JP2021083939A - Absorbent article - Google Patents

Abstract

To provide an absorbent article that is thin and light-weight but has excellent body fluid absorbability.SOLUTION: An absorbent article 1 comprises: a liquid permeable top sheet 10; a liquid impermeable back sheet 13; and an absorption layer 12 therebetween. The absorption layer 12 includes a fiber assembly made from tow and a highly absorbent polymer supported therein. The absorbent article comprises compound type nonwoven fabric 11 that wraps the absorption layer 12 as a whole. The nonwoven fabric 11 is obtained by integrating spunbond nonwoven fabric with a pulp fiber web layer and has at least one aperture 11a facing the top sheet 10 on each of positions that are between the top sheet 10 and the absorption layer 12, are at an approximately center part in a width direction, and are close to both ends in a longer direction. A distance between the center side end in the longer direction of the aperture 11a and an excretion part enter is shorter than a distance between the excretion part enter and a side end part in the width direction of the absorption body 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to absorbent articles.

Absorbent articles such as light incontinence products and urine absorbing pads are generally composed of a liquid permeable top sheet, a liquid permeable back sheet, and an absorbent layer arranged between the top sheet and the back sheet. Has been done. Body fluids such as urine are absorbed by the absorption layer through the top sheet.

As the absorbent layer, an embodiment including an absorbent core containing a fluff pulp and a super absorbent polymer (hereinafter, also referred to as “SAP”) and a carrier sheet such as crepe paper wrapping the absorbent core is provided. Widely known. Such an absorbent layer is a manufacturing method including a step of producing an absorbent core by stacking fluff pulp short fibers and SAP on a fiber stacking drum, and a step of wrapping the obtained absorbent core with a carrier sheet. Made in. These absorption layers are known as absorption layers having relatively high rigidity.

On the other hand, it has been proposed to use a fiber aggregate composed of tow, which is obtained by opening a tow (fiber bundle) composed of filamentous long fiber webs, as an absorption layer instead of a fluff pulp short fiber product. There is. By using a fiber aggregate made of tow instead of the fluff pulp short fibers, an absorption layer having excellent flexibility and flexibility can be obtained. When such an absorbent layer is provided, it becomes less noticeable that the absorbent article is worn under the clothes, and the fit of the absorbent article is also improved.

Absorbent articles are widely used in society, but in recent years, it is not noticeable that absorbent articles are worn under clothes, and there is no discomfort (feeling of wearing) when wearing them, and absorption with good fit. Sexual goods are especially sought after in the market for active users. As one of the means for meeting these demands, various absorbent articles using an absorbent layer containing a fiber aggregate made of tow have been proposed.

For example, in Patent Document 1, an absorption layer containing a fiber aggregate composed of tow and SAP particles is used, and the absorption layer corresponds to a main absorption portion corresponding to a crotch portion and a secondary absorption corresponding to both sides of the crotch portion. An absorbent article is disclosed in which the SAP particles of the slave-absorbing portion have a smaller basis weight than the main absorbing portion, and the slave-absorbing portion flexibly fits around the legs.

Further, in Patent Document 2, a fiber aggregate composed of tow, an absorption layer having SAP particles contained in the aggregate, and an absorption layer provided on the back surface (non-skin) side of the absorption layer are provided from the aggregate. An absorbent article comprising a holding sheet for holding the escaped SAP particles is disclosed.

JP-A-2007-268218 Japanese Unexamined Patent Publication No. 2006-149674

However, when the absorbent article is made thinner and lighter in the manner described in Patent Documents 1 and 2, the absorbency must be sacrificed to some extent. In particular, light incontinence products and urine absorbing pads with a small absorption layer area do not maintain sufficient absorbency. Therefore, even if the fiber aggregate made of tow and the absorption layer containing SAP particles are used to reduce the thickness and weight, the absorption performance is maintained at a high level, and the body fluid such as urine is absorbed to increase the weight. There is a demand from the market for an absorbent article that does not cause twisting even when worn in a worn state and has excellent wearing comfort and fit.

An object of the present invention is to provide an absorbent article which is thin and lightweight and has excellent absorption of body fluids.

As a result of intensive research to solve the above problems, the present inventor has succeeded in obtaining an absorbent article satisfying the purpose, and has completed the present invention.
The present invention provides, as a preferred embodiment, the absorbent articles (1) to (9) below.
(1) An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbing layer provided between the top sheet and the back sheet.
The absorbent layer further comprises a composite non-woven fabric containing a fiber aggregate made of tow and a highly absorbent polymer fixedly supported inside the fiber aggregate made of tow, and wraps the absorbent layer as a whole. The composite non-woven fabric is an integral product of a spunbonded non-woven fabric and a pulp fiber web layer, and is located at a substantially central portion in the width direction of the absorbent article in a region interposed between the top sheet and the absorbent layer. At least one opening is provided at substantially both ends of the absorbent article in the longitudinal direction to expose the absorbent layer toward the top sheet, and the end portion on the central side in the longitudinal direction of the opening is provided. An absorbent article, characterized in that the distance from the center of the excretory part is shorter than the distance between the center of the excretion part and the side end in the width direction of the absorber.
(2) The composite non-woven fabric is an integral product of a spunbonded nonwoven fabric and a pulp fiber web layer, and the basis weight of the spunbonded nonwoven fabric is 7 g / m ² or more and 20 g / m ² or less, and the basis weight of the pulp fiber web. Is 30 g / m ² or more and 70 g / m ² or less, and the ratio of the spunbonded non-woven fabric to the pulp fiber web layer (weight of the spunbonded non-woven fabric / weight of the pulp fiber web layer) is 40/60 or more and 10/90 or less. An absorbent article according to (1) above.
(3) The absorbent article according to (1) or (2) above, wherein the opening is a substantially rectangular shape extending in a strip shape in the longitudinal direction of the absorbent article.
(4) Any of the above (1) to (3), wherein the pair or a plurality of pairs of openings provided at substantially both ends of the absorbent article in the longitudinal direction are symmetrical in the longitudinal direction, respectively. Absorbent article.
(5) The absorbent article according to any one of (1) to (4) above, wherein the size of the opening is 5 mm or more and 100 mm or less in the width direction of the absorbent article.
(6) The dimension of the opening in the longitudinal direction of the absorbent article is 20% or more and 80% or less of the maximum dimension of the absorbent layer, and the dimension of the opening in the width direction of the absorbent article. However, the absorbent article according to any one of (1) to (5) above, which is 20% or more and 80% or less of the maximum dimension of the absorbent layer.
(7) The composite nonwoven fabric encloses the absorbent layer as a whole so that the pulp fiber web layer faces and / or touches the absorbent layer, any of the above (1) to (6). Absorbent article.
(8) The composite non-woven fabric is an integrated product in which at least a part of pulp fibers contained in the pulp fiber web layer is entwined on one surface of the spunbonded non-woven fabric, and a part of the pulp fibers is spunbonded. The absorbent article according to any one of (1) to (7) above, which has a structure exposed on the other surface of the non-woven fabric.
(9) The material of the spunbonded non-woven fabric is one or more selected from the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, and polystyrene (1) to (8). Any of the absorbent articles.

