JP6400462B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as disposable diapers and urine pads.

  As an absorbent used for absorbent articles such as disposable diapers, an absorbent core obtained by mixing and mixing hydrophilic fibers such as pulp and a superabsorbent polymer, and a hydrophilic core that wraps the absorbent core and maintains the shape retention of the absorbent core There are things that consist of sex core wrap sheets. A thin paper, a hydrophilic nonwoven fabric, or the like is used as the material for the core wrap sheet. Several proposals have been made for such absorbers.

For example, Patent Literature 1 describes an absorbent article with an indicator that informs the replacement time of an absorbent core that has a high basis weight part and a low basis weight part as an absorbent core. The high basis weight portion and the low basis weight portion of the absorbent core are alternately arranged along the direction in which the indicator extends so that the indicator changes color even with a small amount of excretion.
Patent Document 2 describes an absorbent body in which a liquid-absorbing mixture and a nonwoven fabric are covered with tissue paper. The nonwoven fabric has anisotropy in tensile strength so that fuzz is likely to occur due to friction or the like.
Patent Document 3 describes an absorbent body in which a pulp layer, a superabsorbent polymer layer, and a fiber sheet are covered with a core wrap sheet. In order to carry the absorbent material containing the superabsorbent polymer, the fiber sheet has the raised region dispersed on the front surface.

JP2013-255559A JP 2008-142424 A JP 2013-5880 A

In conventional absorbent articles with an indicator, if the absorbent core includes a superabsorbent polymer, the indicator may be accidentally discolored prior to use of the article. This is because the superabsorbent polymer easily absorbs moisture in the air and contains moisture before use. Inside the absorbent body, if the superabsorbent polymer spills from the absorbent core stack while containing moisture and is strongly pressed against the indicator through the core wrap sheet, this moisture will ooze out and discolor the indicator .
For example, disposable diapers and the like are folded and closely packed in a packaging bag for sale, so that the absorbent body is easily pressed against the indicator, and changes such as spot-like discoloration may occur even before use. is there. Further, even after the disposable diaper is taken out from the packaging bag, a change such as a spot-like discoloration may occur in the same manner depending on the humidity state until storage and the storage state. When this discoloration or the like is extremely small, the function of the indicator is not impaired. However, this may give the user misunderstanding and anxiety regarding hygiene and quality of the product at the point of sale. In order to get rid of such anxiety and to use it with peace of mind, such discoloration must be avoided.

  Usually, if the core wrap sheet is a paper material such as thin paper, the core wrap sheet has a certain amount of water retention, so that the influence of the moisture can be prevented to some extent. However, when the core wrap sheet is a hydrophilic non-woven fabric, it has poor water retention even though it has water permeability.

  On the other hand, a nonwoven fabric is particularly preferred as a core wrap sheet for covering an absorbent core from the viewpoint of softness of the absorbent article incorporating the absorbent body and prevention of tearing. Therefore, when a hydrophilic nonwoven fabric is used as the core wrap sheet, it is strongly desired to prevent the influence of the minute moisture contained in the superabsorbent polymer on the indicator.

  Accordingly, the present invention uses a core wrap sheet made of a hydrophilic non-woven fabric, and at the same time, has a soft touch and at the same time prevents an unnecessary discoloration of the indicator and improves the reliability of the indicator. About.

  The present invention is an absorbent article comprising a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorber disposed between both sheets, Between the back sheet and the absorbent body, an indicator part that changes visually by contact with liquid is disposed, and the absorbent body includes an absorbent core having hydrophilic fibers and a superabsorbent polymer. A core wrap sheet made of a hydrophilic non-woven fabric covering the absorbent core, and the core wrap sheet is non-skin-contacted via a side portion from the skin-contact surface side of the absorbent core. Covering the surface side, forming an overlapping portion by both end portions of the core wrap sheet on the non-skin contact surface side, and wrapping the absorbent core, the overlapping portion being out of both end portions of the core wrap sheet At least at the end located on the non-skin contact surface side, It is provided with a raised portion where the fibers of the nonwoven fabric are raised, and the region having the raised portion of the overlapping portion is arranged to overlap the indicator portion, and the overlapping portion of the core wrap sheet is joined with an adhesive, Provided is an absorbent article in which the area ratio of the adhesive applied to the area of the region having the raised portion of the overlapping portion is 50% or less.

  The absorbent article of the present invention should be used with peace of mind by using a core wrap sheet made of a hydrophilic non-woven fabric to prevent changes in the indicator such as unnecessary discoloration at the same time as soft touch and improve the reliability of the indicator. Can do.

