GB2557151A

GB2557151A - Sheet-like article and method for producing sheet-like article

Info

Publication number: GB2557151A
Application number: GB1804072.5A
Authority: GB
Inventors: Kuramae Ryota; Latif Muhamad Nor Salehuddin Bin; Kobayashi Kenji
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 2015-10-07
Filing date: 2016-10-06
Publication date: 2018-06-13
Anticipated expiration: 2036-10-06
Also published as: KR20180048708A; CN108024887A; DE112016004589T5; GB2557151B; CN108024887B; KR101909425B1; JP6193328B2; DE112016004589B4; WO2017061566A1; GB201804072D0; JP2017070498A; RU2670053C1

Abstract

This sheet-like article (1) for absorbent articles is provided with a plurality of absorbent units (4), each equipped with a long base part (2) and absorbent polymer particles (3) fixed on the surface on one side of the long base part (2). The sheet-like article (1) is configured to have the respective absorbent units (4) arranged such that the longitudinal directions thereof are oriented in a single direction. Before the absorbent polymer particles (3) absorb a liquid, the absorbent polymer particles (3) are fixed on the surface of one side of the long base part (2) so as to be fixed on side edges (2s) of the long base part (2) parallel to the longitudinal direction thereof.

Description

(56) Documents Cited:

JP 2004121390 A JPH10508528 (58) Field of Search:

INT CLA61F

A61F 13/15 (2006.01) A61F 13/537 (2006.01)

JP 2002224162 A

PCT/JP2016/079843 Ja 06.10.2016 (87) International Publication Data:

WO2017/061566 Ja 13.04.2017 (71) Applicant(s):

Kao Corporation (Incorporated in Japan)

14-10 Nihonbashi kayabacho 1-chome, Chuo-ku, Tokyo 103-8210, Japan (72) Inventor(s):

Ryota Kuramae

Bin Latif Mu ha mad Nor Salehuddin Kenji Kobayashi (74) Agent and/or Address for Service:

Withers & Rogers LLP

More London Riverside, LONDON, SE1 2AU, United Kingdom (54) Title of the Invention: Sheet-like article and method for producing sheet-like article Abstract Title: Sheet-like article and method for producing sheet-like article (57) This sheet-like article (1) for absorbent articles is provided with a plurality of absorbent units (4), each equipped with a long base part (2) and absorbent polymer particles (3) fixed on the surface on one side of the long base part (2). The sheet-like article (1) is configured to have the respective absorbent units (4) arranged such that the longitudinal directions thereof are oriented in a single direction. Before the absorbent polymer particles (3) absorb a liquid, the absorbent polymer particles (3) are fixed on the surface of one side of the long base part (2) so as to be fixed on side edges (2s) of the long base part (2) parallel to the longitudinal direction thereof.

THIS INTERNATIONAL APPLICATION HAS ENTERED THE NATIONAL PHASE EARLY.

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FIG. 3

FIG. 4

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DESCRIPTION

Title of Invention: SHEET-LIKE ARTICLE AND METHOD FOR PRODUCING SHEETLIKE ARTICLE

Technical Field [0001]

The present invention relates to a sheet-like article that is used for an absorbent article and a method for producing the sheet-like article.

Background Art [0002]

Generally, absorbent members used for absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads are produced by sucking and accumulating a raw material for an absorbent member, the raw material containing pulp fibers and an water-absorbent polymer and being supplied on an airflow, into a depression that is formed on an outer circumferential surface of a rotating drum, and then covering a fiber stack that is thus accumulated in the depression with a water-permeable sheet material. However, the weight of the water-absorbent polymer is extremely larger than the weight of the pulp fibers, and the water-absorbent polymer tends to be non-uniformly distributed. With such a non-uniform absorbent member, inhibition of swelling, such as gel blocking, is likely to occur, and the maximum absorption performance of the water-absorbent polymer cannot be exhibited.

[0003]

Patent Document 1 discloses a bodily fluid absorbent member in which two sheets are fixed to each other via a plurality of fixing parts, channel spaces that are each continuous in the longitudinal direction are formed between the fixing parts that are adjacent to each other, and an absorbing material is disposed within each channel space, the absorbing material being formed by integrating a bodily fluid absorbent material containing a superwater-absorbent polymer with a shrinkable material. With the bodily fluid absorbent member disclosed in Patent Document 1, the entire absorbent member can be effectively used.

[0004]

Patent Document 2 discloses an absorbent article including an absorbent member that has, in its excretory portion-facing part, an excretory portion slit region in which longitudinal slits extending in the longitudinal direction are formed in a distributed state and that also has a central slit region in the central portion of the excretory portion slit region in the lateral direction and the longitudinal direction. With the absorbent article disclosed in Patent Document 2, the wearing comfort can be increased.

[0005]

Patent Document 3 discloses an absorbent article including an absorbent member in which four or more slits are arranged at intervals. With the absorbent article disclosed in Patent Document 3, the stiffness of the absorbent member can be alleviated, and the absorbency can be increased.

Citation List

Patent Documents [0006]

Patent Document 1: JP 2002-224162A

Patent Document 2: JP 2015-42244A

Patent Document 3: JP S63-18122U

Summary of Invention [0007]

The present invention relates to a sheet-like article for an absorbent article, including a plurality of absorbent units each absorbent unit including a long base portion having a lateral direction, a longitudinal direction that is longer than the lateral direction, and a thickness direction, and water-absorbent polymer particles that are fixed to a surface on a first side of the long base portion, the absorbent units being arranged such that the absorbent unit’s longitudinal direction is oriented at least in one direction.

Before the water-absorbent polymer particles absorb a liquid, the water-absorbent polymer particles are fixed to the surface on the first side of the long base portions and also fixed to each long base portion’s lateral side edge portions that extend along the longitudinal direction.

[0008]

Also, the present invention relates to a method for producing a sheet-like article for an absorbent article, the sheet-like article including a plurality of absorbent units each including a long base portion that has a lateral direction, a longitudinal direction that is longer than the lateral direction, and a thickness direction, and water-absorbent polymer particles that are fixed to a surface on a first side of the long base portion, the absorbent units being arranged such that the absorbent unit’s longitudinal directions are oriented at least in one direction, wherein, before the water-absorbent polymer particles absorb liquid, the water-absorbent polymer particles are fixed to the surface on the first side of each of the long base portions and also fixed onto lateral side edge portions of each of the long base portions, the lateral side edge portions extending along the longitudinal direction. The method for producing a sheet-like article of the present invention includes a cutting step of cutting a base material sheet to form a plurality of the long base portions; a widening step of a widening portion widening a distance between the long base portions that are adjacent to each other, of the plurality of long base portions that have been formed in the cutting step; and an water-absorbent polymer particle spreading step of spreading the waterabsorbent polymer particles onto the plurality of long base portions, with the distance between the long base portions that are adjacent to each other having been widened in the widening step.

Brief Description of Drawings [0009] [FIG. 1] FIG. 1 is a schematic cross-sectional view of an embodiment of a sheet-like article for an absorbent article of the present invention, illustrating a state before water-absorbent polymer particles absorb liquid.

[FIG. 2] FIG. 2 is a schematic cross-sectional view of the sheet-like article shown in FIG. 1, illustrating a state in which the water-absorbent polymer particles have swelled as a result of absorbing liquid.

[FIG. 3] FIG. 3 is a perspective view of the sheet-like article shown in FIG. 1 when viewed from an upper side.

[FIG. 4] FIG. 4 schematically shows an embodiment of an apparatus for producing the sheet-like article shown in FIG. 1.

[FIG. 5] FIG. 5 is a schematic perspective view of a base material sheet cutting portion that is included in the production apparatus shown in FIG. 4.

[FIG. 6] FIG. 6 is a schematic perspective view of a widening portion that is included in the production apparatus shown in FIG. 4.

[FIG. 7] FIG. 7 is a perspective view of another embodiment of the sheet-like article of the present invention when viewed from the upper side, illustrating a state before the waterabsorbent polymer particles absorb liquid (FIG. 7 corresponds to FIG. 3).

Description of Embodiments [0010]

In the absorbent member disclosed in Patent Document 1, the absorbing material containing the superwater-absorbent polymer is disposed within each of the channel spaces that are formed by the fixation via the fixing parts. Thus, even after the superwaterabsorbent polymer has swelled as a result of absorbing bodily fluid, it is difficult for the superwater-absorbent polymer to move in the thickness direction, and the maximum absorption performance of the superwater-absorbent polymer cannot be exhibited.

[0011]

Moreover, Patent Documents 2 and 3 make no mention whatsoever of the position at which the water-absorbent polymer is fixed to the membe—r that is formed by slitting.

[0012]

Thus, the present invention relates to providing a sheet-like article that is capable of addressing the drawbacks of the above-described conventional techniques. Also, the present invention relates to providing a method for producing a sheet-like article, the method being capable of addressing these drawbacks of the conventional techniques.

[0013]

Hereinafter, the present invention will be described based on preferred embodiments thereof with reference to the drawings.

A sheet-like article of the present invention is used for an absorbent article. The absorbent article is generally used to absorb and retain excreted bodily fluid such as urine and menstrual blood. The absorbent article encompasses, for example, disposable diapers, sanitary napkins, incontinence pads, and the like. However, the absorbent article is not limited to these examples, and is to be construed as encompassing a wide range of articles that are used to absorb liquid excreted from the human body.

[0014]

The absorbent article typically has a liquid-retentive absorbent member, atopsheet that is disposed on a skin-facing surface side of the absorbent member, and a backsheet that is disposed on a non-skin-facing surface side of the absorbent member. The absorbent member has the sheet-like article of the present invention and a liquid-permeable core-wrap sheet that covers the sheet-like article. That is to say, the sheet-like article of the present invention is used for an absorbent article as, for example, an absorbent member in which the sheet-like article is covered with the liquid-permeable core-wrap sheet. It should be noted that the absorbent article may also include a so-called sublayer sheet on at least one of the skin-facing surface and the non-skin-facing surface of the absorbent member.

[0015]

Materials that are usually used in the art can be used without limitation as the topsheet, the backsheet, and the core-wrap sheet. For example, liquid-permeable sheets, such as various types of nonwoven fabrics that have been subjected to hydrophilization treatment, perforated films, and the like, can be used as the topsheet. Moreover, liquidpermeable or water-repellant sheets, such as a thermoplastic resin film, a laminate of this film and a nonwoven fabric, and the like, can be used as the backsheet. The backsheet may be permeable to water vapor. Moreover, a piece of thin paper (tissue paper) that is produced using a wet papermaking method, a liquid-permeable nonwoven fabric, and the like can be used as the core-wrap sheet. Moreover, the absorbent article may further include various types of members in accordance with specific uses of the absorbent article. Such members are known to those skilled in the art. For example, when the absorbent article is applied to a disposable diaper or a sanitary napkin, one or two or more pairs of leak-proof cuffs can be arranged on both lateral sides of the topsheet.

