JP2021019785A - Absorbent article - Google Patents

Abstract

To provide an absorbent article that is superior in absorption performance such as absorption holding/diffusing capacity in repetitive absorption, and is good in wearing feeling.SOLUTION: An absorbent article 1 of the present invention has a liquid permeable top sheet 10, a liquid-impermeable back sheet 20, and an absorbing layer 30 provided between the top sheet 10 and the back sheet 20. The absorbing layer 30 has a first absorbing sheet 31 of the top sheet 10 side in the thickness direction, and a two-layer structure comprising at least a second absorbing sheet 32 of the back sheet 20 side. The first and second absorbing sheets 31, 32 have two sheets of liquid permeable sheets 301, a fiber assembly comprising a fiber bundle between the two sheets of liquid permeable sheets 301, and a high-absorbent polymer 302 fixed and carried in the inside of the fiber assembly. The first and second absorbing sheet 31, 32 are shaped in a shape of the nested embossment, and the first and second absorbing sheets 31, 32 are partially bonded to each other.SELECTED DRAWING: Figure 2

Description

The present invention relates to absorbent articles.

Generally, an absorbent article is composed of a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent layer arranged between the top sheet and the back sheet, whereby urine and the like can be treated. Body fluids are absorbed into the absorption layer through the top sheet.
Further, as an absorbent layer, it is widely known that an absorbent core containing fluff pulp and a super absorbent polymer (also referred to as SAP) is wrapped with a carrier sheet such as crepe paper. ..

These absorbent layers are formed by stacking fluff pulp short fibers and a highly absorbent polymer on a fiber stacking drum to prepare an absorbent core, and then wrapping the absorbent core in a carrier sheet. On the other hand, instead of the fluff pulp short fiber slab, a tow (fiber bundle) composed of filamentous long fiber webs is opened (hereinafter referred to as a fiber aggregate composed of tow) as an absorption layer. It has been proposed to be used for. By using a fiber aggregate made of tow instead of fluff pulp, it is possible to make it less noticeable to wear an absorbent article under clothing by using an absorbent layer with excellent flexibility and flexibility. It can be done and the fit is improved.

In recent years, there has been a demand for a product in which it is inconspicuous to wear an absorbent article, and there is no sense of discomfort when wearing it, and there is a desire for a product that does not feel comfortable to wear. Aspects of absorbent articles have been proposed. For example, Patent Document 1 states that it has an aggregate of filaments in which tow is opened and highly absorbent polymer particles, and that the basis weight of the highly absorbent polymer particles on both sides of the crotch portion is smaller than that of the main absorbing portion. An absorbent article using a characteristic absorbent layer is disclosed. Further, Patent Document 2 includes an aggregate of filaments in which tow is opened and an absorbent layer having highly absorbent polymer particles, and holds a highly absorbent polymer that has escaped from the filament on the back surface side of the absorbent layer. An absorbent article provided with a holding sheet is disclosed.

Japanese Unexamined Patent Publication No. 2006-320443 Japanese Unexamined Patent Publication No. 2008-295645

However, when the absorbent article is made thinner and lighter in the above manner, some absorption performance must be sacrificed. In particular, light incontinence products and urine absorbing pads with a narrow absorption layer area do not maintain sufficient absorption performance. In addition, there is a problem that the wearing feeling is poor if the absorption performance is not maintained.

In view of the above problems, it is an object of the present invention to provide an absorbent article which is thin and lightweight, has excellent absorption performance such as absorption retention / diffusion ability in repeated absorption, and has a good wearing feeling.

The inventor of the present invention has conducted diligent research in view of the above problems. As a result, two absorbent sheets, which do not contain fluff pulp and are composed of a fiber aggregate made of tow and a liquid permeable sheet, are used as the absorbent layer, and the two absorbent sheets are shaped and partially joined. We have found that the above-mentioned problems can be solved by the space formed by the above, and have completed the present invention. Specifically, the present invention provides the following.

(1) The first aspect of the present invention is an absorbent having a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent layer provided between the top sheet and the back sheet. An article, the absorption layer has a two-layer structure including at least a first absorption sheet on the top sheet side and a second absorption sheet on the back sheet side in the thickness direction, and the first and first absorption layers. The two-absorbent sheet has two liquid-permeable sheets, a fiber aggregate made of tow between the two liquid-permeable sheets, and a highly absorbent polymer fixedly supported inside the fiber aggregate. The first and second absorbent sheets are shaped into a nested embossed shape, and the first and second absorbent sheets are partially joined to each other.