It is the partially notched top view which showed typically the state seen from the non-skin contact surface side in the state which expand | deployed and expand | deployed the expansion | deployment type disposable diaper as preferable one Embodiment of the absorbent article of this invention. It is sectional drawing of the II-II line cross section of FIG. It is explanatory drawing which showed typically the method of measuring the number of the raising fiber of a nonwoven fabric, (A) is a figure which shows the state which folded the nonwoven fabric, (B) is a nonwoven fabric of (A) with a window. It is a figure which shows the state which accumulated the black mount, (C) is a figure which shows a mode that a raising fiber is observed from the window of a black mount. It is the top view which showed typically the state which wants to planarly view another preferable aspect of the arrangement | positioning area | region of a raising part from the back surface sheet side. It is the top view which showed typically the state which wants to planarly view another preferable aspect of the arrangement | positioning area | region of a raising part from the back surface sheet side. It is the top view which showed typically the state which wants to planarly view another preferable aspect of the arrangement | positioning area | region of a raising part from the back surface sheet side. It is the partially expanded sectional view which showed typically another preferable aspect about the absorber used for this embodiment. It is the top view which showed typically the state which planarly viewed the aspect preferable as a coating area | region of the adhesive agent which joins a back surface sheet and an absorber from the back surface sheet side. It is a figure which shows one specific example of a raising part process process, (A) shows partial extending | stretching process, (B) is the cross section which expanded partially and showed the meshing state of a pair of uneven | corrugated roll in partial extending | stretching process It is a figure, (C) shows raising process, (D) is the schematic diagram which expanded and showed the part shown with the circle | round | yen of the code | symbol d1 in (C).

  As a preferred embodiment of the absorbent article according to the present invention, a deployable disposable diaper 10 (hereinafter also simply referred to as diaper 10) will be described below with reference to the drawings.

  In this specification, unless otherwise specified, the side that is relatively in contact with the human body is referred to as the skin contact surface side, the skin surface side, or the surface, and the opposite side is referred to as the non-skin contact surface side or the non-skin surface side. Or called the back side. The direction located on the ventral side of the human body when worn is called the front, its end is called the front end, the direction located on the back side or the buttock side is called the back, and its end is called the rear end. Moreover, the normal line direction of the surface or back surface of an absorbent article is called thickness direction, and the quantity is called thickness. Furthermore, the direction from the abdominal side part through the crotch part to the dorsal side part when viewed in plan with the absorbent article deployed is called the longitudinal direction (Y direction), and the direction perpendicular to the longitudinal direction is the width. It is called a direction (X direction). The longitudinal direction coincides with the front-rear direction of the human body when worn.

  As shown in FIGS. 1 and 2, the deployable disposable diaper 10 of the present embodiment includes a liquid-permeable surface sheet 1 disposed on the skin contact surface side, a moisture permeable surface disposed on the non-skin contact surface side, and A liquid-impermeable back sheet 2 and an absorber 3 interposed between the two sheets are provided. Furthermore, it has the exterior sheet | seat 8 which consists of a nonwoven fabric in the non-skin contact surface side of the back surface sheet 2. FIG. As a result, the outer surface has a soft touch. On the other hand, it has a pair of side sheets 9 and 9 on both sides in the longitudinal direction of the top sheet 1. A leak-proof cuff 92 is formed by disposing elastic members 91, 91 in an expanded state at the inner free end in the width direction of the side seat 9. Wreck gathers are formed by disposing elastic members 93, 93 outside the side sheets 9, 9 in the width direction. The diaper 10 integrated in this configuration is in the deployed state in the longitudinal direction (Y direction) on the abdominal side F, crotch C and back side R corresponding to the wearer's abdomen, crotch and dorsal side. You can ward. As a whole, the shape of the hourglass is such that the crotch part C is bound inward in the width direction. The back side portion R and the ventral side portion F have a back side flap portion 17 and a ventral side flap portion 18 extending in the width direction. Fastening tapes 19, 19 which are fixing members to the portion corresponding to the abdomen side portion F of the exterior sheet 8 at the time of wearing are disposed on the back flap 17.

  In the present embodiment, between the absorber 3 and the back sheet 2, the color or the like is changed by the contact with the liquid disposed corresponding to the raised portions 7 that adjust the contact with the liquid. It has an indicator section 6. This change of the indicator part 6 can be visually recognized from the outside when the diaper 10 is worn, and can notify the replacement time of the diaper 10 accompanying urination or the like. This “visible change” means a color change from one color to another, a color disappearance from colored to colorless, and a color expression from colorless to colored by contact with the liquid.

  The indicator part 6 is formed along the longitudinal direction centering on the crotch part C so that it can be visually recognized at an appropriate timing and can be visually recognized from the outside. In the present embodiment, three indicator portions 6 (6a, 6b, 6c) are arranged from the crotch portion C to the ventral side portion F and the back side portion R near the center in the width direction of the absorber 3. More specifically, the indicator part 6b is arrange | positioned in the width direction (X direction) centerline C1 vicinity of the diaper 10, and indicator parts 6a and 6c are arrange | positioned at equal intervals in the left-right width direction. The indicator portion 6a to the indicator portion 6c are arranged in a range of the width H3 with respect to the width H1 of the absorber 3. Each indicator section 6 is shorter than the length T1 of the absorbent body 3 and is arranged with a length T3 centering on the crotch part C that receives the liquid most. This length T3 is a length up to a position where the indicator portion 6 can be seen from the outside when the diaper 10 is mounted. An area where the three indicator portions 6 a to 6 c are arranged is an indicator area 61. Note that the number of the indicator units 6 and the interval between them are not limited to those in the present embodiment, and can be arbitrarily set depending on the application, the size of the article, and the like. In accordance with this setting, the range of the indicator area 61 also changes.

  The indicator part 6 is formed using the hydrophilic composition containing the coloring indicator which a color changes with a change of pH, for example. Moreover, it is preferable that the indicator part 6 consists of a hot-melt composition containing the mixture of the said color indicator and an adhesive substance. With the adhesive substance, the color indicator is fixed to the application surface, and adhesion of the color indicator to other members and penetration into the absorber can be prevented. As a method for arranging the indicator section 6, a method used for this type of article can be adopted. For example, a method of directly applying a discolorable agent such as the above composition to the non-skin contact surface of the back sheet 2, or a sheet member such as a tissue paper or hydrophilic nonwoven fabric coated or impregnated with the above agent is disposed. Methods and the like.