According to the present invention, it is possible to provide an absorbent article which is thin and lightweight and has excellent absorption of body fluids.

It is a schematic diagram which shows the structure of the absorbent article which is 1st Embodiment of this invention. (A) is a schematic plan view seen from the top sheet side. (B) is a schematic cross-sectional view in _X 1 -X ₁ section line (a). (C) is a schematic cross-sectional view in _X 2 -X ₂ section line (a). It is a schematic diagram which shows the structure of the absorbable article which is the 2nd Embodiment of this invention. (A) is a schematic plan view seen from the top sheet side. (B) is a schematic cross-sectional view in _X 3 -X ₃ cut lines (a). It is a schematic diagram which shows the structure of the absorbable article which is the 3rd Embodiment of this invention. (A) is a schematic plan view seen from the top sheet side. (B) is a schematic cross-sectional view along _X 4 -X ₄ cutting line in (a). It is a schematic diagram explaining the effect of the absorbent article of 1st Embodiment. (A) is a schematic perspective view. (B) is a schematic cross-sectional view in the width direction. It is a drawing explaining the method of measuring the support rate of a highly absorbent polymer on a fiber assembly composed of tow.

Hereinafter, the absorbent articles 1, 2 and 3 of the present embodiment will be described in detail with reference to the drawings. 1A and 1B are schematic views showing the configuration of the absorbent article 1 according to the first embodiment, FIG. 1A is a schematic plan view seen from the top sheet 10 side, and FIG. 1B is FIG. 1A. ) Is a schematic cross-sectional view in the width direction at the _{X 1-} X ₁ cutting line, and FIG. 1 (c) is a schematic cross-sectional view in the width direction at the _{X 2-} X _{2 cutting line in FIG. 1 (a).} 2A and 2B are schematic views showing the configuration of the absorbent article 2 according to the second embodiment, FIG. 2A is a schematic plan view seen from the top sheet 10 side, and FIG. 2B is FIG. 2A. ) Is a schematic cross-sectional view in the width direction at the X _{3- X 3 cutting line.} FIG. 3 is a schematic view showing the configuration of the absorbent article 3 according to the third embodiment. 3 (a) is a schematic plan view as viewed from the top sheet 10 side, FIG. 3 (b) is a schematic sectional view in the width direction of the _X 4 -X ₄ section line of FIG. 3 (a). 4A and 4B are schematic views for explaining the effect of the absorbent article 1, FIG. 4A is a schematic perspective view, and FIG. 4B is a schematic cross-sectional view in the width direction. Note that FIG. 4 shows the configuration of the main part of the absorbent article 1 of the first embodiment. Further, each figure does not define the magnitude relationship of the dimensions in the longitudinal direction and the width direction of each of the constituent members of the absorbent articles 1, 2, and 3.

In the present specification, when the absorbent articles 1, 2 and 3 are worn, it means at least one of the absorbent articles 1, 2 and 3 when and after being worn. Wearing refers to a state in which absorbent articles 1, 2, and 3 are worn on the body. The absorbent articles 1, 2 and 3 are usually worn on the body inside the clothing, but the absorbent articles 1, 2 and 3 are worn on the body so that at least a part of the absorbent articles 1, 2 and 3 is exposed to the outside. You may. The longitudinal direction of the absorbent articles 1, 2 and 3 is a direction extending in the front-rear direction of the body through the crotch portion of the wearer when the absorbent articles 1, 2 and 3 are worn, and is indicated by reference numeral Y in the figure. The width directions of the absorbent articles 1, 2, and 3 are directions (width directions) substantially orthogonal to the longitudinal direction, and are indicated by reference numerals X in the drawings. The thickness direction of the absorbent articles 1, 2 and 3 is the stacking direction of each member such as the top sheet 10, the absorbent layer 12 coated with the composite non-woven fabric 11, and the back sheet 13, and is indicated by reference numeral Z in the drawing. The skin side surface is a surface that comes into contact with the wearer's skin or faces the wearer's skin when worn, out of the front and back surfaces of each member of the absorbent articles 1, 2, and 3, and the non-skin side surface is a non-skin side surface. Of the front and back surfaces of each of the absorbent articles 1, 2, and 3, the surface that comes into contact with the wearer's clothing when worn or the surface that faces the wearer's clothing. Body fluid refers to the liquid excreted from the body such as urine, blood, and water in loose stool.

Examples of the absorbent articles 1, 2 and 3 include, but are not limited to, light incontinence pads, pants-type disposable diapers, tape-stopping disposable diapers, etc., regardless of whether they are for babies or adults. It may be a sex article. Further, various paper diapers as an outer and an absorbent article 1 as an inner can be used in combination.

