JP2002369840A - Absorbent articles - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an absorptive article in which excretion can be visually recognized from the outside. SOLUTION: A back sheet 3 in an absorbent article 1 is provided with a porous sheet having moisture permeability, and a part of the porous sheet can be transferred into an adhesive base polymer and into pores of the porous sheet. The transparent or translucent region 10 was formed by a clearing agent composition containing a component that was present and was liquid at room temperature. The total light transmittance of the region 10 is 5
0% or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an absorbent article such as a disposable diaper or a sanitary napkin, and more particularly, to an absorbent article which allows the user to visually confirm that excrement has been excreted.

[0002]

2. Description of the Related Art There have been known various absorbent articles in which the excretion can be visually recognized from the outside. For example, there has been proposed an absorbent article that uses a color indicator due to a change in pH and changes color by excretion of urine or the like. However, in this type of absorbent article, the pH inside is biased toward the acidic side, and the skin is easily irritated. Particularly, it is not preferable for an infant whose skin is sensitive. Further, depending on the storage state, the color indicator may be discolored by ultraviolet rays or moisture of sunlight, and the storage stability cannot be said to be sufficiently high.

[0003] A porous sheet is used as a back sheet of an absorbent article, and the porous sheet is embossed,
An absorbent article in which the embossed portion is made transparent is also known. However, since porous sheets are generally thin,
Pinholes are easily generated by embossing. In addition, in order to change the design of the transparent portion, it is necessary to prepare a new embossing roll, so that it is not easy to change the design. Further, in the manufacturing process, an embossing process of the porous sheet is required, which complicates the manufacturing process.

[0004] It is also known to apply a plasticizer such as paraffin wax to make the application site transparent, instead of using the embossing process. However, the plasticizer easily migrates to the opposite side of the application surface, and stickiness occurs, and when such sheets are stacked and stored, the plasticizer migrates to another sheet. In addition, bleeding occurs due to the transfer of the plasticizer, and it is difficult to obtain a clear contour.

Accordingly, the present invention is an absorbent article in which the excretion can be visually recognized from the outside, has high safety and storage stability, and is easy to change the design and manufacture of the transparent part. It is an object of the present invention to provide an absorbent article having no stickiness and having a clear outline of a transparent portion.

[0006]

According to the present invention, there is provided an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retentive absorber interposed between the two sheets. A backing sheet comprising a porous sheet having moisture permeability, a clarifying agent containing, at a part of the porous sheet, a component of an adhesive base polymer and a liquid component at room temperature which can be transferred into the micropores of the porous sheet. The above object has been achieved by providing an absorbent article wherein a transparent or translucent region is formed by the composition, and the total light transmittance of the region is 50% or more.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a preferred embodiment of an absorbent article according to the present invention will be described with reference to the drawings, taking a disposable diaper as an example. Here, FIG. 1 is a partially cutaway plan view of a disposable diaper as a first embodiment of the absorbent article according to the present invention, as viewed from a back sheet side.

As shown in FIG. 1, the disposable diaper 1 of the present embodiment comprises a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and a liquid interposed between these two sheets 2, 3. And a holding absorber 4.
The absorber 4 is formed in a curved hourglass shape in which a region corresponding to the crotch region of the diaper is formed, and the top sheet 2 and the back sheet 3 also have regions corresponding to the crotch region of the diaper in accordance with the shape of the absorber 4. It is curved. The absorber 4 is sandwiched and fixed between the top sheet 2 and the back sheet 3. The top sheet 2 is made of a nonwoven fabric, a perforated film, or the like. The absorber 4 is formed by wrapping a mixture of pulp and particles of a superabsorbent polymer in a mount (for example, tissue paper).

A back waist portion 5 and an abdominal waist portion 5 'formed by a top sheet 2 and a back sheet 3 extending outward from front, rear, left and right edges of the absorber 4.
And a pair of leg portions 6,6, elastic elastic members 7 for fitting the leg portions 6,6 and / or the respective waist portions 5,5 'to the wearer's body when the diaper is worn.
Are fixedly provided by the top sheet 2 and the back sheet 3.