(2) In the configuration of (1) above, the basis weight of the fiber aggregate composed of the tow is 20 g / m ² or more and 100 g / m ² or less, and the basis weight of the highly absorbent polymer is 60 g / m ² or more. It is 500 g / m ² or less, and is 0.6 times or more and 5.0 times or less with respect to the basis weight of the fiber aggregate composed of the tow.

(3) In the configuration of the above (1) or (2), the loading ratio of the highly absorbent polymer to the fiber aggregate composed of the tow is 70% or more.

(4) In any one of the above (1) to (3), the constituent fibers of the fiber aggregate made of tow are fibers made of cellulose acetate.

(5) In the configuration of any one of (1) to (4) above, the two liquid permeable sheets are non-woven fabrics.

(6) In the configuration of any one of (1) to (5) above, the first and second absorbent sheets are partially joined, and the total area of the joined portions is the first absorbent sheet. It is characterized in that it is 1% or more and 50% or less with respect to the area of the overlapping region of the second absorption sheet.

According to the present invention, it is possible to provide an absorbent article having excellent absorption performance such as absorption retention / diffusion ability in repeated absorption and having a good wearing feeling.

It is a top sheet view of the absorbent article which concerns on embodiment of this invention. It is sectional drawing in Y1-Y1 of the absorbent article 1 of FIG. It is an enlarged view of the 1st absorption sheet and the 2nd absorption sheet arranged in the absorbent article. It is a drawing used for demonstrating the method of measuring the support rate of a highly absorbent polymer on a fiber assembly composed of tow.

Hereinafter, embodiments for carrying out the present invention (hereinafter, embodiments) will be described in detail, but these are listed for the purpose of exemplification, and the present invention is not limited thereto. The same elements are designated by the same reference numerals throughout the description of the embodiments.

Further, in the description of the present specification, the time when the absorbent article 1 is worn means at least one of the time when the absorbent article 1 is worn and the time after the absorbent article 1 is worn. The longitudinal direction of the absorbent article 1 is a direction extending in front of and behind the wearer when the absorbent article 1 is worn, and is a direction indicated by reference numeral Y in the drawing. The width direction of the absorbent article 1 is a direction laterally or orthogonal to the longitudinal direction, and is a direction indicated by reference numeral X in the drawing. Further, the skin contact surface is the surface of the front and back surfaces of each member such as the absorbent layer that is arranged on the wearer's skin side when worn, and the non-skin contact surface is each member such as the absorbent layer. Of the front and back sides of the above, the side that faces the wearer's skin side when worn. Body fluid refers to the liquid discharged from the body to the outside of the body, such as urine, blood, and water in loose stool. Further, the absorbent article 1 is an absorbent article fixed inside the disposable diaper and used as an auxiliary pad, and the disposable diaper is preferably a pants-type disposable diaper, but the present invention is not limited to the tape. It may be a stop-type disposable diaper or the like.

<Absorbable article>
FIG. 1 is a plan view of the absorbent article 1 according to the embodiment of the present invention as viewed from the top sheet 10 side, and FIG. 2 is a cross-sectional view of the absorbent article 1 of FIG. 1 in Y1-Y1.
As shown in FIG. 1 or 2, the absorbent article 1 is arranged on the liquid-permeable top sheet 10 arranged on the skin contact surface side and on the non-skin contact surface side facing the top sheet 10. It has a liquid-impermeable back sheet 20 and an absorption layer 30 arranged between the top sheet 10 and the back sheet 20. As a result, the absorption layer 30 has a structure sandwiched between the top sheet 10 and the back sheet 20. The absorbent article 1 is thin, lightweight, and has excellent absorbency, and can be particularly applied to a light incontinence product, a urine absorbing pad, and the like.

It is preferable that the dimension of the absorbent article 1 in the longitudinal direction is 100 mm or more and 600 mm or less, and the dimension in the width direction is 30 mm or more and 300 mm or less. By adjusting the dimensions of the absorbent article 1 within the above range, the absorbent article 1 suitable for incontinence products, urine absorbing pads and the like can be obtained.