[0016]

FIGS. 1 and 2 show schematic cross-sectional views of a sheet-like article 1 (hereinafter also referred to simply as “sheet-like article 1”), which is a preferred embodiment of the sheet-like article of the present invention. The sheet-like article 1 shown in FIG. 1 is in a state before water-absorbent polymer particles absorb liquid (hereinafter also referred to simply as “state before use”. The sheet-like article 1 shown in FIG. 2 is in a state in which the water-absorbent polymer particles have swelled as a result of absorbing liquid (hereinafter also referred to simply as “state after swelling”). Here, the “state after swelling” means a state of the water-absorbent polymer particles after the absorbent member 1 has been immersed in a physiological saline solution (0.9 mass% aqueous solution of sodium chloride) whose temperature is controlled to 25°C, for 60 minutes. FIG. 3 shows a perspective view of the sheet-like article 1 in a state before use.

[0017]

The sheet-like article 1 shown in FIG. 1 includes a plurality of absorbent units 4 each including a long base portion 2 that has a lateral direction (direction X), a longitudinal direction (direction Y) that is longer than the lateral direction (direction X), and a thickness direction (direction Z), and water-absorbent polymer particles 3 (hereinafter also referred to simply as “water-absorbent polymer 3”) that are fixed to a surface on a first side of the long base portion 2, and the absorbent units 4 are arranged such that their longitudinal directions (directions Y) are oriented at least in one direction. Here, the lateral direction (direction X), the longitudinal direction (direction Y), and the thickness direction (direction Z) of each long base portion 2 coincide with the lateral direction (direction X), the longitudinal direction (direction Y), and the thickness direction (direction Z), respectively, of each absorbent unit 4, and, according to the present embodiment, also coincide with the lateral direction (direction X), the longitudinal direction (direction Y), and the thickness direction (direction Z) of the sheet-like article 1 (see FIG. 3). It should be noted that the longitudinal direction (direction Y) of the sheet-like article 1 also coincides with the frontrear direction of a wearer when wearing an absorbent article including the sheet-like article 1.

[0018]

In the sheet-like article 1 shown in FIG. 1, the plurality of absorbent units 4 are arranged such that the absorbent units 4’s longitudinal directions (directions Y) are oriented in the longitudinal direction (direction Y) of the sheet-like article 1 (see FIG. 3). From the standpoint of facilitating movements of the absorbent units 4, no interposed material is present between the absorbent units 4,4 that are adj acent to each other in the lateral direction (direction X) of the long base portions 2 (absorbent units 4). That is to say, each absorbent unit 4 is not enveloped in an interposed material. In FIGS. 1 and 2, an upper side, which is the first side, of each long base portion 2, constitutes the skin-facing surface that opposes the wearer's skin, and a lower side, which is a second side, of each long base portion 2 constitutes the non-skin-facing surface that opposes the backsheet. That is to say, a side that is opposite to the first side is the second side.

[0019]

In a state before use, each absorbent unit 4 of the sheet-like article 1 is formed into a rectangular shape that is elongated in the longitudinal direction Y. Each absorbent unit 4 has a length Lx preferably between 0.5 mm and 10 mm inclusive and more preferably between 1 mm and 5 mm inclusive in the lateral direction X. In the longitudinal direction Y, each absorbent unit 4 has a length Ly that is preferably between 20 times and 200 times inclusive and more preferably between 40 times and 80 times inclusive the length Lx in the lateral direction X. On the condition that this factor should be satisfied, the length Ly of each absorbent unit 4 in the longitudinal direction Y is preferably between 10 mm and 500 mm inclusive and more preferably between 200 mm and 400 mm inclusive. As described above, the absorbent units 4 each have a long and narrow shape.

In the present embodiment patent, the water-absorbent polymer particles 3 are fixed to lateral side edge portions of each of the long base portions, and thus, a relation in magnitude between the width W2 of each of the long base portions and the length Lx of each of the absorbent units 4 in the lateral direction X is preferably 0 pm < (Lx-W2) < 1400 pm and more preferably 200 pm < (Lx-W2) < 1000 pm.

[0020]

In the present embodiment, the sheet-like article 1 is formed into a rectangular shape that is elongated in the longitudinal direction (direction Y) in a state before use. The sheet-like article 1 has a length approximately between 100 mm and 1000 mm inclusive in the longitudinal direction (direction Y), and a length approximately between 50 mm and 300 mm inclusive in the lateral direction (direction X).

[0021]

The sheet-like article 1 has an absorption region AT in which the plurality of absorbent units 4 are arranged in such a manner as to be oriented in at least one direction in a state before use. From the standpoint of facilitating the absorption of liquid in regions in which the water-absorbent polymer particles 3 are fixed, in plan view of the sheet-like article 1 in a state before use, the ratio of the absorption region AT to the entire sheet-like article 1 is preferably not less than 20% and more preferably not less than 50% and preferably not more than 100% and more preferably not more than 90%, and specifically, this ratio is preferably between 20% and 100% inclusive and more preferably between 50% and 90% inclusive. Here, the ratio of the absorption region AT being 100% means a form in which, for example, if the plurality of absorbent units 4 are arranged side-by-side in the lateral direction (direction X) of the sheet-like article 1 such that the absorbent units 4’s longitudinal directions(directions Y) are oriented in the longitudinal direction (direction Y) of the sheet-like article 1, the absorbent units 4 are arranged over the entire region of the sheet-like article 1, spanning between both ends of the sheet-like article 1 in the longitudinal direction (direction Y). Alternatively, if the plurality of absorbent units 4 are arranged side-by-side in the longitudinal direction (direction Y) of the sheet-like article 1 such that the absorbent units 4’s longitudinal directions(directions Y) are oriented in the lateral direction (direction X) of the sheet-like article 1, the ratio of the absorption region AT being 100% means a form in which the absorbent units 4 are arranged over the entire region of the sheet-like article 1, spanning between both lateral sides, which extend along the longitudinal direction (direction Y), of the sheet-like article 1. It should be noted that, in plan view of the sheet-like article 1, regions excluding the absorption region AT constitute non-slit regions NT, which will be described later.

[0022]

In the case where the absorbent units 4 are arranged such that their longitudinal directions (directions Y) are oriented in the longitudinal direction (direction Y) of the sheetlike article 1, the number of absorbent units 4 that are arranged per single sheet-like article is preferably not less than 3 and more preferably not less than 50 and preferably not more than 1000 and more preferably not more than 500, and specifically, the number of absorbent units 4 that are arranged per single sheet-like article is preferably between 3 and 1000 inclusive and more preferably between 50 and 500 inclusive. In the case where the absorbent units 4 are arranged such that their longitudinal directions (directions Y) are oriented in the lateral direction (direction X) of the sheet-like article 1, the number of absorbent units 4 that are arranged per single sheet-like article is preferably not less than 3 and more preferably not less than 50 and preferably not more than 3500 and more preferably not more than 2000, and specifically, the number of absorbent units 4 that are arranged per single sheet-like article is preferably between 3 and 3500 inclusive and more preferably between 50 and 2000 inclusive. The absorbent units 4 are counted as follows: when a certain straight line is drawn in the lateral direction X, the maximum number of absorbent units intersecting that straight line is defined as the number of absorbent units 4.

[0023]

In light of the ease of conveyance during production, it is preferable that the sheetlike article 1 in a state before use has a form in which the plurality of absorbent units 4 are arranged such that their longitudinal directions (directions Y) are oriented in the longitudinal direction (direction Y) of the sheet-like article 1, and it is more preferable that the plurality of absorbent units 4 are arranged in such a manner as not to intersect with one another. The sheet-like article 1 shown in FIG. 1 is formed by using a plurality of absorbent units 4 respectively having long base portions 2 with uniform widths, and arranging those absorbent units 4 such that the absorbent units 4’s longitudinal directions(directions Y) are oriented in the longitudinal direction (direction Y) of the sheetlike article 1.

[0024]

It is preferable that the sheet-like article 1 includes non-slit regions NT in which a plurality of long base portions 2 are connected together in the lateral direction (direction X) on both ends of the sheet-like article 1 in the longitudinal direction (direction Y) or both lateral sides, which extend along the longitudinal direction (direction Y), of the sheet-like article 1. As shown in FIG. 3, the sheet-like article 1 of the present embodiment includes the non-slit regions NT on both ends of the sheet-like article 1 in the longitudinal direction (direction Y). That is to say, the sheet-like article 1 of the present embodiment includes a single base material sheet, the non-slit regions NT are provided on both ends of the base material sheet in the longitudinal direction (direction Y), and the plurality of long base portions 2 that are formed through a cutting step, which will be described later, are provided between the non-slit regions NT. When such non-slit regions NT are provided, the following effects are obtained: in a state before use, the sheet shape of the sheet-like article 1 is easily maintained, the structure is unlikely to come apart, and conveyance is easy during production. It is preferable that the water-absorbent polymer particles 3 are not disposed in the non-slit regions NT. When the water-absorbent polymer particles 3 are not disposed in the non-slit regions NT as described above, even after the water-absorbent polymer particles 3 have absorbed liquid, the water-absorbent polymer particles 3 in the non-slit regions NT are unlikely to swell, and the following effects are obtained: in a state after swelling as well, the sheet shape of the sheet-like article 1 is easily maintained, the structure is unlikely to be come apart, liquid is easily absorbed in the region in which the waterabsorbent polymer particles 3 are fixed, and a balance can be easily achieved in the sheetlike article 1 as a whole. Moreover, as in the case of the sheet-like article 1 shown in FIG. 3, in the case where non-slit regions NT are provided on both ends of the sheet-like article in the longitudinal direction (direction Y), when using this sheet-like article 1 for an absorbent article, it is preferable that both ends of the sheet-like article 1 in the longitudinal direction (direction Y) are fixed to the absorbent article, because the sheet shape of the sheet-like article 1 is then easily maintained, the structure is unlikely to come apart, and the absorption region AT has improved softness and is unlikely to give an uncomfortable feeling to the wearer.

[0025]

In the sheet-like article 1 shown in FIG. 1, in view of the amount of waterabsorbent polymer particles 3 that are supported by the long base portions 2, inhibition of swelling, flexibility, air-permeability, maintaining the sheet shape, and the like, the ratio (W2/W1) of the width (W2) (length in the lateral direction (direction X)) of each long base portion 2 to the width (Wl) of the sheet-like article 1 is preferably not less than 0.001 and more preferably not less than 0.002 and preferably not more than 0.200 and more preferably not more than 0.040, and specifically, this ratio is preferably between 0.001 and 0.200 inclusive and more specifically between 0.002 and 0.040 inclusive.

