阅读说明：本技术 吸收性物品 (Absorbent article ) 是由 巢山润之介 于 2018-08-24 设计创作，主要内容包括：在保持吸收性物品的片的薄度的同时，进一步提高片的每单位面积的隆起高度，吸收更多的排泄液。本发明的吸收性物品具有表面侧片(51)和配置于其背面侧的背面侧片(52)，表面侧片(51)和背面侧片(52)被接合而形成多个小室(55)，在小室(55)内收纳包含高吸收性聚合物颗粒(53)的粉粒体而构成吸收体(50)，包含高吸收性聚合物颗粒(53)的粉粒体的至少一部分未固着于表面侧片(51)和背面侧片(52)中的至少任一者，表面侧片(51)和背面侧片(52)中的至少一者的片彼此接合的部位以外的部位被收缩加工成褶皱型。(The absorbent article sheet has a thin thickness, and the height of the sheet per unit area is further increased to absorb more excretory fluid. The absorptive article comprises a front side sheet (51) and a back side sheet (52) disposed on the back side of the front side sheet, wherein the front side sheet (51) and the back side sheet (52) are joined to form a plurality of cells (55), an absorptive body (50) is configured by accommodating a powder-based material containing highly absorptive polymer particles (53) in the cells (55), at least a part of the powder-based material containing highly absorptive polymer particles (53) is not fixed to at least one of the front side sheet (51) and the back side sheet (52), and a portion other than a portion where the sheets of at least one of the front side sheet (51) and the back side sheet (52) are joined to each other is processed into a wrinkle shape by shrinkage.)

1. An absorbent article characterized in that,

comprising a front side sheet and a back side sheet disposed on the back side of the front side sheet,

the front side sheet and the back side sheet are joined to form a plurality of cells,

an absorbent is formed by containing a powder or granule containing superabsorbent polymer particles in the cells,

at least a part of the particulate matter containing the super absorbent polymer particles is not fixed to at least either one of the front side sheet and the back side sheet,

the front side sheet and the back side sheet are each formed into a corrugated shape by shrinking at a portion other than a portion where the sheets are joined to each other.

2. The absorbent article according to claim 1, wherein the wrinkle shape is a wave shape contracting in a width direction of the absorbent body.

3. The absorbent article according to claim 1 or claim 2, wherein the shrinkage rate of the wrinkle-like shape after the shrinkage processing is 15 to 50%.

4. The absorbent article according to any one of claims 1 to 3, wherein the cells are in the form of a rectangular lattice that is long in the width direction of the absorbent.

5. The absorbent article according to claim 4, wherein the joint portions forming the cells in the rectangular lattice shape are weak joint portions extending in the front-rear direction.

6. The absorbent article according to any one of claims 1 to 5, wherein at least one of the front side sheet and the back side sheet is repeatedly processed to a range where the shrinkage rate is high and a range where the shrinkage rate is low.

7. The absorbent article of claim 6, wherein the basis weight of the super absorbent polymer particles is higher in a range where the shrinkage rate is high than in a range where the shrinkage rate is low.

Technical Field

The present invention relates to an absorbent article such as a disposable diaper and a sanitary napkin.

Background

The absorbent article includes an absorbent body and a liquid-permeable top sheet covering the front surface side of the absorbent body, and excretory fluid such as urine or menstrual blood passes through the top sheet and is absorbed and retained by the absorbent body. As the absorbent, an absorbent obtained by mixing super absorbent polymer particles (SAP) with hydrophilic short fibers such as ground pulp and stacking the mixture in a cotton form is widely used. Therefore, patent document 1 proposes "an absorbent article in which, when the absorbent part absorbs body fluid, the superabsorbent polymer particles swell, the first sheet in the absorbent part protrudes upward in the thickness direction and swells, and the second sheet protrudes downward in the thickness direction and swells, or does not swell and thicken, and the absorbent article is formed such that the size of the swelling of the first sheet upward is larger than the size of the swelling of the second sheet downward, whereby the contact area between the wet absorbent part and the skin is small, a feeling of wetness is hardly given to the skin, and a gap of air permeability is generated between the skin and the non-absorbent part. That is, in this document, the difference in swelling between the 1 st and 2 nd sheets using materials having different elongations is used to ensure good air permeability.

Disclosure of Invention

Problems to be solved by the invention

However, in the method of patent document 1, since the elongation of the sheet itself is determined, the volume in the surrounding portion (cell) is also determined. Therefore, there is a limit to the amount of superabsorbent polymer particles contained, and if the amount exceeds the allowable amount for containing superabsorbent polymer particles, gel blocking may occur, or the superabsorbent polymer particles themselves may flow out of the sheet through gaps between fibers of the elongated sheet. Therefore, it has to be said that there is a limit to the height of the ridge of the sheet in this document.

Accordingly, an object of the present invention is to provide an absorbent article that can absorb more excreta liquid by further increasing the height of the sheet per unit area while maintaining the thinness of the sheet.

Means for solving the problems

Typical means for solving the above problems are as follows.

< invention of aspect 1 >

An absorbent article characterized in that,

comprising a front side sheet and a back side sheet disposed on the back side of the front side sheet,

the front side sheet and the back side sheet are joined to form a plurality of cells,

an absorber is formed by housing a powder or granule containing superabsorbent polymer particles in the chamber,

at least a part of the particulate matter containing the super absorbent polymer particles is not fixed to at least one of the front side sheet and the back side sheet,

the front side sheet and the back side sheet are each formed by shrinking a portion other than a portion where the sheets are joined to each other.

(Effect)

The front side sheet and the back side sheet, at least one of which is processed into a wrinkle shape by shrinkage, are joined to form a plurality of cells. The superabsorbent polymer particles inside the cells swell due to the excretory fluid, stretching the folds of the sheet. As a result, the sheet has an effect of rising up and down with respect to the plane of the absorbent body. In particular, in the case where the sheet is a nonwoven fabric, if the super absorbent polymer particles swell, the nonwoven fabric will swell to some extent due to its own elongation characteristics even without wrinkles, but will swell more significantly due to the presence of wrinkles. In addition, by having the wrinkled shape, the free movement of the powder or granule in the cell is restricted.

< invention of aspect 2 >

The absorbent article according to claim 1, wherein the wrinkle-like pattern is a wave pattern shrinking in the width direction of the absorbent body.