  The absorbent body 3 is laminated on the skin contact surface side of the indicator part 6, and the thick overlapping part 53 and the bulky raised part 7 of the core wrap sheet 5 constituting the absorbent body 3 are arranged correspondingly. ing. Thereby, the unnecessary discoloration etc. of the indicator part 6 before using the diaper 10 are prevented. This configuration and its operation will be described in detail below.

  As shown in FIG. 2, the absorbent body 3 is composed of an absorbent core 4 that absorbs and holds liquid and a single core wrap sheet 5 made of a hydrophilic nonwoven fabric. The absorptive core 4 contains a hydrophilic fiber 41 and a superabsorbent polymer 42, and is mixed and woven. The core wrap sheet 5 covers the outer surface in order to maintain the shape of the absorbent core 4. Specifically, the core wrap sheet 5 covers the non-skin contact surface side through the side portion from the skin contact surface side of the absorbent core 4. At this time, the core wrap sheet 5 wraps the absorbent core 4 by forming an overlapping portion 53 by both end portions 51 and 52 of the core wrap sheet 5 on the non-skin contact surface side. The both end portions 51 and 52 are regions having a width for wrapping and fixing the absorbent core 4 and have a width that can sufficiently cover the above-described region where the indicator portion 6 is disposed. When the core wrap sheet 5 is made of a nonwoven fabric, the shape retention of the absorbent body 3 is enhanced, and at the same time, the softness when the diaper 10 is touched from the top sheet 1 side is improved.

  The overlapping portion 53 is formed by joining both end portions 51 and 52 with an adhesive such as a hot melt type, and has a thickness of two sheets. The adhesive maintains the distance between the absorbent core 4 and the indicator part 6 without shifting the stacking of the ends of the overlapping part 53.

  The overlapping portion 53 covers the region 61 of the indicator portion 6 as a thick portion. In the present embodiment, the absorber 3 is formed along the longitudinal direction (Y direction) with a width H2 at the center in the width direction. The overlapping portion 53 is formed over the entire length T1 in the longitudinal direction (Y direction) of the core wrap sheet 5. This length T1 coincides with the entire length of the absorbent body 3 in the longitudinal direction (Y direction). The width H2 and the length T1 in the longitudinal direction of the overlapping portion 53 are a width and a length that can sufficiently cover the region 61 where the indicator portion 6 is disposed.

  The overlapping portion 53 further has a bulky raised portion 7. The raised portions 7 are bulky portions where a plurality of non-woven fibers forming the core wrap sheet 5 are fluffed. It becomes a layer with a coarse fiber density due to the fluff of the fibers, and the thick overlapping portion 53 is further bulked. Thereby, distance further spreads between the absorptive core 4 and the indicator part 6, and the contact area of the indicator part 6 and the core wrap sheet | seat 5 is suppressed.

  The raised portion 7 is disposed on the end portion 51 located at least on the non-skin contact surface side of the both end portions 51 and 52 of the core wrap sheet 5 (the raised portion disposed on the end portion 51 is the other end portion 52. The raised portion is also referred to as a raised portion 7A). In the present embodiment shown in FIG. 2, the raised portions 7A are arranged on the end portion 51 located on the non-skin contact surface side. The raised portion 7A may be either one of the non-skin contact surface and the skin contact surface of the end portion 51, or may be on both surfaces. In the present embodiment shown in FIG. 2, the raised portions 7 </ b> A are disposed on the non-skin contact surface side of the end portion 51.

  The raised portion 7 is formed in a range that covers the indicator portion 6. That is, the region 53 </ b> A provided with the raised portions 7 of the overlapping portion 53 is arranged so as to overlap the indicator portion 6. In the present embodiment, the raised portion 7 has a width that matches the width H2 of the overlapping portion 53 and has a length T2 that is slightly longer than the length T3 in the longitudinal direction (Y direction) of the indicator portion 6 with the crotch portion C as the center. It is arranged. The region where the raised portions 7 are disposed is the aforementioned region 53A.

  Thus, the region 53A provided with the bulky and rough raised portions 7 of the thick overlapping portion 53 is arranged so as to overlap the indicator portion 6 described above. This area | region 53A prevents the transfer to the indicator part 6 of minute moisture before using the diaper 10. FIG. The operation of the region 53A will be described below.

  The region 53A has a thickness in which the fluff of the raised portion 7 and the overlapping portion 53 are combined. Moreover, in the raised portion 7, the distance between the absorbent core 4 and the indicator portion 6 located outside the absorbent body 3 can be maintained like a brush of fibers. Thereby, the transfer (exudation) of minute moisture of the superabsorbent polymer 42 is suppressed by the physical distance due to the thickness of the overlapping portion 53 and the fluffing of the raised portion 7. As a result, unnecessary discoloration or the like of the indicator unit 6 before using the diaper 10 can be prevented. Moreover, the raising part 7 can reduce the contact area between the members by the pressing force from the outside, and can avoid contact | adherence. This is an effect that cannot occur if the smooth surfaces of the sheets simply overlap. For example, when the raised portion 7 is at the end portion 51 on the non-skin contact surface side of the overlapping portion 53, even if the absorbent core 4 is in contact with the other end portion 52, it is between the end portion 52 and the indicator portion 6. I can make a distance. This is the same regardless of whether the raised portion 7A is on the non-skin contact surface or the skin contact surface of the end portion 51. Thereby, even if the pressure by which the diaper 10 is folded and compressed for packaging is applied, the absorptive core 4 is prevented from closely contacting the indicator part 6 via the overlapping part 53.

