JPH06218007A - Absorptive article - Google Patents

Abstract

PURPOSE:To provide absorptive articles such as a disposable diaper, an incontinence pad, a physiologic napkin which decrease effectively humidity in fitting, provide no unpleasant feeling such as being stuffy and sticky and pleasant touch and do not produce any skin trouble such as being itchy and poisoned when the absorptive articles are used. CONSTITUTION:In an absorptive articles consisting of a liq. permeable surface sheet 11, a liq. unpermeable rear face sheet 12 and an absorptive body 13 positioned between both sheets, the absorptive article contains a hygroscopic material and moisture absorption of the absorptive article is at least 0.10g/hr under an environment of 35 deg.C/75% RH.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to absorbent articles such as disposable diapers, incontinence pads, sanitary napkins and the like, which have excellent hygroscopicity and do not cause discomfort such as stuffiness and stickiness during wearing.

[0002]

2. Description of the Related Art An absorbent article comprises a liquid-permeable surface material, a liquid-impermeable leak preventer, and an absorbent body which is interposed between the absorbent material and the absorbent body for absorbing and retaining liquid. It is well known. The function required for the absorbent article is to promptly absorb the excreted body fluid, not to return the absorbed body fluid, and to exhibit a high leakage prevention effect. Has been improved.

On the other hand, in recent years, in the above-mentioned absorbent article,
In addition to the enhancement of the functions described above, various functions related to the feeling of use are required. For example, it is strongly desired that the color of body fluid diffused in the absorber is shielded, that the surface contacting the skin is cloth-like in appearance and feel, and has a good texture. In particular, regarding the texture, how to reduce the feeling of stuffiness and stickiness on the body during use is an important issue.

The above-mentioned absorbent article is a form of use in which a specific part of the user's body is covered for a long period of time. With the recent improvement in the absorption performance of the absorbent article, the usage time per sheet is increased. There is a tendency to increase, the reduction of stuffiness and stickiness is
It is more important than a texture improvement. That is, if no improvement in this respect is made, the contacting part of the absorbent article is exposed to thermal stress for a long time,
As a result of further skin swelling under high humidity, if this is extreme, skin problems such as itchiness and rash occur,
There is a problem that even cases that cannot be used appear.

Conventionally, various techniques for improving the top sheet have been proposed as a method for reducing the feeling of stuffiness and stickiness. For example, a non-woven fabric, which is a hydrophobic fine fiber aggregate, is used as the surface material, and a hydrophobic atmosphere space is formed between the body surface and the absorbent body to prevent the liquid from returning without impairing the liquid permeability. Technology to improve (Japanese Patent Laid-Open No. 58-1806)
No. 02) or a hydrophobic sheet having pores, specifically, a film having pores is used as a surface material,
Technology for improving the liquid return prevention property (Actual No. 54-1243
98, JP 57-1340, and JP 61.
No. 45753) is proposed. The point of these conventional techniques is to improve the liquid return prevention performance, that is, to prevent the body fluid absorbed inside the absorbent article from seeping out between the top sheet and the skin, and By reducing the chances of direct contact with each other, the feeling of stuffiness and stickiness are reduced.

However, the above-mentioned conventional technique merely reduces the chance of direct contact between the skin and body fluid, and suppresses the moisture absorbed by the absorbent article evaporating due to body temperature and escaping to the skin side. In addition, it does not have any function of removing water vaporized as vapor from the skin side, and tentatively, it was possible to raise the liquid return amount to 0 by maximizing the liquid return prevention performance in the above-mentioned conventional technique. However, the feeling of stuffiness and stickiness cannot be essentially eliminated.

Therefore, an object of the present invention is to effectively reduce the humidity inside the absorbent article during use of the absorbent article so that it does not cause discomfort such as stuffiness and stickiness and has a comfortable texture.
An object of the present invention is to provide absorbent articles such as disposable diapers, incontinence pads, sanitary napkins, etc., which do not cause skin problems such as itchiness and rash.

[0008]

Means for Solving the Problems As a result of various studies, the present inventors achieved the above object by providing an absorbent article with a hygroscopic material so that the hygroscopic amount of the absorbent article becomes a certain amount or more. It was found that it could be done.

That is, the present invention has been made on the basis of the above findings, and is an absorbent material having a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber positioned between these two sheets. In the article, the absorbent article comprises a moisture absorbent, and the moisture absorption of the absorbent article is 35 ° C./75% RH.
The present invention provides an absorbent article which is 0.10 g / hr or more under the above environment.

The absorbent article of the present invention will be described in detail below. As the liquid-permeable top sheet, the liquid-impermeable back sheet, and the absorber, which are members constituting the absorbent article of the present invention, known materials can be used without particular limitation. Further, examples of the absorbent article of the present invention include disposable diapers, incontinence pads, winged or wingless sanitary napkins, and the like.

The absorbent article of the present invention contains a hygroscopic material,
The absorbent article has a specific moisture absorption amount.

The specific moisture absorption of the absorbent article of the present invention is 0.10 g / h in an environment of 35 ° C./75% RH.
r or more, preferably 0.35 to 1.00 g / hr
Is the range. If the amount of moisture absorption is less than 0.10 g / hr, the humidity of the site covered with the absorbent article will increase with the passage of wearing time even if there is no excretion of body fluid, which is practical. Not.