(Effect)

By arranging the wrinkle-like longitudinal stripes formed by the contraction processing in the transverse direction in the front-rear direction of the absorber, the diffusion of the excretory fluid in the transverse direction and the movement of the powder or granule can be prevented to some extent.

< invention of aspect 3 >

The absorbent article according to claim 1 or 2, wherein the shrinkage rate of the wrinkle-like structure after the shrinkage processing is 15 to 50%.

(Effect)

By selecting the shrinkage ratio arbitrarily, an absorber having a different height of the ridge and different ease of movement of the powder or granule can be formed. If the amount is less than 15%, since shrinkage hardly occurs, the effect of wrinkle-like elongation and the sheet bulging cannot be obtained. On the other hand, if it exceeds 50%, the wrinkle type of the sheet becomes too dense, and the absorbent body becomes thick, and the thinness, which is an advantage of the absorbent body, cannot be utilized.

< invention of aspect 4 >

The absorbent article according to any one of claims 1 to 3, wherein the cells are in a rectangular lattice shape that is long in the width direction of the absorbent body.

(Effect)

Since the lattice of each cell is rectangular and the sheet is contracted in the lateral direction, more powder and granular material can be accommodated in each cell and the cells can be raised higher than a lattice composed of squares. Therefore, the effect of absorbing more excretory fluid is obtained.

< invention of aspect 5 >

The absorbent article according to claim 4, wherein the joint portions forming the cells in the rectangular lattice shape are weak joint portions extending in the front-rear direction.

(Effect)

When the powder or granule in the cell adjacent to the weak bond absorbs the excretion liquid and rises, the bond is peeled off, and the adjacent cells are joined to each other to form a large cell. Since the sheet of the large cell is also subjected to shrinkage processing, the bulge of the sheet can be further increased, and the absorption amount of the excretory fluid can be increased. In addition, since the normal joint portion (non-weak joint portion) does not swell, the diffusion of the excretory fluid is directed.

< invention of aspect 6 >

The absorbent article according to any one of claims 1 to 5, wherein at least one of the front side sheet and the back side sheet is repeatedly processed to a range where the shrinkage rate is high and a range where the shrinkage rate is low.

(Effect)

Since the processing is repeated regularly to a high shrinkage ratio range and a low shrinkage ratio range, the high shrinkage ratio can be raised to a high degree, and the low shrinkage ratio is low. That is, the height of the ridges has irregularities, and there is an effect that unevenness can be generated such that the absorption amount of the excretory fluid is increased in a high range and the absorption amount of the excretory fluid is decreased in a low range.

< invention of aspect 7 >

The absorbent article according to claim 6, wherein the basis weight of the super absorbent polymer particles is higher in a range where the shrinkage rate is high than in a range where the shrinkage rate is low.

(Effect)

By setting the basis weight of the super absorbent polymer particles to be high or low, the variation in the absorption amount of the excretory fluid can be made significant.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, an absorbent article is provided which can further increase the height of the ridge per unit area of the sheet and can absorb more excretory fluid.

Drawings

Fig. 1 is a plan view showing the inner surface of a loop type disposable diaper in a state where the diaper is unfolded.

Fig. 2 is a plan view showing the outer surface of the disposable loop-type diaper in a state where the diaper is unfolded.

Fig. 3 is a cross-sectional view taken along line 6-6 of fig. 1.

Fig. 4 is a cross-sectional view taken along line 7-7 of fig. 1.

Fig. 5 (a) is a sectional view taken along line 8-8 of fig. 1, and (b) is a sectional view taken along line 9-9 of fig. 1.

Fig. 6 is a cross-sectional view taken along line 5-5 of fig. 1.

Fig. 7 shows an example of processing of the front side sheet and the back side sheet.

Fig. 8 is a schematic view of wave-type processing of the surface side sheet and the back side sheet.

Fig. 9 is a top view of an embodiment of a bonding pattern of a bonding portion and a 4-4 line sectional view thereof.

Fig. 10 is a top view of an embodiment of a bonding pattern of a bonding portion.

Fig. 11 is a sectional view of an absorbent body having a strong and weak contraction rate.

Fig. 12 is a cross-sectional view of the absorbent body before and after swelling.

Detailed Description

Hereinafter, specific embodiments of the present invention will be described.

Conventionally, absorbent articles have been used for various purposes such as disposable diapers and sanitary napkins. The mode of mounting the absorbent article inside the disposable diaper will be described in detail. The following description and the drawings merely show one embodiment of the present invention.

As shown in fig. 1 to 7, the absorbent article of the present invention includes a front side sheet 51 and a back side sheet 52 disposed on the back side of the front side sheet 51, wherein the front side sheet 51 and the back side sheet 52 are joined to form a plurality of cells 55, an absorbent body 50 is configured by containing a powder or granule containing highly absorbent polymer particles 53 in the cells 55, at least a part of the powder or granule containing the highly absorbent polymer particles 53 is not fixed to at least one of the front side sheet 51 and the back side sheet 52, and a portion of at least one of the front side sheet and the back side sheet other than the portion where the sheets are joined to each other is processed into a wrinkle shape by shrinkage. In addition, the wrinkle-like pattern is preferably subjected to a shrinking process in the width direction WD of the absorbent body 50.

(shape of wrinkles)

The wrinkles of the front-side sheet 51 and the back-side sheet 52 (hereinafter, simply referred to as " sheets 51 and 52" when the front side and the back side are not specified) are surfaces on which protrusions and depressions are regularly and repeatedly formed in the sheets 51 and 52. As described later, a liquid-permeable material, a liquid-impermeable material, a nonwoven fabric, or the like can be used as the material of the sheets 51, 52. The nonwoven fabric is, for example, folded regularly and subjected to a pressure treatment to form a corrugated wrinkle. Further, by performing a pressing process with a concave-convex roller, a corrugated or concave-convex corrugated pattern is formed. The processed pleated nonwoven fabric can maintain its shape and does not naturally return to a state without pleats before processing.

Preferably, the interval (one period) between the wrinkles is 3 to 25mm, and the amplitude of the wrinkles is 1 to 25 mm.