Preferably, from the same point of view, the width (W2) of each long base portion is preferably not less than 0.3 mm and more preferably not less than 0.6 mm and preferably not more than 10 mm, more preferably not more than 2.0 mm, and even more preferably not more than 1.8 mm, and specifically, the width (W2) of each long base portion 2 is preferably between 0.3 mm and 10 mm inclusive, more preferably between 0.6 mm and 2.0 mm inclusive, and even more preferably between 0.6 mm and 1.8 mm inclusive.

The “width (W2) of each long base portion 2” refers to the distance between both lateral side edge portions, which extend along the longitudinal direction Y, of each long base portion 2. The “width (Wl) of the sheet-like article 1” refers to the distance between both lateral side edge portions, which extend along the longitudinal direction Y, of the sheet-like article 1.

[0026]

It is preferable that the long base portions 2 (base material sheet) constituting the respective absorbent units 4 are formed from a hydrophilic sheet, because liquid then easily diffuses in the absorption region AT, and the utilization efficiency of the water-absorbent polymer 3 is improved. A “hydrophilic sheet” is defined as a sheet with a contact angle relative to a single constituent fiber being less than 90°, or a sheet with a contact angle relative to its surface being less than 90° if the sheet is not made of a fiber material. It should be noted that the contact angle is measured in conformity with a method described below. For example, a sheet-like article containing a hydrophilic material can be used as the hydrophilic sheet. Examples of the hydrophilic sheet include a piece of paper, a nonwoven fabric, a fabric, and a synthetic sponge that is formed by foaming a synthetic resin, and among these hydrophilic sheets, a nonwoven fabric is preferably used, because nonwoven fabrics have a relatively high tensile strength despite a small thickness, and are thin and can be made to be flexible. These hydrophilic sheets can be used alone or in combination of two or more. Hydrophilic nonwoven fabrics that contain hydrophilic fibers as the constituent fibers, hydrophilic nonwoven fabrics that contain fibers obtained by imparting hydrophilicity to synthetic fibers as the constituent fibers, and the like are preferably used as the nonwoven fabric. The basis weight of the nonwoven fabric is preferably between 5 g/m² and 100 g/m² inclusive and more preferably between 10 g/m²and 40 g/m² inclusive. For example, hydrophilic nonwoven fabrics that are known in the art, such as spun-bonded nonwoven fabrics, melt-blown nonwoven fabrics, spunlaced nonwoven fabrics, and air-through nonwoven fabrics can be used without limitation as the hydrophilic nonwoven fabric.

[0027]

Method for Measuring Degree of Hydrophilicity of Long base portions

The contact angle of water relative to a constituent fiber of a sheet (hydrophilic sheet) from which the long base portions are formed or the contact angle of water relative to a surface of the long base portions is measured in the following manner. An automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used as a measuring device. To measure the contact angle, distilled water is used. The amount of liquid discharged from an ink-jet water droplet discharge portion (Pulselnjector CTC-25 manufactured by Cluster Technology Co., Ltd., and having a discharge portion opening diameter of 25 pm) is set at 20 picoliters, and a water droplet is dropped directly onto the constituent fiber. Images of how the water droplet is dropped are recorded on a highspeed image recording device connected to a horizontally placed camera. From the standpoint of subsequently performing image analysis and image analysis, it is desirable that the image recording device is a personal computer in which a high-speed capture device is incorporated. In this measurement, an image is recorded every 17 msec. The first image of the recorded images in which the water droplet is deposited on the constituent fiber that forms the skin-facing surface or the non-skin-facing surface of the nonwoven fabric is analyzed using a piece of attached software FAMAS (version of the software: 2.6.2, analysis technique: sessile drop method, analysis method: Θ/2 method, image processing algorithm: nonreflective, image-processing image mode: frame, threshold level: 200, and curvature correction: non), and the angle formed by a surface of the water droplet that is in contact with air and the constituent fiber is calculated and used as the contact angle.

It should be noted that in the case where the long base portions are formed from a nonwoven fabric, measurement samples (constituent fibers removed from the nonwoven fabric) are obtained by cutting constituent fibers of the nonwoven fabric to a fiber length of mm from the outermost layer, the constituent fibers are placed on a sample stand of the contact angle meter and kept horizontal, and the contact angle is measured at two positions per single constituent fiber. For each of the above-described various portions, the contact angle is measured to the first decimal place with respect to N = 5 constituent fibers, and an average value (rounded off to one decimal place) of measurement values measured at a total of 10 positions is defined as the contact angle of that portion.

[0028]

Various water-absorbent polymers that are conventionally used in the field of the absorbent article can be used as the water-absorbent polymer 3 that is fixed to one surface of each long base portion 2. Examples of such water-absorbent polymers include sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymers, crosslinked sodium polyacrylate, (starch-acrylic acid) graft polymers, (isobutylene-maleic anhydride) copolymers and saponified products thereof, potassium polyacrylate, and cesium polyacrylate, and these water-absorbent polymers can be used alone or as a mixture of two or more. There are various types of water-absorbent polymer particles 3 based on differences in shape, such as an irregular shape type, a clump-shape type, a barrel-shape type, a spherical-particleagglomerate type, a spherical type, and the like, but any type can be used. In the sheetlike article 1, a spherical type is used.

[0029]

As the method for fixing the water-absorbent polymer particles 3 onto the surface of each long base portion 2, for example, a method that uses an adhesive, a chemical fixation method that uses hydrogen bonding or the like, or in the case where the long base portions 2 are formed from a nonwoven fabric or a fabric, a method of napping the constituent fibers of the nonwoven fabric or the fabric and fixing the water-absorbent polymer particles 3 between the napped constituent fibers can be adopted. In the sheetlike article 1 shown in FIGS. 1 and 2, an adhesive 5 is used. That is to say, the waterabsorbent polymer particles 3 of the sheet-like article 1 are fixed to the surface of each long base portion 2 via the adhesive 5. When the water-absorbent polymer particles 3 are fixed to the surface of each long base portion 2 via the adhesive 5 in this manner, in a state before use of the sheet-like article 1 or in a state after swelling, the water-absorbent polymer particles 3 are unlikely to detach, and for this reason, the adhesive 5 is preferably used.

[0030]

For example, a hot-melt adhesive is preferably used as the adhesive 5. Examples of the hot-melt adhesive include styrene-based or olefin-based hot-melt adhesives and the like. Examples of styrene-based hot-melt adhesives that can be used include a styrenebutadiene-styrene copolymer (SBS), a styrene-isoprene-styrene copolymer (SIS), a styrene-ethylene-butylene-styrene copolymer (SEBS), which is produced by hydrogenating SBS, and a blended hot-melt adhesive obtained by blending two or more of these adhesives. Among these, in light of the ease of achieving a balance between the tacking force and the cohesion, a blended hot-melt adhesive obtained by blending SIS and SBS or a blended hotmelt adhesive obtained by blending SIS and SEBS is particularly preferably used. The amount of hot-melt adhesive to be applied is preferably between 0.5 g/m² and 100 g/m²inclusive and more preferably between 5 g/m² and 50 g/m² inclusive.

[0031]

In the sheet-like article 1 shown in FIG. 1, in a state before use (before swelling), the water-absorbent polymer particles 3 are fixed not only to the surface on the first side (upper side) of each long base portion 2 but also to lateral side edge portions 2s of each long base portion 2, the lateral side edge portions 2s extending along the longitudinal direction (direction Y). Preferably, in the sheet-like article 1 of the present embodiment, as shown in FIG. 1, the adhesive 5 is applied to a region of each long base portion 2, spanning from one lateral side edge portion 2s to the other lateral side edge portion 2s, the lateral side edge portions 2s extending along the longitudinal direction (direction Y), via the surface on the first side (upper side). Therefore, in the sheet-like article 1 of the present embodiment, the water-absorbent polymer particles 3 are fixed to the lateral side edge portions 2s of the individual long base portions 2 via the adhesive 5, and the waterabsorbent polymer particles 3 are also fixed to the surfaces on the first side (upper side) of the individual long base portions 2 via the adhesive 5.

[0032]

As shown in FIG. 1, in the sheet-like article 1 of the present embodiment, in a state before use (before swelling), the water-absorbent polymer particles 3 are fixed to the lateral side edge portions 2s of each long base portion 2, and therefore, when the sheet-like article is used for an absorbent article, after the water-absorbent polymer particles 3 fixed to the lateral side edge portions 2s have swelled as a result of absorbing liquid, as shown in FIG. 2, the position of each long base portion 2 in the thickness direction (direction Z) is likely to become different from that before absorbing liquid. Here, the position of each long base portion 2 in the thickness direction (direction Z) in a state after swelling of the sheetlike article 1 becoming different from that before absorbing liquid means that the sheet-like article 1 is formed such that the position of each long base portion 2 in a state after the water-absorbent polymer particles 3 have swelled, the state being shown in FIG. 2, and the position of that long base portion 2 in a state before use (before swelling) of the waterabsorbent polymer particles 3, the state being shown in FIG. 1, are different from each other in a vertical direction. Specifically, a case in which the position of each long base portion is shifted vertically, a case in which the position is shifted obliquely, a case in which the position is shifted both vertically and obliquely, or the like is conceivable.

[0033]

When the sheet-like article 1 is used for an absorbent article, as shown in FIG. 2, if the positions of the water-absorbent polymer particles 3 on the long base portions 2 are likely to become different from those before the water-absorbent polymer particles 3 absorb liquid in the thickness direction (direction Z), even when the water-absorbent polymer particles 3,3 on the lateral side edge portions 2s of the long base portions 2 in the absorbent units 4,4 that are adjacent to each other come into contact with each other when the waterabsorbent polymer particles 3 are absorbing bodily fluid and swelling, it is easy for the adjacent absorbent units 4,4 to freely move in the thickness direction (direction Z), and thus, collisions between the water-absorbent polymer particles 3,3 that have swelled are alleviated, pressure that is applied to the water-absorbent polymer particles 3 that have swelled can be reduced, and the water-absorbent polymer particles 3 are unlikely to be inhibited from absorbing the bodily fluid. Accordingly, with the sheet-like article 1 of the present embodiment, when the water-absorbent polymer particles 3 are absorbing bodily fluid and swelling, the inhibition of swelling of the water-absorbent polymer particles 3 is unlikely to occur, and the water-absorbent polymer particles 3 can exhibit the maximum absorption performance. Therefore, the absorption performance is easily improved. In particular, in the sheet-like article 1 of the present embodiment, since no interposed material is present between the absorbent units 4,4 that are adjacent to each other, it is easy for the absorbent units 4 to move, and thus, the above-described effects are even more easily achieved.

[0034]

Moreover, in the sheet-like article 1, in a state after swelling as shown in FIG. 2, the positions of the long base portions 2 constituting the absorbent units 4 that are adjacent to each other are likely to become different in the thickness direction (direction Z) in such a manner that the positions are vertically shifted, slant, and so on. Therefore, it is easy for the adjacent absorbent units 4,4 to freely move in the thickness direction (direction Z), collisions between the water-absorbent polymer particles 3,3 that have swelled are likely to be alleviated, pressure that is applied to the water-absorbent polymer particles 3 that have swelled can be reduced, and the water-absorbent polymer particles 3 are unlikely to be inhibited from absorbing the bodily fluid.