[Absorbent article]
The absorbent article 1 of the present embodiment shown in FIG. 1 includes a liquid-permeable top sheet 10 located on the skin side when worn, a liquid-impermeable back sheet 13 located on the non-skin side when worn, and a top sheet. An absorption layer 12 provided between the 10 and the back sheet 13 and entirely covered with the composite non-woven fabric 11 and a three-dimensional gather 14 are provided. Here, the composite non-woven fabric 11 is an integral product of a spunbonded non-woven fabric (not shown) and a pulp fiber web layer (not shown), and the basis weight of the spunbonded non-woven fabric is preferably 7 g / m ² or more and 20 g / m ^2. Hereinafter, the basis weight of the pulp fiber web is preferably 30 g / m ² or more and 70 g / m ² or less, and the ratio of the spunbonded non-woven fabric to the pulp fiber web layer (spunbonded non-woven fabric weight / pulp fiber web layer weight) is preferably 40. It is / 60 or more and 10/90 or less. Further, the composite nonwoven fabric 11 is a substantially central portion in the width direction (a central portion in the width direction and a region near the center portion in the width direction) in a region interposed between the top sheet 10 and the absorption layer 12, and is in the longitudinal direction. Each of the openings 11a for exposing the absorption layer 12 toward the top sheet 10 is provided at substantially both ends (regions around both ends). Further, the distance a from the excretion portion center 26 at the central end portion in the longitudinal direction of the opening 11a is shorter than the distance b between the excretion portion center 26 and the widthwise side end portion of the absorption layer 12. In this specification, the same members are designated by the same reference numerals, and the description thereof will be omitted.

The dimensions of the absorbent article 1 in the longitudinal direction and the width direction are not particularly limited, but are, for example, 100 mm or more and 800 mm or less, and 50 mm or more and 500 mm or less, respectively. By adjusting the dimensions of the absorbent article 1 within the above range, an absorbent article 1 suitable for a light incontinence pad, a pants-type disposable diaper, a tape-stopping disposable diaper, or the like can be obtained. The dimensions in the longitudinal direction and the width direction described above can also be applied to the absorbent articles 2 and 3.

Although the absorption layer 12 in which the highly absorbent polymer is fixed and / or supported on the fiber aggregate composed of tow, which is also used in the present embodiment, has excellent body fluid absorption, the fiber aggregate composed of tow contains body fluid. It has the characteristics that it is easy to diffuse in the longitudinal direction (direction in which the fibers are aligned) and it is difficult to diffuse the body fluid in the width direction. Therefore, the absorption layer 12 has a problem that the body fluid diffusibility is not sufficient. As a result of intensive research to solve this problem, the present inventor has the above-mentioned structure on the top sheet 10 side of the absorption layer 12, and is a composite non-woven fabric that easily diffuses body fluids in the longitudinal direction and the width direction. It was found that by arranging 11, the above-mentioned problems of the absorption layer 12 were solved, and the diffusivity of the body fluid was improved as a whole. However, the combination of the composite non-woven fabric 11 and the absorbent layer 12 alone has a large amount with respect to the substantially central region (the central portion in the longitudinal direction and the width direction and its vicinity) of the absorbent layer 12 mainly facing the excretory portion of the wearer. Further research by the present inventor shows that when the body fluid is discharged vigorously, the body fluid is momentarily shielded by the composite non-woven fabric 11 and is not efficiently absorbed by the absorption layer 12, leading to lateral leakage. Turned out by.

As a result of further research based on the above-mentioned findings, the present inventor of the composite type non-woven fabric 11 covers the absorption layer 12 entirely with the composite type non-woven fabric 11 and then mainly faces the excretory part of the wearer. Not the central region of the side surface of the top sheet 10, but both sides in the longitudinal direction of the central region, that is, both ends of the side surface of the top sheet 10 in the longitudinal direction are provided with openings 11a in which the absorption layer 12 is directly exposed toward the top sheet 10. As shown in FIG. 4A, the distance a from the excretion portion center 26 at the longitudinal central end of the opening 11a is the distance b between the excretion center 26 and the widthwise end of the absorption layer 12. By making it shorter than, unexpectedly, the body fluid diffusivity of the absorption layer 12 is remarkably improved, and the body fluid is more quickly drawn into the fiber aggregate composed of the tow in the absorption layer 12. , Found that body fluids diffuse and are absorbed in both the longitudinal and width directions.

Here, as shown in FIGS. 4 (a) and 4 (b), which are schematic views showing the configuration of the main part of the absorbent article 1 (the side surface of the top sheet 10 of the composite non-woven fabric 11 and the absorbing layer 12), absorption is performed. Due to the action of the two openings 11a, the body fluid absorbed by the layer 12 efficiently and temporally becomes concentric circles 25 at substantially the same diffusion rate in all directions from the central portion in the longitudinal direction and the width direction of the absorption layer 12. It becomes easy to diffuse, and both absorption rate and diffusivity are achieved at a high level. Further, the length of the opening 11a is before the body fluid that has been vigorously discharged and temporarily accumulated in the shape of a water pool on the skin side surface (the surface on the top sheet 10 side) of the composite non-woven fabric 11 reaches the widthwise end portion of the absorption layer 12. Lateral leakage is prevented because it reaches the central end in the direction, is absorbed by the lower absorption layer 12, and is then efficiently diffused in the longitudinal direction. As a result, by using the absorbent layer 12 wrapped with the composite non-woven fabric 11 and forming the opening 11a with respect to the composite non-woven fabric 11, the thin and lightweight body fluid is excellently absorbed and lateral leakage is remarkably prevented. Absorbent article 1 can be provided. The same effect can be obtained with the absorbent articles 2 and 3 described later.
Hereinafter, each of the sheet-shaped or plate-shaped constituent members will be described in detail step by step. In addition, each constituent member may have a three-dimensional shape other than a sheet shape and a plate shape.

(Top sheet)
In the present embodiment, the top sheet 10 is provided so as to cover the entire surface of the composite nonwoven fabric 11 that totally covers the absorbent layer 12 on the top sheet 10 side. The top sheet 10 is composed of a base material having a liquid permeability such that the body fluid moves to the absorption layer 12 via the composite non-woven fabric 11. Examples of the liquid-permeable base material for the top sheet include non-woven fabrics such as air-through non-woven fabrics, thermal bond non-woven fabrics, and spunbond non-woven fabrics, composite non-woven fabrics in which the same or different kinds of non-woven fabrics such as thermal bond / spunbond are laminated, urethane foam, and polyethylene. Examples thereof include a foamed film made of foam and the like, a composite sheet which is a laminate of two or more of these, and the like. Among these, a thermal bond non-woven fabric, a spunbond non-woven fabric, a thermal bond / spunbond composite non-woven fabric, and the like are preferable from the viewpoints of transferability of the body fluid to the absorption layer 12, diffusivity of the body fluid in the absorbent article 1, and the like.