When a force is applied to the sheets 51, 52 processed into a wrinkle shape in a direction in which the wrinkle is stretched, the wrinkle can be easily stretched. Therefore, when the sheets 51 and 52 processed into a wrinkled shape and containing the super absorbent polymer particles 53 are made to absorb liquid, the wrinkles of the sheets 51 and 52 are also stretched by at least the shrinkage rate (the shrinkage rate is defined as described later) due to the expansion of the super absorbent polymer particles 53. Note that the nonwoven fabric itself also has some degree of stretchability.

As shown in fig. 7, the corrugated processing of the sheets 51 and 52 may be, for example, wave-shaped processing, concave-convex processing, deformation-type concave-convex processing in which the bottoms of concave-convex recesses are widened, or processing in which semicircular tracks are continuously arranged in zigzag lines.

Further, the wrinkle-type processing may be performed in a planar manner. For example, the projection shape may be processed to spread out in a planar manner like a plurality of dots.

However, the method is not limited to these processes. The corrugated shape of the sheets 51, 52 may be processed in the following manner: the wrinkles are unfolded by the expansion of the super absorbent polymer particles 53, and the area of the sheets 51, 52 of the cells 55 when the cells 55 are swollen is increased as compared with the area of the cells 55 themselves before swelling.

The absorbent article is basically composed of the front side sheet 51, the back side sheet 52, and the super absorbent polymer particles 53 formed by these processes, and can be kept thin as it is, since it is not necessary to separately interpose a new sheet or the like.

(direction of fold)

As shown in fig. 8, regarding the direction of the wrinkles, in the case of performing the wave-type processing on the sheets 51 and 52, a so-called stripe pattern is formed in which a large number of straight lines of mountain fold portions are formed in parallel on the surfaces of the sheets 51 and 52 and the same number of straight lines of valley fold portions are formed in parallel on the back surface. The straight line direction of the folded portion may be arranged in parallel to the front-back direction LD of the absorbent body 50 or may be arranged perpendicularly thereto. However, hereinafter, for convenience, the description will be made in a parallel arrangement unless otherwise mentioned.

(shrinkage)

The processed sheets 51 and 52 shrink as compared with the sheets 51 and 52 before processing. Here, the shrinkage ratio is defined as follows.

Shrinkage (%) (area of sheets 51 and 52 before processing-area of sheets 51 and 52 after processing)/(area of sheets 51 and 52 before processing) × 100

The above-mentioned elongation is an elongation with respect to an original sheet length when the sheet is stretched by stretching the sheet in opposite directions from both sides of the sheet, and is a concept different from the shrinkage rate mentioned here.

In addition, from the viewpoint that it is preferable to absorb more excretory fluid, it is preferable to increase the shrinkage rate and to wrap a large amount of the super absorbent polymer particles 53. However, if the shrinkage rate is higher than necessary, since the folds of the wrinkles are dense in the initial state, that is, in the stage before the product is used, the sheets 51 and 52 are bulky, the thickness of the absorbent body 50 is large, and the thinness, which is an advantage of the absorbent body 50, cannot be utilized, which is inconvenient. On the other hand, if the shrinkage ratio is less than the predetermined value, the effect of the wrinkled stretching and bulging of the sheets 51 and 52 cannot be sufficiently obtained. Therefore, the shrinkage rate is, for example, 15 to 50%, and more preferably 35%.

(shape of cell 55)

The cell 55 is a partitioned space having a certain volume formed by joining the front side sheet 51 and the back side sheet 52 disposed on the back side of the front side sheet 51. For example, in the case of forming the square cells 55, the front side sheet 51 and the back side sheet 52 disposed on the front side sheet 51 may be joined to each side of the square.

In principle, the superabsorbent polymer particles 53 are contained in cells 55. However, in order to prevent the super absorbent polymer particles 53 present in the vicinity of the edge portions of the front side sheet 51 and the back side sheet 52 from flowing out, edge joining portions preferably extend around the edge portions of the front side sheet 51 and the back side sheet 52.

The sheets 51, 52 of the cells 55 are shrunk to have a wrinkle shape, and thus the wrinkle shape is expanded by the expansion of the super absorbent polymer particles 53 when the super absorbent polymer particles 53 in the cells 55 absorb the excretory fluid. Thereby, the sheets 51, 52 of the cell 55 are inflated into a balloon shape.

(Joint Pattern)

As shown in fig. 9 and 10, the pattern of the joint portion may be as follows. In fig. 9, the front side sheet 51 is shown as an example, but it is needless to say that the back side sheet 52 may be expanded, or both the front side sheet 51 and the back side sheet 52 may be expanded.

The pattern 1 may have lattice-shaped joints. Further, it is more preferable that the laterally wide rectangular lattice-shaped joining portions 54 be arranged along the front-rear direction LD of the absorbent body 50. The length aa in the width direction WD of each cell 55 partitioned in a lattice shape is longer than the length bb in the front-rear direction LD. The size of the cell 55 is preferably about 8 to 30mm in the vertical direction and 10 to 50mm in the horizontal direction, for example. Since the direction of the fold-type mountain fold portion is parallel to the front-rear direction LD, the volume of the sheets 51 and 52 increases when the sheets stretch and swell in the width direction WD, and accordingly, more excretory fluid can be absorbed than before. Further, the bulky ridge reduces the contact area with the skin of the wearer, and reduces the uncomfortable feeling during wearing. Further, as described below, a part of the super absorbent polymer particles 53 may not be fixed at least with the sheets 51, 52. In this case, the super absorbent polymer particles 53 can move freely in the cells 55, but the sheets 51 and 52 are wrinkled and caught by the wrinkles, so that the free movement is restricted to some extent, and there is an effect of preventing the occurrence of unevenness of the super absorbent polymer particles 53.

In pattern 2, as shown in the upper left of fig. 10, first, as in pattern 1, rectangular lattice-shaped junctions 54 are arranged, and then two adjacent cells 55 located at the center in the width direction WD are identified. Among the rows of the cells 55 extending in the front-rear direction LD from the two cells 55, groups of the cells 55 are further defined in a staggered manner. The joint 54 is provided in a rectangular shape equally divided into 4 sections for each group of the cells 55. In this way, when swelling, the direction of diffusion of the excretory fluid changes because the volume of swelling varies in the central 2 rows in the width direction WD of the absorbent body 50.