[0035]

Moreover, as shown in FIG. 1, in the sheet-like article 1 of the present embodiment, in a state before use (before swelling), the water-absorbent polymer particles 3 are fixed to the surface on the first side (upper side) and both lateral side edge portions 2s of each long base portion 2 via the adhesive 5. Since the water-absorbent polymer particles 3 are fixed not only to the surface on the first side (upper side) of each long base portion 2 but also to both lateral side edge portions 2s of each long base portion 2, the amount of water-absorbent polymer particles 3 that are supported by the long base portions 2 is increased. Therefore, when the sheet-like article 1 is used for an absorbent article, the absorption capacity is improved.

[0036]

In a state before use (before swelling) of the sheet-like article 1, the state being shown in FIG. 1, the water-absorbent polymer particles 3 that are fixed to the surface on the first side (upper side) of each long base portion 2 may be present inward of the lateral side edge portions 2s of that long base portion 2 or may be disposed in the vicinity of the lateral side edge portions 2s of that long base portion 2. From the standpoint of allowing the water-absorbent polymer particles 3a to swell out beyond the lateral side edge portions 2s of each long base portion 2 as is the case with the water-absorbent polymer particles 3 a in a state after swelling shown in FIG. 2, allowing the absorbent units 4,4 that are adjacent to each other to freely move in the thickness direction (direction Z), and thereby making the inhibition of swelling of the water-absorbent polymer particles 3 even less likely to occur, the water-absorbent polymer particles 3 are preferably disposed in the vicinity of the lateral side edge portions 2s of each long base portion 2, and are more preferably present extending beyond the lateral side edge portions 2s of each long base portion 2 from the beginnig, like water-absorbent polymer particles 3b in the state before use (before swelling) shown in FIG. 1, for example. Here, the water-absorbent polymer particles 3 extending beyond the lateral side edge portions 2s of each long base portion 2 means, in other words, that the water-absorbent polymer particles 3 are present straddling the lateral side edge portions 2s of each long base portion 2, like the water-absorbent polymer particles 3b shown in FIG. 1 or water-absorbent polymer particles 3a that have swelled shown in FIG. 2, for example.

[0037]

Furthermore, in the sheet-like article 1, from the standpoint of allowing the absorbent units 4,4 that are adjacent to each other to freely move in the thickness direction (direction Z) and making it even less likely that the inhibition of swelling of the waterabsorbent polymer particles 3 will occur, it is preferable that the distance between both lateral side edge portions 2s,2s , which extend in the longitudinal direction (direction Y), of each long base portion 2 is larger than the average particle diameter of the waterabsorbent polymer particles 3 in a state before use (before swelling) and smaller than the average particle diameter of the water-absorbent polymer particles 3 in a state after swelling. It should be noted that the distance between both lateral side edge portions 2s,2s of each long base portion 2 is herein used in the same sense as the above-described width (W2) of each long base portion 2. The average particle diameter of the water-absorbent polymer particles 3 in a state before use (before swelling) is preferably not less than 20 pm and more preferably note less than 200 pm and preferably not more than 700 pm and more preferably not more than 500 pm, and specifically, this average particle diameter is preferably between 20 pm and 700 pm inclusive and more preferably between 200 pm and 500 pm inclusive. On the other hand, the average particle diameter of the water-absorbent polymer particles 3 in a state after swelling is preferably not less than 200 pm and more preferably not less than 800 pm and preferably not more than 3000 pm and more preferably not more than 2000 pm, and specifically, this average particle diameter is preferably between 200 pm and 3000 pm inclusive and more preferably between 800 pm and 2000 pm inclusive. The average particle diameters of the water-absorbent polymer particles 3 are obtained using measurement methods described below.

[0038]

Method for Measuring Average Particle Diameter dl of Water-absorbent polymer Particles in a State Before Use

The average particle diameter dl in a state before use is measured using waterabsorbent polymer particles before use. The diameters or the major axes of the waterabsorbent polymer particles are measured through optical microscopy. Here, “diameter” applies to the case where the water-absorbent polymer particles have a spherical shape. “Major axis” applies to the case where the water-absorbent polymer particles have an unusual shape such as a rhombic shape, a rectangular shape, a cluster shape, or a footballlike shape. The diameters or the major axes of a total of 50 water-absorbent polymer particles are measured, and a number average particle diameter is used as the average particle diameter of the water-absorbent polymer particles in a state before use.

[0039]

Method for Measuring Average Particle Diameter d2 of Water-absorbent polymer Particles in a State after Swelling

The average particle diameter d2 in a state after swelling is measured in the following manner. The sheet-like article 1 is immersed in a physiological saline solution (0.9 mass% aqueous solution of sodium chloride) whose temperature is controlled to 25°C. The sheet-like article 1 is removed from the physiological saline solution after an hour from the start of the immersion, and vertically suspended for 30 minutes for draining. Then, the diameters or the major axes of the water-absorbent polymer particles on the surfaces of the long base portions 2 are measured through optical microscopy. “Diameter” as used herein applies to the case where the water-absorbent polymer particles have a spherical shape. “Major axis” applies to the case where the water-absorbent polymer particles have an unusual shape such as a rhombic shape, a rectangular shape, a cluster shape, or a footballlike shape. The diameters or the major axes of a total of 50 water-absorbent polymer particles are measured, and a number average particle diameter is used as the average particle diameter of the water-absorbent polymer particles in the state after swelling.

[0040]

Next, a preferred embodiment of a method for producing a sheet-like article of the present invention will be described with reference to FIG. 4, taking a case where the sheetlike article 1 having the above-described configuration is to be produced as an example. FIG. 4 shows a production apparatus 100 that is preferably used for the method for producing a sheet-like article of the present embodiment. The production apparatus 100 of the present embodiment includes a base material sheet cutting portion 110, a widening portion 170, an adhesive application portion 120, and an water-absorbent polymer spreading portion 130 in this order from an upstream side toward a downstream side of the production process. It should be noted that although the production apparatus 100 shown in FIG. 4 uses an apparatus into which the adhesive application portion 120 and the waterabsorbent polymer spreading portion 130 are integrated, the adhesive application portion 120 and the water-absorbent polymer spreading portion 130 are not necessarily required to be integrated. The above-described integrated apparatus has a configuration in which the adhesive application portion 120 is disposed on the upstream side in this apparatus and the water-absorbent polymer spreading portion 130 is disposed on the downstream side in this integrated apparatus.

[0041]

The base material sheet cutting portion 110 is a portion in which a continuous base material sheet 20, which is the raw material for the long base portions 2, are cut to obtain a plurality of long base portions 2. To cut the base material sheet 20, various types of known cutting apparatuses can be used without limitation. As shown in FIG. 5, the production apparatus 100 uses a cutting apparatus 113 including a rotary die 111b with a plurality of cutter blades 111a, 111a, 111a··· arranged on a circumferential surface of the rotary die 111b and a receiving roller 112 that has a flat circumferential surface and that is disposed opposing the rotary die 1 lib. The cutter blades 11 la of the cutting apparatus 113 extend along a rotating direction of the rotary die 111b. The plurality of cutter blades 111a,111a,111a are lined up in a direction (direction XI) that is orthogonal to a conveyance direction (direction Yl) of the continuous base material sheet 20. Distances between the cutter blades 111 a, 111a that are adjacent to each other in the direction (direction XI) that is orthogonal to the conveyance direction (direction Yl) correspond to the widths (lengths in the lateral direction (direction X)) of the long base portions 2 to be formed. Here, the conveyance direction (direction Yl) of the base material sheet 20 corresponds to the longitudinal direction (direction Y) of the sheet-like article 1 to be produced, and the direction (direction XI) that is orthogonal to the conveyance direction (direction Yl) corresponds to the lateral direction (direction X) of the sheet-like article 1 to be produced. It should be noted that, to cut the base material sheet 20, a shear cutting type cutting apparatus, which performs cutting by sliding side surfaces of an upper blade and a lower blade against each other may be used, or an apparatus in which a plurality of score cutting knives are arranged side-by-side in the direction (direction XI) that is orthogonal to the conveyance direction (direction Yl) or a laser apparatus that performs fusion cutting through irradiation with a laser beam may be used.

[0042]

As in the case of the sheet-like article 1 shown in FIG. 3, in the case where the sheet-like article 1 includes the non-slit regions NT on both ends of the sheet-like article 1 in the longitudinal direction (direction Y), a depression 114 can be formed in a circumferential surface of each cutter blade 111a as shown in FIG. 5, for example. The length of a circular arc of the depression 114 portion in the outer circumference of each of the rotary cutter blades 11 la is set to correspond to the sum of the lengths in the longitudinal direction (direction Y) of the non-slit regions NT, which are disposed on both ends of the sheet-like article 1 shown in FIG. 3. A rotary die 111b that is obtained by preparing a plurality of cutter blades 111a, 111 a, 111a··· that respectively have such depressions 114 and arranging the cutter blades 111a with the positions of the depressions 114,114 of the cutter blades 111a that are adjacent to each other in the direction XI being aligned can be used. It should be noted that the length of a circular arc of a portion excluding the depression 114, of the outer circumference of each of the rotary cutter blades 111a corresponds to the length in the longitudinal direction (direction Y) of the long base portions 2 of the sheet-like article 1 shown in FIG. 3. Moreover, in the case where the sheet-like article 1 includes non-slit regions NT on both lateral sides, which extend along the longitudinal direction (direction Y), of the sheet-like article 1, it is sufficient that the cutter blades 11 la are not disposed at positions corresponding to those non-slit regions NT.

[0043]

The widening portion 170, which is located downstream of the base material sheet cutting portion 110, is a portion in which distances between the long base portions 2,2 that are adjacent to each other in the direction XI are widened. To widen the distances between the long base portions 2,2 , various known widening apparatuses can be used without limitation. Examples of such known widening apparatuses include arc-shaped curved rollers such as a crown roller, an expander roller, and the like. As shown in FIG. 6, the production apparatus 100 includes a crown roller 171. The crown roller 171 is formed to have such a length in the direction XI that corresponds to the width (length in lateral direction (direction X)) of the absorption region AT of the sheet-like article 1, and has a circumferential surface that is curved outward as shown in FIG. 6.

[0044]

The adhesive application portion 120, which is located downstream of the widening portion 170, is a portion in which the adhesive 5 is applied from above the surfaces on the first side (upper side) of the long base portions 2. As shown in FIG. 4, the production apparatus 100 includes an application head 121. Various known application apparatuses can be used without limitation as the application head 121. The application head 121 is formed such that, in the direction XI, the application head 121 has a length corresponding to the width (length in the lateral direction (direction X)) of the absorption region AT of the sheet-like article 1. The application head 121, which is formed as described above, is disposed above the first side (upper side) of the long base portions 2.