A pair of fasteners 8 and 8 made of a tape fastener or the like are attached to both ends in the width direction of the back waist portion 5, and a rectangular shape is formed on the back sheet 3 at the abdominal waist portion 5 '. An adherend 9 made of a shaped landing tape or the like is affixed. And when the disposable diaper 1 of this embodiment is worn, the fastening tools 8 and 8 are fastened on the to-be-attached article 9.

Thus, in the diaper 1 of the present embodiment, the back sheet 3 is composed of a porous sheet having moisture permeability and a non-woven fabric bonded to the outer surface of the porous sheet. (Hereinafter, these areas are collectively referred to as a transparent area) 1 in a part of the transparent sheet, which is made transparent or translucent by a clarifying agent composition described later.
0 is formed. Two transparent regions 10 are formed in the crotch part of the diaper 1 in the longitudinal direction of the diaper 1. As a result, excretions such as urine absorbed by the absorbent body 4 of the diaper 1 can be visually recognized from the outside of the diaper 1 through the transparent region 10 and the nonwoven fabric, and it is possible to easily determine the time to replace the diaper 1.

The transparent region 10 has a total light transmittance of 50
% Or more, and preferably 60% or more. By setting the total light transmittance to 50% or more, the excrement can be easily visually recognized from the outside. The total light transmittance of the transparent region 10 of the back sheet 3 is determined according to JIS K 7105.
[Measurement device: HR-100, a transmission / reflectance meter manufactured by Murakami Color Research Laboratory Co., Ltd.]

The clarifying agent composition for making the porous sheet transparent or semi-transparent can be transferred into the pores of the adhesive base polymer and the porous sheet and is a liquid component at room temperature (hereinafter referred to as a liquid component). ). The clarifying agent composition is applied directly to the surface of the porous sheet opposite to the surface bonded to the nonwoven fabric (that is, the surface facing the absorber 4). The liquid component in the clarifying agent composition is a component that makes the porous sheet transparent or translucent. on the other hand,
The bonding base polymer is a component for bonding and fixing the clarifying agent composition to the porous sheet, and is a solid or semi-solid at room temperature.

The following effects (1) to (4) are mainly exhibited by making the porous sheet transparent or translucent using the clarifying agent composition. (1) The adhesive base polymer prevents the liquid component from bleeding out of a predetermined portion of the porous sheet, and can form the transparent region 10 having a sharp outline. Specifically, the base polymer for adhesion is in a solid or semi-solid state at room temperature, and by containing a liquid component therein, the bleeding of the liquid component is compared with a case where a liquid component such as a softener is simply used. The discharge speed and the bleeding area can be controlled. As a result, it is possible to prevent discomfort caused by the porous sheet being excessively transparent and the excrement becoming too visible from the outside, and to prevent deterioration of the appearance of the diaper caused by the outline of the transparent region 10 being unclear. it can. (2) The adhesive base polymer also eliminates the stickiness of the transparent region 10. Furthermore, there is no migration of liquid components even when the absorbent articles overlap in the package for a long period of time.
These effects are more remarkably exhibited when the back sheet 3 is a laminate of a porous sheet and a nonwoven fabric. (3) The porous sheet is hardly damaged. This is particularly effective when it is desired to make the porous sheet thin. In addition, the pattern of the transparent region can be easily changed by changing the application pattern of the clarifying agent composition, and various desired patterns (for example, stripes and various patterns) can be obtained. Furthermore,
It is easy to form a transparent area. (4) High safety and transparent area 1 even after long-term storage
0 is less likely to be opaque.

The clarifying agent composition used in the present invention is roughly classified into composition A and composition B depending on the type of the base polymer for adhesion. In the composition A, a styrene elastomer is used as a bonding base polymer, and in the composition B, an amorphous polyalphaolefin is used as a bonding base polymer. Hereinafter, each composition will be described.