Further, in order to prevent lateral leakage of the body fluid excreted by the wearer, the absorbent article 1 has a pair of three-dimensional objects having elastic members for three-dimensional gathers on the top sheet 10 along the longitudinal direction of the absorbent article 1. It may be provided with gathers 14. The outer end of the three-dimensional gather 50 in the width direction of the absorbent article 1 is fixed to the back sheet 20, the inner end thereof is fixed to the top sheet 10, and the center thereof is a free end not fixed to the top sheet 10. A three-dimensional gather sheet is arranged. By providing the elastic member for three-dimensional gather along the longitudinal direction, the three-dimensional gather 50 has an upright property and can be deformed according to the body shape of the wearer. As the elastic member for three-dimensional gathering, for example, a thermal bond nonwoven fabric, a spunbonded nonwoven fabric, a polyethylene film, or a sheet obtained by combining and joining these sheets can be used. From the viewpoint of strength and workability, the basis weight of the three-dimensional gather 50 is preferably 10 g / m ² or more and 50 g / m ² or less.

<Top sheet>
The top sheet 10 may be formed of a base material having a liquid permeability that allows body fluid to move to the absorption layer 30, and for example, known hydrophilic non-woven fabrics such as thermal-bonded non-woven fabrics and spunbonded non-woven fabrics can be used. .. Further, the surface of the top sheet 10 may be embossed or perforated in order to improve the liquid permeability. As a method for performing these embossing and drilling processes, known methods can be carried out 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.
From the viewpoint of strength, workability and liquid return amount, the basis weight of the top sheet 10 is preferably 15 g / m ² or more and 200 g / m ² or less, and 20 g / m ² or more and 100 g / m ² or less. More preferred. The shape of the top sheet 10 is not particularly limited, but may be any shape that covers the absorption layer 30, which is required to guide the body fluid to the absorption layer 30 so as not to leak.

<Back sheet>
The back sheet 20 may be formed by using a base material having a liquid impermeable property so that the body fluid held by the absorption layer 30 does not wet the clothes, and is breathable or non-breathable liquid impermeable. Plastic film can be used.

From the viewpoint of strength and workability, the basis weight of the back sheet 20 is preferably 15 g / m ² or more and 40 g / m ² or less, and more preferably 20 g / m ² or more and 35 g / m ² or less. In order to provide the back sheet 20 with breathability, for example, a filler may be blended in the resin film of the base material, or the back sheet 20 may be embossed. Calcium carbonate can be mentioned as the filler, and a known method can be used without limitation as the blending method.

<Absorption layer>
In the absorbent article 1 of the present invention, the dimension of the absorbent layer 30 in the longitudinal direction is preferably 50 mm or more and 550 mm or less, and more preferably 100 mm or more and 500 mm or less. The width direction of the absorption layer 30 is preferably 10 mm or more and 250 mm or less, and more preferably 30 mm or more and 200 mm or less.

(Absorption sheet)
Figure 2 is a cross-sectional view of the _X 1 -X ₁ in Fig. 1 or 2. As shown in FIG. 2, the absorption layer 30 has a two-layer structure including at least a first absorption sheet 31 on the top sheet 10 side and a second absorption sheet 32 on the back sheet 20 side in the thickness direction.

As shown in FIG. 1 or 2, the first absorbent sheet 31 and the second absorbent sheet 32 are shaped into a nested embossed shape, and the first absorbent sheet 31 and the second absorbent sheet 32 are partially formed. They are joined to each other by the joining portions 33a to 33i.
Regarding the shape portion of the nested method embossing, the first absorbing sheet 31 is formed with convex portions 31a to 31d so as to be convex toward the top sheet 10, and the second absorbing sheet 32 is convex toward the top sheet 10. The convex portions 32a to 32d are formed so as to form a mold. By forming the convex portions 31a to 31d of the first absorption sheet 31 larger than the convex portions 32a to 32d of the second absorption sheet 32, a space is provided between the first absorption sheet 31 and the second absorption sheet 32. Is trying to form.