In pattern 3, the lattice-like joints 54 and the direction of the corrugated pattern are arranged in the same manner as in pattern 1. However, the joint strength of the joint portion in the front-rear direction LD is weak. The size of the cell 55 is preferably about 8 to 30mm in the vertical direction and about 10 to 50mm in the lateral direction (the distance between the weak bond parts 54 b). Thus, the weak bond 54b is peeled off due to the expansion of the super absorbent polymer particles 53. The pieces 51 and 52 are raised to have a substantially semi-cylindrical shape extending in the width direction WD. Since the plurality of substantially semi-cylindrical extensions are formed in parallel in the front-rear direction LD, the excretory fluid is less likely to spread in the front-rear direction LD. Further, the weak bond 54b also has room for swelling compared to the pattern 1, and therefore, absorption of more excretory fluid can be expected.

In the pattern 4, the joining portion 54 is formed in a wavy shape from the end portion in the width direction WD to the other end portion, and a plurality of the wavy shapes are arranged in the front-rear direction LD. By densely arranging the plurality of undulations, a substantially closed space (cell 55) is formed between the undulations. The wave-like dimension is preferably, for example, about 20 to 100mm in period length and about 8 to 30mm in amplitude. Since the joint 54 is not straight, the excretory fluid does not spread linearly, and the diffusion of the excretory fluid to the end of the absorbent body 50 is slowed, thereby providing an effect of preventing leakage.

The pattern 5 may have a rhombic shape in which diamonds are laid out on a plane without gaps, that is, an oblique lattice shape. The diagonal length of the rhombic cells 55 is preferably about 8 to 30mm in length and 10 to 50mm in width, for example. In this way, the diffusion of the excretory fluid spreads diagonally, and direct diffusion in the width direction WD and the front-rear direction LD can be prevented.

(bump)

Next, the expansion of the super absorbent polymer particles 53 will be described.

When the excretion liquid permeates the sheets 51 and 52 and is absorbed by the super absorbent polymer particles 53 in the cells 55, the super absorbent polymer particles 53 expand to a predetermined volume. The adjacent super absorbent polymer particles 53 also continue to swell due to absorption of the discharged liquid. In this way, the adjacent super absorbent polymer particles 53 are expanded one by one, expanding the wrinkle-like shape of the sheets 51, 52 formed in the cells 55. As a result, the wrinkle-like shapes of the shrunken sheets 51 and 52 before the excretion is initially absorbed are expanded and spread by the expansion force of the superabsorbent polymer particles 53 inside, and become a swollen state. Fig. 12 shows an example in which the front side sheet 51 is swollen, but a case in which the back side sheet 52 is swollen, and a case in which both the front side sheet 51 and the back side sheet 52 are swollen are also possible.

In patent document 1, the sheet is raised by the absorption of the super absorbent polymer particles 53, but this depends on the elongation of the sheet itself. On the other hand, the swelling in the present invention is not dependent on the elongation of the sheet itself, but is caused by the wrinkle-like development and expansion processed in advance, and the means of swelling is completely different. In addition, the invention has the following advantages: by changing the contraction rate arbitrarily, the volume of the bulge can be adjusted according to the purpose of the absorbent article.

(high and Low shrinkage)

Sheets 51 and 52 having a difference in shrinkage rate may be used. That is, a sheet which is regularly and repeatedly processed to a high shrinkage ratio range and a low shrinkage ratio range can be used. For example, in the wave processing, the processing may be performed such that a portion having a shrinkage rate of 30% (high shrinkage rate) and a portion having a shrinkage rate of 15% (low shrinkage rate) are alternately repeated.

(example with height Difference)

As shown in fig. 11, when the lattice-shaped cells 55 of the pattern 1 are provided with a difference in the degree of shrinkage, the absorbent body 50 can be formed in which the rows of cells 55 having a high degree of shrinkage and the rows of cells 55 having a low degree of shrinkage alternately repeat in the width direction WD. When the absorbent body 50 absorbs the excretory fluid, the cells 55 that are raised high and the cells 55 that are raised low are alternately formed in the width direction WD, and therefore an effect of preventing the excretory fluid from diffusing in the width direction WD can be expected.

Further, when the contraction rates of the sheets 51 and 52 are set to be high in the rows of cells 55 near the center in the width direction WD and low in the rows of cells 55 at the left and right ends, the absorbent body 50 is formed in which the rows of cells 55 near the center are raised higher than the rows of cells 55 at the ends by absorption of the excretory fluid. This absorbent body 50 can cope with a case where excretion is performed a plurality of times, particularly, although the amount of excretion liquid per time is small.

Further, in order to make the difference in the ridge height significant, a difference may be provided in the basis weight of the super absorbent polymer particles 53. The basis weight of the super absorbent polymer particles 53 in the cells 55 formed with a high shrinkage ratio can be set to 200 to 350g/m²The base weight of the cell 55 formed with a low shrinkage is 50 to 200g/m². Fig. 11 shows an example in which the front side sheet 51 is swollen, but it is needless to say that a case in which the back side sheet 52 is swollen and a case in which both the front side sheet 51 and the back side sheet 52 are swollen are also possible.

< example of absorbent article >

Fig. 1 to 6 show an example of a loop type disposable diaper, in which the symbol X indicates the entire width of the diaper except for the fastening tape, and the symbol L indicates the entire length of the diaper. The respective constituent members are fixed or joined as necessary in the same manner as in a known diaper except for the fixing or joining portions described below. As means for fixing or joining, hot melt adhesive or welding (heat welding or ultrasonic welding) can be appropriately selected.

The disposable diaper of the loop type has a basic structure in which an absorbent body 50 is interposed between a liquid-permeable top sheet and a liquid-impermeable sheet 11 positioned on the outer surface side, and has a abdomen-side end flap portion EF and a back-side end flap portion EF, and has a pair of side flap portions SF which extend to the front side and the back side of the absorbent body 50, respectively, and which do not have the absorbent body 50, and the pair of side flap portions SF extend further to the side than the side edge of the absorbent body 50. Fastening tapes 13 are provided on the side flaps SF of the back side section B, respectively, and the fastening tapes 13 are locked to appropriate portions of the outer surface of the abdomen side section F in a state where the side flaps SF of the back side section B are overlapped with the outer sides of the side flaps SF of the abdomen side section F when the diaper is worn.