[Composition A] Composition A contains a styrenic elastomer as an adhesive base polymer and a softener as a liquid component. Styrene-based elastomers include styrene-butadiene rubber, styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer, styrene-
Examples thereof include an ethylene / butylene / styrene block copolymer and a styrene / ethylene / propylene / styrene block copolymer.

The softener is a liquid at room temperature (25 ° C., which is referred to as room temperature in the present specification), and has a number average molecular weight of about 200 to 3000, particularly 200
Those having a size of ~ 1000 are preferably used. For example, petroleum oils such as low molecular weight polyolefins, paraffinic process oils, naphthene process oils, aromatic process oils, etc .; liquid rubbers such as liquid polyisobutylene, liquid polybutene, liquid polyisoprene; various synthetics such as dibasic ester plasticizers Plasticizers; vegetable oils such as castor oil and tall oil; and liquid tackifying resins. Specifically, paraffin oils such as "Shell Flex" (trade name) manufactured by Shell Chemical and "PW-90" (trade name) manufactured by Idemitsu Kosan; tetraoctyl pyrrolate, di-dodecyl phthalate, trioctyl trimellit Preference is given to ester oils such as tate.

The amount of the styrenic elastomer in the composition A is 10 to 80% by weight, especially 10 to 70% by weight, especially 10 to 60% by weight, and the amount of the softener is 15 to 60% by weight, especially The content of 20 to 60% by weight, particularly 25 to 50% by weight is preferable because the effects (1) to (3) are remarkably exhibited.

It is preferable that the composition A contains a tackifier in place of a part of the styrene-based elastomer from the viewpoint of improving the adhesion to the composition A porous sheet.
The compounding amount of the tackifier can be appropriately selected according to the compounding amount of the softener, and is 10 to 70% by weight, particularly 20 to 70% by weight in the composition A.
Preferably, it is selected to replace part of the styrenic elastomer by weight, especially in the range of 30-70% by weight. As the tackifier, a solid at room temperature is preferably used. Examples include C5 petroleum resins,
C9 petroleum resin, dicyclopentadiene petroleum resin, rosin petroleum resin, polyterpene resin, terpene phenol resin. Specifically, preferred are hydrogenated terpene resins such as "Clearon" (trade name) manufactured by Yasuhara Chemical, and hydrogenated aromatic petroleum resins such as "Arcon" (trade name) manufactured by Arakawa Chemical.

The composition A may further contain an antioxidant. As the antioxidant, “Irganox 1010” (trade name) and “Irganox 1076” (trade name) manufactured by Ciba Geigy Co., Ltd., and “Sumilyzer GM” (trade name) manufactured by Sumitomo Chemical Co., Ltd. are used. be able to. The compounding amount of the antioxidant is the composition A100
It is preferable that the amount is 1 to 3 parts by weight based on parts by weight.

The composition A has a composition similar to that of a so-called hot-melt pressure-sensitive adhesive, but is different from the hot-melt pressure-sensitive adhesive in that the blending amount of the softener is considerably higher than that of the hot-melt pressure-sensitive adhesive. It is completely different.

[Composition B] For the composition B, only the differences from the above-described composition A will be described, and as for the points which are not particularly described, the detailed description regarding the composition A is appropriately applied. Composition B contains an amorphous polyalphaolefin (hereinafter APAO) as a base polymer for adhesion and as a liquid component. APA
As O, conventionally known ones can be used without particular limitation. For example, as APAO, a propylene / ethylene copolymer, a propylene / butene-1 copolymer, a propylene / ethylene / butene-1 copolymer, or the like can be used. These APAOs are commercially available, for example, under the trade names of “Ubetac” manufactured by Ube Lexen and “Eastflex” manufactured by Eastman Kodak.
Also, a propylene / ethylene / butene-1 terpolymer can be used as the APAO. The terpolymer is commercially available from Hürz under the trade name "Bestplast". APAO has a low molecular weight (for example, a molecular weight of 10
00 or less) polyolefin, and such a low molecular weight polyolefin acts as a liquid component.