The surface of the top sheet 10 may be embossed or perforated, for example, in order to improve liquid permeability. The embossing and drilling can be carried out by a known method without limitation. Further, in order to reduce irritation to the skin, the top sheet 10 may contain a lotion, an antioxidant, an anti-inflammatory component, a pH adjuster, an antibacterial agent, a moisturizer and the like.

The basis weight of the top sheet 10 of the present embodiment is not particularly limited, but is preferably ^{18 g / m 2} or more and 40 g / m ^{2 or less from the viewpoint of strength, workability and liquid return amount.} The shape of the top sheet 10 is not particularly limited, but may be any shape that covers the absorption layer 12, which is required to guide the body fluid to the absorption layer 12 so as not to leak.

(Composite non-woven fabric)
In the present embodiment, the composite non-woven fabric 11 encloses the absorbent layer 12 as a whole. Here, wrapping as a whole means that the skin side surface, the non-skin side surface, and the side surface of the absorption layer 12 are all covered with the composite non-woven fabric 11 except for the opening 11a described later. The composite non-woven fabric 11 of the present embodiment may be in a form in which the absorbent layer 12 is wrapped in the composite non-woven fabric 11 (however, the packaging form is not limited), and the composite non-woven fabric 11 is specified according to the three-dimensional shape of the absorbent layer 12. The absorbent layer 12 may be stored in a box-shaped composite non-woven fabric 11 which is molded into a bag shape and the absorbent layer 12 is stored therein. Further, when the absorbent layer 12 is wrapped with the composite non-woven fabric 11, it is preferable that the pulp fiber web layer described later faces the absorbent layer 12 and / or is in contact with the absorbent layer 12. As a result, the effect of suppressing the displacement and movement of the absorbent layer 12, particularly the highly absorbent polymer, can be obtained.

In the composite non-woven fabric 11 of the present embodiment, a region in which the surface of the top sheet 10 side (skin side surface, hereinafter referred to as "top sheet side surface") is interposed between the top sheet 10 of the composite non-woven fabric 11 and the absorbent layer 12. It can also be said. Further, on the side surface of the top sheet of the composite non-woven fabric 11, when the absorbent article 1 is worn, the region from one end to the center in the longitudinal direction mainly faces the front side of the body, and the other end from the center in the longitudinal direction. The area up to is mainly facing the posterior side of the body. Therefore, in the present specification, the region facing the front side of the body is indicated by the anterior region (the region indicated by "front" in FIG. 4), and the region facing the rear side of the body is indicated by the posterior region (indicated by "rear" in FIG. Area). Here, the front side region and the rear side region are referred to as a longitudinal center line on the side surface of the top sheet (a virtual center line extending equidistant from both ends of the surface in the longitudinal direction in the width direction, hereinafter simply referred to as a "longitudinal center line". It is almost symmetrical with respect to (referred to as), and has almost equidistant area, preferably almost equidistant area and almost the same shape.

In the composite nonwoven fabric 11 of the present embodiment, on the side surface of the top sheet, the absorbing layer 12 is exposed toward the top sheet 10 at the central portion in the width direction and the vicinity thereof in the width direction, at both ends in the longitudinal direction and the periphery thereof. It has one opening 11a each. That is, the composite nonwoven fabric 11 has a pair of openings 11a in the front region and the posterior region on the side surface of the top sheet. The two openings 11a are substantially rectangular regions extending in a strip shape in the longitudinal direction, and are formed at positions substantially symmetrical with respect to the center line in the longitudinal direction (positions symmetrical to the left and right). It is considered that such symmetry of the opening 11 contributes to the substantially uniform diffusion of the body fluid, and the diffusion of the concentric 25-shaped body fluid shown in FIG. 4 can be realized. Further, it is preferable that the outer edges of the two openings 11a in the longitudinal direction are separated from one edge and the other edge of the side surface of the top sheet in the longitudinal direction by a predetermined width. As a result, a substantially uniform diffusion of the body fluid into the absorption layer 12 is obtained, and the strength of the composite nonwoven fabric 11 that encloses the absorption layer 12 as a whole is maintained. As described above, the planar shape of the opening 11a of the present embodiment is substantially rectangular (or substantially rectangular), but the present invention is not limited to this, and for example, a square, a circle, an oval, an ellipse, or a rounded corner of a square. It may be a round rectangle or the like.

The dimensions of the opening 11a are not particularly limited. For example, when the maximum dimension of the absorption layer 12 in the longitudinal direction is 50 mm or more and 750 mm or less and the maximum dimension in the width direction is 20 mm or more and 470 mm or less, the longitudinal dimension of the opening 11a is 10 mm. It is preferable that the length is 600 mm or less and the width direction dimension is 5 mm or more and 100 mm or less. As a result, a rectifying action of the body fluid is generated, and uniform and rapid absorption of the body fluid into the absorption layer 12 is likely to occur. Further, the longitudinal dimension of the opening 11a is 20% or more and 80% or less of the longitudinal maximum dimension of the absorption layer 12, and the width direction dimension thereof is 20% or more and 80% or less of the widthwise maximum dimension of the absorption layer 12. It is preferable to have. As a result, the strength of the composite non-woven fabric 11 that wraps the absorbent layer 12 as a whole, the ability to prevent the highly absorbent polymer from falling off from the absorbent layer 12, the morphological stability of the absorbent article 1 and the like are maintained, and the body fluid is absorbed. The diffusibility to the layer can be further enhanced. When a plurality of openings are arranged side by side in the longitudinal direction or the width direction, the total in that direction is defined as the dimensional ratio.

