CN117500468A - Absorbent sheets and absorbent articles - Google Patents

Abstract

The absorbent sheet (1) of the present invention comprises a first fibrous sheet (11), a second fibrous sheet (12), and particles of a water-absorbent polymer (13) disposed between these fibrous sheets. The absorbent sheet (1) has a non-overlapping region (N1) in which the position of the peripheral edge of the first fibrous sheet (11) and the position of the peripheral edge of the second fibrous sheet (12) do not overlap in a plan view. Preferably, the non-overlapping region (N1) is formed by the first fibrous sheet (11) having a different plan view dimension from the second fibrous sheet (12).

Description

Absorbent sheets and absorbent articles

Technical field

The present invention relates to absorbent sheets and absorbent articles.

Background technique

For the purpose of improving liquid absorbency, a sheet-like article in which a water-absorbent polymer is arranged between two sheets, and an absorbent article having the sheet-like article have been developed. For example, Patent Document 1 discloses an absorbent article having an absorbent body that includes a front side sheet and a back side sheet; a large number of cells surrounded by joints and in which the front side sheet and the back side sheet are not joined; and highly absorbent polymer particles contained within the chamber.

Patent Document 2 discloses an absorbent core having an absorbent material containing an absorbent particulate polymer disposed between a first base material and a second base material. One base material and the second base material are combined by an adhesive.

existing technical documents

patent documents

Patent Document 1: US2019/125596A1

Patent Document 2: US2016/270987A1

Contents of the invention

The present invention relates to a water-absorbent sheet including a first fiber sheet, a second fiber sheet, and particles of a water-absorbent polymer disposed between these fiber sheets.

In one embodiment, it is preferable that the water-absorbent sheet has a non-overlapping region in which the position of the peripheral edge of the first fiber sheet does not overlap with the position of the peripheral edge of the second fiber sheet when viewed from above.

In addition, the present invention relates to an absorbent article having a longitudinal direction corresponding to the front-rear direction of the wearer and a width direction orthogonal to the longitudinal direction, and including an absorbent main body having an absorbent body disposed on a surface facing the skin. A front sheet on the side, a back sheet disposed on the non-skin-facing side, and an absorber disposed between these two sheets.

In one embodiment, it is preferable that the absorbent article has the absorbent sheet as the absorber.

Description of the drawings

(a) to (e) of FIG. 1 are cross-sectional views schematically showing one embodiment of the absorbent sheet.

(a) to (c) of FIG. 2 are cross-sectional views schematically showing other embodiments of the absorbent sheet.

(a) to (f) of FIG. 3 are plan views schematically showing one embodiment of the absorbent sheet.

Fig. 4 is a cross-sectional view schematically showing another embodiment of the absorbent sheet.

Fig. 5 is a cross-sectional view schematically showing yet another embodiment of the absorbent sheet.

FIG. 6 is a perspective view schematically showing the absorbent sheet shown in FIG. 5 .

FIG. 7 is a cross-sectional view schematically showing one embodiment of an absorbent article having an absorbent sheet.

Fig. 8 is a cross-sectional view schematically showing another embodiment of an absorbent article having an absorbent sheet.

FIG. 9 is a schematic diagram showing one embodiment of a manufacturing apparatus used for manufacturing an absorbent sheet.

Detailed ways

In actual use scenarios of the absorbent sheets described in Patent Documents 1 and 2, excreted body fluids spread toward the surface of the sheet, and liquid reaching the periphery of the sheet cannot be fully absorbed, leaving room for improvement in improving liquid absorbency.

Therefore, the present invention relates to an absorbent sheet with improved liquid absorbency and an absorbent article having the sheet.

Hereinafter, the present invention will be described based on its preferred embodiments with reference to the drawings. One embodiment of the absorbent sheet of the present invention is shown in FIGS. 1 and 2 . The absorbent sheet 1 includes a first fiber sheet 11 , a second fiber sheet 12 , and particles of the water-absorbent polymer 13 arranged between the two fiber sheets 11 and 12 . A plurality of particles of the water-absorbent polymer 13 shown in this figure are arranged in the surface direction of the sheet. The first fiber sheet 11 and the second fiber sheet 12 may be the same sheet or different sheets. There are no other components on the outer surfaces of the first fiber sheet 11 and the second fiber sheet 12. However, as described later, other components such as auxiliary layers may be disposed on the outer surfaces of the fiber sheets 11 and 12.

The absorbent sheet 1 has a non-overlapping region N1 in which the position of the peripheral edge of the first fiber sheet 11 and the position of the peripheral edge of the second fiber sheet 12 do not overlap when viewed from above. The non-overlapping region N1 formed in the absorbent sheet 1 may be formed in at least a part of the periphery of the absorbent sheet 1 , or may be formed in the entire periphery of the absorbent sheet 1 . The water-absorbent polymer 13 is not arranged in the non-overlapping area N1. The geometric shape of the absorbent sheet 1 in plan view may be a polygonal shape such as a square, a rectangle, or a quadrilateral, or a circular shape such as a perfect circle or an ellipse.

In the following description, for convenience of explanation, unless otherwise stated, the plan view shape of the absorbent sheet will be described as a rectangle.

In the embodiment shown in FIGS. 1 (a) to (d), by making the cross-sectional size of one fiber sheet (the size along the transverse direction Y in the figure) larger than the cross-sectional size of the other fiber sheet, the absorbency is improved. At least one end of the sheet 1 is formed with a non-overlapping area N1. In the embodiment shown in (a) and (b) of FIG. 1 , non-overlapping regions N1 are formed on both sides of the absorbent sheet 1 . In the embodiment shown in (c) and (d) of FIG. 1 , the one side edges 1 a and 2 a of the two fiber sheets 11 and 12 do not overlap, and a non-overlapping region N1 is formed on one side edge of the absorbent sheet 1 . In addition, the other side edge of the absorbent sheet 1 shown in (c) and (d) of FIG. 1 overlaps at the position of the side edges 1b and 2b of the two fiber sheets 11 and 12, and no non-overlapping region N1 is formed.

In the embodiment shown in FIG. 1(e) , the cross-sectional dimensions of the two fiber sheets 11 and 12 are made the same as each other, and the both side edges of the two fiber sheets 11 and 12 are arranged differently, so that the absorbent sheet 1 Non-overlapping areas N1 are formed at both ends.

In any of the embodiments shown in (a) to (e) of FIG. 1 , both sides of the absorbent sheet 1 are open, and the water-absorbent polymer 13 is exposed when viewed from the side of the sheet.

In the embodiment shown in (a) and (b) of FIG. 2 , the second fiber sheet 12 as one fiber sheet is rolled up so as to cover the side edge 1 b of the first fiber sheet 11 as the other fiber sheet. One side edge 2 b of the second fiber sheet 12 in the rolled position is located on the outer surface of the first fiber sheet 11 . In the form shown in FIG. 2(a) , the fiber sheets 11 and 12 in the rolled position are not joined to each other. In the form shown in FIG. 2( b ), a joint portion 19 in which the fiber sheets 11 and 12 are jointly joined is formed at a position where the second fiber sheet 12 is rolled up. In the forms of (a) and (b) of Figure 2, the side edge of the fiber sheet is not rolled up, and the side of the absorbent sheet 1 is open. When viewed from the side of the sheet, the water-absorbent polymer 13 exposed. As described above, when the second fiber sheet 12 is rolled up so as to cover the side edge 1 b of the first fiber sheet 11 , the first fiber sheet 11 in the rolled position may be folded back outward.

As shown in this embodiment, when one fiber sheet is rolled up to another fiber sheet, the non-overlapping area N1 is based on the state in which the fiber sheets are unrolled, bent, and joined and the fiber sheets are compared according to the designed size. , the position of the peripheral edge of the first fiber sheet 11 and the position of the peripheral edge of the second fiber sheet 12 are judged.

In the embodiment shown in FIG. 2(c) , the fiber sheets 11 and 12 are joined by the joining portion 19 in a state where one fiber sheet is not rolled up to the other fiber sheet. In the embodiment shown in FIG. 2(c) , the bonding portion 19 may be formed on the entire periphery of the absorbent sheet 1 , or the bonding portion 19 may be formed on a part of the periphery. The side edges of the absorptive sheet 1 where the joint portion 19 is not formed are open, and the water-absorbent polymer 13 is exposed when viewed from the side of the sheet.

In order to provide the absorbent sheet 1 with the non-overlapping region N1, for example, as shown in (a) to (f) of Fig. 3, the shape or size of one fiber sheet in plan view can be compared with the shape or size of the other fiber sheet in plan view. The shapes or sizes are different from each other. In this case, the fiber sheets may be arranged so that their centroids are at the same position when viewed from above, or they may be arranged so that they are at different positions from each other. In FIG. 3 , the direction indicated by reference numeral X is a direction orthogonal to the transverse direction Y.

The absorbent sheets shown in (a) to (f) of FIG. 3 all have a longitudinal direction X and a transverse direction Y, and the lengths of the two fiber sheets 11 and 12 in the longitudinal direction X are the same as each other.

The absorbent sheet 1 shown in FIG. 3( a ) includes a rectangular first fiber sheet 11 and a rectangular second fiber sheet 12 having a longer short side than the first fiber sheet 11 . In the embodiment shown in FIG. 3( a ), the fiber sheets 11 and 12 are arranged so that their centroids coincide with each other. The non-overlapping area N1 in this embodiment is formed outside both side edges 1a and 1b in the transverse direction Y of the first fiber sheet 11, and the two side edges in the longitudinal direction X corresponding to the short sides of the fiber sheets 11 and 12 are consistent with each other. Therefore, in this embodiment, the lengths of the two fiber sheets 11 and 12 in the longitudinal direction X and the length of the absorbent sheet 1 in the longitudinal direction X are the same as each other. The cross section along the transverse direction Y in this embodiment typically has at least the form shown in (a) of FIG. 1 .

The absorbent sheet 1 shown in FIG. 3( b ) includes a rectangular-shaped first fiber sheet 11 and a rectangular-shaped second fiber sheet 12 having a shorter short side than the first fiber sheet 11 . In the embodiment shown in FIG. 3( b ), the centroids of the fiber sheets 11 and 12 are aligned with each other. The non-overlapping area N1 of this embodiment is formed outside both side edges 2a and 2b in the transverse direction Y of the second fiber sheet 12, and the two side edges in the longitudinal direction X corresponding to the short sides of the fiber sheets 11 and 12 are consistent with each other. Therefore, in this embodiment, the lengths of the two fiber sheets 11 and 12 in the longitudinal direction X and the length of the absorbent sheet 1 in the longitudinal direction X are the same as each other. The cross section along the transverse direction Y in this embodiment typically has at least the form shown in (b) of FIG. 1 .