  Thus, the combination of the sheet thickness of the overlapping portion 53 and the fluff thickness of the raised portion 7 maintains a distance that hinders the transfer of minute moisture due to compression. In particular, at least the raised portions 7A at the end portion 51 on the non-skin contact surface side can directly separate the flat surface of the core wrap sheet 5 from the indicator portion 6 and reduce the contact area. As a result, even if the superabsorbent polymer 42 slightly containing moisture adheres to the end portion 52 of the overlapping portion 53 before the diaper 10 is used, the minute moisture is hardly transferred to the indicator portion 6. As such a raised portion 7, in addition to the raised portion 7A of the end portion 51 on the non-skin contact surface side, and the raised end portion 7B at the other end portion 52 (not shown), the above action is further achieved. It will be effective. The raised portion 7B in this case may be on either the non-skin contact surface or the skin contact surface of the end portion 52, similarly to the raised portion 7A.

  On the other hand, when the diaper 10 is used, the raised portion 7 can be transferred from the absorbent body 3 to the indicator portion 6 with good timing without hindering permeation of normal urination or the like. Thereby, discoloration of the indicator part 6 which notifies a diaper replacement time arises with sufficient timing. This is realized in combination with the above-described prevention of migration of minute moisture before use, because the raised portion 7 is made of fibers constituting a hydrophilic nonwoven fabric and is a rough layer of fluffed fibers. That is, the raised portion 7 maintains a physical distance in which the indicator portion 6 is difficult to be in close contact with the absorbent core 4 with a coarse fiber layer before use, and prevents the transfer of minute moisture. On the other hand, when the diaper 10 is used, the hydrophilic rough layer is shifted to the indicator unit 6 without particularly hindering a large amount of urination during use.

  As described above, the end portion 51 and the end portion 52 are joined to the overlapping portion 53 provided with the raised portions 7 with an adhesive such as a hot melt type. However, the coating area of the adhesive is suppressed to be small so that the fluffing of the raised portions 7 having the above-described effects is sufficiently maintained. Specifically, the coating area ratio of the adhesive with respect to the area of the region 53A including the raised portions 7 of the overlapping portion 53 is set to 50% or less. The coating area ratio is more preferably 45% or less, still more preferably 40% or less. On the other hand, 10% or more is preferable, 20% or more is more preferable, and 30% or more is still more preferable from the viewpoint of securing the bonding strength between the end portion 51 and the end portion 52.

The coating area ratio is measured by the following method.
A test piece is cut out from the core wrap sheet 5 so as to include the entire overlapping portion 53. After spraying toner on the test piece to color the adhesive, a part of the overlapping portion 53 is cut out to a predetermined size and the area of the colored portion is measured. By dividing the area of the colored portion by the area of a predetermined size cut out, the coating area ratio can be obtained.

  The adhesive is preferably applied in a pattern with the above-mentioned coating area ratio, with a plurality of non-coated portions interposed in the region of the coated surface. Thereby, the part which continues raising | lifting in the coating surface can be left in a coating surface, ensuring the joining strength of the whole coating surface. Thereby, in the region 53 </ b> A where the raised portions 7 are present, it is possible to achieve both strong joining of the end portions 51 and 52 that are difficult to peel off and fluffing of the raised portions 7. Examples of the coating pattern include a linear shape, a spiral shape, a Ω-shape, and a summit shape. Moreover, what is used for this kind of article can be employed without any particular restriction as a base material for the hot melt adhesive. For example, an olefin type, a rubber type, and an ethylene-vinyl acetate copolymer (EVA) type may be mentioned.

  The raised portion 7 is a portion where the number of fibers measured by a method described later is 5 / cm or more in a state where the above-described adhesive is applied. Further, the raised portion 7 preferably has a fiber number of 10 / more, more preferably 15 or more. Further, the upper limit is preferably 30 or less, more preferably 25 or less, and more preferably 20 from the viewpoint that the nonwoven fabric forming the core wrap sheet 5 retains the breaking strength that can withstand the shear stress caused by the wearer's thigh. The following is more preferable.