In the composite non-woven fabric 11 of the present embodiment, as described above and as shown in FIG. 4, the distance a from the excretion portion center 26 at the central side end portion in the longitudinal direction of the opening 11a is the excretion portion center 26 and the absorption layer 12. Shorter than the distance to the widthwise end of. That is, in the longitudinal direction, the distance (or the shortest distance) a from the edge of the opening 11a on the center side in the longitudinal direction to the center 26 of the excretion portion is the center of the excretion portion from the side surface of the top sheet or the edge of the absorption layer 12 in the width direction. Each opening 11a is arranged so that it is shorter than the distance (or the shortest distance) b to 26. As a result, the above-mentioned excellent effect can be obtained. Here, the excretion portion center 26 is a region mainly facing the excretion portion in the crotch portion of the wearer, but in order to obtain the effect of the present embodiment, the center in the longitudinal direction on the side surface of the top sheet of the composite nonwoven fabric 11. It can be rephrased as the intersection of the line and the center line in the width direction, or the intersection and the region in the vicinity thereof.

The composite non-woven fabric 11 of the present embodiment is an integral product of a spunbonded non-woven fabric and a pulp fiber web. Here, the fact that the spunbonded non-woven fabric and the pulp fiber web are integrated means that the pulp fibers do not easily fall off from the spunbonded non-woven fabric in normal use. In particular, when the pulp fibers are water-entangled with the spunbonded nonwoven fabric by a water jet, the pulp fibers are very unlikely to fall off from the spunbonded nonwoven fabric. As a preferred embodiment of the integrated product, for example, on one surface of the spunbonded nonwoven fabric, a part of the fibers constituting the spunbonded nonwoven fabric and a part of the pulp fibers constituting the pulp fiber web layer are entangled with each other and spunbonded. Examples thereof include a form in which the non-woven fabric and the pulp fiber web layer are firmly fixed, and a part of the pulp fibers penetrates the spunbonded non-woven fabric in the thickness direction and is exposed on the other surface of the spunbonded non-woven fabric. Such an integral body can be obtained, for example, by the water flow confounding method.

As the spunbonded non-woven fabric contained in the composite non-woven fabric 11, a non-woven fabric produced by a spunbond method, a melt blow method, a flash spinning method or the like can be used without particular limitation, and examples of the material of the fibers constituting the non-woven fabric include, for example. Synthetic resins such as nylon (trade name), vinylon, polyester, acrylic resin, polyethylene, polypropylene, and polystyrene can be preferably used. The spunbonded non-woven fabric is produced by using synthetic resin fibers made of these materials, and may contain a plurality of synthetic resin fibers. The basis weight of the spunbonded non-woven fabric 11 is not particularly limited, but is 7 g / m ² or more and 20 g / m ² or less from the viewpoint of tensile strength and softness of touch.

As the pulp fiber web, a non-woven fabric mainly composed of pulp fibers can be used without particular limitation, and a pulp fiber web formed by spraying pulp fibers on the surface of a spunbonded non-woven fabric by a water flow entanglement method may be used. The pulp fiber used here is not particularly limited, but is preferably softwood bleached kraft pulp (NBKP) such as radiata pine, slash pine, southern pine, lodgepole pine, spruce and Douglas fur. NBKP can be used alone or in combination of two or more. The basis weight of the pulp fiber web is not particularly limited, but is preferably 30 g / m ² or more and 70 g / m ² or less from the viewpoint of uniformity, tactile sensation, absorbability and the like.

The weight composition ratio of the spunbonded nonwoven fabric and the pulp fiber web in the composite nonwoven fabric 11 is preferably (weight of the spunbonded nonwoven fabric / weight of the pulp fiber web), for example, from the viewpoint of absorbability and diffusivity of body liquid. Is 40/60% by weight or more and 10/90% by weight or less.

In the present embodiment, as will be described later, the composite nonwoven fabric 11 may be produced by a water flow confounding method. In the composite non-woven fabric 11, when the water flow entanglement (pulp fiber web) surface of the spunbonded non-woven fabric is arranged so as to face the non-skin side surface, the absorption layer 12 containing a highly absorbent polymer is below the water flow entanglement surface. Is placed. As a result, the unevenness caused by the water jet formed on the confounding surface of the water flow remarkably suppresses the displacement and movement of the absorption layer 12, so that the absorption and absorption rate of the body fluid are maintained at a high level, and after the absorption of the body fluid. The thickness and tactile sensation can be kept more uniform in the longitudinal direction and the width direction, so that the wearing sensation is improved.

Further, with respect to the composite nonwoven fabric 11, the force (tensile strength) required to stretch the test piece formed in a width of 25 mm by 2 mm in the vertical direction in the tensile strength test with Tencilon is not particularly limited, but for example, the absorbent article 1 From the viewpoint of the overall strength of the non-woven fabric and the pullability of the absorbent article 1 at the time of replacement, it is preferably 1.5 N / 25 mm or more and 5.0 N / 25 mm or less.

<Manufacturing method of composite non-woven fabric>
The composite nonwoven fabric 11 of the present embodiment includes, for example, a step of laminating and integrating a spunbonded nonwoven fabric and a pulp fiber web, and pressurizing and / or pressurizing the obtained laminate using a roll or the like as necessary. Alternatively, it can be produced by a production method including a step of heating. Further, the spunbonded non-woven fabric and the pulp fiber web may be integrated by using an adhesive or by sewing. The composite nonwoven fabric 11 can also be obtained by a manufacturing method including a water flow entanglement step of injecting pulp fibers constituting a pulp fiber web together with a water jet (water stream) onto the spunbonded nonwoven fabric. The composite nonwoven fabric 11 may be embossed.

Among the above-mentioned manufacturing methods, a method using a water flow confounding method is preferable from the viewpoint of achieving both softness and strength in appearance and touch. In the water flow entanglement step, the hole diameter Φ of the water jet nozzle for injecting the water jet is preferably 0.06 mm or more and 0.15 mm or less, and the water jet nozzle The interval is preferably 0.4 mm or more and 1.0 mm or less.

(Absorption layer)
As described above, the absorption layer 12 contains a fiber aggregate made of tow and a highly absorbent polymer fixedly supported on the fiber aggregate. The use of these materials greatly contributes to, for example, the absorption performance of the absorbent article 1, weight reduction, thinning, and the like.