The absorbent sheet 1 shown in FIG. 3(c) includes a rectangular first fiber sheet 11 and a rectangular second fiber sheet 12 having a longer short side than the first fiber sheet 11 . In the embodiment shown in FIG. 3(c) , the fiber sheets 11 and 12 are arranged so as to have different centroids. The non-overlapping area N1 in this embodiment is formed outside one side edge 1a in the transverse direction Y of the first fiber sheet 11, the other side edges 1b, 2b in the transverse direction Y of each fiber sheet 11, 12 and with each fiber sheet 11, 12. The two edges of the longitudinal direction X corresponding to the short side are consistent with each other. Therefore, in this embodiment, the lengths of the two fiber sheets 11 and 12 in the longitudinal direction X and the length of the absorbent sheet 1 in the longitudinal direction X are the same as each other. The cross section along the transverse direction Y in this embodiment typically has at least the form shown in (c) of FIG. 1 .

In the form shown in FIG. 3( c ), a rectangular-shaped first fiber sheet 11 and a rectangular-shaped second fiber sheet 12 having a shorter short side than the first fiber sheet 11 are configured. Below, the cross section along the width direction Y of the absorbent sheet 1 typically has at least the form shown in (d) of FIG. 1 .

The absorbent sheet 1 shown in FIG. 3(d) includes a rectangular-shaped first fiber sheet 11 and a rectangular-shaped second fiber sheet 12 having the same size as the first fiber sheet 11. That is, the shape and plan view size of one fiber sheet and the shape and plan view size of the other fiber sheet are the same as each other. In the embodiment shown in FIG. 3(d) , the fiber sheets 11 and 12 are arranged so as to have different centroids. The non-overlapping region N1 of this embodiment is formed on both sides of the absorbent sheet 1 in the transverse direction Y, specifically, it is formed outside one side edge 1 a of the first fiber sheet 11 in the transverse direction Y and the second fiber sheet 12 in the transverse direction. Outside one side edge 2b of Y, both sides of the longitudinal direction X corresponding to the short sides of the fiber sheets 11 and 12 are aligned with each other. Therefore, in this embodiment, the lengths of the two fiber sheets 11 and 12 in the longitudinal direction X and the length of the absorbent sheet 1 in the longitudinal direction X are the same as each other.

In the absorbent sheet 1 shown in FIG. 3(d) , when the plan view shape of each fiber sheet is a rectangle, in plan view, one set of opposite sides of each fiber sheet overlaps each other, and the other side of each fiber sheet overlaps in the plan view. A set of opposite sides may be arranged so that the positions thereof do not overlap, and a non-overlapping region N1 is formed in the absorbent sheet 1. Alternatively, the fiber sheets may be arranged so that all sides do not overlap in plan view. The cross section along the transverse direction Y in this embodiment typically has at least the form shown in (e) of FIG. 1 .

The absorbent sheet 1 shown in FIGS. 3 (e) and (f) includes a first fiber sheet 11 having a parallelogram shape or a shape in which the long sides are a combination of straight lines or curves, and a rectangular second fiber sheet 12 And constitute. In the embodiment shown in (e) and (f) of FIG. 3 , the fiber sheets 11 and 12 are arranged so that their centroids overlap. The non-overlapping region N1 of this embodiment is formed outside both edges of the absorbent sheet 1 in the transverse direction Y, and the two edges in the longitudinal direction X corresponding to the short sides of the fiber sheets 11 and 12 are aligned with each other. Therefore, in this embodiment, the lengths of the two fiber sheets 11 and 12 in the longitudinal direction X and the length of the absorbent sheet 1 in the longitudinal direction X are the same as each other. The cross section along the transverse direction Y in this embodiment typically has at least the form shown in (e) of FIG. 1 .

In any of the above-mentioned forms, if necessary, one fiber sheet may be rolled up to another fiber sheet or the joint part 19 may be formed to have the structure shown in (a) to (c) of FIG. 2 constitute.

Among these structures, it is more preferable that the absorbent sheet 1 has a rectangular shape when viewed from above, and that there is no non-overlapping of the two sets of sides facing each other in the plan view, as shown in (a) to (d) of Figure 3 . In the area N1, there is a non-overlapping area N1 on one side or both sides of the other set of sides. In addition, it is more preferable that both fiber sheets 11 and 12 are rectangular, and it is more preferable that the directions along the long sides of both fiber sheets 11 and 12 (the X direction in FIG. 3 ) are aligned with each other. By having such a structure, the excretion liquid and the water-absorbent polymer are easily brought into contact at the side portions of the absorbent sheet 1, and the liquid absorbency at the side portions of the sheet is improved, thereby obtaining an absorbent sheet with further improved liquid absorbency.

The non-overlapping region N1 is preferably formed at the longitudinal X end and the transverse Y end, and more preferably is formed at the transverse Y end.

From the viewpoint of improving the contact efficiency between the water-absorbent polymer on the side of the absorbent sheet 1 and excreted body fluids (hereinafter also referred to as excretion fluid) and further improving the liquid absorbency, it is preferable that one fiber sheet does not extend toward the other. It is also preferable that the fiber sheet is rolled up and that the joint portion 19 is not formed. That is, as shown in (a) to (e) of Fig. 1 , it is preferable that the side portion of the absorbent sheet 1 is open and the water-absorbent polymer 13 is exposed when viewed from the side portion of the sheet.

In the absorbent sheet 1, it is preferable that the non-overlapping region N1 is formed by the plan view size of the first fiber sheet 11 and the plan view size of the second fiber sheet 12 being different from each other. The difference in plan view size means that the length of any side of the sheet differs by more than 1 mm if it is a quadrilateral shape such as a rectangle, and the diameter or the length of the major or minor axis differs by more than 1 mm if the sheet is circular.

Furthermore, as shown in (a) or (b) of FIG. 3 , it is preferable that the geometric shape of the first fiber sheet 11 in plan view and the geometric shape of the second fiber sheet 12 in plan view are the same as each other. The same geometric shape means that, for example, the shapes of each fiber sheet are square, rectangular, or circular. Specifically, for example, when one fiber sheet has a rectangular shape and the other fiber sheet has a rectangular shape, the geometric shapes are the same, and when one fiber sheet has a square shape and the other fiber sheet has a rectangular shape, the geometric shapes are the same. Below, the geometry is different.

By adopting such a structure, the water-absorbent polymer can be exposed on the side portions of the absorbent sheet 1, so that the excretion liquid can easily come into contact with the water-absorbent polymer, and the liquid absorbency on the side portions of the sheet can be improved, thereby achieving liquid absorption. Absorbent sheet with improved performance. In order to obtain such an absorbent sheet, for example, it can be produced using original material rolls in which the length in the width direction of one fiber sheet original roll is different from the length in the width direction of the other fiber sheet original roll.

As shown in FIG. 4 , the absorbent sheet 1 preferably has a non-polymer region, which is a region where the water-absorbent polymer 13 is not present, between the first fiber sheet 11 and the second fiber sheet 12 when viewed inwardly from its peripheral edge. N3. The non-polymer region N3 shown in the figure is located on both sides of the first fiber sheet 11 on the inside of the non-overlapping region N1 and shorter than the length along the short side direction (transverse direction Y) of the second fiber sheet 12 1a and 1b are located on the inside. The non-polymer region N3 may be formed on the entire periphery of the absorbent sheet 1 , or may be formed on a portion of the periphery of the absorbent sheet 1 on one pair of equal pairs of side edges of the absorbent sheet 1 . By adopting such a structure, the water-absorbent polymer is exposed on the side portions of the absorbent sheet, thereby improving the liquid absorbency on the side portions of the sheet and effectively preventing the water-absorbent polymer from falling off and moving from the side portions. Therefore, an absorbent sheet with further improved liquid absorbency can be obtained. In order to obtain such an absorbent sheet, for example, when applying the adhesive 15 described below, the application area may be adjusted so that the adhesive 15 is not applied at the position where the non-polymer area N3 is to be formed.

From the viewpoint of improving the liquid absorbency of the absorbent sheet 1 and improving the handleability by preventing the polymer from falling off even when the water-absorbent polymer swells (swollen), the absorbent sheet 1 is The length D1 of the non-overlapping region N1 along the plane direction of the sheet in the cross-sectional view (refer to FIG. 4. For convenience of explanation, in this figure, it is shown as the length along the transverse direction Y) is preferably 1 mm or more, more preferably It is 3 mm or more, more preferably 5 mm or more, preferably 20 mm or less, more preferably 10 mm or less.

From the viewpoint of improving the liquid absorbency of the absorbent sheet 1 and improving the workability by preventing the polymer from falling off even when the water-absorbent polymer swells, the cross-sectional view of the absorbent sheet 1 The length D3 of the non-polymer region N3 along the plane direction of the sheet (see FIG. 4. For convenience of explanation, in this figure, it is shown as the length along the transverse direction Y) is preferably 1 mm or more, and more preferably 3 mm or more. , more preferably 5 mm or more, preferably 20 mm or less, and more preferably 10 mm or less. The length D3 is the length between the peripheral edge of the smaller one of the two fiber sheets 11 and 12 and the position of the water-absorbent polymer when viewed inward from the peripheral edge.

As shown in FIGS. 1 (a) to (e) and FIG. 4 , it is preferable that the first fiber sheet 11 and the second fiber sheet 12 are not joined to each other on the periphery of the absorbent sheet 1 . That is, it is preferable that the absorbent sheet 1 does not have the joint part 19 on its peripheral edge, and it is also preferable that it does not have the adhesive 15 mentioned later. The portions where the first fiber sheet 11 and the second fiber sheet 12 are not joined to each other may be formed in the entire peripheral area of the absorbent sheet 1, or may be formed in, for example, a pair of equal pairs of side edges of the absorbent sheet. A part of the periphery of the absorbent sheet 1 . By forming such a structure, excretion liquid and the water-absorbent polymer are easily brought into direct contact at the periphery of the absorbent sheet 1, and the liquid absorbency in the side portion of the sheet can be improved. As a result, an absorbent sheet with further improved liquid absorbency can be obtained. In particular, by forming a portion where the first fiber sheet 11 and the second fiber sheet 12 are not joined to each other in the entire peripheral area of the absorbent sheet 1, this effect is more remarkably achieved.

In addition, as shown in FIGS. 1 (a) to (e) and FIG. 4 , it is preferable that the periphery of the absorbent sheet 1 is rolled up so that the end of one fiber sheet does not cover the end of the other fiber sheet. By forming such a structure, it is easy for excretion liquid and a water-absorbent polymer to come into direct contact at the periphery of the absorbent sheet 1, and the liquid absorbency in the side part of the sheet can be improved. As a result, an absorbent sheet with further improved liquid absorbency can be obtained. In order to obtain such an absorbent sheet, for example, the length in the width direction of one fiber sheet original material is different from the length in the width direction of another fiber sheet original material, and it can be produced using a material in which the length in the width direction of each original material is appropriately adjusted. .