In the disposable diaper of the loop type, the entire outer surface of the absorbent body portion 10 and the side flap portions SF is formed of the outer sheet 12. In particular, in the region including the absorber 50, the liquid-impermeable sheet 11 is fixed to the inner surface side of the outer sheet 12 with an adhesive such as a hot-melt adhesive, and the absorber 50, the intermediate sheet 40, and the top sheet 30 are laminated in this order on the inner surface side of the liquid-impermeable sheet 11. The top sheet 30 and the liquid-impermeable sheet 11 are rectangular in the illustrated example and have dimensions slightly larger than the absorbent body 50 in the front-back direction LD and the width direction WD, and the peripheral portion of the top sheet 30 extending from the side edge of the absorbent body 50 and the peripheral portion of the liquid-impermeable sheet 11 extending from the side edge of the absorbent body 50 are joined by a hot melt adhesive or the like. In addition, the liquid-impermeable sheet 11 is formed slightly wider than the topsheet 30.

Further, side three-dimensional containment flaps 60 protruding (standing) toward the skin of the wearer are provided on both sides of the absorbent main body 10, and containment sheets 62 forming the side three-dimensional containment flaps 60 are fixed to each other from both sides of the top sheet 30 to the inner surfaces of the side flaps SF.

The details of each part will be described in turn below.

(exterior sheet)

The exterior sheet 12 is a sheet constituting the outer surface of the product. The outer sheet 12 is formed in a shape in which the central portions of both side portions in the front-rear direction LD are narrowed, and here, the outer sheet is a portion surrounding the leg of the wearer. The exterior sheet 12 is preferably a nonwoven fabric, but is not limited thereto. The kind of the nonwoven fabric is not particularly limited, and the material fiber may be, for example, a fiberThe processing method may be a spunlace method, a spunbond method, a thermal bond method, a hot air method, a needle punching method, or the like, using olefin-based fibers such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, regenerated fibers such as rayon and cuprammonium fibers, and natural fibers such as cotton. Among them, a spun-bond nonwoven fabric, an SMS nonwoven fabric, an SMMS nonwoven fabric, or the like is preferable from the viewpoint of compatibility between the texture and strength. One nonwoven fabric may be used, or a plurality of nonwoven fabrics may be used in a stacked manner. In the latter case, the nonwoven fabrics are preferably bonded to each other with a hot-melt adhesive or the like. When a nonwoven fabric is used, the basis weight of the fiber is preferably 10 to 50g/m²Particularly preferably 15 to 30g/m². The outer sheet 12 may be omitted, and in this case, the liquid-impermeable sheet 11 may be formed in the same shape as the outer sheet 12 to constitute the outer surface of the product.

(liquid-impermeable sheet)

The material of the liquid-impermeable sheet 11 is not particularly limited, and examples thereof include olefin resins such as polyethylene and polypropylene, laminated nonwoven fabrics obtained by laminating nonwoven fabrics on a polyethylene sheet or the like, nonwoven fabrics having a water-impermeable film interposed therebetween and substantially ensuring liquid impermeability (in this case, the liquid-impermeable sheet is formed of a water-impermeable film and a nonwoven fabric), and the like. Of course, in addition to these, a material having liquid impermeability and moisture permeability which has been preferably used in recent years from the viewpoint of prevention of stuffiness can be exemplified. Examples of the sheet of the material having liquid impermeability and moisture permeability include a microporous sheet obtained by kneading an inorganic filler with an olefin resin such as polyethylene or polypropylene, molding the sheet, and then stretching the sheet in a uniaxial or biaxial direction. Further, as the liquid-impermeable sheet 11, a sheet made liquid-impermeable by the following method without using a waterproof film may be used: nonwoven fabrics using microdenier fibers; leakage resistance reinforcement by reducing the fiber voids by applying heat or pressure; coating the high water absorption resin, the hydrophobic resin and the water repellent.

(Top sheet)

The topsheet 30 may be a liquid-permeable nonwoven fabric having holes or holes. The type of the constituent fibers of the nonwoven fabric is not particularly limited. Examples thereof include olefin-based fibers such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, regenerated fibers such as rayon and cuprammonium fibers, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of these fibers. Further, the nonwoven fabric may be manufactured by any process. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bonding method, a melt blowing method, a needle punching method, a hot air method, and a point bonding method. For example, if flexibility and drapability are sought, the hydroentangling method is a preferred processing method; when bulkiness and flexibility are required, the thermal bonding method is a preferable processing method.

(intermediate sheet)

The intermediate sheet 40 is joined to the back surface of the top sheet 30 in order to allow the excretory fluid that has passed through the top sheet 30 to rapidly migrate toward the absorbent body 50 and to prevent rewet. The joining between the intermediate sheet 40 and the top sheet 30 may be performed by hot embossing or ultrasonic welding, in addition to the hot melt adhesive. As the intermediate sheet 40, a resin film having a plurality of through holes may be used in addition to the nonwoven fabric. As the nonwoven fabric, the same materials as those described in the section of the top sheet 30 can be used, and a material having higher hydrophilicity than the top sheet 30 or a material having higher fiber density than the top sheet 30 is preferable because the transfer property of liquid from the top sheet 30 to the intermediate sheet 40 is excellent.

The intermediate sheet 40 in the illustrated embodiment is disposed at the center so as to be narrower than the width of the absorber 50, but may be provided across the entire width. The length of the intermediate sheet 40 in the front-rear direction LD may be the same as the entire length of the diaper, may be the same as the length of the absorbent body 50, or may be within a short length range centered on the liquid-receiving region.

(side three-dimensional guard)

In order to prevent lateral movement of excrement in the top sheet 30 and to prevent side leakage, it is preferable to provide side body barriers 60 protruding (standing up) from the inner surfaces of both sides of the product in the width direction WD.

The side three-dimensional apron 60 includes an apron piece 62 and an elongated elastic stretchable member 63, and the elastic stretchable member 63 is fixed to the apron piece 62 in an extended state in the front-rear direction LD. The leg-protecting sheet 62 may be a water-repellent nonwoven fabric, and the elastic stretchable member 63 may be an elastic yarn or the like. As shown in fig. 1 and 3, the number of the elastically stretchable members 63 may be plural, or 1 member may be provided.