[0045]

The water-absorbent polymer spreading portion 130, which is located downstream of the adhesive application portion 120, is a portion in which the water-absorbent polymer particles 3 are spread over the surfaces on the first side (upper side) of the long base portions 2 to form the absorbent units 4. As shown in FIG. 4, the production apparatus 100 includes an water-absorbent polymer inlet portion 131. Various types of known inlet apparatuses can be used without limitation as the water-absorbent polymer inlet portion 131. The water-absorbent polymer inlet portion 131 is formed such that, in the direction XI, the water-absorbent polymer inlet portion 131 has a length corresponding to the width (length in the lateral direction (direction X)) of the absorption region AT of the sheet-like article 1. The water-absorbent polymer inlet portion 131, which is formed as described above, is disposed above the first side (upper side) of the long base portions 2.

[0046]

Moreover, in the production apparatus 100 shown in FIG. 4, a vacuum conveyor

141 is disposed at a position that opposes the apparatus into which the adhesive application portion 120 and the water-absorbent polymer spreading portion 130 are integrated and that is located on the lower side of the plurality of long base portions 2 that are conveyed. The vacuum conveyor 141 includes an endless, air-permeable belt 144 that extends around a drive roller 142 and a plurality of driven rollers 143, and a vacuum box 145 that is disposed at a position opposing the aforementioned integrated apparatus with the air-permeable belt 144 held between this apparatus and the vacuum box 145. The plurality of long base portions 2, with the distances between the long base portions 2,2 that are adjacent to each other in the direction XI having been widened in the widening portion 170, are introduced onto the vacuum conveyor 141.

[0047]

Moreover, the production apparatus 100 shown in FIG. 4 includes a drive roller 151 that draws out the base material sheet 20 from a raw fabric roller of the continuous base material sheet 20 and a drive roller 152 that conveys a produced precursor lb of the sheetlike article 1, the drive roller 152 being provided on the most downstream side.

[0048]

Next, a method for continuously producing sheet-like articles 1 using the abovedescribed production apparatus 100 of the present embodiment, that is, an embodiment of the method for producing a sheet-like article according to the present invention will be described.

The method for producing the sheet-like article 1 according to the present embodiment includes a cutting step of cutting the continuous base material sheet 20 to form a plurality of long base portions 2; a widening step of widening, using the widening portion 170, distances between the long base portions 2,2 that are adjacent to each other, of the plurality of long base portions 2 that have been formed in the cutting step; and an waterabsorbent polymer particle spreading step of spreading the water-absorbent polymer particles 3 onto the plurality of long base portions 2, with the distances between the long base portions 2,2 that are adjacent to each other having been widened in the widening step. Moreover, according to the present embodiment, an adhesive application step of applying the adhesive 5 is provided as a step upstream of the water-absorbent polymer particle spreading step. That is to say, the method for producing the sheet-like article 1 according to the present embodiment includes the widening step as a step downstream of the cutting step, the adhesive application step as a step downstream of the widening step, and the waterabsorbent polymer particle spreading step as a step downstream of the adhesive application step.

[0049]

Before performing the cutting step, first, a negative pressure is generated in the vacuum box 145 by starting up an evacuation apparatus connected to the vacuum box 145.

[0050]

Next, the drive roller 151 and the drive roller 152 are driven, the cutting apparatus 113 and the air-permeable belt 144 are rotated, and the vacuum conveyor 141 runs. Then, the base material sheet 20 is drawn out by the drive roller 151 from the raw fabric roller of the continuous base material sheet 20 and supplied between the receiving roller 112 and the plurality of cutter blades 11 la in the cutting apparatus 113 of the base material sheet cutting portion 110, and the continuous base material sheet 20 is cut to form a plurality of long base portions 2 (cutting step). According to the present embodiment, as shown in FIG. 5, the plurality of cutter blades 111a, which extend in the rotating direction of the rotary die 11 lb, are lined up in the direction (direction XI) that is orthogonal to the conveyance direction (direction Yl) of the continuous base material sheet 20. Therefore, the continuous base material sheet 20 is cut along the conveyance direction (direction Yl) of the base material sheet 20, at a plurality of portions of the continuous base material sheet 20 in the direction (direction XI) that is orthogonal to the conveyance direction (direction Yl). Thus, the plurality of long base portions 2 are formed. Moreover, the portions that have been cut by the cutter blades 111a constitute the lateral side edge portions 2s of the individual long base portions 2.

[0051]

Moreover, according to the present embodiment, each of the plurality of cutter blades 111a has a depression 114. Therefore, while the continuous base material sheet 20 is conveyed, non-cut portions NTb are intermittently formed in the base material sheet 20 at intervals corresponding to the length of the long base portions 2 in the longitudinal direction (direction Y). The length of each non-cut portion NTb corresponds to twice the length of each non-slit region NT in the longitudinal direction (direction Y). The plurality of long base portions 2 that have been formed in the cutting step extend parallel to the conveyance direction (direction Yl) and are arranged side-by-side in the direction (direction XI) that is orthogonal to the conveyance direction (direction Yl).

[0052]

Next, distances between the long base portions 2,2 that are adjacent to each other, of the plurality of long base portions 2 that have been formed in the cutting step, are widened in the widening portion 170 (widening step). According to the present embodiment, as shown in FIG. 6, the plurality of long base portions 2 that are arranged side-by-side in the direction (direction XI) that is orthogonal to the conveyance direction (direction Yl) are conveyed onto the circumferential surface of the crown roller 171, and the distances between the long base portions 2,2 that are adjacent to each other in the direction XI are widened while the long base portions 2 are conveyed on the circumferential surface of the crown roller 171.

[0053]

Next, the adhesive 5 is applied from above the first side (upper side) of the plurality of long base portions 2 with the distances between the long base portions 2,2 that are adjacent to each other having been widened in the widening step (adhesive application step). According to the present embodiment, while the plurality of long base portions 2, with the distances between the long base portions 2,2 that are adjacent to each other in the direction XI having been widened in the widening step, are conveyed by the vacuum conveyor 141 and located on the vacuum box 145, the adhesive 5 is applied, except to the non-cut portions NTb, intermittently from above the first side (upper side) of the plurality of long base portions 2, which are arranged side-by-side in the direction (direction XI) that is orthogonal to the conveyance direction (direction Yl), by the application head 121 of the adhesive application portion 120. The adhesive 5 is applied from above the first side (upper side) of the long base portions 2 with the distances between the long base portions 2,2 that are adjacent to each other in the direction XI having been widened, and thus, the adhesive 5 is applied to the surfaces on the first side (upper side) and the lateral side edge portions 2s of the individual long base portions 2.

[0054]

Next, the water-absorbent polymer particles 3 are spread onto the adhesive 5, which has been applied from above the first side (upper side) of the plurality of long base portions 2 in the adhesive application step (water-absorbent polymer particle spreading step). According to the present embodiment, while the long base portions 2 that have been formed in the adhesive application step, with the adhesive 5 being applied to the surfaces on the first side (upper side) and the lateral side edge portions 2s of the long base portions 2, are conveyed by the vacuum conveyor 141 and located on the vacuum box 145, the water-absorbent polymer particles 3 are spread onto the adhesive 5, which has been applied to the surfaces on the first side (upper side) and the lateral side edge portions 2s of the plurality of long base portions 2 that are arranged side-by-side at intervals in the direction (direction XI) that is orthogonal to the conveyance direction (direction Yl), except onto the non-cut portions NTb, by the water-absorbent polymer inlet portion 131 of the waterabsorbent polymer spreading portion 130. As a result of spreading the water-absorbent polymer particles 3 in this manner, a plurality of absorbent units 4 are formed, in each of which the water-absorbent polymer particles 3 are fixed to the lateral side edge portions 2s and the surface on the first side (upper side) of the long base portion 2 via the adhesive 5. The plurality of absorbent units 4 that have been thus formed are arranged such that their longitudinal directions (directions Y) are oriented in the conveyance direction (direction Yl), and form the precursor lb of the sheet-like article 1.

[0055]

Next, the precursor lb of the sheet-like article 1 is conveyed downstream by the drive roller 152 and cut at each position that bisects the length of the individual non-cut portions NTb in the conveyance direction (direction Yl), using a known cutting apparatus (not shown). Thus, sheet-like articles 1 each having non-slit regions NT on both ends in the longitudinal direction (direction Y) are continuously produced. As described above, with the production apparatus 100 of the present embodiment and the production method of the present embodiment in which the production apparatus 100 is used, sheet-like articles 1 can be stably and efficiently manufactured.

[0056]

The present invention is not limited to the foregoing embodiments and the production method of the foregoing embodiment, and changes can be made thereto as appropriate.

In the above-described sheet-like article 1 shown in FIG. 1, the water-absorbent polymer particles 3 are fixed to the surface on the first side (upper side) of each long base portion 2. However, from the standpoint of improving the liquid absorption performance of the sheet-like article 1, the water-absorbent polymer particles 3 may be fixed not only to the surface on the first side (upper side) but also to the surface on the second side (lower side) of each long base portion 2. To fix the water-absorbent polymer particles 3 to both sides (upper and lower sides) of each long base portion 2, for example, production can be performed, using the production apparatus 100 shown in FIG. 4, by fixing the waterabsorbent polymer particles 3 to the surfaces on the first side (upper side) and the lateral side edge portions 2s of the long base portions 2, then inverting the long base portions 2 via an inverting roller, and then spreading and fixing the water-absorbent polymer particles 3 onto the surfaces on the second side (lower side) of the long base portions 2 using another water-absorbent polymer spreading portion 130.

[0057]

When fixing the water-absorbent polymer particles 3 to both sides (upper and lower sides) of each long base portion 2, from the standpoint of making the above-described effects even more prominent, it is preferable that the weight of the water-absorbent polymer 3 fixed per unit area of the surface on the second side (lower side) of a long base portion 2 is larger than the weight of the water-absorbent polymer 3 fixed per unit area of the surface on the first side (upper side) of that long base portion 2. The weight of the water-absorbent polymer 3 fixed per unit area of the surfaces on the first side (upper side) of the long base portions 2 is preferably between 10 g/m² and 250 g/m² inclusive and more preferably between 30 g/m² and 150 g/m² inclusive. The weight of the water-absorbent polymer 3 fixed per unit area of the surfaces on the second side (lower side) of the long base portions is preferably between 30 g/m² and 400 g/m² inclusive and more preferably between 50 g/m² and 300 g/m² inclusive.

The weight of the water-absorbent polymer 3 fixed per unit area on the first side (upper side) of the long base portions 2 and the weight of the water-absorbent polymer 3 fixed per unit area on the second side (lower side) of the long base portions 2 are measured using a method below.