The fiber sheet constituting the absorbent sheet is an aggregate of fibers and has a thickness of 5 mm or less when measured under a pressure of 1.7 kPa. The fiber sheets are independent and preferably inelastic fiber sheets. The thickness of the fiber sheet can be measured using a laser displacement meter, for example.

The thickness of the fiber sheets measured under the application of a pressure of 1.7 kPa is preferably 3 mm or less, more preferably 1 mm or less, still more preferably 0.5 mm, preferably 0.1 mm or more, and more preferably 0.3 mm or more.

Examples of the constituent fibers of each of the fiber sheets 11 and 12 include wood pulp, natural pulp such as cotton and linen, modified pulp such as mercerized pulp and chemically cross-linked pulp, and resins containing polyethylene, polypropylene, etc. Various fibers such as synthetic fibers or fibers subjected to hydrophilization treatment or hydrophobization treatment. Examples of the material of each of the fiber sheets 11 and 12 include paper, woven fabric, film, or non-woven fabric. Each of the fiber sheets 11 and 12 may independently be a single layer or multiple layers. In addition, each of the fiber sheets 11 and 12 may independently be composed of only one fiber assembly (regardless of single layer or multi-layer), or may have a first fiber assembly and a fiber assembly other than this assembly or a fiber assembly. A multi-layer laminated structure in which sheet materials other than fiber aggregates are overlapped. From the viewpoint of achieving both liquid absorbency and air permeability at a high level, it is preferable that each of the fiber sheets 11 and 12 is a single-layer sheet.

When the fiber sheets 11 and 12 constituting the absorbent sheet 1 are stretched by applying the same load, it is preferable that the elongation magnification E1 of the first fiber sheet and the elongation magnification E2 of the second fiber sheet are different from each other.

Specifically, the elongation ratio E1 of the first fiber sheet 11 is preferably 1.03 times or more, more preferably 1.05 times or more, preferably 1.20 times or less, and more preferably 1.15 times or less. In addition, the elongation ratio E2 of the second fiber sheet 12 is preferably 1.01 times or more, more preferably 1.02 times or more, preferably 1.15 times or less, and more preferably 1.10 times or less.

By configuring the fiber sheets 11 and 12 in such a manner that the elongation ratios of the fiber sheets 11 and 12 are different within the above-mentioned range, wrinkles are easily generated in the fiber sheets due to differences in dimensional changes between the fiber sheets. Therefore, the sides of the absorbent sheet 1 Easy to speak. As a result, the liquid absorbency from the side portion of the absorbent sheet 1 can be further improved.

It is preferable that each of the above-mentioned elongation magnifications E1 and E2 is satisfied when a load of 5 N is applied and elongation occurs in the measurement method described below.

The elongation ratio can be measured as described below. First, the absorbent sheet in the natural state to be measured is cut into a rectangular shape so that the size is 200 mm in the X direction and 50 mm in the Y direction. Then, the first fiber sheet 11 and the second fiber sheet 12 were peeled off from the cut pieces and used as test pieces. When the fiber sheets are joined by an adhesive or the like, they are solidified by blowing cold air through cold spraying or the like, and are carefully taken out so as not to apply excessive external force to the fiber sheets.

Next, a tensile and compression testing machine (Shimadzu Corporation, AG-IS) was used for each test piece. The distance between the chucks was set to 150 mm, and the test piece was stretched in the X direction at a tensile speed of 150 mm. Stretch at 300mm/min and measure the distance between the chucks at a load of 5N/50mm. This elongation condition is regarded as the maximum elongation condition in this specification. This measurement was performed five times, and the arithmetic mean was used as the sheet elongation (mm). Furthermore, based on the obtained sheet elongation, the elongation ratio was calculated according to the following formula.

Elongation ratio [times] = (sheet elongation [mm])/(150 [mm])

Examples of combinations of fiber sheets 11 and 12 include: (i) paper having an elongation ratio E1 of 1.10 times is used as the first fiber sheet, and nonwoven fabric having an elongation ratio E2 of 1.03 times is used as the second fiber sheet. combination; (ii) a combination of using paper with an elongation ratio E1 of 1.05 times as the first fiber sheet, and using a non-woven fabric with an elongation ratio E2 of 1.01 times as the second fiber sheet; or (iii) as the first fiber A combination of a nonwoven fabric having an elongation ratio E1 of 1.12 times as the sheet, and a nonwoven fabric having an elongation ratio E2 of 1.03 times as the second fiber sheet is used.

From the viewpoint of improving liquid absorbency, it is preferable to use, for example, a combination of the above (i).

In either case, the elongation ratio of each fiber sheet can be determined by, for example, using materials with different Young's modulus (for example, polyethylene, polypropylene, polystyrene, polyurethane, etc.), or changing the length of the constituent fibers or The thickness can be appropriately adjusted by performing cogging in which the fiber sheet is bitten between concave and convex gears to stretch it, or by changing conditions such as hot air or embossing rate to change the thermal melting rate of the fiber.

The water-absorbent polymer 13 can generally use a hydrogel material capable of absorbing and retaining water, for example, a polymer or copolymer of acrylic acid or an alkali metal salt of acrylate can be used. Examples thereof include polyacrylic acid and its salts and polymethacrylic acid and its salts. Specifically, an acrylic acid polymer metasodium salt can be exemplified. The shape of the water-absorbent polymer 13 is not particularly limited, and may be, for example, spherical, cluster-shaped, block-shaped, pillow-shaped, fibrous, irregular-shaped particles and combinations thereof. From the viewpoint of improving the uniformity of dispersion of the water-absorbent polymer 13 during the production of the absorbent sheet 1 and improving the liquid-absorbing performance, it is preferable to use particles of the same shape as the water-absorbent polymer 13, and spherical particles are also preferred.

The basic weight of each of the fiber sheets 11 and 12 constituting the absorbent sheet is preferably 4 g/m ² or more, more preferably 6 g/m ² or more, and preferably 100 g/m ² or less, more preferably 50 g/m 2 or more. m ² or less, more preferably 30 g/m ² or less.

In the above-mentioned absorbent sheet, the basis weight of the water-absorbent polymer is preferably 60 g/m ² or more, more preferably 100 g/m ² or more, and preferably 500 g/m ² or less, more preferably 400 g/m ² or less.

Another embodiment of the absorbent sheet 1 is shown in FIGS. 5 and 6 . In the following description, only the parts different from the above-described embodiment will be described, and the above description shall be appropriately applied to other parts. In addition, the same components as those in the above-described embodiment are denoted by the same reference numerals.

The absorbent sheet 1 shown in FIGS. 5 and 6 includes a first fiber sheet 11 , a second fiber sheet 12 , and a plurality of particles of the water-absorbent polymer 13 arranged between the two fiber sheets 11 and 12 . On this basis, it is preferable that the first fiber sheet 11 and the second fiber sheet 12 are bonded to each other through the adhesive 15 . By configuring such a structure, the bonding strength between the two fiber sheets 11 and 12 is high, and the strength of the absorbent sheet 1 can be improved. The adhesive 15 shown in FIGS. 5 and 6 is respectively arranged on the surface of each fiber sheet 11 and 12 facing the water-absorbent polymer 13 .

In particular, when the two fiber sheets 11 and 12 are joined to each other through the adhesive 15, it is preferable that the first fiber sheet 11 and the second fiber sheet 12 are connected directly through the adhesive 15 without passing through the water-absorbent polymer 13. The joined portion 17 (hereinafter also simply referred to as "directly joined portion 17"); and the portion 18 where the two fiber sheets 11 and 12 are joined via the adhesive 15 via the water-absorbent polymer 13 (hereinafter also referred to as It is "indirect joint part 18".). By forming such a structure, the water-absorbent polymer 13 is held at a predetermined position in the absorbent sheet 1, and even in a state where the side portion of the absorbent sheet 1 is open and the water-absorbent polymer 13 is exposed, the water absorbency can be further reduced. Undesired movement and deviation (uneven distribution) of the polymer 13 can further improve the liquid absorbency of the absorbent sheet 1 .

The direct bonding sites 17 shown in FIGS. 5 and 6 respectively form gaps between the particles of the water-absorbent polymer 13 in the region where the water-absorbent polymer 13 is arranged. When the direct joint portion 17 is viewed cross-sectionally in the sheet thickness direction, the adhesive 15 forms a columnar shape and directly joins the two fiber sheets 11 and 12 to each other. In addition, as shown in FIG. 5 , when the absorbent sheet 1 is viewed in the sheet plane direction, a plurality of direct bonding sites 17 are formed in a regular or irregular scattered dot shape.

In addition, as shown in FIG. 5 , the indirect joint portion 18 is a portion where the adhesive 15 is applied and the water-absorbent polymer 13 exists in the first fiber sheet 11 when the absorbent sheet 1 is viewed in cross-section. The applied portions of the adhesive 15 in the second fiber sheet 12 overlap in the thickness direction.

As the adhesive 15, it is preferable to use an adhesive having flexibility that can follow the swelling change caused by the water-absorbent polymer 13 absorbing liquid and elongate. Examples of such raw materials include one or more vinyl groups represented by 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, cyanoacrylate, vinyl acetate, methyl methacrylate, etc. Acrylic adhesives such as monomeric (co)polymers (ethylene-vinyl acetate copolymer, etc.); silicone adhesives containing polydimethylsiloxane polymers, etc.; and natural rubber, etc. Natural rubber adhesives; isoprene adhesives containing more than one type of polyisoprene, chloroprene, etc.; containing more than one type of styrene-butadiene copolymer (SBR), styrene -Isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butadiene-styrene block copolymer (SEBS) ), styrene-based adhesives such as styrene-ethylene-propylene-styrene block copolymer (SEPS), rubber-based adhesives, etc. They can be used alone or in combination of two or more. As shown in FIGS. 5 and 6 , when the adhesive 15 is disposed on the surfaces of the fiber sheets 11 and 12 facing the water-absorbent polymer 13 , the adhesive disposed on the first fiber sheet 11 and The adhesives arranged on the second fiber sheet 12 may be of the same type or of different types.

Among them, it is excellent in flexibility and stretchability. Even after the water-absorbent polymer swells, it maintains the state of direct joining between the fiber sheets 11 and 12 and exhibits shrinkage force so that the water-absorbent polymer 13 can be easily maintained in the state. From the viewpoint between the two fiber sheets 11 and 12, it is preferable to use a rubber-based adhesive as the adhesive 15, and among the rubber-based adhesives, a styrene-based adhesive is more preferably used.