Measurement of the number of raised constituent fibers is performed as follows.
Sampling and measurement are performed at 22 ° C. and 65% Rh.
First, a measurement piece of 20 cm × 5 cm is cut out in a region 53A of the overlapping portion 53 to be measured with a sharp blade (razor), and the measurement piece is piled so that the raised side faces outward as shown in FIG. The measurement sample 104 is formed by folding (in the direction of the arrow in FIG. 3A). However, when the raised portions 7A and / or 7B are on the adhesive-coated surface of the overlapping portion 53 to be measured, the adhesive ability of the adhesive is lost by heating with a dryer or cooling by cold spray or the like. The measurement sample 104 is formed by eliminating the overlapping state of the overlapping portion 53. Next, this measurement sample 104 is placed on an A4 size black mount, and as shown in FIG. 3 (B), an A4 size black mount with a 1 cm vertical by 1 cm wide window 107 is further formed thereon. Overlapping. At this time, as shown in FIG. 3B, the fold 105 of the measurement sample 104 is arranged so that it can be seen from the upper black mount window 107. For both mounts, “Kenran (black) continuous weight 265 g” of Fuji Kyowa Paper Co., Ltd. was used. Thereafter, a weight of 50 g is placed on each side of the upper mount window 107 at a position spaced 5 cm outward along the fold line 105 so that the measurement sample 104 is completely folded.
Next, as shown in FIG. 3C, the inside of the mount window 107 is observed at a magnification of 30 times using a microscope (VHX-900 manufactured by KEYENCE Corp.), and the folds 105 to 0 of the measurement sample 104 are displayed. Measure the number of raised fibers that are raised above the imaginary line 108 formed at the position translated parallel by 2 mm. In the nonwoven fabric to be measured at this time, three pieces of 20 cm × 5 cm measurement pieces are cut out and measured so as to include the raised portions. The above operation is measured for three sheets of the nonwoven fabric to be measured, and a total of nine average values (rounded off to the second decimal place) is taken as the number of raised constituent fibers.

  The raised height in the raised portion 7 is preferably 0.4 mm or more, more preferably 0.7 mm or more, and still more preferably 1 mm or more from the viewpoint of the above action. The upper limit is not particularly limited, but is preferably 4 mm or less, more preferably 3 mm or less, and still more preferably 2 mm or less from the viewpoint of maintaining the adhesive strength of the overlapped portion and suppressing damage during processing. The raising height can be measured by using the above-described raising fiber measuring method.

The width H2 and the length T2 of the raised portions 7 can be appropriately changed as long as the above-described effect is exhibited. For example, as shown in FIG. 4, the raised portion 7 may be provided so as to match the length T3 of the indicator portion 6 in the longitudinal direction. Further, in consideration of the moisture oozing range by the superabsorbent polymer 42, the raised portions 7 may be provided on the length T1 in the longitudinal direction of the overlapping portion 53 (the length of the absorber) as shown in FIG. Further, in the width direction, the raised portion 7 may be formed beyond the region 61 of the indicator portion 6 as shown in FIG. 6 in consideration of the moisture oozing range by the superabsorbent polymer 42. In FIG. 6, the raised portions 7 are formed to extend by H4 and H4 on both sides of the width H2 of the overlapping portion 53. In this case, the raised portions 7 are also formed in the portion of the core wrap sheet 5 outside the overlapping portion 53 in addition to the overlapping portion 53. About this width H4, you may make it expand the width | variety of the overlap part 53 not only in the aspect of FIG. In the embodiment of FIG. 6, the length T2 in the longitudinal direction can be set as appropriate, and the lengths of FIGS. 1 and 5 may be applied.
As shown in FIGS. 5 and 6, by preventing the raised region 7 from being disposed, the moisture-preventing property of the superabsorbent polymer 42 can be improved. However, when the arrangement | positioning area | region of the raising part 7 becomes wide and it extends to the skin contact surface side, the liquid transferability at the time of use of the diaper 10 may be reduced. Moreover, when the arrangement | positioning area | region is too large, adhesive strength will not come out, but fixation with other members, such as the absorber 3 and the back surface sheet 2, will become weak, and will affect the integrity as a diaper. Therefore, the arrangement area of the raised portions 7 is preferably limited in accordance with the arrangement area of the indicator section 6 with respect to the surface area of the absorber 3.
In addition, in said FIGS. 4-6, in order to understand the arrangement | positioning area | region of the raising part 7, members other than the absorber 3, the indicator part 6, and the back surface sheet 2 were abbreviate | omitted, and it planarly viewed from the back surface sheet 2 side. Shown as a state. The same applies to FIG.

  The diaper 10 preferably further has the following configuration in addition to the above configuration. Any one of the following configurations may be selectively incorporated into the diaper 10 or may be combined and incorporated into the diaper 10.

As a 1st structure, it is preferable that the absorptive core 4 is the following structures from a viewpoint which raises further the effect | action of the transfer suppression of the micro moisture by the overlap part 53 and the raising part 7. FIG.
That is, the absorbent core 4 is made into two or more layers, and the content of the hydrophilic fibers 41 is increased in the lowermost layer (the layer on the non-skin contact surface side of the absorbent article) than in the upper layer. FIG. 8 shows an example of the above-described configuration, and the absorbent core 4 has two layers, and a lowermost layer 48 made of only hydrophilic fibers 41 is provided on the lower side. This shows an example in which the superabsorbent polymer 42 is not contained in the lowermost layer 48. Thus, the high content of the hydrophilic fibers 41 means that the ratio of the superabsorbent polymer 42 is suppressed. Thereby, it becomes difficult for the superabsorbent polymer 42 to contact the core wrap sheet 5 on the non-skin contact surface side, and unnecessary discoloration of the indicator unit 6 can be more reliably suppressed. The lowermost layer 48 having a high hydrophilic fiber content is not limited to a layer that can be clearly distinguished from the upper layer, and may have a configuration in which the content of hydrophilic fibers is gradually increased from the upper layer side.