The inner surface of the barrier sheet 62 has a fixing start end in the width direction WD on the side portion of the top sheet 30, and the portion outside the fixing start end in the width direction WD is fixed to the side portion of the liquid-impermeable sheet 11 and the side portion of the exterior sheet 12 located in this portion by a hot melt adhesive or the like.

In the leg hole, the inner side in the width direction WD of the fixing start end of the side three-dimensional apron 60 is fixed to the top sheet 30 at both ends in the front-rear direction LD of the product, but the portion therebetween is an unfixed free portion which rises by the contraction force of the elastic stretchable member 63. When the diaper is worn, the diaper is worn on the body in a boat shape, and the contraction force of the elastic stretchable member 63 acts, so that the side three-dimensional containment flaps 60 rise by the contraction force of the elastic stretchable member 63 and are in close contact with the leg circumferences. As a result, so-called side leakage from the leg band can be prevented.

Unlike the illustrated embodiment, the inner side portion in the width direction WD of the barrier sheet 62 may be fixed at both ends in the front-rear direction LD in a folded state having a base end side portion extending from the outer side portion in the width direction WD to the inside and a distal end side portion folded back from the end edge on the center side in the width direction WD of the base end side portion to the body side and extending to the outside in the width direction WD, and the portion between the base end side portion and the distal end side portion may be a free portion that is not fixed.

(plane guard)

As shown in fig. 1 to 3, in each wing portion SF, a leg hole elastic and stretchable member 64 made of elastic cord or the like is fixed between the barrier sheet 62 and the liquid-impermeable sheet 11 in a state of being stretched in the front-rear direction LD on the outer side in the width direction WD in the vicinity of the fixing start end in the fixing portion of the barrier sheet 62, whereby the leg hole portion of each wing portion SF is configured as a planar barrier. The leg hole elastic stretchable member 64 may be disposed between the liquid-impermeable sheet 11 and the outer sheet 12 in the side flap portion SF. The leg hole elastic and stretchable members 64 may be provided in a plurality of pieces on each side as shown in the example, or may be provided in only 1 piece on each side.

(fastening tape)

As shown in fig. 1, 2 and 6, the fastening tape 13 has: a sheet base material that constitutes a belt attachment portion 13C fixed to a side portion of the diaper and a belt body portion 13B protruding from the belt attachment portion 13C; and a locking portion 13A for the ventral side, which is provided in an intermediate portion in the width direction WD of the belt main body portion 13B in the sheet base material, and a portion closer to the distal end side than the locking portion 13A is regarded as a grip portion. The tape attaching portion 13C of the fastening tape 13 is sandwiched between the inner-layer surrounding sheet 62 and the outer-layer covering sheet 12 in the side flap portion, and is bonded to the two sheets 62, 12 with a hot-melt adhesive. The locking portion 13A is bonded to the sheet base material by an adhesive so as not to be peelable.

As the locking portion 13A, a hook (a convex piece) of a mechanical fastener (a surface fastener) is preferable. The hook has a plurality of engaging projections on an outer surface side thereof. The shape of the engaging projection may be any of レ, J, mushroom, T, double J (i.e., a shape in which J-shaped engaging projections are joined back to back). Of course, an adhesive material layer may be provided as the locking portion of the fastening tape 13.

As the sheet base material formed from the tape mounting portion to the tape main body portion, various nonwoven fabrics such as a spunbond nonwoven fabric, a through-air nonwoven fabric, and a spunlace nonwoven fabric, and a plastic film, a composite laminate nonwoven fabric, paper, or a composite material thereof may be used.

(fastening object sheet)

It is preferable to provide a fastening target piece 12T having a fastening target (target) for facilitating the locking at the locking portion of the fastening band 13 of the stomach side portion F. The sheet to be fastened 12T may be one in which a plurality of loop threads capable of winding the engaging protrusions of the hook member are provided on the surface of a sheet base material made of a plastic film or nonwoven fabric when the engaging portion is the hook member 13A, or one in which a peeling treatment is applied to the surface of a sheet base material made of a plastic film having a smooth surface and a high adhesiveness when the engaging portion 13A is an adhesive material layer. In the case where the locking portion of the fastening tape 13 of the stomach-side portion F is formed of a nonwoven fabric, for example, in the case where the exterior sheet 12 is formed of a nonwoven fabric and the locking portion of the fastening tape 13 is the hook member 13A in the illustrated embodiment, the fastening target sheet 12T may be omitted and the hook member 13A may be wound around the nonwoven fabric of the exterior sheet 12 to be locked. In this case, the fastening target sheet 12T may be provided between the exterior sheet 12 and the liquid-impermeable sheet 11.

(absorber)

The absorbent body 50 is a part that absorbs and holds the liquid component of excrement. The absorber 50 is composed of a front side sheet 51, a back side sheet 52 disposed on the back side of the front side sheet 51, and superabsorbent polymer particles 53. In order to prevent the super absorbent polymer particles 53 from falling off from the absorbent body, the super absorbent polymer particles 53 are held between the surface side sheet 51 and the back side sheet 52 and are accommodated in the cells 55 formed by joining the peripheries thereof. As such, the absorbent 50 may have a plurality of cells 55. Further, an intermediate sheet 80, not shown, may be further disposed between the front side sheet 51 and the back side sheet 52.

The absorber 50 may be bonded (joined) to at least one of the front and back surfaces thereof by an adhesive such as a hot melt adhesive. The joining portions 54 of the cells 55 were joined in the same pattern, and the front side sheet 51 and the back side sheet 52 were subjected to the above-described wrinkle-like processing. By distributing and holding the super absorbent polymer particles 53 in the plurality of cells 55 surrounded by the joined portions 54, it is possible to prevent the occurrence of unevenness of the super absorbent polymer particles 53 in the absorbent body 50.