[0058]

Method for Measuring Weight of Water-absorbent polymer 3 Fixed per Unit Area on First Side (Upper Side) of Long base portions 2 and Weight of Water-absorbent polymer

Fixed per Unit Area on Second Side (Lower Side) of Long base portions 2

The water-absorbent polymer on the second side (lower side) of the long base portions 2 is fixed again using an adhesive or the like from above this water-absorbent polymer lest this water-absorbent polymer detach. Then, the water-absorbent polymer fixed to the first side (upper side) is separated from the long base portions 2 using a solvent or the like, and the adhesive adhering to the water-absorbent polymer is washed oif. The water-absorbent polymer is dried. After that, the weight of the water-absorbent polymer that has been fixed to the first side (upper side) is measured. Based on the area of that portion of the long base portions 2 to which the water-absorbent polymer has been fixed and the weight of the separated water-absorbent polymer, the weight of the water-absorbent polymer that has been fixed per unit area is calculated and used as the weight of the water30 absorbent polymer per unit area on the first side (upper side). The measurement is performed on five samples, and an average value is calculated.

For the weight of the water-absorbent polymer per unit area on the second side (lower side), after the water-absorbent polymer on the first side (upper side) is fixed in advance, separation of the water-absorbent polymer on the second side (lower side), washing, and calculation are performed in the same manner as described above.

[0059]

Moreover, when fixing the water-absorbent polymer particles 3 to both sides (upper and lower sides) of each long base portion 2, from the standpoint of allowing a large amount of liquid to be retained by the non-skin-facing surface (lower side) that is located away from the wearer's skin and improving the tactile feel by preventing liquid from remaining on the skin-facing surface (upper side), it is preferable that the water-absorbent polymer 3 that is fixed to the surface on the first side (upper side) of a long base portion 2 has higher liquid-passing performance under pressure and a lower centrifugal retention capacity than the water-absorbent polymer 3 that is fixed to the surface on the second side (lower side) of the long base portion 2. From the above-described standpoint, with respect to the water-absorbent polymer 3 that is fixed to the surfaces on the first side (upper side) of the long base portions 2, the liquid-passing rate under pressure at 2.0 kPa is preferably not less than 20 ml/min and more preferably not less than 40 ml/min and preferably not more than 1000 ml/min and more preferably not more than 800 ml/min, and specifically, this liquid-passing rate is preferably between 20 ml/min and 1000 ml/min inclusive and more preferably between 40 ml/min and 800 ml/min inclusive. Also, with respect to the water-absorbent polymer 3 that is fixed to the surfaces on the second side (lower side) of the long base portions 2, the liquid-passing rate under pressure at 2.0 kPa is preferably not less than 0 ml/min and more preferably not less than 10 ml/min and preferably not more than 400 ml/min and more preferably not more than 200 ml/min, and specifically, this liquid-passing rate is preferably between 0 ml/min and 400 ml/min inclusive and more preferably between 10 ml/min and 200 ml/min inclusive. The liquid-passing rate under pressure is obtained using a measurement method below.

[0060]

Method for Measuring Liquid-Passing Rate under Pressure

The liquid-passing rate under pressure is measured using a measurement method and a measurement apparatus that are disclosed in JP 2003-235889A. That is to say, in a 100-mL glass beaker, 0.32 ± 0.005 g of an water-absorbent polymer, which serves as a measurement sample, is immersed in a physiological saline solution (0.9 mass% aqueous solution of sodium chloride) in an amount that is enough to cause the water-absorbent polymer to swell, for example, the physiological saline solution in an amount that is at least five times the saturation absorption amount of the water-absorbent polymer, and left to stand for 30 minutes. Separately, a filtration cylindrical tube is prepared. The filtration cylindrical tube includes a cylinder (internal diameter: 25.4 mm) that is vertically placed as well as a wire net (mesh size: 150 pm, a bio-column sintered stainless steel filter 30SUS commercially available from Sansyo Co., Ltd.) and a narrow tube (internal diameter: 4 mm, length: 8 cm) equipped with a stopcock (internal diameter: 2 mm), the wire net and the narrow tube with the stopcock being provided at a lower end of an opening of the cylinder. The entire content of the beaker including the measurement sample that has swelled is placed in the prepared cylindrical tube in a state in which the stopcock is closed. Then, a cylindrical rod having a diameter of 2 mm and provided with a wire net at a leading end of the cylindrical rod, the wire net having a mesh size of 150 pm and a diameter of 25 mm, is inserted into the filtration cylindrical tube such that the wire net is brought into contact with the measurement sample. Furthermore, a weight is placed so that a load of 2.0 kPa is applied to the measurement sample. The measurement sample is left to stand in this state for 1 minute. After that, the stopcock is opened to drain the solution, and the time (TI) (sec) until the liquid level in the filtration cylindrical tube changes from a scale mark at 60 mL to a scale mark at 40 mL (i.e., 20 mL of the solution passes) is measured. Based on the measured time TI (sec), the liquid-passing rate under pressure at 2.0 kPa is calculated using an equation below. It should be noted that, in the equation, TO (sec) represents a value that is obtained by measuring the time taken for 20 ml of the physiological saline solution to pass through the wire net when the measurement sample is not placed in the filtration cylindrical tube.

Liquid-passing rate under pressure (ml/min) = 20 x 60 / (TI - TO)

The measurement is performed five times (n = 5), the largest value and the smallest value are eliminated, and the average of the remaining three values is used as the measurement value. Moreover, the measurement is performed at 23 ± 2 °C and a humidity of 50 ± 5%, and before the measurement, the samples are stored in the same environment for 24 hours or more. Further details of the method for measuring the liquid-passing rate under pressure are disclosed in paragraphs 0008 and 0009 of JP 2003-235889A, and the measurement apparatus is disclosed in FIGS. 1 and 2 of JP 2003-235889A.

[0061]

From the above-described standpoint, with respect to the water-absorbent polymer 3 that is fixed to the surfaces on the first side (upper side) of the long base portions 2, the centrifugal retention capacity (water absorption capacity) is preferably not less than 20 g/g and more preferably not less than 25 g/g and preferably not more than 50 g/g and more preferably not more than 45 g/g, and specifically, the centrifugal retention capacity is preferably between 20 g/g and 50 g/g inclusive and more preferably between 25 g/g and 45 g/g inclusive. Also, with respect to the water-absorbent polymer 3 that is fixed to the surfaces on the second side (lower side) of the long base portions 2, the centrifugal retention capacity (water absorption capacity) is preferably not less than 25 g/g and more preferably not less than 30 g/g and preferably not more than 65 g/g and more preferably not more than 55 g/g, and specifically, the centrifugal retention capacity is preferably between 25 g/g and 65 g/g inclusive and more preferably between 30 g/g and 55 g/g inclusive. The centrifugal retention capacity (water absorption capacity) is measured using a measurement method below.

[0062]

Method for Measuring Centrifugal Retention Capacity (Water Absorption Capacity)

The centrifugal retention capacity (water absorption capacity) is measured in conformity with JIS K 7223 (1996). A nylon woven fabric (commercially available from

Sanriki Seisakusyo, product name: nylon net, specifications: 250 meshes) is cut into a rectangular shape with a width of 10 cm and a length of 40 cm and folded in two at the center in the longitudinal direction, and both lateral sides are heat-sealed to create a nylon bag with a width of 10 cm (internal dimension of 9 cm) and a length of 20 cm. Next, 1.00 g of an water-absorbent polymer, which serves as a measurement sample, is precisely weighed and uniformly placed in a bottom portion of the created nylon bag. Then, the nylon bag containing the sample is immersed in a physiological saline solution (0.9 mass% aqueous solution of sodium chloride) whose temperature is controlled to 25 °C. The nylon bag is removed from the physiological saline solution after an hour from the start of the immersion, vertically suspended for an hour for draining, and then dewatered using a dewatering centrifuge (manufactured by Kokusan Co., Ltd., model: H-130C special type). With respect to the dewatering conditions, dewatering is performed at 143 G (800 rpm) for 10 minutes. After dewatering has been completed, the mass of the sample is measured, and the target centrifugal retention capacity (water absorption capacity) is calculated in accordance with an equation below.

Centrifugal retention capacity (g/g) = (a¹ - b - c) / c

In the equation, “a¹” represents the total mass (g) of the sample and the nylon bag after centrifugal dewatering has been completed, “b” represents the mass (g) of the nylon bag before absorbing water (in dry state), and “c” represents the mass (g) of the sample before absorbing water (in dry state).

The measurement is performed five times (n = 5), the largest value and the smallest value are eliminated, and the average of the remaining three values is used as the measurement value. Moreover, the measurement is performed at 23 ± 2 °C and a humidity of 50 ± 5%, and before the measurement, the samples are stored in the same environment for 24 hours or more.

[0063]

Moreover, although the above-described sheet-like article 1 shown in FIG. 1 is formed using a plurality of absorbent units 4 that have respective long base portions 2 with uniform widths, the long base portions 2 may also have non-uniform widths. Preferably, in plan view of the sheet-like article 1, the water-absorbent polymer particles 3 are fixed in an unevenly distributed manner, and in a portion where the weight of the water-absorbent polymer 3 fixed per unit area is relatively large, the distance between both lateral side edge portions 2s,2s , which extend along the longitudinal direction (direction Y), of each long base portion 2 may be relatively small. That is to say, when a comparison is made between a portion where the weight of the water-absorbent polymer 3 fixed per unit area is large and a portion where the weight of the water-absorbent polymer 3 fixed per unit area is small, the distance between both lateral side edge portions 2s,2s of each long base portion 2 in the portion where the weight of the water-absorbent polymer 3 fixed per unit area is large may be shorter than the distance between both lateral side edge portions 2s,2s of each long base portion 2 in the portion where the weight of the water-absorbent polymer 3 fixed per unit area is small. With the sheet-like article 1 having the above-described configuration, in the portion where the weight of the water-absorbent polymer 3 fixed per unit area is large, it is easy for the absorbent units 4,4 that are adjacent to each other to freely move in the thickness direction (direction Z), the sheet-like article 1 is unlikely to be hard, and the water-absorbent polymer particles 3 can exhibit the maximum absorption performance. Therefore, the absorption performance of the sheet-like article 1 is easily improved.

[0064]

Moreover, in the above-described sheet-like article 1 shown in FIG. 3, the plurality of absorbent units 4 are arranged such that their longitudinal directions (directions Y) are oriented in the longitudinal direction (direction Y) of the sheet-like article 1. However, as shown in FIG. 7, for example, the plurality of absorbent units 4 may also be arranged such that their longitudinal directions (directions Y) are oriented in the lateral direction (direction X) of the sheet-like article 1. It should be noted that the sheet-like article 1 shown in FIG. 7 includes non-slit regions NT on both lateral sides that extend along the longitudinal direction (direction Y). To produce the sheet-like article 1 shown in FIG. 7, the sheet-like article 1 can be formed by using a rotary die in which cutter blades that extend parallel to the axial direction of the roller are arranged at intervals in the circumferential direction of the rotary die as well as a receiving roller, and supplying the base material sheet 20 between the rotary die and the receiving roller.