The convex portions 31a to 31d of the first absorption sheet 31 and the convex portions 32a to 32d of the second absorption sheet 32 are joined by the joint portions 33f, 33g, 33h, 33i. Further, the flat portion of the first absorption sheet 31 and the second absorption sheet is joined by the joint portions 33a, 33b, 33c, 33d, 33e.

FIG. 3 is an enlarged view of the first absorbent sheet 31 and the second absorbent sheet 32 arranged in the absorbent article 1. As shown in FIG. 3, the first absorption sheet 31 and the second absorption sheet 32 are both placed between the first and second liquid permeable sheets 301 and the first and second liquid permeable sheets 301 from the toe. It has a fiber aggregate and a highly absorbent polymer (fiber aggregate composed of tow and SAP302) fixedly supported inside the fiber aggregate.
Examples of the first and second liquid permeable sheets 301 include non-woven fabrics such as tissue, absorbent paper, spunbonded non-woven fabric, and air-laid non-woven fabric, and it is preferable to use the non-woven fabric from the viewpoint of liquid diffusivity, water retention, and cost.

(Fiber aggregate consisting of tow)
The fiber aggregate composed of tow is an aggregate of long fiber filaments in which the tow is opened, and is converged so that the orientation directions of the long fibers are aligned. In the present invention, 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 the constituent fibers 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, bulky It is preferable to use a fiber made of cellulose acetate, which is easy to obtain and can impart flexibility and flexibility to the first absorption sheet 31 and the second absorption sheet 32.
The fineness of the fiber aggregate made of tow is not particularly limited, but from the viewpoint of ensuring that the first absorption sheet 31 and the second absorption sheet 32 exhibit desired performance and have sufficient strength for use, for example. , 0.1 dtex or more and 10 dtex or less.

Further, in the fiber aggregate composed of tow, since 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, and more preferably 30 g / m ² or more and 80 g / m ² or less. When the basis weight of the fiber aggregate composed of tow is within the above range, a highly absorbent polymer can be supported to the extent that absorbability can be ensured, and the first absorbent sheet 31 and the second absorbent sheet 31 and the second absorbent which are excellent in flexibility and flexibility can be supported. The sheet 32 can be obtained. 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 first absorption sheet 31 and the second absorption sheet 32 increases, and the fiber aggregate composed of tow It is not preferable because the original flexibility and flexibility are impaired.

(Highly absorbent polymer)
The highly absorbent polymer is not particularly limited as long as it can absorb body fluids and prevent backflow. Sodium polyacrylate-based, polyaspartate-based, (starch-acrylic acid) graft copolymers, Those formed from materials such as (acrylic acid-vinyl alcohol) copolymers, (isobutylene-maleic anhydride) copolymers and their saponified products can be used. Among these, sodium polyacrylate is preferable from the viewpoint of the amount of absorption per weight.

The basis weight of the highly absorbent polymer is preferably 60 g / m ² or more and 500 g / m ² or less, and the basis weight of the highly absorbent polymer is 0.6 with respect to the basis weight of the fiber aggregate composed of tow. It is preferably more than double and 5.0 times or less. As a result, the absorbent article 1 can secure the required absorption amount, and the fiber aggregate composed of the tow can support the highly absorbent polymer well, which causes a rough and uncomfortable feeling when worn. The decline can be avoided. 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 cannot satisfactorily support the highly absorbent polymer.
Further, the basis weight of the highly absorbent polymer is more preferably 100 g / m ² or more and 400 g / m ² or less, and the basis weight of the highly absorbent polymer is relative to the basis weight of the fiber aggregate composed of tow. More preferably, it is 0.8 times or more and 4.0 times or less.

In the absorbent article 1 of the present invention, the loading ratio of the highly absorbent polymer to the fiber assembly composed of tow is preferably 70% or more, and more preferably 80% or more. When the support rate of the highly absorbent polymer on the fiber aggregate made of tow is 70% or more, it is possible to avoid a decrease in wearing feeling due to a rough feeling of discomfort when wearing the absorbent article 1. FIG. 4 is a drawing used to explain a method for measuring the loading rate of a highly absorbent polymer on a fiber assembly composed of tow. Hereinafter, a method for measuring the loading rate of the highly absorbent polymer on the fiber assembly composed of tow will be described with reference to FIG.