The adhesive 15 is preferably a hot melt adhesive from the viewpoint of balancing both the flexibility of the adhesive and the adhesion to the sheet. As the hot-melt adhesive, for example, among the above-mentioned various adhesives, it is possible to use a tackifier such as petroleum resin or polyterpene resin, a plasticizer such as paraffin oil, and optionally containing phenols and amines. Hot melt adhesives based on antioxidants such as phosphorus, benzimidazole and other antioxidants.

In addition, as shown in FIG. 6 , it is preferable that an adhesive is applied to each of the surface of the first fiber sheet 11 facing the water-absorbent polymer 13 and the surface of the second fiber sheet 12 facing the water-absorbent polymer 13 . 15. By forming such a structure, the adhesives applied to the fiber sheets 11 and 12 are bonded to each other, and the direct bonding portion 17 can be effectively formed in the absorbent sheet 1, while maintaining the water-absorbent polymer 13 in place and maintaining it in place. Both ensure a space where the water-absorbent polymer 13 can swell. Furthermore, since the adhesive 15 can easily exist in the gaps between the fibers constituting the fiber sheets 11 and 12 , there is also an advantage that peeling is less likely to occur at the interface between the fiber sheets 11 and 12 and the adhesive 15 .

As shown in FIG. 6 , it is preferable that the coating area of the adhesive 15 in the second fiber sheet 12 is larger than the coating area of the adhesive 15 in the first fiber sheet 11 . By forming such a structure, the water-absorbent polymer 13 is evenly held on the second fiber sheet 12 whose coating area of the adhesive 15 is larger than that of the first fiber sheet 11 , and undesired movement of the water-absorbent polymer 13 can be suppressed. and peeling off, and the liquid permeability from the side of the first fiber sheet 11 whose coating area of the adhesive 15 is smaller than that of the second fiber sheet 12 can be ensured, and the liquid absorbency can be further improved. The coating areas of the two fiber sheets 11 and 12 were compared by laminating the two fiber sheets 11 and 12 having the same shape and area so that non-overlapping portions of the sheets would not occur. The coating area of the adhesive 15 can be determined by, for example, using toner or the like to visualize the area where the adhesive 15 is present on the surface of each fiber sheet 11 or 12 on which the adhesive 15 is attached, and using an image of the area of the area. Processing software, etc. calculate it separately. If identification is difficult, you can also use cold spraying or other methods to peel off the two pieces and then measure them.

When focusing on the portions of the fiber sheets 11 and 12 where the adhesive 15 is applied, it is preferable that the first gram weight of the adhesive 15 applied to the first fiber sheet 11 is smaller than that of the adhesive 15 applied to the second fiber sheet. The second grammage of the adhesive 15 of the sheet 12 is high. By forming such a structure, the direct bonding portion 17 with the second fiber sheet 12 can be easily formed through the adhesive 15 applied on the first fiber sheet 11 , and the adhesive 15 applied on the second fiber sheet 12 can Since the water-absorbent polymer 13 is held in place, the liquid absorbing performance can be further improved.

From the same viewpoint, the first gram weight is preferably 400 g/m ² or less, more preferably 250 g/m ² or less, still more preferably 100 g/m ² or less, and 20 g/m ² or more is realistic. In addition, the second gram weight is preferably 30 g/m ² or less, more preferably 15 g/m ² or less, still more preferably 10 g/m ² or less, and 2 g/m ² or more is realistic.

The above-mentioned first gram weight and the second gram weight are the gram weights respectively measured and calculated using only the coating portions of the fiber sheets 11 and 12 where the adhesive 15 is applied. Specifically, after each of the fiber sheets 11 and 12 in the absorbent sheet 1 is separated, the mass A1 (g) of the first fiber sheet 11 to which the adhesive 15 is attached is measured. In addition, on the surface of the first fiber sheet 11 on which the adhesive 15 is adhered, the presence of the adhesive 15 is visualized using toner or the like, and in this state, the presence of the adhesive 15 is measured using image processing software. The total area of the site S (m ² ). Next, the first fiber sheet 11 is immersed in an organic solvent, and the mass A2 (g) of the fiber sheet after the adhered adhesive 15 is dissolved is measured. The first gram weight (g/m ² ) can be calculated based on the calculation formula of "(A1-A2)/S". Similarly, the second basic weight (g/m ² ) can be calculated using the same method as the above using the second fiber sheet 12 as an object.

From the viewpoint of easily diffusing liquid in the surface direction of the sheet, further improving the utilization efficiency of the water-absorbent polymer 13, and achieving high liquid absorbency, it is preferable that the first fiber sheet 11 is paper. Paper refers to a product made by bonding plant fibers such as pulp and other fibers based on the provisions of JIS P0001, and is preferably produced by a wet process. By using paper as the first fiber sheet 11, liquid can be easily diffused to a wide range of the sheet periphery in the plane direction, and the liquid diffused to the sheet periphery is also absorbed from the side, so the liquid absorbency can be further improved. This structure enables the liquid that spreads in the surface direction to be absorbed from the periphery or side of the sheet even when the constituent fibers of the paper swell with liquid and the liquid permeability in the sheet thickness direction decreases. aspects are more favorable.

From the viewpoint of improving liquid absorbency, the thickness of the absorbent sheet 1 is preferably 0.3 mm or more, and more preferably 0.6 mm or more. In addition, from the viewpoint of improving the user's comfort when using the absorbent sheet or an absorbent article containing the sheet, the thickness of the absorbent sheet is preferably 4 mm or less, more preferably 3 mm or less, and still more preferably 2 mm or less. The thickness of the above-mentioned absorbent sheet is the thickness of the entire absorbent sheet measured under a pressure of 1.7 kPa.

The absorbent sheet 1 having the above structure has a non-overlapping region N1 formed in which the peripheral edge of the first fiber sheet 11 and the peripheral edge of the second fiber sheet 12 are formed. When the exudate that spreads in the surface direction of the sheet moves to When the side portion of the absorbent sheet 1 is placed, the excretion liquid can directly contact the water-absorbent polymer located on the side portion. In addition, it is possible to prevent the water-absorbent polymer from unintentionally falling off and moving from the side portion of the sheet. As a result, the liquid absorption efficiency can be improved and the liquid absorbency can be improved.

The absorbent sheet 1 of the above embodiment can be used as it is. In this case, one absorbent sheet 1 may be used, or a plurality of sheets may be used in a state of being laminated. When using a plurality of absorbent sheets 1, the absorbent sheets 1 of the same or different embodiments may be used in combination.

Moreover, the absorbent sheet 1 of each embodiment mentioned above can be used as a component of an absorbent article. Typically, the absorbent article has a longitudinal direction along the front-rear direction of the wearer and a width direction orthogonal to the longitudinal direction, and has a front sheet located on the skin-facing side and a back sheet located on the non-skin-facing side. The sheet can be used in a state where the absorbent sheet of the present invention is placed between the front sheet and the back sheet. The absorbent sheet constitutes a part of the absorbent body in the absorbent article. Examples of absorbent articles include diaper pads, sanitary napkins, disposable diapers, and the like, and disposable diapers are preferred.

The absorbent article typically has a ventral region disposed on the ventral side of the wearer when worn, a dorsal region disposed on the dorsal side, and a crotch region located between the ventral region and the dorsal region. The abdominal area, the crotch area, and the back area virtually divide the entire longitudinal length of the absorbent article into three equal parts, and extend continuously along the front-to-back direction of the wearer. The crotch region has an excretion part opposing part arranged to face the wearer's excretion part when the absorbent article is worn.

In this specification, the "skin-facing surface" refers to the surface of an absorbent article or its component (for example, an absorbent body to be described later) that faces the wearer's skin side when the absorbent article is worn, that is, the surface that faces the wearer's skin. The side relatively close to the skin, the "non-skin-facing surface" is the surface of the absorbent article or its components that faces the side opposite to the skin side when the absorbent article is worn, that is, faces the wearer's skin. The far side. In addition, "while wearing" here refers to a state in which a normal appropriate wearing position, that is, a correct wearing position of the absorbent article is maintained.

As the front sheet and back sheet used for absorbent articles, sheets conventionally used for absorbent articles can be used without particular limitation. As the front sheet, for example, various liquid-permeable nonwoven fabrics, perforated films, etc. can be used. As the back sheet, a liquid-impermeable or water-repellent resin film, a laminate of a resin film and a nonwoven fabric, or the like can be used.

The absorbent body is typically composed of an absorbent core and a core sheet covering the absorbent core. The absorbent core is composed of, for example, at least one of a fiber-packed body of water-absorbent natural fibers such as pulp fibers, a mixed fiber-packed body containing water-absorbent natural fibers and a water-absorbent polymer, and/or the absorbent sheet 1 described above. When the absorbent core is composed of both a fiber-laid body and an absorbent sheet, the sizes in plan view may be the same or different. The chip package is made of tissue paper or water-permeable non-woven fabric. The chip covering covers at least the skin-facing side of the absorbent core, and preferably covers the entire skin-facing side and non-skin-facing side of the absorbing core.

In addition to the above-mentioned front sheet, back sheet and absorbent body, depending on the specific use of the absorbent article, it is preferable to arrange leakage-proof flaps extending in the longitudinal direction on both sides of the skin-facing side along the longitudinal direction. side. Leak-proof flanges usually have a base end and a free end. The leak-proof cuff has a base end portion on the skin-opposite side of the absorbent article and stands up from the skin-opposite side. Leak-proof cuffs are made of liquid-repellent or water-repellent and breathable materials. An elastic member made of rubber wire or the like may also be arranged in an extended state at or near the free end of the leak-proof cuff. When the absorbent article is worn, the elastic member contracts and the leak-proof cuffs stand up toward the wearer's body, effectively preventing liquid excreted on the front sheet from spreading on the front sheet and leaking outward in the width direction of the absorbent article. .

A cross-sectional view of one embodiment of the absorbent article 1A having the absorbent sheet 1 is schematically shown in FIGS. 7 and 8 . The width direction of the absorbent article 1A is represented by the symbol Y, and is the same as the direction of the transverse direction Y in FIGS. 1 to 4 . The absorbent article 1A shown in FIGS. 7 and 8 includes an absorbent main body 2 having a front sheet 3, a back sheet 4, and an absorbent body 5; and a pair of leakage-preventing cuffs 8. On this basis, the absorbent article 1A shown in FIGS. 7 and 8 has an outer body 90 arranged on the non-skin-facing side of the absorbent main body 2 , and the absorbent main body 2 and the outer body 90 are used through the leakage-preventing cuff 8 Adhesive etc. are joined.

The absorbent main body 2 typically has a rectangular shape in plan view, with its longitudinal direction aligned with the longitudinal direction of the absorbent article 1A, and is disposed at the center of the outer body 90 in the width direction Y, and in the ventral region and the longitudinal direction of the outer body 90 . Extends throughout the crotch area and dorsal area. For convenience of description, although the core sheet covering the outer surface of the absorber 5 is not shown, it is preferable that the outer surface of the absorber 5 in this embodiment is covered with the core sheet.