The absorbent body 50 may be wrapped with a wrapping sheet not shown. In this case, one packaging sheet may be wound in a roll shape so as to surround the front and back surfaces and both side surfaces of the absorbent body 50, or 2 packaging sheets may be wrapped so as to sandwich the front and back surfaces. As the packaging sheet, a tissue paper, particularly a crepe paper, a nonwoven fabric, a composite laminated nonwoven fabric, a sheet with small holes, and the like can be used. Among them, the super absorbent polymer particles 53 are preferredA sheet that will come out. When a nonwoven fabric is used for the packaging sheet, a hydrophilic SMS nonwoven fabric (SMS, SSMMS, etc.) is particularly preferable, and as the material thereof, polypropylene, polyethylene/polypropylene composite material, etc. can be used. The basis weight is preferably 5 to 40g/m²Particularly preferably 10 to 30g/m². When the absorbent body 50 is wrapped with a wrapping sheet, pulp fibers may be stacked on either one of the front and back surfaces of the absorbent body 50, and the stacked pulp fibers may be wrapped with a wrapping sheet.

The front side sheet 51 is a material forming the absorbent body 50, and is used in pair with the back side sheet 52 to hold the super absorbent polymer particles 53 in the absorbent body 50. The front side sheet 51 may be a liquid-permeable material or a liquid-impermeable material, and when it is positioned on the top sheet 30 side as shown in the figure, a liquid-permeable material is preferable. The surface side sheet 51 may be a nonwoven fabric or a porous plastic sheet having holes or holes, as in the top sheet 30. When the surface side sheet 51 is a nonwoven fabric, the constituent fibers thereof may be, for example, without particular limitation, olefin-based fibers such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide (including conjugate fibers in addition to single-component fibers), regenerated fibers such as rayon and cuprammonium fibers, natural fibers such as cotton, and the like, and fibers of thermoplastic resins are preferable from the viewpoint of excellent hot workability. The fiber bonding method of the nonwoven fabric is not particularly limited, and a bonding method with an increased fiber density such as a spunbond method, a melt blown method, or a needle punching method is preferable in order to prevent the superabsorbent polymer particles 53 from falling off. In the case of using a porous plastic sheet, the pore diameter is preferably smaller than the outer shape of the super absorbent polymer particles 53 in order to prevent the super absorbent polymer particles 53 from falling off. When the material of the surface side sheet 51 is hydrophobic, a hydrophilic agent may be contained.

In order to facilitate the disposition of the super absorbent polymer particles 53 during the production and to ensure the volume after the absorption and expansion, it is preferable that a recess is formed in the portion of the front side sheet 51 constituting each cell 55 from the back side toward the front side, but the formation may be omitted.

The back side sheet 52 is used in pair with the front side sheet 51 to hold the super absorbent polymer particles 53 in the absorbent body 50. The back side sheet 52 may be made of the same material as the front side sheet 51, but when the front side sheet 51 is made of a liquid-permeable material, a liquid-impermeable material may be used for the back side sheet 52. As the liquid-impermeable material that can be used for the back side sheet 52, it is possible to appropriately select and use from the materials explained in the item of the liquid-impermeable sheet 11. Although not shown, the front side sheet 51 and the back side sheet 52 may be one layer and the other layer formed by folding and overlapping one sheet of material.

The intermediate sheet 80 may be made of the same material as the front side sheet 51, a liquid-permeable material, or a liquid-impermeable material. Although not shown, the front side sheet 51, the intermediate sheet, and the back side sheet 52 may be formed of three layers formed by folding one sheet of material into three layers.

In principle, the super absorbent polymer particles 53 are not fixed to the surface side sheet 51 and the back side sheet 52, and can move freely. However, it is not always necessary that all the super absorbent polymer particles 53 are not fixed, and a part of the particles 53 (for example, 0 to 50 mass%, preferably 0 to 30 mass%, more preferably 0 to 10 mass% of the total amount of the particles 53) may be bonded or adhered to the front side sheet 51 and the back side sheet 52. In addition, the super absorbent polymer particles 53 may be agglomerated to some extent.

As the super absorbent polymer particles 53, polymer particles used in such an absorbent article may be used as they are. The particle diameter of the super absorbent polymer particles 53 is not particularly limited, and for example, it is preferable that the particles falling on the sieve in the sieving are sieved (vibrated for 5 minutes) by using a standard sieve of 500 μm (JIS Z8801-1: 2006), and the particles are sieved (vibrated for 5 minutes) by using a standard sieve of 180 μm (JIS Z8801-1: 2006), and at this time, the proportion of the particles remaining on the standard sieve of 500 μm is 30 wt% or less, and the proportion of the particles remaining on the standard sieve of 180 μm is 60 wt% or more.

The material of the super absorbent polymer particles 53 is not particularly limited, and those having a water absorption capacity of 40g/g or more are preferable. The super absorbent polymer particles 53 include starch-based, cellulose-based, synthetic polymer-based particles, and particles of starch-acrylic acid (salt) graft copolymer, saponified product of starch-acrylonitrile copolymer, crosslinked product of sodium carboxymethylcellulose, acrylic acid (salt) polymer, and the like can be used. The shape of the super absorbent polymer particles 53 is preferably a powder shape which is generally used, but particles having other shapes may be used.

As the super absorbent polymer particles 53, particles having a water absorption rate of 70 seconds or less, particularly 40 seconds or less are preferably used. If the water absorption rate is too low, so-called rewet occurs in which the liquid supplied into the absorbent body 50 is easily returned to the outside of the absorbent body 50.

In addition, as the super absorbent polymer particles 53, particles having a gel strength of 1000Pa or more are preferably used. This can effectively suppress the sticky feeling after liquid absorption even when the absorbent body 50 is formed into a bulky shape.

The basis weight of the super absorbent polymer particles 53 can be determined appropriately according to the absorption amount required for the use of the absorbent body 50. Therefore, it can be 50-350 g/m². If the basis weight is less than 50g/m²It is difficult to secure the absorption amount. If it exceeds 350g/m²The effect is saturated.

The joining portions 54 joining the front side sheet 51 and the back side sheet 52 are provided in the same arrangement throughout the absorbent body 50, but may be partially changed. The joining portion 54 is preferably joined by welding the front side sheet 51 and the back side sheet 52 as in ultrasonic welding or heat sealing, but may be joined by a hot melt adhesive.

The joint portion 54 between the front side sheet 51 and the back side sheet 52 may be formed in a continuous line shape (discontinuous in the direction surrounding each cell 55) in addition to a continuous line shape as illustrated, as long as it is arranged so as to surround each cell 55 and a boundary between adjacent cells 55 is formed. When the bonding portions 54 are formed intermittently, the superabsorbent polymer particles 53 are not present between the bonding portions 54 in the direction surrounding the cells 55, or are present in a smaller amount than the inside of the cells 55.