(1) First, before the first absorption sheet 31 and the second absorption sheet 32 are produced, the sheet (length 370 mm, width 110 mm) in which a highly absorbent polymer is supported on a fiber aggregate made of tow and falls off after measurement. Prepare a container for collecting the highly absorbent polymer.
(2) Hold both ends in the horizontal direction (reference numeral a in FIG. 4) 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 30 cm from the bottom surface of the container.
(3) After that, the shaking operation of displacing by about 5 cm in the downward direction (direction of the arrow b in FIG. 4) and returning to the original position is continuously performed 20 times.
(4) Weigh the highly absorbent polymer that fell off the container, and {(weight of the highly absorbent polymer carried on the sheet before shaking-weight of the highly absorbent polymer that fell off) / the sheet before shaking. The value calculated by the formula of} × 100 of the weight of the highly absorbent polymer carried in the above is taken as the carrying ratio (%) of the highly absorbent polymer on the fiber aggregate composed of tow.

<Joint>
As shown in FIG. 1, in the absorbent article 1 of the present invention, the first absorbent sheet 31 and the second absorbent sheet 32 are partially joined to each other at the joint portions 33a to 33i. By partially joining the first absorption sheet 31 and the second absorption sheet 32 at the joining portions 33a to 33i, the absorption layer 30 swells unevenly after the absorption of the body fluid, and the absorption retention and diffusion are maintained even after repeated use. It is possible to obtain an absorbent article 1 having a good wearing feeling while maintaining absorption performance such as ability.
The first absorbent sheet 31 and the second absorbent sheet 32 are joined in a dot-like pattern over the entire sheet as shown in FIG. At this time, as the joining method, a known method such as hot melt, heat seal, ultrasonic seal or the like can be appropriately used.

Further, the total area of the joint portions 33a to 33i in the first absorption sheet 31 and the second absorption sheet 32 is 1% with respect to the area of the overlapping region of the first absorption sheet 31 and the second absorption sheet 32. It is preferably 50% or more, and more preferably 2% or more and 30% or less. When the ratio of the total area of the joint portions 33a to 33i is within the above range, it is possible to obtain an absorbent article having excellent absorption performance such as absorption retention / diffusion ability and a good wearing feeling.

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 described in the above-described embodiments and examples. It will be apparent to those skilled in the art that various changes or improvements can be made to the above embodiments. Further, it is clear from the description of the claims that the form in which such a modification or improvement is added may be included in the technical scope of the present invention.

1 Absorbent article 10 Top sheet 20 Back sheet 30 Absorbent layer 31, 32 Absorbent sheet 33a to 33i Joint 50 Three-dimensional gather 301 Liquid permeable sheet 302 Fiber aggregate consisting of toe and SAP

Claims (6)

An absorbent article having 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 has a two-layer structure including at least a first absorbent sheet on the top sheet side and a second absorbent sheet on the back sheet side in the thickness direction.
The first and second absorbent sheets are a highly absorbent fiber aggregate formed of a tow between two liquid permeable sheets and the two liquid permeable sheets and fixedly supported inside the fiber aggregate. Has a polymer and
The first and second absorbent sheets are absorbent articles characterized in that the first and second absorbent sheets are shaped into a nested embossed shape and the first and second absorbent sheets are partially joined to each other. The basis weight of the fiber aggregate composed of the tow is 20 g / m ² or more and 100 g / m ² or less, and the basis weight of the highly absorbent polymer is 60 g / m ² or more and 500 g / m ² or less. It is 0.6 times or more and 5.0 times or less with respect to the basis weight of the fiber aggregate.
The absorbent article according to claim 1. The loading ratio of the highly absorbent polymer to the fiber assembly composed of the tow is 70% or more.
The absorbent article according to claim 1 or 2. The constituent fibers of the fiber aggregate made of tow are fibers made of cellulose acetate.
The absorbent article according to any one of claims 1 to 3. The two liquid permeable sheets are non-woven fabrics.
The absorbent article according to any one of claims 1 to 4. The first and second absorbent sheets are partially joined, and the total area of the joined portions is 1% with respect to the area of the area where the first absorbent sheet and the second absorbent sheet overlap. It is characterized by being 50% or more and 50% or less.
The absorbent article according to any one of claims 1 to 5.