The top sheet 3 shown in FIGS. 7 and 8 traverses the skin-facing surface side of the absorber 5 in the width direction Y, and is rolled up to the non-skin-facing surface side of the absorber 5 .

In this embodiment, the front sheet 3 has a size that can cover the entire area of the skin-facing surface of the absorber 5 , and covers the entire area of the skin-facing surface of the absorber 5 and both edges in the width direction Y of the absorber 5 . Cover, and cover a predetermined range of areas from the both side edges of the non-skin-facing surface of the absorber 5 to the inside in the width direction Y.

In this embodiment, the pair of extended portions 3E, 3E of the front sheet 3 are respectively fixed between the absorbent body 5 and the leakage-preventing cuff forming sheet 80 described later by the fixing portions 81 of the leakage-preventing cuffs 8 described below. . The front sheet 3 does not cover the entire area of the non-skin-facing surface of the absorbent body 5 , and the central portion of the non-skin-facing surface of the absorbent body 5 in the width direction Y (the portion located between the pair of fixing parts 81 and 81 ) is not covered by the front sheet 3 3 coverage.

In the embodiment shown in FIGS. 7 and 8 , a pair of leakage-preventing cuffs 8 and 8 are provided on both sides along the longitudinal direction of the absorbent main body 2 (absorbent body 5 ). Each leakage-preventing cuff 8 is composed of a liquid-repellent or water-repellent and air-permeable leakage-preventing cuff-forming sheet 80 , and includes a portion of the sheet 80 folded in half in the width direction Y to form a double-layer structure. Each leak-proof cuff 8 (leak-proof cuff forming sheet 80 ) is continuously arranged along the longitudinal side of the absorbent main body 2 over substantially the entire longitudinal length of the absorbent main body 2 . As the sheet 80 for forming leak-proof cuffs, a sheet used as a material for leak-proof cuffs in such absorbent articles can be used without particular limitation. For example, a single-layer or multi-layer water-repellent nonwoven fabric, Laminated materials such as resin films and non-woven fabrics, etc.

The leak-proof cuff 8 has a fixing part 81 in which the leak-proof cuff-forming piece 80 is fixed to another member, and a rising part 82 in which the piece 80 stands up toward the wearer. The rising portion 82 is a non-fixed portion with other components in the leakage-preventing cuff forming sheet 80 and is composed of a free end. The rising portion 82 is present at least in the crotch region.

The fixed portion 81 is a portion that constitutes a fixed end portion of the rising portion 82 when it rises toward the wearer's skin when the absorbent article is worn. The leak-proof cuff forming sheet 80 is formed by using an adhesive such as hot melt or heat. It is joined to other components, specifically, the part of the absorbent main body 2 and/or the exterior body 90 by a well-known fixing method, such as welding. That is, the leak-proof cuff forming sheet 80 and/or the outer body 90 constitute adjacent non-skin-side members on the non-skin-facing surface of the absorbent main body 2 . The fixing portion 81 extends continuously or discontinuously in the longitudinal direction over substantially the entire longitudinal length of the leak-proof cuff forming sheet 80 .

The rising portion 82 includes a stretchable portion in the length direction. In this embodiment, as shown in FIG. 7 , the free end portion of the rising portion 82 (the portion closest to the wearer's skin when the rising portion 82 is raised) is arranged to extend in the length direction. There is a first leak-proof cuff-forming elastic member 83, and a second leak-proof cuff-forming elastic member 83 is disposed at an intermediate position between the free end of the rising portion 82 and the fixed portion 81 so as to extend in the length direction. Elastic member 84. The elastic members 83 and 84 are joined in an extended state between the leakage-proof cuff-forming sheets 80 and 80 forming a double-layer structure by a fixing method such as an adhesive. The standing portion 82 has elasticity in the longitudinal direction at the fixed portion of the elastic members 83 and 84 .

The number of elastic members 83 and 84 is not particularly limited, and each of them may be one or a plurality of elastic members independently. The second leakage-proof cuff-forming elastic member 84 (an elastic member disposed at an intermediate position between the free end of the rising portion 82 and the fixed portion 81 ) may not be disposed.

As shown in FIGS. 7 and 8 , the rising portion 82 uses the shrinkage force of the elastic members 83 and 84 for forming leak-proof cuffs, and uses the fixing portion 81 and its vicinity or the width direction end portion of the auxiliary layer 60 described below as the The base end is raised toward the wearer's skin. In such an upright state of the leak-proof cuff 8, the upright portion 82 blocks the movement of body fluids such as urine excreted by the wearer to the outside in the width direction Y. The combination of the blocking effects of body fluids produced by the pair of standing portions 50 and 50 on both sides of the width direction Y of 5 can effectively suppress side leakage. In addition, although not shown in the figure, in the erect state of the leakage-proof cuffs 8, the entire absorbent article 1A is aligned in the longitudinal direction of the absorbent main body 2 due to the contraction force of the leakage-proof cuff-forming elastic members 83 and 84. The central portion is bent and deformed so as to bulge toward the non-skin-facing side (the back sheet 4 side), so the absorbent article 1A easily conforms to the shape of the wearer's body.

At both ends of the leakage-preventing cuff 8 in the longitudinal direction, rise-inhibiting portions are typically formed as portions that prevent the leakage-preventing cuff-forming sheet 80 from rising. The rising blocking portion is formed in the ventral region and the dorsal region, and the rising portion 82 is formed in a portion sandwiched between the two rising blocking portions in the longitudinal direction. The standing obstruction part is formed by fixing the leak-proof cuff forming sheet 80 to the skin-facing surface of the absorbent main body 2 (front sheet 3).

The absorbent body 5 has, at least in the crotch region, a pair of standing portions located at both sides in the width direction across a central portion of the absorbing body 5 in the width direction Y and capable of standing up toward the skin side of the wearer when worn. 50, 50; and a non-rising portion 51 located in the central area in the width direction Y and sandwiched between the pair of standing portions 50, 50. The absorbent core 6 has a laminated structure of the auxiliary layer 60 located on the skin-facing side (front sheet 3 side) and the absorbent sheet 1 located on the non-skin-facing side (back sheet 4 side). Instead of this structure, the auxiliary layer 60 may be disposed on the non-skin-facing side of the absorbent sheet 1 . That is, the auxiliary layer 60 is arranged on at least one of the skin-facing surface and the non-skin-facing surface of the absorbent sheet 1 , preferably on the skin-facing surface of the absorbent sheet 1 .

As shown in FIGS. 7 and 8 , it is preferable that the non-standing portion 51 in the absorber 5 has a multilayer structure. In the embodiment shown in the figure, the absorbent core 6 constituting the non-rising portion 51 has an auxiliary layer 60 located on the skin-facing side (front sheet 3 side) and a non-skin-facing side (back sheet 4 side). The laminated structure of the absorbent sheet 1. On the other hand, at least the absorbent sheet 1 is present in the pair of standing portions 50 and 50 .

The auxiliary layer 60 is composed of, for example, a fiber piling body of at least one of synthetic fibers and water-absorbent natural fibers, or a mixed fiber piling body of at least one kind of synthetic fibers and water-absorbent natural fibers and particles of an absorbent polymer. . The auxiliary layer 60 in the absorbent article 1A is a mixed fiber body composed of water-absorbent natural fibers such as fluff pulp and a water-absorbent polymer. This structure is preferable in terms of increasing the liquid absorption capacity of the absorbent body 5 .

In the present embodiment, the absorbent core 6 in the pair of standing portions 50 and 50 which are portions that can stand up toward the wearer's skin does not have the auxiliary layer 60 and is composed only of the absorbent sheet 1 . That is, it is preferable to form the pair of standing portions 50 and 50 so that the length in the width direction Y of the auxiliary layer 60 constituting the absorbent article 1A is shorter than the length in the width direction Y of the absorbent sheet 1 . The comparison between the length in the width direction Y of the auxiliary layer 60 and the length in the width direction Y of the absorbent sheet 1 was performed at the position where the length in the width direction Y is the shortest.

By having such a structure, the rising portion 50 can improve liquid absorbency and can be formed in a thin shape. Therefore, the wearing feeling when wearing the absorbent article is improved, and the fit of the absorbent article to the wearer can be further improved. In addition, since the absorption amount and absorption speed of the liquid in the non-rising portion 51 are increased, and the diffusion of the liquid in the thickness direction is suppressed, side leakage can be prevented more reliably.

The absorbent article 1A is preferably provided with a pair of side elastic members 52 for erecting the erecting portion 50 on both sides of the absorbent body 5 along the longitudinal direction or in the vicinity thereof. The side elastic members 52 are arranged in a state of being stretched in the longitudinal direction between the absorbent body 5 and the top sheet 3 . The side elastic members 52 are fixed in an extended state to at least the absorber 5 and further to the top sheet 3 by a known fixing method such as an adhesive. The side elastic member 52 is arranged at least in the crotch region, and may be one piece or multiple pieces as shown in the figure.

As shown in this embodiment, the side elastic members 52 are fixed in an extended state to both sides of the absorber 5 in the width direction Y. Therefore, when the absorbent article 1A is worn, as shown in FIG. 7 , as shown in FIG. The two sides of the absorbent body 5 in the width direction Y that can be erected by contraction of the side elastic members 52 serve as a pair of erected portions 50, 50, with the absorbent main body 2 and the leak-proof cuffs as non-skin side members. The fixing portion 81 , which is the joining position of the forming sheet 80 and/or the exterior body 90 , is used as a starting point and stands up toward the wearer's skin side. At this time, when viewed in the cross-section along the width direction Y shown in FIG. 7 , the absorber 5 has the non-rising portion 51 as a bottom and a pair of standing portions extending obliquely from the bottom toward the wearer's skin side. 50, 50 as a tray shape on the side. Furthermore, a gap capable of absorbing liquid is formed between the rising portion 50 and the leak-proof cuff 8 .

In addition, the side elastic members 52 may be arranged inside the absorber 5 . Specifically, for example, the side elastic members 52 may be disposed in a longitudinally extended state between the absorbent core 6 and the core sheet at or near both edges of the absorbent body 5 along the longitudinal direction. In this case, the side elastic members 52 can be fixed to one or both of the absorbent core 6 and the core cover by a known fixing method such as an adhesive.

As raw materials for the various elastic members in the absorbent article 1A, unless otherwise specified, various well-known elastic materials commonly used in such absorbent articles can be used without particular limitation. For example, styrene-butylene can be exemplified. Synthetic rubber such as olefin, butadiene, isoprene, chloroprene, natural rubber, EVA, stretchable polyolefin, polyurethane, etc. As the form of the elastic member, it is preferable to use a filament-shaped (rubber thread, etc.) or strip-shaped (rubber strip, etc.) elastic member or a multifilament-shaped elastic member having a cross-section of a rectangular, square, circular, polygonal, etc. shape.