The fiber aggregate composed of tow is an aggregate of long fiber filaments (hereinafter, also simply referred to as “long fibers”) in which the tow is opened, and is converged so that the orientation directions of the long fibers are aligned. In the present embodiment, it is preferable to arrange the long fibers so that the orientation direction is the longitudinal direction of the absorbent article 1. For example, by opening a tow of a continuous filament and cutting it to an appropriate length, a fiber aggregate composed of a bundle of long fibers can be produced. As described above, the fiber aggregate composed of tow has a characteristic that the body fluid easily diffuses in the orientation direction of the long fibers.

As the base material of the fiber aggregate composed of tow, natural cellulose derived from cotton or the like, regenerated cellulose such as rayon, cellulose acetate, polyethylene, polypropylene, PET or the like can be used, and among these, it is derived from cotton or the like. It is preferable to use fibers such as natural cellulose, regenerated cellulose such as rayon, and fibers such as cellulose acetate, and it is more preferable to use fibers made of cellulose acetate, which can easily obtain bulkiness and can impart flexibility and flexibility to the absorption layer 12. preferable.

The fineness of the fiber aggregate composed of tow is not particularly limited, but is, for example, 0.1 dtex or more and 10 dtex or less from the viewpoint of ensuring that the absorption layer 12 exhibits desired performance and has sufficient strength for use. All you need is.

Further, in the fiber aggregate composed of tow, when the entanglement between the fibers is weak, it is preferable to use a binder for the purpose of fusing and fixing the entanglement. As the binder, triacetin or the like can be used.

The basis weight of the fiber aggregate composed of tow is preferably 20 g / m ² or more and 100 g / m ² or less. When the basis weight of the fiber aggregate composed of tow is in the above range, a highly absorbent polymer can be supported to such an extent that sufficient absorbability can be ensured, and an absorbent layer 12 having excellent flexibility and flexibility can be obtained. it can. When the basis weight of the fiber aggregate composed of tow ^{exceeds 100 g / m 2} , the degree of compression when reducing the thickness of the absorption layer 12 increases, and the original flexibility and flexibility of the fiber aggregate composed of tow Is not preferable because it tends to be impaired.

The highly absorbent polymer that is fixedly supported on the fiber aggregate composed of tow is not particularly limited as long as it can absorb body fluid and prevent backflow of body fluid, and is, for example, polyacrylic acid salt and polyaspartate. , (Stand-acrylic acid) graft copolymer, (acrylic acid / vinyl alcohol) copolymer, (isobutylene / maleic anhydride) copolymer and polymers containing carboxyl group-containing monomers such as saponified products thereof. Be done. The highly absorbent polymer may be used alone or in combination of two or more. Among these highly absorbent polymers, polyacrylate is preferable, and sodium polyacrylate is more preferable, from the viewpoint of the amount of body fluid absorbed per weight.

Further, it is preferable to use a highly absorbent polymer in the form of particles. The particle size of the highly absorbent polymer particles is not particularly limited, but is preferably 50 μm or more and 1000 μm or less. If it is less than 50 μm, the highly absorbent polymer particles tend to be difficult to fall off from the absorption layer 12, and if it exceeds 1000 μm, a foreign body sensation tends to occur when the body fluid is absorbed. In another embodiment, the highly absorbent polymer may be molded into fibrous form and mixed with a fiber assembly consisting of tow.

The basis weight of the highly absorbent polymer is preferably 60 g / m ² or more and 500 g / m ² or less, and more preferably 60 g / m ² or more and 300 g / m ² or less. The basis weight of the highly absorbent polymer is preferably 0.6 times or more and 5.0 times or less, more preferably 0.6 times or more and 3.0 times or less, with respect to the basis weight of the fiber aggregate composed of tow. Is. As a result, the required amount of absorption can be secured, and the fiber aggregate composed of tow can support the highly absorbent polymer well, and it is possible to avoid a decrease in wearing feeling due to a rough feeling of discomfort when wearing. it can. If the basis weight of the highly absorbent polymer exceeds 5.0 times the basis weight of the fiber aggregate composed of tow, the fiber aggregate composed of tow tends to be unable to support the highly absorbent polymer well. ..

In the present embodiment, the loading ratio of the highly absorbent polymer on the fiber aggregate composed of tow is preferably 70% or more. As a result, it is possible to further reduce the decrease in wearing feeling due to the occurrence of a rough feeling of discomfort when wearing. The lower limit of the loading rate may be appropriately set according to the amount of body fluid such as urine absorbed in the absorption layer 12. Hereinafter, a method for measuring the loading rate of the highly absorbent polymer on the fiber aggregate composed of tow will be described with reference to FIG. The measurement is carried out in the order of (a), (b), (c), and (d).

(A) Prepare a sheet (length 370 mm, width 110 mm) which is an absorption layer 12 in which a highly absorbent polymer is supported on a fiber aggregate made of tow, and a container for collecting the highly absorbent polymer that falls off after the test.
(B) Grasp both ends in the horizontal direction (reference numeral a in FIG. 5) of one end in the vertical direction so that the other end in the vertical direction of the sheet is on the bottom. At this time, the other end of the sheet in the vertical direction is adjusted to be at a position of about 30 cm from the bottom surface of the container.
(C) Next, the shaking operation of displacing by about 5 cm in the downward direction (direction of arrow b in FIG. 5) and returning to the original position is continuously performed 20 times back and forth.
(D) The weight of the highly absorbent polymer dropped into the container is measured, and the carrying ratio A (%) of the highly absorbent polymer on the fiber aggregate composed of tow is calculated based on the following formula.
A (%) = [(BC) / B] x 100
[In the formula, B indicates the weight (g) of the highly absorbent polymer supported on the sheet before the shaking operation. C indicates the weight (g) of the highly absorbent polymer that has fallen off. ]

The absorbent layer 12 can be produced, for example, by mixing a highly absorbent polymer with a fiber aggregate made of tow, but from the viewpoint of preventing the highly absorbent polymer from falling off, the fiber aggregate made of tow is made of a highly absorbent polymer. It is preferable to fix and support the fiber. As a fixing method, a known method can be adopted without limitation. For example, heat-resistant sheets are laminated on both sides in the thickness direction of a fiber assembly made of tow containing a highly absorbent polymer, and this is heated and / or pressurized to achieve high absorption. The sex polymer may be fixedly supported on the fiber aggregate composed of tow. Further, the highly absorbent polymer may be fixedly supported on the fiber aggregate made of tow by using a binder such as a hot melt adhesive.