[0065]

Moreover, in the sheet-like article 1, the absorbent units 4 may also be arranged such that the absorbent units 4’s longitudinal directions(directions Y) are oriented in a plurality of directions. An example of the sheet-like article 1 in which the absorbent units 4 are arranged such that their longitudinal directions (directions Y) are oriented in a plurality of directions is a form in which the sheet-like article 1 has regions in which a plurality of absorbent units 4 are arranged such that their longitudinal directions (directions Y) are oriented in the longitudinal direction (direction Y) of the sheet-like article 1, on both lateral sides of the sheet-like article 1 that extend along the longitudinal direction (direction Y), and a region in which a plurality of absorbent units 4 are arranged such that their longitudinal directions (directions Y) are oriented in the lateral direction (direction X) of the sheet-like article 1, in a central portion that is sandwiched between the two lateral sides. A sheet-like article 1 such as that described above, in which the absorbent units 4 are arranged such that their longitudinal directions (directions Y) are oriented in a plurality of directions, can be formed by, for example, cutting both lateral sides, which extend along the conveyance direction (direction Yl), of the base material sheet 20 that is conveyed, at a plurality of positions using the plurality of cutter blades 111a and the receiving roller 112, and then cutting the central portion in the direction (direction XI) that is orthogonal to the conveyance direction (direction Yl), of the base material sheet 20 that is conveyed, at a plurality of positions using cutting rollers that are arranged at intervals in the circumferential direction and a receiving roller.

[0066]

Moreover, in the above-described sheet-like article 1 shown in FIG. 1, the absorbent units 4 and the long base portions 2 extend in straight lines substantially parallel to the longitudinal direction (direction Y). However, irrespective of the shapes that the absorbent units 4 and the long base portions 2 have, it is sufficient that the absorbent units 4 and the long base portions 2 extend in the longitudinal direction (direction Y). For example, the absorbent units 4 and the long base portions 2 may extend while repeatedly drawing S-shapes in the longitudinal direction (direction Y), or may extend in a serrated manner in the longitudinal direction (direction Y).

[0067]

Moreover, the above-described method for producing the sheet-like article 1 according to the present embodiment includes the adhesive application step as a step downstream of the cutting step and the water-absorbent polymer spreading step as a step downstream of the adhesive application step; however, in the case where napping is performed on the surface on the first side of the base material sheet 20, the adhesive application step can be replaced with the napping step. Such a napping step can be provided as a step upstream of the cutting step. For example, the method disclosed in JP 2012-092476A or the method disclosed in JP 2013-028891A can be used as the napping method.

[0068]

With regard to the foregoing embodiments, the following sheet-like articles will be further disclosed.

[0069] < 1 > A sheet-like article for an absorbent article, comprising a plurality of absorbent units each including a long base portion that has a lateral direction, a longitudinal direction that is longer than the lateral direction, and a thickness direction, and water-absorbent polymer particles that are fixed to a surface on a first side of the long base portion, the absorbent units being arranged such that the absorbent unit’s longitudinal directions are oriented at least in one direction, wherein, before the water-absorbent polymer particles absorb liquid, the waterabsorbent polymer particles are fixed to the surface on the first side of the long base portions and also fixed to lateral side edge portions of the long base portions, extending along the longitudinal direction.

[0070] <2> The sheet-like article as set forth in clause 1, wherein the sheet-like article comprises, on both ends of the sheet-like article in the longitudinal direction, non-slit regions in which a plurality of the long base portions are connected together in the lateral direction, and the water-absorbent polymer particles are not disposed in the non-slit regions. <3 > The sheet-like article as set forth in clause 1 or 2, wherein both ends of the sheetlike article in the longitudinal direction are fixed to the absorbent article.

<4> The sheet-like article as set forth in any one of clauses 1 to 3, wherein, in a plan view of the sheet-like article, the water-absorbent polymer particles are fixed in an unevenly distributed manner, and a distance between both lateral side edge portions, which extend along the longitudinal direction, of each of the long base portions is relatively short in a portion where a weight of the water-absorbent polymer fixed per unit area is relatively large.

< 5 > The sheet-like article as set forth in any one of clauses 1 to 4, wherein, before the water-absorbent polymer particles absorb liquid, the water-absorbent polymer particles are also fixed to a surface on a second side of each of the long base portions.

[0071] <6> The sheet-like article as set forth in any one of clauses 1 to 5, wherein no interposed material is present between the absorbent units that are adjacent to each other in the lateral direction of the long base portions.

< 7 > The sheet-like article as set forth in any one of clauses 1 to 6, wherein the absorbent units are not enveloped in an interposed material.

<8> The sheet-like article as set forth in any one of clauses 1 to 7, wherein the absorbent units are each formed into a rectangular shape that is elongated in the longitudinal direction, and the absorbent units each have a length Lx between 0.5 mm and 10 mm inclusive and preferably between 1 mm and 5 mm inclusive in the lateral direction.

< 9 > The sheet-like article as set forth in any one of clauses 1 to 8, wherein the absorbent units each have a length Ly in the longitudinal direction that is between 20 times and 200 times inclusive and preferably between 40 times and 80 times inclusive a length Lx of each absorbent unit in the lateral direction.

< 10 > The sheet-like article as set forth in any one of clauses 1 to 9, wherein the absorbent units each have a length Ly between 10 mm and 500 mm inclusive and preferably between 200 mm and 400 mm inclusive in the longitudinal direction.

< 11 > The sheet-like article as set forth in any one of clauses 1 to 10, wherein a relation in magnitude between a width W2 of each of the long base portions and a length Lx of each of the absorbent units in the lateral direction is 0 mm < (Lx-W2) <1.4 mm and preferably 0.2 mm < (Lx-W2) < 1 mm.

[0072] < 12> The sheet-like article as set forth in any one of clauses 1 to 11, wherein the sheet-like article in a state before use is formed into a rectangular shape that is elongated in the longitudinal direction, and the sheet-like article has a length between 100 mm and 1000 mm inclusive in the longitudinal direction and a length between 50 mm and 300 mm inclusive in the lateral direction.

< 13 > The sheet-like article as set forth in any one of clauses 1 to 12, wherein the sheet-like article in a state before use has an absorption region in which a plurality of the absorbent units are arranged in such a manner as to be oriented in at least one direction, and in a plan view of the sheet-like article in the state before use, a ratio of the absorption region to the entire sheet-like article is not less than 20% and preferably not less than 50% and not more than 100% and preferably not more than 90%.

< 14> The sheet-like article as set forth in any one of clauses 1 to 13, wherein the absorbent units are arranged such that the absorbent unit’s longitudinal directions are oriented in the longitudinal direction of the sheet-like article, and the number of the absorbent units that are arranged per one said sheet-like article is not less than 3 and preferably not less than 50 and not more than 1000 and preferably not more than 500.

< 15 > The sheet-like article as set forth in any one of clauses 1 to 13, wherein the absorbent units are arranged such that the absorbent unit’s longitudinal directions are oriented in the lateral direction of the sheet-like article, and the number of the absorbent units that are arranged per one said sheet-like article is not less than 3 and preferably not less than 50 and not more than 3500 and preferably not more than 2000.

<16> The sheet-like article as set forth in any one of clauses 1 to 14, wherein, in the sheet-like article in a state before use, a plurality of the absorbent units are arranged such that the plurality of absorbent unit’s longitudinal directions are oriented in the longitudinal direction of the sheet-like article, and the plurality of absorbent units are arranged in such a manner as not to intersect with one another.

[0073] < 17> The sheet-like article as set forth in any one of clauses 1 to 16, wherein the sheet-like article comprises, on both ends of the sheet-like article in the longitudinal direction, non-slit regions in which a plurality of the long base portions are connected together in the lateral direction, and when the sheet-like article is used for an absorbent article, the both ends of the sheet-like article in the longitudinal direction are fixed to the absorbent article.

< 18> The sheet-like article as set forth in any one of clauses 1 to 17, wherein a ratio of a width W2 of each of the long base portions to a width W1 of the sheet-like article is not less than 0.001 and preferably not less than 0.002 and not more than 0.200 and preferably not more than 0.040.

< 19> The sheet-like article as set forth in any one of clauses 1 to 18, wherein the long base portions each have a width W2 not less than 0.3 mm and preferably not less than 0.6 mm and not more than 10 mm, preferably not more than 2.0 mm, and more preferably not more than 1.8 mm, and specifically, preferably between 0.3 mm and 10 mm inclusive. <20> The sheet-like article as set forth in any one of clauses 1 to 19, wherein the long base portions constituting the respective absorbent units are formed from a hydrophilic sheet.

<21 > The sheet-like article as set forth in any one of clauses 1 to 20, wherein the long base portions constituting the respective absorbent units are formed from a nonwoven fabric.

[0074] <22> The sheet-like article as set forth in any one of clauses 1 to 21, wherein the waterabsorbent polymer particles of the sheet-like article are fixed onto the long base portions via an adhesive.

<23 > The sheet-like article as set forth in any one of clauses 1 to 22, wherein, when the sheet-like article is used for an absorbent article, after the water-absorbent polymer particles that are fixed to the lateral side edge portions, which extend along the longitudinal direction, of the long base portions have swelled as a result of absorbing a liquid, a position of each of the long base portions in the thickness direction is different from the position of that long base portion before absorbing the liquid.

<24> The sheet-like article as set forth in any one of clauses 1 to 23, wherein, in the sheet-like article in a state after swelling, positions of the long base portions constituting the absorbent units that are adjacent to each other are different from each other in the thickness direction.

<25> The sheet-like article as set forth in any one of clauses 1 to 24, wherein a distance between both lateral side edge portions, which extend along the longitudinal direction, of each of the long base portions is larger than an average particle diameter of the waterabsorbent polymer particles before swelling and smaller than the average particle diameter of the water-absorbent polymer particles after swelling.

[0075] <26> An absorbent member for an absorbent article, comprising:

the sheet-like article as set forth in any one of clauses 1 to 25; and a liquid-permeable core-wrap sheet that covers the sheet-like article.

<27> An absorbent article comprising:

the absorbent member as set forth in clause 26;

a topsheet that is disposed on a skin-facing surface side of the absorbent member;

and a backsheet that is disposed on a non-skin-facing surface side of the absorbent member.