The outer body 90 is disposed relatively far from the absorbent body 5 and includes an outer layer sheet 91 that forms the outer surface of the absorbent article 1A, and an outer sheet 91 that is disposed relatively close to the absorbent body 5 and forms the absorbent article 1A. The inner surface is composed of an inner layer sheet 92. The two pieces 91 and 92 are joined to each other using a joining method such as an adhesive to form one body. One or more elastic members 94 are arranged in an extended state between the outer sheet 91 and the inner sheet 92 constituting the outer body 90. When the absorbent article is worn, the elastic members 94 shrink to form a shape along the wearer's surface. Leg folds around the patient's legs.

The two pieces 91 and 92 constituting the exterior body 90 may be the same type of pieces or different types of pieces. Each of the sheets 91 and 92 may have stretchability, especially stretchability in the width direction Y. As each of the sheets 91 and 92, nonwoven fabrics formed by various manufacturing methods can be used. Specifically, examples thereof include air-through nonwoven fabrics, hot-rolled nonwoven fabrics, spunlace nonwoven fabrics, spunbond nonwoven fabrics, and melted nonwoven fabrics. A single layer of non-woven fabric or a laminated non-woven fabric of two or more layers is used. In addition, the sheets 91 and 92 may be composite sheets in which these nonwoven fabrics and films are laminated and integrated.

When the absorbent sheet 1 is used as a component of an absorbent article, it is preferable to arrange the first fiber sheet 11 in the absorbent sheet 1 so that it becomes the liquid-receiving surface which is the surface of the sheet that first comes into contact with liquid. That is, it is preferable to arrange the absorbent sheet 1 so that the first fiber sheet 11 is arranged on the side opposite to the skin.

The absorbent sheet 1 disposed in the absorbent article is more preferably rectangular in plan view, and among the two opposite sets of sides of the sheet 1, there is no non-overlapping area N1 on one set of sides, and on the other set of sides There are non-overlapping areas on one or both sides. In addition, it is preferable to arrange the absorbent sheet so that a pair of sides of the absorbent sheet 1 that do not have the non-overlapping region N1 are located at both ends in the longitudinal direction of the absorbent core 6 of the absorbent article. In this case, the other set of sides having the non-overlapping region N1 of the absorbent sheet 1 is disposed so as to be located at both end edges in the width direction of the absorbent core 6 .

Specifically, as shown in FIG. 7 , the absorbent sheet 1 in the absorbent article preferably has a width along the width direction Y of the first fiber sheet 11 that is shorter than a width along the width direction Y of the second fiber sheet 12 . In this state, the absorbent sheet 1 is disposed so that the first fiber sheet 11 is disposed on the skin-facing side of the absorbent article. The non-overlapping areas N1 of the absorbent sheet 1 shown in this figure are located at both ends of the absorbent core 6 in the width direction. By having such a structure, the excretion liquid excreted on the surface opposite to the skin reaches the side portion of the absorbent sheet 1 while spreading in the surface direction of the front sheet and is easily absorbed directly by the water-absorbent polymer, and the liquid passes along the width direction Y The second fiber piece 12 with a larger width is indirectly absorbed by the water-absorbent polymer. As a result, the absorbency of liquid is further improved.

Instead of this structure, as shown in FIG. 8 , the absorbent sheet 1 in the absorbent article is preferably such that the width of the first fiber sheet 11 in the width direction Y is longer than the width of the second fiber sheet 12 in the width direction Y. In this state, the absorbent sheet 1 is disposed so that the first fiber sheet 11 is disposed on the skin-facing side of the absorbent article. The non-overlapping areas N1 of the absorbent sheet 1 shown in this figure are located at both ends of the absorbent core 6 in the width direction Y. By having such a structure, when excretion liquid accidentally leaks between the rising portion 50 of the absorbent body 5 and the leakage-preventing cuffs 8 when the absorbent article is worn, the side contact between the excretion liquid and the absorbent sheet can be improved. The contact efficiency of the absorbent article is further improved, and the absorbency of liquid is further improved, and the leakage of excretion liquid to the outside of the absorbent article can be effectively prevented.

The above is the description of the absorbent sheet of the present invention and the absorbent article including the sheet. Next, a suitable manufacturing method of the absorbent sheet of the present invention will be described. FIG. 9 shows an embodiment of a manufacturing apparatus 100 suitable for use in this manufacturing method. This manufacturing method is suitable for manufacturing the absorbent sheet 1 in which two fiber sheets 11 and 12 are joined to each other via an adhesive 15 .

The manufacturing device 100 shown in FIG. 9 includes a first blank roll 110 and a second blank roll 120 . The first raw material roll 110 can feed the long strip-shaped first fiber sheet 11 along the conveyance direction R, and can supply it to the first adhesive coating part 130 described below. The second raw material roll 120 can feed the long strip-shaped second fiber sheet 12 along the conveyance direction R, and can supply it to the second adhesive coating part 140 described below.

The manufacturing apparatus 100 has a first adhesive application part 130 and a second adhesive application part 140 . The first adhesive coating unit 130 can continuously or intermittently apply the adhesive 15 to one surface of the first fiber sheet 11 supplied from the first blank roll 110 . The first adhesive application part 130 shown in this figure applies the adhesive 15 intermittently. The second adhesive coating unit 140 can continuously or intermittently apply the adhesive 15 to one surface of the second fiber sheet 12 supplied from the second blank roll 120 . The second adhesive application part 140 shown in this figure is a method of continuously applying the adhesive 15 . In FIG. 9 , the adhesive 15 applied to the first fiber sheet 11 and the adhesive 15 applied to the second fiber sheet 12 are shown in a state where the same type of adhesive is applied, but they may also be applied. Use different types of adhesives.

The manufacturing apparatus 100 has a polymer spreading part 150 . The polymer spreading part 150 is located above the second fiber sheet 12 and is configured to spread the water-absorbent polymer 13 on the surface of the second fiber sheet 12 on which the adhesive 15 is applied.

The manufacturing apparatus 100 preferably further has a pressure roller 160 . The pressing roller 160 is a roller that presses a laminate in which the first fiber sheet 11 is overlapped on the second fiber sheet 12 containing the water-absorbent polymer 13 via the guide roller 161 . In this embodiment, a pair of pressure rollers 160 are arranged, and it is preferable that the peripheral surface of each roller is smooth. Thereby, the long strip-shaped absorbent sheet 1 in which the plurality of direct bonding sites 17 are formed can be formed.

The manufacturing apparatus 100 may have a sheet cutting part (not shown) downstream of the pressure roller 160 . The sheet cutting part is a member that cuts the long strip-shaped absorbent sheet 1 at a predetermined position to form the absorbent sheet 1 having a predetermined size. As the sheet cutting unit, for example, a cutting roller having a cutting blade extending in a direction orthogonal to the conveyance direction R can be used.

The manufacturing method of the absorbent sheet using the manufacturing apparatus 100 which has the above-mentioned structure is as follows. First, the adhesive 15 is applied to at least one of the two fiber sheets 11 and 12 , preferably one surface of the first fiber sheet 11 and one surface of the second fiber sheet 12 respectively. In the mode shown in FIG. 9 , the adhesive 15 supplied from the first adhesive application part 130 is applied to one surface of the first fiber sheet 11 while the fiber sheet is being transported. In addition, while the fiber sheet is being transported, the adhesive 15 supplied from the second adhesive application unit 140 is applied to one surface of the second fiber sheet 12 . The adhesive 15 may be applied to one fiber sheet and then to the other fiber sheet sequentially, or may be applied to each of the fiber sheets 11 and 12 at the same time. When the adhesive 15 is applied to only one of the two fiber sheets 11 and 12, the adhesive 15 is supplied from either the first adhesive application part 130 or the second adhesive application part 140. Just apply adhesive 15.

In order to form the non-overlapping area N1 in the target absorbent sheet 1, for example, the length in the width direction of the raw material of the first fiber sheet 11 supplied from the first raw material winding roll 110 can be equal to the length in the width direction of the raw material supplied from the second raw material winding roll 120. The lengths of the second fiber sheets 12 in the width direction of the blanks are different. The two fiber sheets 11 and 12 can be joined together in a state where the widthwise central portions of the respective sheets are aligned, or the lengths of the two blanks can be aligned in the conveying direction. The two fiber sheets 11 and 12 are joined together with one side overlapped. Alternatively, the length in the width direction of the original material of the first fiber sheet 11 supplied from the first original material winding roller 110 may be equal to the length in the width direction of the original material of the second fiber sheet 12 supplied from the second original material winding roller 120 . The two fiber sheets 11 and 12 are joined together while being conveyed so that the center portions of the respective sheets in the width direction do not coincide with each other.

From the viewpoint of bonding the adhesives applied to the fiber sheets 11 and 12 to each other and efficiently forming the direct bonding portion 17 in the absorbent sheet 1, the application method of the first adhesive application portion 130 is preferably The method that can be adjusted so as to increase the basis weight of the adhesive 15 in the coated portion of the adhesive 15 is preferably an adhesive formed by spiral coating, summit coating, omega coating, etc. 15. Pattern coating method for non-coated parts. From the same viewpoint, the coating method of the second adhesive coating part 140 is preferably a method that can continuously apply the adhesive 15 with a low basic weight. Specifically, spray coating or a coater is preferably used. Coating, more preferably using a coater. The basic weight applied to each of the fiber sheets 11 and 12 may be adjusted individually so as to fall within the above-mentioned range.

Next, the water-absorbent polymer 13 is spread from the polymer spreading part 150 to the adhesive 15-coated surface of the second fiber sheet 12 . The water-absorbent polymer 13 is adhered to the adhesive 15 in the second fiber sheet 12 and is supported. The water-absorbent polymer 13 is preferably evenly dispersed in the sheet surface direction of the second fiber sheet 12 . When the water-absorbent polymer 13 is spread, the amount of the water-absorbent polymer 13 spread in the sheet surface direction of the second fiber sheet 12 can be changed depending on the target absorbent sheet 1 . In addition, in order to form the non-polymer region N3, for example, while conveying the blank, the adhesion can be adjusted to a range smaller than the length in the width direction of the blank (the direction orthogonal to the conveyance direction R at the time of manufacturing). After the coating area of the agent 15 is applied to the blank, the water-absorbent polymer 13 is spread to form.

