content of titanium oxide in the lower layer nonwoven fabric was 3.0% by mass. Moreover, the convex part of the laminated nonwoven fabric of uneven structure was 4 mm in length in the vertical direction (X direction), 3 mm in length in the horizontal direction (Y direction), and 2 mm in height.

<Example 4>
In the sample of Example 3, the sublayer was disposed between the top sheet and the absorber to prepare the sample of Example 4. The sublayer has a fiber density of 0.035 g / cm ³ , a basis weight of 40 g / m ² , a fiber fineness of 7.8 dtex, and a titanium oxide content of 0.3 mass. % Or less.

<Example 5>
In the sample of Example 3, the fiber density of the upper non-woven fabric was changed to 0.033 g / cm ^3, and the basis weight of the upper non-woven fabric was changed to 20 g / m ^2. The sample of Example 5 was produced by arranging the layers. The sublayer has a fiber density of 0.035 g / cm ³ , a basis weight of 40 g / m ² , a fiber fineness of 7.8 dtex, and a titanium oxide content of 0.3 mass. % Or less.

<Comparative Example 1>
In the sample of Example 1, the surface sheet was changed to a single-layer air-through nonwoven fabric, and the sample of Comparative Example 1 was produced in the same manner as in Example 1 except that. The single-layer air-through nonwoven fabric has a fiber density of 0.028 g / cm ³ , a basis weight of 25 g / m ² , a fiber fineness of 3.0 dtex, and a titanium oxide content of It was 0.3 mass% or less.

<Evaluation>
With respect to the pants-type disposable diapers of Examples 1 to 5 and Comparative Example 1, each diaper was unfolded and stretched, and the color difference at the time of DRY (ΔE ^* value) and the color difference at the time of WET (ΔE ^* ) by the method described above ^. Value). The results are shown in Table 1 below.

Moreover, regarding the pants-type disposable diapers of Examples 1 to 5 and Comparative Example 1, each diaper was unfolded and stretched and placed on a horizontal table so that the topsheet was on top. And 10 professional panelists evaluated the appearance at the time of the said DRY and the appearance at the time of the said WET. The evaluation criteria were scored with 3 points when the indicator was difficult to visually permeate through the top sheet, 2 points when the indicator was slightly difficult to visually recognize, and 1 point when the indicator was easily visible, and the average value was calculated. Evaluation was scored according to the following criteria.

A: Average value is 2.5 or more and 3 or less B: Average value is 2.0 or more and less than 2.5 C: Average value is 1.0 or more and less than 2.0

  According to the results in Table 1, the disposable diapers of Example 1 to Example 5 are compared with the disposable diaper of Comparative Example 1 in that the measured value and the sensory evaluation are transmitted through the top sheet at the DRY. It can be expected that it will be difficult to be mistaken for urinating before use. Moreover, according to the result of Table 1, the disposable diaper of Example 1- Example 5 compared with the disposable diaper of the comparative example 1, and both the measured value and sensory evaluation have an indicator as a surface sheet at the time of WET. It is difficult to see through and can be expected to improve the impression of the diaper when viewed from the surface sheet side after use.

1A, 1B Pants-type disposable diaper 2 Top sheet 21 Upper layer 22 Lower layer 23 Upper layer nonwoven fabric 24 Lower layer nonwoven fabric 3 Back sheet 4 Absorber 40 Absorbent core 41 Core wrap sheet 42 Non-stacked fiber part 5 Side cuff 6 Absorbent body 7 Exterior body 8 Adhesive 9 Indicator 10 Sublayer A Ventral area, B Dorsal area, C Inseam area

Claims (7)

A surface sheet disposed on the skin facing surface side, a back sheet disposed on the non-skin facing surface side, and a vertically long absorbent body disposed between both sheets, the back sheet and the absorber In the meantime, disposable diapers in which indicators that indicate urination due to color changes are arranged continuously in the vertical direction,
The top sheet is a sheet having two layers,
The absorbent body has an absorbent core containing an absorbent polymer, and the absorbent core is formed with a non-stacked fiber portion extending in the longitudinal direction,
In cross-sectional view along the lateral direction, the indicator overlaps the non-stacked portion in the thickness direction,
When the disposable diaper is measured with a color difference meter from the top sheet side, when the disposable diaper is DRY, the color of the top sheet at the position of the absorbent core excluding the indicator and the non-stacked portion, The color of the topsheet at the position overlapping the indicator and the non-stacked fiber portion is a color difference (ΔE ^* value) of 8 or less in the L ^* a ^* b ^* color system, and the disposable diaper at the time of WET The color of the topsheet at a position overlapping the indicator and the non-stacked fiber portion and the color of the topsheet at the position overlapping the indicator and the non-stacked fiber portion at the time of DRY of the disposable diaper are the color difference ( A disposable diaper having a ΔE ^* value of 32 or less.   The disposable diaper according to claim 1, wherein the topsheet is a laminated nonwoven fabric having a concavo-convex structure.   The disposable diaper according to claim 1 or 2, wherein the surface sheet has a fiber density on the skin facing surface side that is higher than a fiber density on the non-skin facing surface side. The top sheet and the absorber are fixed with an adhesive,
The cross-sectional view along a horizontal direction WHEREIN: The said adhesive agent is distribute | arranged laterally outward rather than the both-sides edge along the vertical direction of the said non-stacking part in thickness direction. The disposable diaper of any one of Claims.   The disposable diaper according to any one of claims 1 to 4, wherein the surface sheet contains titanium oxide on the skin facing surface side.   The disposable diaper according to any one of claims 1 to 5, wherein the surface sheet has a larger content of titanium oxide on the skin facing surface side than a content of titanium oxide on the non-skin facing surface side. Between the top sheet and the absorbent body, comprising a liquid-permeable sublayer wider than the non-stacked portion,
The disposable diaper according to any one of claims 1 to 6, wherein the sub-layer overlaps the non-stacked portion and the indicator in a thickness direction as viewed in a cross-section along a lateral direction.

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