[0076] <28> A method for producing a sheet-like article for an absorbent article, the sheet-like article comprising a plurality of absorbent units each including a long base portion that has a lateral direction, a longitudinal direction that is longer than the lateral direction, and a thickness direction, and water-absorbent polymer particles that are fixed to a surface on a first side of the long base portion, the absorbent units being arranged such that the absorbent unit’s longitudinal directions are oriented at least in one direction, wherein, before the water-absorbent polymer particles absorb liquid, the waterabsorbent polymer particles are fixed to the surface on the first side of the long base portions and also fixed onto lateral side edge portions of the long base portions, extending along the longitudinal direction, the method comprising a cutting step of cutting a base material sheet to form a plurality of the long base portions; a widening step of a widening portion widening a distance between the long base portions that are adjacent to each other, of the plurality of long base portions that have been formed in the cutting step; and an water-absorbent polymer particle spreading step of spreading the water-absorbent polymer particles onto the plurality of long base portions, with the distance between the long base portions that are adjacent to each other having been widened in the widening step.

[0077] <29> The method for producing a sheet-like article as set forth clause 28, comprising an adhesive application step of applying an adhesive as a step upstream of the water-absorbent polymer particle spreading step.

<30> The method for producing a sheet-like article as set forth clause 29, comprising the widening step as a step downstream of the cutting step, the adhesive application step as a step downstream of the widening step, and the water-absorbent polymer particle spreading step as a step downstream of the adhesive application step, wherein, in the adhesive application step, the adhesive is applied from above the surfaces on the first side of the plurality of long base portions, with the distance between the long base portions that are adjacent to each other having been widened in the widening step, to thereby apply the adhesive to the first side and the lateral side edge portions of each of the long base portions; and in the water-absorbent polymer particle spreading step, the water-absorbent polymer particles are spread from above the surfaces on the first side of the plurality of long base portions to thereby form the sheet-like article in which the waterabsorbent polymer particles are fixed to the lateral side edge portions of the long base portions via the adhesive.

Industrial Applicability [0078]

According to the present invention, a sheet-like article that makes the inhibition of swelling unlikely to occur and allows the water-absorbent polymer to exhibit the maximum absorption performance is provided. Moreover, according to the present invention, a method for producing a sheet-like article with which such a sheet-like article can be efficiently produced is provided.

Claims

CLAIMS [Claim l] A sheet-like article for an absorbent article comprising a plurality of absorbent units, each absorbent unit including:

a long base portion having a lateral direction, a longitudinal direction that is longer than the lateral direction, and a thickness direction; and water-absorbent polymer particles that are fixed to a surface on a first side of the long base portion, the absorbent units being arranged such that the absorbent unit’s longitudinal direction is oriented at least in one direction, wherein before the water-absorbent polymer particles absorb a liquid, the water-absorbent polymer particles are fixed to the surface on the first side of the long base portions and also fixed to each long base portion’s lateral side edge portions that extend along the longitudinal direction.
[Claim 2] The sheet-like article according to claim 1, wherein the sheet-like article comprises, on both ends of the sheet-like article in the longitudinal direction, non-slit regions in which a plurality of the long base portions are connected together in the lateral direction, and the water-absorbent polymer particles are not disposed in the non-slit regions.
[Claim 3] The sheet-like article according to claim 1 or 2, wherein both ends of the sheet-like article in the longitudinal direction are fixed to the absorbent article.
[Claim 4] The sheet-like article according to any one of claims 1 to 3, wherein, in a plan view of the sheet-like article, the water-absorbent polymer particles are fixed in an unevenly distributed manner, and a distance between both lateral side edge portions, which extend along the longitudinal direction, of each of the long base portions is relatively short in a portion where a weight of the water-absorbent polymer fixed per unit area is relatively large.
[Claim 5] The sheet-like article according to any one of claims 1 to 4, wherein, before the water-absorbent polymer particles absorb liquid, the water-absorbent polymer particles are also fixed to a surface on a second side of each of the long base portions.
[Claim 6] The sheet-like article according to any one of claims 1 to 5, wherein no interposed material is present between the absorbent units that are adjacent to each other in the lateral direction of the long base portions.
[Claim 7] The sheet-like article according to any one of claims 1 to 6, wherein the absorbent units are not enveloped in an interposed material.
[Claim 8] The sheet-like article according to any one of claims 1 to 7, wherein the absorbent units are each formed into a rectangular shape that is elongated in the longitudinal direction, and the absorbent units each have a length Lx between 0.5 mm and 10 mm inclusive in the lateral direction.
[Claim 9] The sheet-like article according to any one of claims 1 to 8, wherein the absorbent units each have a length Ly in the longitudinal direction that is between 20 times and 200 times inclusive a length Lx of each absorbent unit in the lateral direction.
[Claim 10] The sheet-like article according to any one of claims 1 to 9, wherein the absorbent units each have a length Ly between 10 mm and 500 mm inclusive in the longitudinal direction.
[Claim 11] The sheet-like article according to any one of claims 1 to 10, wherein a relation in magnitude between a width W2 of each of the long base portions and a length

Lx of each of the absorbent units in the lateral direction is 0 mm < (Lx-W2) <1.4 mm.
[Claim 12] The sheet-like article according to any one of claims 1 to 11, wherein the sheet-like article in a state before use is formed into a rectangular shape that is elongated in the longitudinal direction, and the sheet-like article has a length between 100 mm and 1000 mm inclusive in the longitudinal direction and a length between 50 mm and 300 mm inclusive in the lateral direction.
[Claim 13] The sheet-like article according to any one of claims 1 to 12, wherein the sheet-like article in a state before use has an absorption region in which a plurality of the absorbent units are arranged in such a manner as to be oriented in at least one direction, and in a plan view of the sheet-like article in the state before use, a ratio of the absorption region to the entire sheet-like article is between 20% and 100% inclusive.
[Claim 14] The sheet-like article according to any one of claims 1 to 13, wherein the absorbent units are arranged such that the absorbent unit’s longitudinal directions are oriented in the longitudinal direction of the sheet-like article, and the number of the absorbent units that are arranged per one said sheet-like article is between 3 and 1000 inclusive.
[Claim 15] The sheet-like article according to any one of claims 1 to 13, wherein the absorbent units are arranged such that the absorbent unit’s longitudinal directions are oriented in the lateral direction of the sheet-like article, and the number of the absorbent units that are arranged per one said sheet-like article is between 3 and 3500 inclusive.
[Claim 16] The sheet-like article according to any one of claims 1 to 14, wherein, in the sheet-like article in a state before use, a plurality of the absorbent units are arranged such that the plurality absorbent unit’s longitudinal directions are oriented in the longitudinal direction of the sheet-like article, and the plurality of absorbent units are arranged in such a manner as not to intersect with one another.
[Claim 17] The sheet-like article according to any one of claims 1 to 16, wherein the sheet-like article comprises, on both ends of the sheet-like article in the longitudinal direction, non-slit regions in which a plurality of the long base portions are connected together in the lateral direction, and when the sheet-like article is used for an absorbent article, the both ends of the sheet-like article in the longitudinal direction are fixed to the absorbent article.
[Claim 18] The sheet-like article according to any one of claims 1 to 17, wherein a ratio of a width W2 of each of the long base portions to a width W1 of the sheet-like article is between 0.001 and 0.200 inclusive.
[Claim 19] The sheet-like article according to any one of claims 1 to 18, wherein the long base portions each have a width W2 between 0.3 mm and 10 mm inclusive.
[Claim 20] The sheet-like article according to any one of claims 1 to 19, wherein the long base portions constituting the respective absorbent units are formed from a hydrophilic sheet.
[Claim 21] The sheet-like article according to any one of claims 1 to 20, wherein the long base portions constituting the respective absorbent units are formed from a nonwoven fabric.
[Claim 22] The sheet-like article according to any one of claims 1 to 21, wherein the water-absorbent polymer particles of the sheet-like article are fixed onto the long base portions via an adhesive.
[Claim 23] The sheet-like article according to any one of claims 1 to 22, wherein, when the sheet-like article is used for an absorbent article, after the water-absorbent polymer particles that are fixed to the lateral side edge portions, which extend along the longitudinal direction, of the long base portions have swelled as a result of absorbing a liquid, a position of each of the long base portions in the thickness direction is different from the position of that long base portion before absorbing the liquid.
[Claim 24] The sheet-like article according to any one of claims 1 to 23, wherein, in the sheet-like article in a state after swelling, positions of the long base portions constituting the absorbent units that are adjacent to each other are different from each other in the thickness direction.
[Claim 25] The sheet-like article according to any one of claims 1 to 24, wherein a distance between both lateral side edge portions, which extend along the longitudinal direction, of each of the long base portions is larger than an average particle diameter of the water-absorbent polymer particles before swelling and smaller than the average particle diameter of the water-absorbent polymer particles after swelling.
[Claim 26] An absorbent member for an absorbent article, comprising: the sheet-like article according to any one of claims 1 to 25; and a liquid-permeable core-wrap sheet that covers the sheet-like article.
[Claim 27] An absorbent article comprising:

the absorbent member according to claim 26;

a topsheet that is disposed on a skin-facing surface side of the absorbent member;

and a backsheet that is disposed on a non-skin-facing surface side of the absorbent member.
[Claim 28] A method for producing a sheet-like article for an absorbent article, the sheet-like article comprising a plurality of absorbent units each including a long base portion that has a lateral direction, a longitudinal direction that is longer than the lateral direction, and a thickness direction, and water-absorbent polymer particles that are fixed to a surface on a first side of the long base portion, the absorbent units being arranged such that the absorbent unit’s longitudinal directions are oriented at least in one direction, wherein, before the water-absorbent polymer particles absorb liquid, the waterabsorbent polymer particles are fixed to the surface on the first side of the long base portions and also fixed onto lateral side edge portions of the long base portions, extending along the longitudinal direction, the method comprising a cutting step of cutting a base material sheet to form a plurality of the long base portions; a widening step of a widening portion widening a distance between the long base portions that are adjacent to each other, of the plurality of long base portions that have been formed in the cutting step; and an water-absorbent polymer particle spreading step of spreading the water-absorbent polymer particles onto the plurality of long base portions, with the distance between the long base portions that are adjacent to each other having been widened in the widening step.
[Claim 29] The method for producing a sheet-like article according to claim 28, comprising an adhesive application step of applying an adhesive as a step upstream of the water-absorbent polymer particle spreading step.
[Claim 30] The method for producing a sheet-like article according to claim 29, comprising the widening step as a step downstream of the cutting step, the adhesive application step as a step downstream of the widening step, and the water-absorbent polymer particle spreading step as a step downstream of the adhesive application step, wherein, in the adhesive application step, the adhesive is applied from above the surfaces on the first side of the plurality of long base portions, with the distance between the long base portions that are adjacent to each other having been widened in the widening step, to thereby apply the adhesive to the first side and the lateral side edge portions of each of the long base portions; and in the water-absorbent polymer particle spreading step, the water-absorbent polymer particles are spread from above the surfaces on the first side of the plurality of long base portions to thereby form the sheet-like article in which the waterabsorbent polymer particles are fixed to the lateral side edge portions of the long base portions via the adhesive.