  As a 2nd structure, it is preferable that the core wrap sheet | seat 5 and the back surface sheet 2 are joined by the adhesive agent in the outer side of the area | region 61 in which the indicator part 6 was arrange | positioned. Thereby, it is possible to prevent a deviation from occurring in the overlap between the overlapping portion 53 of the absorber 3 and the arrangement region 61 of the indicator portion 6 due to some external force. Moreover, it can prevent that the color indicator of the indicator part 6 adheres to the several places of the core wrap sheet | seat 5 by shift | offset | difference, and can prevent that the grade of change, such as discoloration of the indicator part 6, weakens. In addition, since the adhesive is on the outside of the indicator part 6, the contact between the indicator part 6 and urine or the like when the diaper 10 is used is not hindered. As an application position of the adhesive, for example, an embodiment shown in FIG. In FIG. 8, the adhesives 56, 56 are applied in the longitudinal direction outside the width direction of the region 61 of the indicator unit 6. Furthermore, adhesives 57 and 57 are applied in the width direction at the front and rear end portions of the absorbent body 3 that do not overlap the indicator portion 6. The core wrap sheet 5 and the back sheet 2 of the absorbent body 3 are joined by the adhesives 56 and 57, and positional displacement is prevented. In addition, the application position, width, and length of the adhesive are not limited to the embodiment of FIG. 8, and do not hinder the function of the indicator unit 6, and the bonding strength between the core wrap sheet 5 and the back sheet 2. It can be set appropriately within a range that can be secured.

  Furthermore, as a third configuration, it is preferable that the adhesive for joining the core wrap sheet 5 and the back sheet 2 is applied so as not to overlap the raised portions 7. This means that, for example, when the raised portion 7 is formed in a region wider than the arrangement region 61 of the indicator portion 6, the adhesive is applied further outside the raised portion 7 region. Thereby, without preventing the fluffing of the fibers of the raised portion 7, the overlap between the overlapping portion 53 of the core wrap sheet 5 and the back surface sheet 2 is prevented from being displaced, and the function of the indicator portion 6 is not inhibited. As a mode of application of the adhesive, a mode of combination of the adhesives 56 and 57 of FIG. 8 may be used, and the width and length of the adhesive may be appropriately changed.

  As the adhesive used for joining the core wrap sheet 5 and the back sheet 2, the same adhesive as the hot-melt adhesive used for joining the overlapping portion 53 can be used. The coating pattern may be, for example, linear coating as in the adhesive 56 in FIG. 8, continuous coating in a predetermined range as in the adhesive 57, intermittent coating such as spiral, Ω-shaped, and summit. Can be mentioned.

  In the diaper 10, as a raw material of the absorbent core 4 and the core wrap sheet 5 constituting the absorbent body 3, those used for this type of article can be used without any particular limitation.

Examples of the hydrophilic fibers 41 constituting the absorbent core 4 include natural fibers such as wood pulp, cotton and hemp, polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, and polyvinyl alcohol resins. Single fibers made of synthetic resin, composite fibers containing two or more of these resins, semi-synthetic fibers such as acetate, and regenerated fibers such as rayon can be used. When using a fiber made of a synthetic fiber, the fiber may be a heat-shrinkable fiber whose shape changes due to heat. For example, the fineness is increased by heat but the fiber length is shortened, and the fineness is hardly changed by heat, but the length occupied by the apparent fiber is shortened by changing the shape to a coil shape. Also good.
As the superabsorbent polymer 42, various polymer materials usually used for this type of article can be used. The superabsorbent polymer is preferably a superabsorbent polymer compound having a performance capable of absorbing and retaining water or physiological saline 20 times or more of its own weight.

  The nonwoven fabric used for the core wrap sheet 5 is a hydrophilic nonwoven fabric having softness and strength, and various commonly used ones can be adopted without any particular limitation. Examples thereof include air-through nonwoven fabric, point bond nonwoven fabric, spunlace nonwoven fabric, spunbond nonwoven fabric, and a laminate nonwoven fabric composed of a spunbond layer and a meltblown layer. In particular, from the viewpoint of permeability of urine and the like when using the diaper 10, softness, and strength necessary for the shape retention of the absorbent body 3, a laminate nonwoven fabric of a spunbond layer and a meltblown layer is preferable. Specific examples include spunbond-meltblown-spunbond (SMS) nonwoven fabric, spunbond-meltblown-meltblown-spunbond (SMMS) nonwoven fabric, and the like. When such a laminated nonwoven fabric is used, it has high strength simultaneously with the liquid permeability, and contributes to the shape retention of the absorbent body 3. In particular, since the surface layer of the laminated nonwoven fabric is a spunbond layer made of long fibers, it is easy to carry out the raising process described later, and a sufficient number of bristle feet and the number of raised parts 7 can be formed. The fineness of the laminated nonwoven fabric is preferable because the superabsorbent polymer 42 of the absorbent core 4 is difficult to leak to the outside.

  Next, a method for forming the raised portions 7 of the core wrap sheet 5 will be described. As described above, the raised portion 7 is formed by raising fibers on the surface of the nonwoven fabric, and a method usually used for such raising can be employed without any particular limitation. One specific example is a two-step raised process shown in FIGS. 10 (A) and 10 (C). In this method, the surface of the nonwoven fabric is partially stretched in the first stage to damage the fibers, thereby facilitating the raising process in the next second stage. Moreover, since the core wrap sheet | seat 5 provided with the raising part 7 obtained by this suppresses the excessive damage to the structural fiber, intensity | strength is maintained and it becomes excellent in workability.