The composition B may be composed essentially of only APAO, or may be composed of APAO mixed with other components. As the other components, the tackifier resin and the antioxidant described for the composition A can be mentioned, and the kind and the amount of the composition can be the same as those of the composition A. The amount of APAO is 10-1.
00% by weight, especially 15-85% by weight, especially 15-7%
The content of 0% by weight is preferable because the effects (1) to (3) are remarkably exhibited.

As described above, APAO contains a liquid component, but a softener as a liquid component at room temperature may be separately added to composition B if necessary. The compounding amount of the softener is 0.1 to 60% by weight, particularly 1
The content is preferably 0 to 50% by weight, particularly 15 to 40% by weight, because the effects (1) to (3) are remarkably exhibited. When the tackifier is blended with the composition B, the blending amount can be appropriately selected according to the blending amount of the softener, but is preferably 10 to 70% by weight, more preferably 20 to 7% by weight in the composition B.
0% by weight, more preferably 30 to 70% by weight.

Regardless of whether composition A or composition B is used, the clarifying agent composition has a melt viscosity at 180 ° C. of 6,
000 mPa · s or less, especially 4,000 mPa · s
s or less is preferable from the viewpoint of preventing the application of the clarifying agent composition from uneven coating and dropping. In addition, the coating amount is preferably 15 to 100 g / m ² , more preferably 20 to 80 g / m ² , and particularly preferably 30 to 80 g / m ² , in which a good transparent area 1 is used.
It is preferable from the viewpoint of formation of 0.

The clarifying agent composition includes a coater, a bead, a spray, a slot spray, a spiral spray, and the like.
The coating can be applied to the porous sheet by a coating method generally used for manufacturing an absorbent article. Also, transparent area 1
When 0 is used as a pattern, a foil coater is preferably used.

In the present embodiment, as shown in FIG. 1, two transparent agent compositions are applied in a strip shape to the crotch part of the diaper 1 to form a transparent region 10. The width of the transparent area is set to 2 to make it easier to visualize the excretion.
It is preferably about 40 mm. For the same reason, the area of the transparent region 10 is 2 times the area of the back sheet 3.
It is preferably from about 50%, especially from 2 to 40%, especially from 2 to 30%.

As the moisture-permeable porous sheet to which the clarifying agent composition is applied, those commonly used for absorbent articles can be used without any particular limitation. The porous sheet is obtained by kneading a film or sheet obtained by kneading a filler into a polyolefin resin and melt-molding the film or sheet, using a method known in the art, for example, 1.2 to 5 uniaxially or biaxially.
It is obtained by double stretching.

As the polyolefin resin, for example, a resin mainly containing a monoolefin polymer or copolymer such as ethylene, propylene, or butene is used. Specific examples include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, crystalline ethylene-propylene block copolymer, polybutene, ethylene-vinyl acetate copolymer, and mixtures thereof. Among them, linear low-density polyethylene is desirable because it is flexible and tough. Polyolefin resin is 2
It is preferable to mix 0 to 70% by weight.

As the filler, inorganic and organic fillers are used. Inorganic fillers include calcium carbonate, gypsum, talc, carbon black, clay, kaolin, silica, diatomaceous earth, magnesium carbonate, barium carbonate, magnesium sulfate, barium sulfate, calcium sulfate, calcium phosphate, aluminum hydroxide, zinc oxide, hydroxide Magnesium, calcium oxide, magnesium oxide, titanium oxide, alumina, mica, asbestos powder, shirasu balloon, zeolite, silicate clay, cement, silica fume, mica powder and the like are preferred. On the other hand, as an organic filler, an epoxy resin; a thermosetting resin of sodium polyacrylate; a resin obtained by crosslinking a thermoplastic resin such as polyethylene, polypropylene and polyacrylate with radiation or the like; A higher thermoplastic resin is used. These fillers may be used alone or as a mixture. The filler is preferably blended in an amount of 30 to 80% by weight, particularly 40 to 70% by weight, from the viewpoints of ensuring sufficient moisture permeability, water pressure resistance, strength and moldability.