The shape of the absorption layer 12 as a whole is not particularly limited, and is, for example, a rectangular shape, an hourglass shape, an I shape, a rounded rectangular shape obtained by forming four corners of a rectangle, an oval shape, an elliptical shape, or the like. is there. The absorption layer 12 may be used by stacking two or more layers. The thickness of the absorbing layer 12 is appropriately selected according to the type of body fluid to be absorbed, the form and material of the absorbing layer 12, etc., but the absorbability and retention of the body fluid and the article that the wearer can absorb. From the viewpoint of being able to operate without discomfort even after absorbing the body fluid of No. 1, it is preferable to appropriately select from the range of 1 mm or more and 10 mm or less. Further, it is preferable that the dimension of the absorption layer 12 in the longitudinal direction is 50 mm or more and 500 mm or less, and the dimension in the width direction is 10 mm or more and 250 mm or less.

In the present embodiment, a carrier sheet (not shown) that encloses the entire absorption layer 12 may be used from the viewpoint of preventing the highly absorbent polymer from falling off and stabilizing the shape of the absorption layer 12. That is, the absorbent layer 12 may be wrapped with the carrier sheet and then wrapped with the composite non-woven fabric 11, and the openings 11a may be provided only in the composite non-woven fabric 11 or in both the composite non-woven fabric 11 and the carrier sheet. The base material of the carrier sheet may be any one having hydrophilicity, and examples thereof include hydrophilic non-woven fabrics such as tissue, absorbent paper, and air-laid non-woven fabric. When a plurality of carrier sheets are provided, the base materials of the plurality of carrier sheets may be the same or different.

(Back sheet)
The backsheet 13 is made of a breathable or non-breathable liquid-impermeable substrate that prevents the body fluid held by the absorbent layer 12 from wetting clothing or adhering to the skin surface. Examples of the base material for the back sheet include a resin film, a composite sheet which is a laminate of the resin film and the non-woven fabric, and the like. Examples of the resin film include a film made of a synthetic resin such as polyester, polyvinyl alcohol, polyethylene and polypropylene, and a composite film of polyethylene and polypropylene. The non-woven fabric used for the composite sheet is not particularly limited in the manufacturing method. Examples thereof include a composite non-woven fabric which is a laminated body with.

The basis weight of the back sheet 13 is not particularly limited, but is preferably ^{15 g / m 2} or more and 40 g / m ^{2 or less from the viewpoint of strength and workability.} Further, in order to prevent stuffiness when worn, it is preferable that the back seat 13 has breathability. The method of imparting breathability to the backsheet 13 is not particularly limited, and a known method can be adopted. For example, a method of making the resin film which is the base material for the backsheet porous, and embossing the base material for the backsheet. There is a method of applying. As an example of the method of making the resin film porous, there is a method of adding a filler to the resin to form a film, and removing the filler from the obtained film. Examples of the filler include inorganic salts such as calcium carbonate.

(Three-dimensional gather)
Further, the three-dimensional gather 14 is provided as necessary to prevent lateral leakage of the body fluid excreted by the user of the absorbent article 1. In the present embodiment, the three-dimensional gather 14 is fixed at one end in the width direction to the skin side surface of the back sheet 13, the middle part in the width direction is fixed in the vicinity of the end portion in the width direction of the top sheet 10, and the other end in the width direction is freely bendable. The member is provided so as to be the end 14a, but is not limited to this, for example, along the longitudinal direction of the absorbent article 1, both ends in the width direction of the top sheet 10 and the non-skin side surface of the back sheet 13. It may be formed as a pair of bendable members by extending outward from both ends in the width direction and the like.

The three-dimensional gather 14 includes, for example, an elastic member for three-dimensional gather and a three-dimensional gather sheet. By providing the elastic member for three-dimensional gathers along the longitudinal direction, the three-dimensional gathers 14 can be provided with erectability and can be deformed according to the body shape of the wearer. As the elastic member for three-dimensional gather, for example, a thread-like, string-like, or band-shaped member made of natural rubber, synthetic rubber, polyurethane, or the like can be appropriately used. As the three-dimensional gather sheet, a water-repellent or liquid-impermeable non-woven fabric formed of hydrophobic fibers, for example, a spunbond non-woven fabric, a melt-blow non-woven fabric, a composite non-woven fabric in which spunbond / melt-blow / spunbond is laminated, or the like is used. ..

[Manufacturing method of absorbent articles]
The method for producing the absorbent article 1 is not particularly limited, and a conventionally known method can be adopted. For example, from the clothing side, the back sheet 13, the absorbent layer 12 covered entirely with the composite non-woven fabric 11, and the top. The sheets 10 are laminated in this order, the composite non-woven fabric 11 is arranged so that the opening 11a is located on the top sheet 10 side, and the top sheet 10 and the back sheet 13 are partially or completely covered with a hot melt adhesive or the like. The absorbent article 1 can be manufactured by fixing using heat embossing, ultrasonic embossing, high frequency embossing, or the like. Then, this may be individually wrapped in a package, and then folded in three in the longitudinal direction.

FIG. 2 shows the configuration of the absorbent article 2 according to the second embodiment. The absorbent article 2 has the same configuration as the absorbent article 1 except that the composite nonwoven fabric 20 is provided in place of the composite nonwoven fabric 11, and includes the same modified examples. The composite non-woven fabric 20 is the same as the composite non-woven fabric 11 in terms of material, but has four openings 20a on the side surface of the top sheet.

The four openings 20a are provided near the central portion in the width direction of the side surface of the top sheet, are provided apart from each other in the vicinity of both ends in the longitudinal direction, and have a substantially rectangular planar shape extending in a strip shape in the longitudinal direction. ing. Further, the four openings 20a are arranged substantially symmetrically with respect to the longitudinal center line, and further, a virtual center line in the width direction on the side surface of the top sheet (a virtual position extending equidistant from both ends in the width direction of the surface in the longitudinal direction). It is also arranged almost symmetrically with respect to the center line, hereinafter simply referred to as the "center line in the width direction"). In other words, the composite non-woven fabric 20 has two openings 20a in each of the front side region and the rear side region on the side surface of the top sheet. The dimensions in the longitudinal direction and the width direction of the four openings 20a are appropriately selected according to the dimensions in the longitudinal direction and the width direction of the openings 11a. The four openings 20a are arranged so that their respective edges are separated from the respective edges on the side surface of the top sheet.