First, in the partial extending | stretching process 71, the strip | belt-shaped raw material nonwoven fabric 100 is drawn out, for example from a raw fabric roll (not shown), and is continuously supplied between the convex roll 74 and the concave roll 75 as shown to FIG. 9 (A). . Between the convex roll 74 and the concave roll 75, the raw material nonwoven fabric 100 is pinched by meshing the concaves and convexes of each other, and partial stretching processing is applied to a plurality of portions of the raw material nonwoven fabric 100, thereby damaging the raw material nonwoven fabric 100. The belt-shaped raw material nonwoven fabric 100 can be transported, for example, by transport rolls 73 and 73 provided on the upstream side and the downstream side of the convex roll 74 and the concave roll 75. As the convex roll 74 and the concave roll 75, a nonwoven fabric that is usually used for partial stretching can be employed without any particular limitation. For example, a cylindrical steel matching embossing roller made of metal such as aluminum alloy or steel. Specifically, a plurality of convex portions 74A provided on the peripheral surface of the convex roll 74 and a plurality of concave portions 75A provided on the peripheral surface of the concave roll 75 are formed so as to mesh with each other. It is done. The plurality of convex portions 74A are arranged uniformly and regularly, for example, in the rotation axis direction and the circumferential direction of the roll 74, respectively. A plurality of recesses 75A are arranged so as to correspond to this. The pair of concavo-convex rolls 74 and 75 may be engaged and rotated by transmitting a driving force from a driving means (not shown) to any one of the rotation shafts.
In this way, the convex roll 74 rotates in the direction of the arrow G1, and the concave roll 75 rotates in the direction of the arrow G2. When the rolls rotate, the convex portions and the concave portions are engaged with each other with the raw material nonwoven fabric 100 interposed therebetween. For example, as shown in FIG. 9B, the convex portion 74A of the convex roll 74 and the concave portion 75A of the concave roll 75 mesh with each other with the raw material nonwoven fabric 100 interposed therebetween. Thereby, the raw material nonwoven fabric 100 is extended | stretched in the direction (CD: Cross Direction) orthogonal to a conveyance direction (MD: Machine Direction) and a conveyance direction partially.

  By this partial stretching process 71, the raw material nonwoven fabric 100 is damaged, the fibers are stretched, and a weakening point that is a starting point of raising is formed in the raw material nonwoven fabric 100. Moreover, by carrying out an extending | stretching process to the conveyance direction (MD) and the direction (CD) orthogonal to a conveyance direction, the breaking strength reduction | decrease of the raising nonwoven fabric 59 after a process obtained through a 1st process can be suppressed according to a direction. In addition, from the viewpoint of creating softness, it is preferable that the partial stretching process does not cause thermal fusion between the constituent fibers of the raw material nonwoven fabric 100. Therefore, for example, the pair of rolls 74 and 75 are preferably not heated positively or processed at a temperature equal to or lower than the melting point of the component having the lowest melting point among the components of the fibers constituting the raw nonwoven fabric 100. In particular, it is more preferable to process at a temperature 70 ° C. or more lower than the melting point. For example, it is preferable to carry out under conditions of a temperature of 50 ° C. or lower. Here, the temperature of 50 ° C. or less means that the temperature is normal when the raw nonwoven fabric 100 is stretched without actively applying the temperature to the concave and convex rolls 74 and 75. In other words, from the viewpoint of preventing the raw nonwoven fabric 100 from becoming hard when the raw nonwoven fabric 100 is stretched, the raw nonwoven fabric 100 is harder than the melting point of any type of constituent fiber resin. Means low temperature. In addition, the direction (CD) orthogonal to the conveyance direction is a direction parallel to the rotation axis direction of the roll described above, and is also referred to as a width direction.

  Next, in the raising process 72, as shown in FIG. 9C, the raw material nonwoven fabric 100 that has been partially stretched in the process of FIG. It conveys to the raising roll (partial raising roll) 77 which has the projection part 79. FIG. The constituent fibers on the surface 101 side of the raw nonwoven fabric 100 that has been partially stretched are raised from the surface of the nonwoven fabric by the rotating raising roll 77. At this time, the hair is raised with the weakening point or the like as a base point. Thereby, the raising nonwoven fabric 59 provided with the raising fiber 83 in the conveyance direction (MD) is continuously manufactured. (See FIG. 9D). The raised fibers 83 are those in which the surface fibers of the raw nonwoven fabric 100 are partially broken by the raising process 72 while leaving the fusion fixing ends 83A with other fibers. That is, the raised fiber 83 is a fiber that includes a free end 83B and a fixed end 83A, and stands up in a direction that intersects the surface direction of the nonwoven fabric.

  As materials for the constituent members of the diaper 10, those used for this type of article can be used without particular limitation, other than the constituent members of the absorber 3 described above. Further, a functional structural member, a sheet member, or the like may be provided.

  As a color indicator which comprises the indicator part 6, what changes a color by pH 3-7 is mentioned, for example. Specific examples include bromophenol blue, methyl orange, alizarin S, bromocresol green, methyl red, bromocresol purple, and the like. Particularly preferred among these color indicators are bromophenol blue, bromocresol green, bromocresol purple, and the like.