As the filler, it is preferable to use a filler whose surface has been treated with a fatty acid or the like in order to enhance its dispersibility. When a filler that has not been subjected to such treatment is used, a similar effect can be obtained by adding a fatty acid when kneading with the polyolefin resin.

When kneading the polyolefin resin and the filler, it is preferable to add a softening agent. As the softening agent, a plasticizer or a lubricant which is usually compounded in rubber or plastic can be used. Examples thereof include monoesters of fatty acids and aliphatic alcohols, monoesters or polyesters of aromatic carboxylic acids and aliphatic alcohols, polyesters of aliphatic polycarboxylic acids and polyalcohols, monocarboxylic acids and / or polycarboxylic acids. Polyesters of acids with monoalcohols and / or polyalcohols, esters or polyesters leaving part of alcohols and / or carboxylic acids, fatty acid amides, aromatic amides, metal soaps of fatty acids, metal soaps of aromatic carboxylic acids,
Butadiene oligomer, butene oligomer, petroleum resin,
Coumarone resin, ketone resin, chlorinated paraffin, silicone oil, liquid paraffin, polyethylene wax.

The blending amount of the softener is determined by the affinity between the softener and the polyolefin resin, the affinity between the softener and the filler,
And suitably selected according to the flexibility required for the porous sheet, but preferably 10% by weight or less, particularly preferably 0.1% by weight, in the porous sheet from the viewpoint of preventing stickiness.
-7% by weight.

In the porous sheet, in addition to these components, additives such as a stabilizer, a coloring agent, a lubricant and the like can be blended. These additives are present in the porous sheet at 0.01
Preferably, it is blended in an amount of up to 5% by weight.

The porous sheet has a moisture permeability (JIS Z).
It was measured in accordance with 0208. ) Is 0.5-4g / (100
cm ² · h), in particular ^{0.8~3g / (100cm 2 · h)} , especially 1
It is preferably 2.5 g / (100 cm ² · h) from the viewpoint of preventing stuffiness in the clothing and ensuring sufficient water pressure resistance.

The porous sheet has a basis weight of 10 to 70 g.
/ M ² , especially 10 to 50 g / m ² , especially 10 to 30 g
/ M ² is preferable from the viewpoints of securing sufficient moisture permeability, touch, and economy.

Back sheet 3 laminated with a porous sheet
The heat-rolled nonwoven fabric, the spunbonded nonwoven fabric, the meltblown nonwoven fabric, the nonwoven fabric combining the spunbonded nonwoven fabric (S) and the meltblown nonwoven fabric (M) (SM, SMS, SMMS, etc.), the air-through nonwoven fabric, the spunlace nonwoven fabric Etc. can be used. In particular, from the viewpoint of transparency, heat roll nonwoven fabric,
It is preferable to use a spunbonded nonwoven fabric, an air-through nonwoven fabric, or a spunlace nonwoven fabric.

The fibers constituting the nonwoven fabric are polyethylene,
Polyolefin resins such as polypropylene and propylene-ethylene random copolymer, polyester resins such as polyethylene terephthalate, and polyamide resins can be used. Of these, it is preferable to use polyolefin fibers.
As the fiber structure, any of a single fiber and a composite fiber such as a core-sheath fiber and a side-by-side fiber can be used. From the viewpoint of the feel and feel of the nonwoven fabric, it is preferable to use a conjugate fiber or a mixture of two or more fibers. Further, from the viewpoint of preventing leakage, the fibers constituting the nonwoven fabric are preferably hydrophobic. The fibers constituting the nonwoven fabric may contain a pigment such as titanium oxide, but from the viewpoint of the visibility of the transparent region 10, it is preferable that the pigment does not contain the pigment.

The fibers constituting the nonwoven fabric have a fineness of 0.
1 to 5 dtex, especially 1 to 3 dtex, the transparent region 1
It is preferable from the viewpoint of the visibility of 0 and the texture of the nonwoven fabric.
For the same reason, the basis weight of the nonwoven fabric is preferably 8 to 50 g / m ² , more preferably 8 to 30 g / m ² , and particularly preferably 8 to ²⁰ g / m ² .