By providing a plurality of openings 20a having the same planar shape in the front region and the posterior region while maintaining symmetry in the arrangement of the openings 20a in this way, the strength of the composite nonwoven fabric 20 that encloses the absorption layer 12 is provided. By modifying the diffusion direction of the body fluid in the absorption layer 12, improving the diffusivity and absorption rate of the body fluid, maximizing the body fluid absorption capacity of the absorption layer 12, and preventing lateral leakage. it is conceivable that.

FIG. 3 shows the configuration of the absorbent article 3 according to the third embodiment. The absorbent article 3 has the same configuration as the absorbent article 1 except that the composite nonwoven fabric 21 is provided instead of the composite nonwoven fabric 11, and includes the same modified examples. The composite non-woven fabric 21 is the same as the composite non-woven fabric 11 in terms of material, but has a strip-shaped opening 21a extending in the longitudinal direction and openings on both sides in the width direction in the front and rear regions of the side surface of the top sheet. A group of openings, each of which is arranged substantially parallel to the portion 21a and has two openings 21b having a length shorter than that of the opening 21a, is formed in the front region and the rear region. Since the opening 21a is close to the center of the excretion portion in the longitudinal direction and the body fluid can be drawn into the lower absorption layer 12 more quickly, it is more preferable to exert the effect of preventing lateral leakage. The two openings 21a are arranged on the side surface of the top sheet of the composite nonwoven fabric 21 in the vicinity of the central portion in the width direction and in the vicinity of both ends in the longitudinal direction. The two sets of openings are provided so as to be substantially symmetrical with respect to the longitudinal center line, and each of the two openings 21b is provided so as to be substantially symmetrical with respect to the opening 21a. There is. The dimensions of the openings 21a and 21b in the longitudinal direction and the width direction are appropriately selected according to the dimensions of the openings 11a in the longitudinal direction and the width direction. The openings 21a and 21b are arranged so that their respective edges are separated from the respective edges on the side surface of the top sheet.

Also in this embodiment, by maintaining the symmetry of the arrangement of the openings 21a and 21b, the diffusion direction of the body fluid in the absorption layer 12 is modified to improve the diffusivity and absorption rate of the body fluid, and the body fluid absorption of the absorption layer 12 is achieved. It is thought that it is possible to maximize the ability and prevent lateral leakage.

Although the present invention has been described above using the embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope of the above embodiments, and various changes or improvements are made to the above embodiments. It is clear to those skilled in the art that is possible. Further, it is clear from the description of the scope of claims that the form to which such a modification or improvement is added may be included in the technical scope of the present invention.

1, 2, 3 Absorbent article 10 Top sheet 11, 20, 21 Composite non-woven fabric 11a, 20a, 21a, 21b Opening 12 Absorption layer 13 Back sheet 14 Three-dimensional gather 25 Concentric diffusion of body fluid 26 Center of excretion

Claims (9)

An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbing layer provided between the top sheet and the back sheet.
The absorbent layer contains a fiber aggregate made of tow and a highly absorbent polymer fixedly supported inside the fiber aggregate made of tow.
Further provided with a composite non-woven fabric that completely wraps the absorbent layer,
The composite non-woven fabric is
It is an integrated product of spunbonded non-woven fabric and pulp fiber web layer.
In the region interposed between the top sheet and the absorbent layer, the absorbent layer is provided at substantially the center of the absorbent article in the width direction and at substantially both ends in the longitudinal direction of the absorbent article. Have at least one opening to expose towards the top sheet
An absorbent article, characterized in that the distance from the center of the excretion portion of the central end in the longitudinal direction of the opening is shorter than the distance between the center of the excretion and the end in the width direction of the absorber. The composite non-woven fabric is an integral product of a spunbonded non-woven fabric and a pulp fiber web layer, and the basis weight of the spunbonded non-woven fabric is 7 g / m ² or more and 20 g / m ² or less, and the basis weight of the pulp fiber web is 30 g / m. m ² or more 70 g / ^{m 2} or less, and in that the ratio of the spunbonded nonwoven fabric and the pulp fiber web layer (the spunbonded nonwoven fabric weight / the pulp fiber web layer weight) is 40/60 or more 10/90 or less The absorbent article according to claim 1, wherein the absorbent article is characterized. The absorbent article according to claim 1 or 2, wherein the opening is a substantially rectangular shape extending in a strip shape in the longitudinal direction of the absorbent article. The absorbency according to any one of claims 1 to 3, wherein the pair or a plurality of pairs of openings provided at substantially both ends in the longitudinal direction of the absorbent article are symmetrical in the longitudinal direction, respectively. Goods. The absorbent article according to any one of claims 1 to 4, wherein the size of the opening is 5 mm or more and 100 mm or less in the width direction of the absorbent article. In the longitudinal direction of the absorbent article, the dimension of the opening is 20% or more and 80% or less of the maximum dimension of the absorbent layer, and in the width direction of the absorbent article, the dimension of the opening is said. The absorbent article according to any one of claims 1 to 5, which is 20% or more and 80% or less of the maximum size of the absorbent layer. If there are multiple openings in each case, the total ratio shall be used. The absorption according to any one of claims 1 to 6, wherein the composite nonwoven fabric completely wraps the absorption layer so that the pulp fiber web layer faces and / or contacts the absorption layer. Sex goods. The composite non-woven fabric is an integral product in which at least a part of pulp fibers contained in the pulp fiber web layer is entwined on one surface of the spunbonded nonwoven fabric, and a part of the pulp fibers is other than the spunbonded nonwoven fabric. The absorbent article according to any one of claims 1 to 7, which has a structure exposed on a surface. The material of the spunbonded nonwoven fabric is one or more selected from the group consisting of nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, and polystyrene, according to any one of claims 1 to 8. The absorbent article described.

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