  The surface sheet 1 is made of a liquid-permeable member that is comfortable to touch, and is preferably a hydrophilic nonwoven fabric, for example, an air-through nonwoven fabric, a point bond nonwoven fabric, a spunbond nonwoven fabric, a spunlace nonwoven fabric, or a sheet obtained by laminating and integrating these nonwoven fabrics. Materials and the like. The fiber constituting the nonwoven fabric is preferably a fiber that has been subjected to a hydrophilic treatment with a single fiber of polypropylene, a composite fiber of polypropylene and polyethylene, a composite fiber of polyethylene terephthalate and polyethylene, or the like. Moreover, a hydrophilic perforated film or a hydrophilic nonwoven fabric may be partially overlapped on the crotch portion of the topsheet 1 on the non-skin contact surface side of the topsheet 1.

  The back sheet 2 is not particularly limited as long as it has waterproofness and moisture permeability, but is made of a liquid hardly permeable member from the viewpoint of preventing liquid leakage on the non-skin contact surface side of the absorber 3. For example, a liquid obtained by melt-kneading a hydrophobic thermoplastic resin and a fine inorganic filler made of calcium carbonate or the like or an incompatible organic polymer to form a film, and uniaxially or biaxially stretching the film An impermeable porous film is mentioned. Examples of the thermoplastic resin include polyolefin. Examples of the polyolefin include high-density to low-density polyethylene, linear low-density polyethylene, polypropylene, and polybutene, and these can be used alone or in combination. Moreover, it is preferable to have moisture permeability from a viewpoint of preventing stuffiness.

  Examples of the exterior sheet 8 include nonwoven fabrics, woven fabrics, knitted fabrics, resin films, and the like produced by various manufacturing methods such as air-through nonwoven fabric, heat roll nonwoven fabric, spunlace nonwoven fabric, spunbond nonwoven fabric, and meltblown nonwoven fabric. It is also possible to use a sheet material or the like. In particular, those formed from a nonwoven fabric are preferable from the viewpoint of improving air permeability and texture, and those formed from a water-repellent nonwoven fabric are preferable from the viewpoint of preventing excrement leakage.

The side sheet 9 is preferably a water-repellent nonwoven fabric, and a spunbond nonwoven fabric, a meltblown nonwoven fabric, a spunlace nonwoven fabric, a heat roll nonwoven fabric, a needle punched nonwoven fabric, or the like, or a water-repellent treated various nonwoven fabric is used. be able to. Particularly preferred are, for example, spunbond nonwovens, spunbond-meltblown (SM) nonwovens, spunbond-meltblown-spunbond (SMS), spunbond-meltblown-meltblown-spunbond (SMMS), spunbond-spunbond-meltblown -Spunbond (SSMS) nonwoven fabric or the like is used.
Examples of various elastic members disposed on the diaper 10 include synthetic rubbers such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, stretchable polyolefin, and polyurethane. As the form, for example, a thread shape or string shape (flat rubber or the like) having a rectangular, square, circular, or polygonal cross section, or a multifilament type thread shape can be used.

  The absorbent article of the present invention is not limited to the deployable disposable diaper of the present embodiment. The present invention can be applied to various forms having an indicator part and an absorber containing a superabsorbent polymer. For example, a pants-type disposable diaper, a urine pad, a sanitary napkin, a panty liner, or the like may be used.

DESCRIPTION OF SYMBOLS 1 Top sheet 2 Back sheet 3 Absorber 4 Absorbent core 5 Core wrap sheet 6 Indicator part 7 Brushed part 8 Exterior sheet 9 Side sheet 10 Unfoldable disposable diaper

Claims (6)

An absorbent article comprising a top sheet disposed on the skin contact surface side, a back sheet disposed on the non-skin contact surface side, and an absorbent body disposed between both sheets,
Between the back sheet and the absorbent body, an indicator part that changes visually by contact with liquid is disposed, and the absorbent body includes an absorbent core having hydrophilic fibers and a superabsorbent polymer. A core wrap sheet made of a hydrophilic non-woven fabric covering the absorbent core,
The core wrap sheet covers the non-skin contact surface side through the side from the skin contact surface side of the absorbent core, and on the non-skin contact surface side, an overlapping portion is formed by both end portions of the core wrap sheet. And wraps the absorbent core,
The overlapping portion includes a raised portion in which fibers of the nonwoven fabric are raised at an end portion located on at least the non-skin contact surface side of both end portions of the core wrap sheet, and includes a raised portion of the overlapping portion. However, the overlapping portion of the core wrap sheet is joined with an adhesive, and the application area ratio of the adhesive with respect to the area of the region including the raised portion of the overlapping portion is 50%. Absorbent articles that are:   The absorbent article according to claim 1, wherein the adhesive is subjected to pattern coating with a plurality of non-coating portions interposed in the region of the coated surface.   The absorptive article according to claim 1 or 2 in which said absorptive core consists of two or more layers, and the content rate of the hydrophilic fiber of the lowest layer which contacts said core wrap sheet was raised rather than the upper layer side.   The absorbent article according to any one of claims 1 to 3, wherein the raised portions are arranged at both end portions of the core wrap sheet constituting the overlapping portion.   The core wrap sheet and the back sheet are bonded with an adhesive, and the adhesive is coated so as to surround the arrangement area outside the arrangement area of the indicator portion. The absorbent article of any one of Claims.   The absorbent article according to claim 5, wherein an adhesive that joins the core wrap sheet and the back sheet is coated so as not to overlap the raised portions.

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