The nonwoven fabric and the porous sheet are joined to each other by a predetermined adhesive to form a composite sheet. At the time of bonding, it is preferable to apply, for example, an adhesive in a spiral shape so as not to impair the moisture permeability of the porous sheet. The nonwoven fabric in the composite sheet forms the outer surface of the diaper 1. This gives the diaper 1 a good cloth-like feel.

Next, a second embodiment of the absorbent article of the present invention will be described. For the second embodiment, the first
Only different points from the first embodiment will be described, and the detailed description of the first embodiment will be appropriately applied to the points not particularly described. The second embodiment is different from the first embodiment in that the transparentizing composition is directly applied to the porous sheet in the first embodiment, whereas the transparentizing composition is directly applied to the porous sheet in the second embodiment. The clarifying agent composition is applied to a surface of the support sheet disposed adjacent to the porous sheet, the surface being opposed to the porous sheet.

Specifically, the support sheet is interposed between the back sheet and the absorber, and the clarifying agent composition comprises
It is applied to the back sheet facing surface (porous sheet facing surface) of the support sheet. Then, the surface of the support sheet coated with the clarifying agent composition abuts on the porous sheet, and the clarifying agent composition is transferred to the porous sheet. The area of the sheet becomes the transparent area. In particular, after applying the clarifying agent composition to the support sheet, the clarifying agent composition-coated surface of the support sheet is brought into contact with the porous sheet, and the support sheet and the porous sheet are preferably bonded to each other. It is preferable from the viewpoint of forming a transparent region.

According to the present embodiment, there is an advantage that thermal and / or mechanical damage to the porous sheet is reduced as compared with the case where the clearing composition is directly applied to the porous sheet. This is particularly advantageous when a thin porous sheet is used.

As the support sheet, paper, nonwoven fabric, transparent film, or the like can be used. From the viewpoint of cost, it is preferable to use the backing paper or paper constituting the absorber 4. In particular, polyethylene,
It is preferable to use a transparent film of polypropylene, polyethylene terephthalate, polyvinyl chloride, cellophane, or the like. The thickness of the support sheet is preferably 5 to 50 μm, particularly preferably 10 to 30 μm, from the viewpoint of securing the strength required for processing.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the transparent region is formed at the crotch lower part of the diaper where the excrement is most visible, but the formation region of the transparent region is not limited to this. In addition, the shape of the transparent region may be various patterns, in addition to the band shape (striped shape).

Further, in the above embodiment, the back sheet is constituted by the porous sheet and the nonwoven fabric. However, depending on the specific use of the absorbent article, the back sheet is constituted by the porous sheet without laminating the nonwoven fabric. Is also good.

Further, a transparent region is previously formed on the back sheet with the same or another clarifying agent, and the clarifying agent composition used in the present invention and the clarifying agent composition are added to the transparent region. You may arrange | position so that a transparent area may contact. Thereby, the clarifying agent composition acts on the transparent region having a predetermined light transmittance in advance, and a desired light transmittance can be maintained.

The absorbent article of the present invention can be applied to other absorbent articles such as sanitary napkins and incontinence pads, in addition to disposable diapers.

[0049]

Examples [Examples 1 to 8] Linear low-density polyethylene [Ultzex 2520F, manufactured by Mitsui Chemicals, Inc.] 10
0 parts by weight and surface-treated calcium carbonate (average particle size: 1
μm) 10 parts by weight of an ester composed of stearic acid / trimethylolpropane / adipic acid was added to 150 parts by weight, and the mixture was kneaded with a twin-screw kneader to produce pellets. The obtained pellets were supplied to an inflation molding machine to form an inflation sheet. The obtained sheet was stretched at a stretching temperature of about 2.3 times at a stretching temperature of 50 ° C. using a roll stretching machine to obtain a moisture-permeable porous sheet.
In Examples 1, 2, and 6, a porous sheet having a basis weight of 40 g / m ² and a moisture permeability of 1.8 g / (100 cm ² · h) was used. In Examples 3 to 5, 7, and 8, a porous sheet having a basis weight of 20 g / m ² and a moisture permeability of 1.7 g / (100 cm ² · h) was used.