Next, the fiber sheets 11 and 12 are overlapped so that the adhesive-coated surfaces of the fiber sheets 11 and 12 face each other. The laminate obtained by overlapping the fiber sheets 11 and 12 has a structure in which the water-absorbent polymer 13 is arranged between the two fiber sheets 11 and 12 . If necessary, this laminated body may be directly supplied to the sheet cutting part without being introduced into the press roller 160, and a target absorbent sheet may be formed. Alternatively, without overlapping the two fiber sheets 11 and 12 in advance, the two fiber sheets 11 and 12 are directly introduced between the pressing rollers 160 and overlapped while pressing.

Next, the overlapped fiber sheets 11 and 12 are introduced between a pair of pressing rollers 160 and pressed. This makes it easy to directly bond the adhesive 15 applied to the fiber sheets 11 and 12, so that the directly bonded portion 17 can be easily formed. Furthermore, the adhesiveness between the water-absorbent polymer 13 and the adhesive 15 can be improved. As a result, both the liquid absorbency and the retention property of the water-absorbent polymer can be improved simultaneously.

From the viewpoint of suppressing accidental damage to the product and effectively forming the direct joint portion 17 , it is preferable to use a relatively soft pressure roller 160 whose surface is made of an elastic material or the like to press the fiber sheets 11 and 12 with a relatively high pressure. By pressing the fiber sheets 11 and 12 under such conditions, the peripheral surface of the press roller can follow the unevenness of the fiber sheets 11 and 12 caused by the water-absorbent polymer 13, so that the coating can be effectively pressed. The adhesive 15 spread on each of the fiber sheets 11 and 12 is easily directly bonded. As a material of such a pressure roller 160, elastic materials such as hard rubber, silicone rubber, and silicone sponge can be used, for example. It is preferable that at least the surfaces of both rollers of a pair of pressure rollers are made of an elastic material.

From the viewpoint of improving pressurization properties without easily affecting the composition and placement of fiber sheets and water-absorbent polymers, when a press roller having the above-mentioned elastic material on its surface is used, the pressure applied by the press roller is linearly In terms of pressure, it is preferably 2500 N/m or more, more preferably 3500 N/m or more, preferably 6500 N/m or less, and more preferably 5500 N/m or more. This pressure is a pressure higher than the generally adopted condition of pressing the rollers against each other.

Finally, the long strip-shaped absorbent sheet 1 is cut into a predetermined size by a sheet cutting unit to form an absorbent sheet. The absorbent sheet 1 formed in this way has a square shape or a rectangular shape in plan view, and has a non-overlapping region N1 formed at least on a pair of opposite sides corresponding to both sides of the blank along the conveyance direction. In addition, in the absorbent sheet 1, in order to form non-overlapping areas N1 at positions corresponding to both sides of the sheet material in the direction orthogonal to the conveyance direction, no adhesive is applied to the planned cutting position passing through the sheet cutting portion. It is sufficient to use the adhesive 15 without maintaining the water-absorbent polymer.

When the absorbent sheet 1 is manufactured without using the adhesive 15, it can be manufactured by the method described in FIG. 3 of Japanese Patent Application Laid-Open No. 8-246395, for example. Specifically, a fiber sheet is made by wet papermaking, etc., and the water-absorbent polymer 13 is spread on the wet fiber sheet to exhibit the adhesiveness of the water-absorbent polymer 13 due to water absorption, and is fixed to the fiber sheet. . Thereafter, another fiber sheet is stacked on the surface on which the water-absorbent polymer 13 is spread to form a laminated body, and the laminated body is dried using a known drying method such as a Yankee dryer to produce an absorbent sheet.

As another method for manufacturing the absorbent sheet 1 without using the adhesive 15, the water-absorbent polymer 13 is spread on one fiber sheet, and then water is further spread to exhibit the adhesiveness of the water-absorbent polymer 13. , fixing it on the fiber sheet. Thereafter, another fiber sheet is stacked on the surface on which the water-absorbent polymer 13 is spread to form a laminate, and the laminate is dried by the above-mentioned drying method to produce an absorbent sheet.

Through the above steps, the absorbent sheet of the present invention can be produced. This absorbent sheet not only has high liquid absorbency, but also has liquid diffusivity and breathability at a high level. According to a preferred embodiment, the water-absorbent polymer is fixed at a predetermined position and can swell sufficiently, so that high liquid-absorbing performance can be effectively exhibited.

As mentioned above, the present invention has been described based on the preferred embodiments, but the present invention is not limited to the above-described embodiments.

Regarding the embodiments of the present invention described above, the following absorbent sheets, absorbent articles, and manufacturing methods thereof are further disclosed.

<1>

An absorbent sheet including a first fiber sheet, a second fiber sheet, and water-absorbent polymer particles arranged between the fiber sheets,

In a plan view, there is a non-overlapping region in which the position of the peripheral edge of the first fiber sheet does not overlap with the position of the peripheral edge of the second fiber sheet.

<2>

The absorbent sheet according to the above <1>, wherein:

The above-described non-overlapping region is formed because the plan view size of the first fiber sheet and the plan view size of the second fiber sheet are different.

<3>

The absorbent sheet according to the above <1> or <2>, wherein:

When viewed inward from the periphery of the absorbent sheet, there is a region where the water-absorbent polymer does not exist between the first fiber sheet and the second fiber sheet.

<4>

The absorbent sheet according to <3> above, wherein:

The area where the water-absorbent polymer does not exist is located inside the non-overlapping area.

<5>

The absorbent sheet according to the above <3> or <4>, wherein:

The top view size of the first fiber sheet is smaller than the top view size of the second fiber sheet,

The area where the water-absorbent polymer does not exist is located inward of the peripheral edge of the first fiber sheet.

<6>

The absorbent sheet according to any one of the above <3> to <5>, wherein:

The region where the water-absorbent polymer does not exist is formed over the entire periphery of the absorbent sheet.

<7>

The absorbent sheet according to any one of the above <3> to <5>, wherein:

A region where the water-absorbent polymer does not exist is formed on a part of the periphery of the absorbent sheet.

<8>

The absorbent sheet according to any one of the above <3> to <7>, wherein:

The length of the area in the cross-sectional view of the absorbent sheet where the water-absorbent polymer does not exist along the plane direction of the sheet is preferably 1 mm or more, more preferably 3 mm or more, still more preferably 5 mm or more, and preferably 20 mm or less, More preferably, it is 10 mm or less.

<9>

The absorbent sheet according to any one of the above <1> to <8>, wherein:

The absorbent sheet has a portion at its periphery where the first fiber sheet and the second fiber sheet are not joined to each other.

<10>

The absorbent sheet according to any one of the above <1> to <9>, wherein:

At the periphery of the absorbent sheet, the end of one fiber sheet is rolled up so as to cover the end of the other fiber sheet.

<11>

The absorbent sheet according to any one of the above <1> to <9>, wherein:

At the periphery of the absorbent sheet, the end of one fiber sheet is not rolled up so as to cover the end of the other fiber sheet.

<12>

The absorbent sheet according to any one of the above <1> to <11>, wherein:

When the same load is applied to each of the fiber sheets and the fiber sheets are stretched, the elongation magnification of the first fiber sheet and the elongation magnification of the second fiber sheet are different from each other.

<13>

The absorbent sheet according to any one of the above <1> to <12>, wherein:

The elongation magnification when the first fiber sheet is elongated by applying a load of 5 N, and the elongation magnification when the second fiber sheet is elongated by applying a load of 5 N are different from each other.

<14>

The absorbent sheet according to the above <13>, wherein:

The elongation ratio of the first fiber sheet is preferably 1.03 times or more, more preferably 1.05 times or more, and preferably 1.20 times or less, more preferably 1.15 times or less,

The elongation ratio of the second fiber sheet is preferably 1.01 times or more, more preferably 1.02 times or more, and preferably 1.15 times or less, more preferably 1.10 times or less.

<15>

The absorbent sheet according to any one of the above <1> to <14>, wherein:

The above-mentioned absorbent sheet is rectangular in plan view. In plan view, among the two sets of opposite sides, the non-overlapping area does not exist on one set of sides, and the non-overlapping area exists on one or both sides of the other set of sides.

<16>

The absorbent sheet according to any one of the above <1> to <15>, wherein:

The above-mentioned first fiber sheet and the above-mentioned second fiber sheet are both rectangular,

The first fiber sheet and the second fiber sheet are arranged in a state in which directions along the long sides of the two fiber sheets coincide with each other.

<17>

The absorbent sheet according to any one of the above <1> to <16>, wherein:

The length of the non-overlapping area in the cross-sectional view of the absorbent sheet along the plane direction of the sheet is preferably 1 mm or more, more preferably 3 mm or more, further preferably 5 mm or more, and preferably 20 mm or less, more preferably 10 mm or less. .

<18>

The absorbent sheet according to any one of the above <1> to <17>, wherein:

The basic weight of the first fiber sheet and the second fiber sheet constituting the absorbent sheet are each independently preferably 4 g/m ² or more, more preferably 6 g/m ² or more, and preferably 100 g/m ² or less, and more It is preferably 50 g/m ² or less, and further preferably 30 g/m ² or less.

<19>

The absorbent sheet according to any one of the above <1> to <18>, wherein:

In the absorbent sheet, the weight of the water-absorbent polymer is preferably 60 g/m ² or more, more preferably 100 g/m ² or more, and preferably 500 g/m ² or less, further preferably 400 g/m ² or less.

<20>

The absorbent sheet according to any one of the above <1> to <19>, wherein:

In the above-mentioned absorbent sheet, the above-mentioned first fiber sheet and the above-mentioned second fiber sheet are joined to each other through an adhesive agent.

<21>

The absorbent sheet according to the above <20>, wherein:

The first fiber sheet and the second fiber sheet have a portion directly joined by the adhesive without passing through the water-absorbing polymer, and a portion joined by the adhesive through the water-absorbing polymer.

<22>

The absorbent sheet according to the above <20> or <21>, wherein:

As the above-mentioned adhesive, a rubber-based adhesive is used.

<23>

The absorbent sheet according to the above <22>, wherein:

The rubber-based adhesive mentioned above is a styrene-based adhesive.

<24>

The absorbent sheet according to any one of the above <20> to <23>, wherein:

The above-mentioned adhesive is a hot melt adhesive.

<25>

The absorbent sheet according to any one of the above <20> to <24>, wherein:

The adhesive agent is applied to the surface of the first fiber sheet facing the water-absorbent polymer and the surface of the second fiber sheet facing the water-absorbent polymer, respectively.

<26>

The absorbent sheet according to the above <25>, wherein:

The adhesive coating area in the second fiber sheet is larger than the adhesive coating area in the first fiber sheet.

<27>

The absorbent sheet according to the above <25> or <26>, wherein:

The basic weight of the adhesive coated on the first fiber sheet is higher than the basic weight of the adhesive coated on the second fiber sheet.