In principle, the joint 54 is not peeled off by the expansion tension of the super absorbent polymer particles 53 in the adjacent cells 55. However, the weak bond 54b may peel due to the expansion tension. This is because some of the superabsorbent polymer particles 53 are not fixed to at least the front side sheet 51 or the back side sheet 52, and can move freely within a range sandwiched between these sheets 51 and 52, and may fall off from the end portions of the sheets 51 and 52. In order to prevent the particles from falling off, the cells 55 are provided so as to be joined to each other, and the super absorbent polymer particles 53 are left in the cells 55. When the superabsorbent polymer particles 53 are caused to absorb the excretory fluid, the volume of the single cell 55 after expansion is limited, causing gel blocking, and there is a possibility that a sufficient amount of the excretory fluid cannot be absorbed completely. Therefore, the joining portion can be easily peeled off by the expansion tension of the super absorbent polymer particles 53, and the adjacent cells 55 are joined to each other, whereby more excretory fluid can be absorbed. Therefore, the weak bond 54b may be provided in advance.

On the other hand, the bonding portions 54 located on the outermost sides in the width direction WD are preferably reinforced in strength in advance because the superabsorbent polymer particles 53 or the gelled product thereof may leak out to the sides of the absorbent body 50 when peeling occurs. From the same viewpoint, it is preferable that the front side sheet 51 and the back side sheet 52 extend to a certain extent outward in the width direction WD from the cell 55 formation region, and an edge joining portion 54c for reinforcement is provided in advance in the extending portion.

The difference in the joining strength of the joining portion 54 (the strength against the peeling of the front side sheet 51 and the back side sheet 52) can be easily formed by changing the area of the joining portion 54, but is not limited to this, and for example, in the case of forming the joining portion 54 with a hot melt adhesive, a method of varying the type of the hot melt adhesive depending on the location may be employed. In particular, when the joining portion 54 is formed by welding the front side sheet 51 and the back side sheet 52, the weak joining portion 54b may be formed by forming the joining portion into a dot shape.

In order to enable the weak bond 54b to be peeled off, the type and amount of the super absorbent polymer particles 53 disposed in each cell 55 may be set so that the volume of the super absorbent polymer particles 53 in the cell 55 adjacent to the weak bond 54b at the time of saturated absorption is sufficiently larger than the volume of the cell 55.

In the above example, only the super absorbent polymer particles 53 are contained in the cells 55, but powder or granules other than the super absorbent polymer particles 53 such as deodorant particles may be contained together with the super absorbent polymer particles 53.

< description of terms in the specification >

When the following terms are used in the specification, they have the following meanings unless otherwise specified in the specification.

"LD direction" and "WD direction" refer to a flow direction in a manufacturing apparatus (LD direction) and a transverse direction (WD direction) perpendicular thereto, and either direction is a front-rear direction of a product, and the other direction is a width direction of the product. The LD direction of the nonwoven fabric is the direction in which the fibers of the nonwoven fabric are oriented. The fiber orientation is a direction along which the fibers of the nonwoven fabric run, and can be determined by, for example: a measurement method according to a fiber orientation test method of zero distance tensile strength based on TAPPI standard method T481; or a simple measurement method for determining the fiber orientation direction from the tensile strength ratio in the front-back direction and the width direction.

"expanded state" refers to a state of being expanded flat without contraction or relaxation.

"elongation" means a value when the natural length is 100%.

"Artificial urine" is prepared by mixing urea: 2 wt%, sodium chloride: 0.8 wt%, calcium chloride dihydrate: 0.03 wt%, magnesium sulfate heptahydrate: 0.08 wt% and ion-exchanged water: 97.09 wt%, and the temperature is 40 ℃ unless otherwise specified.

"gel strength" was measured as follows. To 49.0g of artificial urine, 1.0g of a super absorbent polymer was added and stirred by a stirrer. The resulting gel was allowed to stand in a constant temperature and humidity bath at 40 ℃ X60% RH for 3 hours, and then returned to normal temperature, and the gel strength was measured by a curdometer-MAX ME-500 (manufactured by I.techno Engineering Co.).

"basis weight" was determined as follows. After the sample or the test piece was preliminarily dried, it was placed in a laboratory or an apparatus in a standard state (the temperature at the test site was 23. + -. 1 ℃ and the relative humidity was 50. + -. 2%) so as to be in a constant state. Pre-drying refers to bringing the sample or test strip to a constant level in an environment at a temperature of 100 ℃. The pre-drying may not be performed for the fiber having a standard moisture regain of 0.0%. Using a template (template) for specimen cutting (100 mm. times.100 mm), a specimen of 100 mm. times.100 mm size was cut from a test piece which had reached a constant weight state. The weight of the sample was measured and multiplied by 100 to calculate the weight per 1 square meter as the basis weight.

"thickness" measured with an automatic thickness measuring device (KES-G5 hand-held compression tester) under a load of 0.098N/cm²And a pressing area of 2cm²Under the conditions of (1) and (3).

The water absorption was measured in accordance with JIS K7223-1996 "method for testing the Water absorption of a super absorbent resin".

The water absorption rate is the "time to end point" in the case of JIS K7224-1996 "Water absorption Rate test method for superabsorbent resin" using 2g of superabsorbent polymer and 50g of physiological saline.

In the case where there is no description about the environmental conditions in the test or measurement, the test or measurement is performed in a laboratory or apparatus in a standard state (the temperature at the test site is 23 ± 1 ℃, and the relative humidity is 50 ± 2%).

Unless otherwise specified, the dimensions of each part are dimensions in the expanded state, not in the natural length state.

Description of the symbols

11 … liquid-impermeable sheet, 12 … exterior sheet, 12T … fastening object sheet, 13 … fastening tape, 13a … locking portion, 13B … tape main body portion, 13C … tape attaching portion, 30 … top sheet, 40 … intermediate sheet, 60 … side three-dimensional enclosure, 62 … enclosure sheet, 50 … absorber, 51 … front side sheet, 52 … back side sheet, 53 … highly absorbent polymer particle, 54 … joining portion, 54B … weak joining portion, 55 … cell, 80 … intermediate sheet, H … high shrinkage rate, L … low shrinkage rate, LD … front-back direction, WD … width direction.