In Examples 1, 2, and 6, the porous sheet itself was used as the back sheet. Examples 3 to 5, 7
In (8) and (8), an adhesive was applied by a die coater method on a spunbonded nonwoven fabric made of polypropylene having a fineness of 2.2 dtex (application amount: 1.8 g / m ² , application temperature: 150 ° C.), and a porous sheet was applied on the application surface. (Basic weight 20 g / m ² ) was used as a laminated composite sheet, which was used as a back sheet.

The clarifying agent composition comprising the components shown in Table 1 was applied to a pulp mount having a basis weight of 16 g / m ² at an application temperature of 1 g / m ^2.
At 50 ° C., intermittent coating was performed in a belt shape at the basis weight, width, length, number and area ratio shown in Table 1. Next, on the porous sheets of the porous sheets (Examples 1, 2 and 6) and the composite sheets (Examples 3 to 5, 7 and 8), the mount was arranged so that the clarifying agent composition faced the porous sheet. . Then, the mount was brought into close contact with the porous sheet (Examples 1, 2 and 6) or the composite sheet (Examples 3 to 5, 7 and 8) to form a transparent region having the shape shown in FIG. In order to transfer the clarifying agent composition into the pores of the porous sheet in a short time, the composition was stored at 40 ° C. for 3 days. Thereafter, the total light transmittance of the transparent region was measured by the method described above. Table 1 shows the results.

The obtained porous sheet (Examples 1, 2 and 6) and composite sheet (Examples 3 to 5, 7 and 8) were used as a back sheet, and a hydrophilic sheet was used as a top sheet. A disposable diaper shown in FIG. 1 was obtained using a mixture of pulp and a superabsorbent polymer as an absorbent. The area of the transparent region with respect to the area of the backsheet of the disposable diaper is as shown in Table 1.

Example 9 The clarifying agent composition comprising the components shown in Table 1 was replaced by the mount used in Example 4 and the thickness was changed to 1
A disposable diaper having a transparent region on the back sheet was obtained in the same manner as in Example 4 except that the disposable diaper was coated on a 5 μm polyethylene transparent film.

Comparative Example 1 A disposable diaper was obtained in the same manner as in Example 1, except that a clearing agent composition comprising the components shown in Table 2 was used and the coating composition was applied at the coating amount shown in Table 2. .

Comparative Example 2 A disposable diaper was obtained in the same manner as in Example 1, except that a clearing agent composition comprising the components shown in Table 2 was applied at a coating temperature of 25 ° C. using a die coater method.

[Evaluation of Performance] For the disposable diapers obtained in the examples and comparative examples, the visibility, the non-stickiness of the back sheet, the sharpness of the outline of the transparent area, and the total light transmittance 30 days after application (implementation) Examples 1 to 5 and Comparative Example 1 only) were evaluated. Table 1 shows the results.

[Visibility] A saline solution was used in place of urine excreted by infants, and 120 cc of the saline solution was absorbed into a diaper. The visibility of the transparent area was determined based on the following criteria. ：: Sufficiently visible that physiological saline was absorbed. Δ: It can be visually confirmed that physiological saline was absorbed. X: It cannot be visually recognized that physiological saline has been absorbed.

[Backsheet Non-stickiness] The transparent area was touched by hand, and the degree of stickiness was judged according to the following criteria. ：: No stickiness. Δ: Almost no stickiness. ×: There is stickiness.