<28>

The absorbent sheet according to the above <27>, wherein:

The basic weight of the adhesive coated on the first fiber sheet is preferably 400 g/m ² or less, more preferably 250 g/m ² or less, further preferably 100 g/m ² or less, and 20 g/m ² or more,

The basic weight of the adhesive coated on the second fiber sheet is preferably 30 g/m ² or less, more preferably 15 g/m ² or less, further preferably 10 g/m ² or less and 2 g/m ² or more.

<29>

The absorbent sheet according to any one of the above <1> to <28>, wherein:

The above-mentioned first fiber sheet is paper.

<30>

The absorbent sheet according to any one of the above <1> to <29>, wherein:

The thickness of the absorbent sheet is preferably 0.3 mm or more, more preferably 0.6 mm or more, and preferably 4 mm or less, more preferably 3 mm or less, still more preferably 2 mm or less.

<31>

An absorbent article having a length direction corresponding to the front-back direction of the wearer and a width direction orthogonal to the length direction, and including an absorbent main body having a front sheet disposed on the side opposite to the skin, In this absorbent article, a back sheet is disposed on the side not opposite to the skin, and an absorbent body is disposed between the two sheets.

The absorbent body further includes the absorbent sheet according to any one of <1> to <30>.

<32>

The absorbent article as described in <31> above, wherein:

The absorbent body further includes an auxiliary layer disposed on at least one of the skin-facing surface and the non-skin-facing surface of the absorbent sheet,

The length of the auxiliary layer in the width direction is shorter than the length of the absorbent sheet in the width direction.

<33>

The absorbent article as described in <32> above, wherein:

The above-mentioned absorbent main body is joined to a non-skin-side member disposed on the non-skin-facing side of the absorbent main body,

On both sides of the width direction of the absorber, filament-shaped or strip-shaped elastic members are arranged to extend in the longitudinal direction,

By shrinking each of the elastic members, both sides of the absorber in the width direction can stand up from the joint position of the absorber and the non-skin-side member as a starting point,

In the above-mentioned absorbent body, the above-mentioned absorbent sheet is present at least in a portion that can stand upright by contraction of each of the above-mentioned elastic members.

<34>

The absorbent article according to any one of the above <31> to <33>, wherein:

The absorbent sheet is disposed so that the first fiber sheet is disposed on the skin-facing side.

<35>

The absorbent article according to any one of the above <31> to <34>, wherein:

The above-mentioned absorbent sheet is rectangular when viewed from above.

Among the two sets of opposing sides of the absorbent sheet, the non-overlapping region does not exist on one set of sides, and the above-mentioned non-overlapping region exists on one or both sides of the other set of sides.

<36>

The absorbent article according to any one of the above <31> to <35>, wherein:

The above-mentioned absorbent body has an absorbent core,

The absorbent sheet is arranged so that a pair of sides of the absorbent sheet that do not have the non-overlapping area are located at both end edges of the absorbent core in the longitudinal direction of the absorbent article.

<37>

The absorbent article as described in <36> above, wherein,

The other set of sides having the non-overlapping regions of the absorbent sheet are disposed so as to be located at both end edges in the width direction of the absorbent core.

<38>

A method of manufacturing an absorbent sheet, wherein:

Coating at least one fiber sheet among the first fiber sheet and the second fiber sheet with an adhesive,

Spread a water-absorbent polymer on the adhesive-coated surface of the fiber sheet,

Each of the fiber sheets is overlapped such that the length of the first fiber sheet in one direction is different from the length of the second fiber sheet in one direction, and the water-absorbent polymer is disposed between the two fiber sheets,

Press each of the overlapped fiber sheets, and then,

Each of the pressed fiber pieces was cut.

<39>

The manufacturing method as described in the above <38>, wherein,

A pair of press rollers is used, and the overlapping fiber sheets are pressed between the press rollers.

<40>

The manufacturing method as described in <39> above, wherein,

As the press roller, a press roller whose surface is made of an elastic material is used to press each fiber sheet.

<41>

The manufacturing method according to any one of the above <38> to <40>, wherein,

The adhesive is applied to one surface of the first fiber sheet and one surface of the second fiber sheet respectively.

<42>

The manufacturing method as described in the above <41>, wherein,

In such a manner that the basis weight of the adhesive in the coated portion of the first fiber sheet is greater than the basis weight of the adhesive in the coated portion of the second fiber sheet, the coated portion of the first fiber sheet is Apply the above adhesive,

In the above-mentioned second fiber sheet, the basic weight of the adhesive in the coated portion of the second fiber sheet is lower than that of the adhesive in the coated portion of the first fiber sheet, and the adhesive is continuously coated. The above-mentioned adhesive is applied to the coated portion of the fiber sheet.

<43>

The manufacturing method as described in <42> above, wherein,

As a method of applying the adhesive to the application portion of the first fiber sheet, a pattern coating method is used.

<44>

The manufacturing method as described in the above <42> or <43>, wherein,

As a method for applying the adhesive to the application portion of the second fiber sheet, it is preferable to use a spray coating method or a coater coating method, and more preferably, a coater coating method is used.

<45>

The manufacturing method according to any one of the above <38> to <44>, wherein:

While conveying the second fiber sheet in one direction, the coating area of the adhesive is adjusted so that the length in the direction orthogonal to the conveying direction of the second fiber sheet becomes a smaller range. The fiber sheet is coated with the above adhesive,

The water-absorbent polymer is spread on the adhesive-coated surface of the second fiber sheet.

Industrial availability

According to the present invention, it is possible to provide an absorbent sheet having high liquid absorbency and an absorbent article having the absorbent sheet.

Claims (23)

1. An absorbent sheet characterized by:

comprising a first fibrous sheet, a second fibrous sheet, and particles of a water-absorbent polymer disposed between the fibrous sheets,

In plan view, the fiber sheet has a non-overlapping region where the position of the peripheral edge of the first fiber sheet is not overlapped with the position of the peripheral edge of the second fiber sheet.

2. The absorbent sheet of claim 1, wherein:

the non-overlapping region is formed by a top-down dimension of the first fibrous sheet being different from a top-down dimension of the second fibrous sheet.

3. The absorbent sheet according to claim 1 or 2, characterized in that:

when viewed inward from the peripheral edge of the absorbent sheet, there is a region where the water-absorbent polymer is not present between the first fibrous sheet and the second fibrous sheet.

4. An absorbent sheet according to claim 3, wherein:

the region where the water-absorbent polymer is not present is located inside the non-overlapping region.

5. The absorbent sheet according to claim 3 or 4, wherein:

the first fibrous sheet has a smaller top-down dimension than the second fibrous sheet,

the region where the water-absorbent polymer is not present is located inside the peripheral edge of the first fibrous sheet.

6. The absorbent sheet according to any one of claims 3 to 5, wherein:

the region where the water-absorbent polymer is not present is formed over the entire periphery of the absorbent sheet.

7. The absorbent sheet according to any one of claims 3 to 5, wherein:

the region where the water-absorbent polymer is not present is formed at a part of the peripheral edge of the absorbent sheet.

8. The absorbent sheet according to any one of claims 1 to 7, wherein:

the absorbent sheet has a portion at the periphery thereof where the first fibrous sheet and the second fibrous sheet are not joined to each other.

9. The absorbent sheet according to any one of claims 1 to 8, wherein:

at the periphery of the absorbent sheet, the end of one fibrous sheet is rolled up so as to cover the end of the other fibrous sheet.

10. The absorbent sheet according to any one of claims 1 to 7, wherein:

at the periphery of the absorbent sheet, the end of one fibrous sheet is not rolled up in such a manner as to cover the end of the other fibrous sheet.

11. The absorbent sheet according to any one of claims 1 to 10, wherein:

when the same load is applied to each of the fiber sheets to extend the fiber sheets, the first fiber sheet and the second fiber sheet differ from each other in the extension ratio.

12. The absorbent sheet according to any one of claims 1 to 11, wherein:

The elongation percentage when a load of 5N is applied to the first fiber sheet and the elongation percentage when a load of 5N is applied to the second fiber sheet and the elongation percentage when the first fiber sheet and the second fiber sheet are elongated are different from each other.

13. The absorbent sheet according to any one of claims 1 to 12, wherein:

the absorbent sheet has a rectangular shape in a plan view, and in the two sets of opposing sides, the non-overlapping region does not exist on one set of sides, and the non-overlapping region exists on one or both sides of the other set of sides.

14. The absorbent sheet according to any one of claims 1 to 13, wherein:

the first fibrous sheet and the second fibrous sheet are both rectangular,

the first fiber sheet and the second fiber sheet are arranged in a state in which the directions along the long sides of the two fiber sheets coincide with each other.

15. The absorbent sheet according to any one of claims 1 to 14, wherein:

in the absorbent sheet, the first fibrous sheet and the second fibrous sheet are bonded to each other with an adhesive.

16. The absorbent sheet of claim 15, wherein:

the first fiber sheet and the second fiber sheet have a portion directly bonded by the adhesive without the water-absorbent polymer and a portion bonded by the adhesive with the water-absorbent polymer.

17. The absorbent sheet according to claim 15 or 16, wherein:

the adhesive is applied to the surface of the first fibrous sheet facing the water-absorbent polymer and the surface of the second fibrous sheet facing the water-absorbent polymer, respectively.

18. The absorbent sheet of claim 17, wherein:

the adhesive in the second fibrous sheet has a larger application area than the adhesive in the first fibrous sheet.

19. The absorbent sheet according to claim 17 or 18, wherein:

the adhesive applied to the first fibrous sheet has a higher grammage than the adhesive applied to the second fibrous sheet.

20. An absorbent article having a longitudinal direction corresponding to the front-back direction of a wearer and a width direction orthogonal to the longitudinal direction, and comprising an absorbent body having a front sheet disposed on the skin-facing surface side, a back sheet disposed on the non-skin-facing surface side, and an absorber disposed between the two sheets, the absorbent article being characterized in that:

the absorbent sheet according to any one of claims 1 to 19.

21. The absorbent article of claim 20, wherein:

the absorbent body further has an auxiliary layer disposed on at least one of the skin-facing surface and the non-skin-facing surface of the absorbent sheet,

the length of the auxiliary layer in the width direction is shorter than the length of the absorbent sheet in the width direction.

22. The absorbent article of claim 20 or 21, wherein:

the absorbent body is joined to a non-skin-side member disposed on a non-skin-facing surface side of the absorbent body,

in both side regions of the absorber in the width direction, thread-like or band-like elastic members are arranged so as to extend in the longitudinal direction,

by contraction of each elastic member, both widthwise side portions of the absorbent body can be raised from the joining position of the absorbent body and the non-skin-side member,

in the absorbent body, the absorbent sheet is present at least in a portion that can be raised by contraction of the elastic members.

23. The absorbent article of any one of claims 20-22, wherein:

the absorbent sheet is disposed such that the first fibrous sheet is disposed on the skin-facing surface side.