[Clearness of the outline of the transparent region] In order to evaluate the sharpness of the outline of the transparent region together with the storage stability, the diaper was stored at 40 ° C for 2 weeks, and 120 cc of physiological saline was absorbed. Then, the sharpness of the outline of the transparent area was determined based on the following criteria. ：: The outline is clear, and it is sufficiently visible that physiological saline is absorbed. Δ: Although the outline is slightly blurred, it can be visually recognized that physiological saline is absorbed. ×: The outline is blurred and the physiological saline is not absorbed.

[Total Light Transmittance 30 Days After Coating] The total light transmittance of the diaper after storing it at 40 ° C. for 30 days was measured by the method described above.

[0061]

[Table 1]

[0062]

[Table 2]

As is clear from the results shown in Tables 1 and 2, in the disposable diaper of the embodiment (the product of the present invention), the formed transparent area has no stickiness and the outline of the transparent area is clear. It turns out that there is. Further, it can be seen that the transparency does not decrease even after long-term storage. On the other hand, in the diaper of the comparative example, there was stickiness due to the bleed-out component, and the outline of the transparent region was unclear due to the bleed-out. In addition, the transparency decreased after long-term storage.

[0064]

According to the absorbent article of the present invention, by using a clarifying agent composition containing a liquid component in an adhesive base polymer, compared to a case where a liquid component such as a softening agent is simply used. In addition, it is possible to control the bleeding speed and bleeding region of the liquid component, prevent the porous sheet from being excessively transparent, and form a transparent region having a clear pattern. Also, there is no stickiness of the transparent area. Furthermore, there is no migration of liquid components even if the absorbent articles overlap in the package for a long time. In particular, when the back sheet is a laminate of a porous sheet and a nonwoven fabric, these effects are particularly remarkably exhibited. Further, according to the absorbent article of the present invention, the porous sheet is hardly damaged. Therefore, a transparent region can be formed on a porous sheet thinner than before. Further, the pattern of the transparent region can be easily changed by changing the application pattern of the clarifying agent composition, and various desired patterns can be obtained. Furthermore, according to the absorbent article of the present invention, formation of a transparent region is easy. Further, the absorbent article of the present invention has high safety, and the transparent area is hardly opaque even after long-term storage.

[Brief description of the drawings]

FIG. 1 is a partially broken plan view of a disposable diaper as one embodiment of an absorbent article according to the present invention, as viewed from a back sheet side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disposable diaper (absorbent article) 2 Top sheet 3 Back sheet 4 Absorber 10 Transparent area

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3B029 BC03 BC07 4C003 CA01 CA06 4C098 AA09 CC10 CD07 CE06 DD02 DD03 DD06 DD10 DD13 DD16 DD22 DD23 DD24 DD25 DD26 DD27 DD28

Claims (6)

[Claims] 1. An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retentive absorber interposed between the two sheets, wherein the back sheet has moisture permeability. A transparent sheet, and a part of the porous sheet is made transparent or semi-transparent by a clarifying agent composition containing a base polymer for adhesion and a liquid component at room temperature that can be transferred into micropores of the porous sheet. An absorbent article in which a transparent region is formed and the total light transmittance of the region is 50% or more. 2. The clarifying agent composition comprises a styrenic elastomer as the base polymer for adhesion and a softener as a component of the liquid, and the content of the softener is 1
The absorbent article according to claim 1, which is 5 to 60% by weight. 3. The absorbent article according to claim 1, wherein said clarifying composition comprises amorphous polyalphaolefin as said adhesive base polymer and as a component of said liquid. 4. The clarifying agent composition is directly applied to the porous sheet to form the transparent or translucent region, or the clarifying agent composition is applied to the porous sheet. The transparent sheet is applied to a surface of the support sheet disposed adjacent to the porous sheet opposite to the porous sheet, and the transparentizing composition contacts the porous sheet to form the transparent or translucent region. The absorbent article according to any one of claims 1 to 3, wherein the absorbent article is used. 5. The absorbent article according to claim 1, wherein the area of the transparent or semi-transparent region is 2 to 50% of the area of the back sheet. 6. The absorbent article according to claim 1, wherein the back sheet comprises the porous sheet and a nonwoven fabric bonded to an outer surface of the porous sheet.