The hygroscopic material used in the present invention is not particularly limited, but it is preferable that the hygroscopic material does not contain a component harmful or irritating to the human body. In particular, when the hygroscopic material contains a water-soluble component, there is a risk that the component may be dissolved in body fluid during use and may come into contact with the skin. Therefore, as the hygroscopic material, a water-insoluble material is practically used. Alternatively, it is preferable to use a material obtained by subjecting a water-soluble material to an insolubilization treatment.

The amount of moisture absorbed by the moisture absorbent is 35 ° C./7.
0.10g / g under 5% RH environment ^*more than hr
Is preferred, and more preferably 0.35 to 1.20 g / g
^*It is the range of hr. The moisture absorption is 0.10 g / g^*h
When it is less than r, the absorbent article as a whole is practically sufficient.
Moisture absorbent material up to several g is used in order to develop various moisture absorption capacity
It is practical in terms of cost and weight
It is not preferable because it is not.

The above-mentioned water-insoluble materials include activated carbon,
Inorganic / organic porous material that physically and chemically adsorbs moisture such as natural or synthetic silica or synthetic zeolite on its surface, crosslinked polyacrylic acid sodium salt, starch-polyacrylic acid graft polymer, hydrophilic polyurethane, or carboxylate , A known superabsorbent polymer such as a copolymer of a monomer having a sulfonate or sulfate group and a monomer having a phosphate or phosphonate group,
Alternatively, a water-insoluble organic / inorganic hydrophilic gel that swells by absorbing moisture such as silica gel as vapor or liquid may be used.

Examples of the above water-soluble materials include deliquescent salts such as lithium chloride and sodium hydroxide, phosphorus pentoxide, sodium metal, calcium oxide,
Substances that chemically absorb water such as iron powder (including these substances that are generally considered to be insoluble in water [eg, calcium hydroxide, iron oxide, iron hydroxide, etc.] are formed by trace amounts of water. Ions also have a risk of exerting some influence on the human body and, in principle, require insolubilization treatment), substances such as calcium chloride, copper chloride, anhydrous copper sulfate, and the like that take in water as crystal water.

In addition, in order to insolubilize the above water-soluble materials, the above materials alone or a mixture or composite of these materials is used as a polymer having high water vapor permeability such as non-crystalline polyethylene, polystyrene or polypropylene. Coating method, or wrapping with a thin film made of the above polymer, or the like. In this case, the polymer that can be used may have any composition such as a single composition, a blend of a plurality of polymers, or a copolymer of a plurality of monomers. The film used for the above purpose has a large number of fine holes,
A so-called moisture permeable sheet having a high water vapor permeability is very suitably used.

The amount of the hygroscopic material used may be such that the amount of hygroscopicity of the absorbent article falls within the above range.
When the superabsorbent polymer is used as a hygroscopic material for a sanitary napkin, the amount used is preferably 1.0 g or more, more preferably 2 to 10 g. The amount used is 1.0g
If it is less than the above range, the hygroscopic effect is lowered when menstrual blood is absorbed, which is not preferable. Further, if it exceeds 10 g, the flexibility of the absorbent article is deteriorated, which is not preferable.

Examples of forms in which the absorbent article contains the hygroscopic material include the following. A form in which all of the above members are made of the moisture absorbent. A form in which each member is formed by mixing (dispersing) the hygroscopic material with a conventionally used material. A form in which a hygroscopic body is formed of the hygroscopic material, and the hygroscopic body is integrated with each member. A form in which the hygroscopic body is arranged between the respective members.

Specifically, the above-mentioned embodiment uses a method of using a hygroscopic hydrophilic film as a surface sheet, or hydrophilic polyurethane as an absorber, or a monomer having a carboxylate, sulfonate or sulfate group, and a phosphate or phosphonate group. It can be formed by a method using a foam of a copolymer with a monomer having

In the above-mentioned embodiment, a method using a non-woven fabric mixed with hygroscopic hydrophilic fibers, or a known superabsorbent polymer such as a crosslinked sodium polyacrylate or a starch-polyacrylic acid graft polymer is used as an absorber. Mixing (dispersion)
It can be formed by a method such as In particular, the method of mixing the above-described superabsorbent polymer with the absorbent body is effective in achieving high leakage prevention performance, because the superabsorbent polymer is a hygroscopic material and also has an excellent function as an absorbent material. Yes preferred.

In the above embodiment, for example, a hygroscopic body obtained by wrapping the hygroscopic material in a water vapor permeable film,
A method of installing the absorbent body under the absorbent body integrally with the absorbent body, a method of installing the hygroscopic body as a perforated structure in the upper body of the absorbent body or inside the absorbent body, or integrally with the absorbent body. It can be formed by a method of molding a hygroscopic body having a capsule structure encapsulating and dispersing the hygroscopic body in the absorbent body.

Further, the above-mentioned and the above embodiments can be formed by a method of using a water vapor permeable film sandwiching the hygroscopic material or a water vapor permeable film having the hygroscopic material dispersed therein as a backing material of each member. Is.

In the above-mentioned embodiment, the hygroscopic body is replaced by
It can be formed by a method such as disposing a separate member between the liquid-permeable surface sheet and the absorber.

Although hydrophilic fiber materials such as pulp and rayon, which are widely used as absorbers, have hygroscopicity in a general sense, they have sufficient moisture absorption to reduce stuffiness and stickiness. Although it does not show the ability, it is possible to obtain a hygroscopic material satisfying the above-mentioned preferable hygroscopic amount by performing an absolute dry treatment. That is, after placing a conventional absorbent article in a vacuumed environment (absolutely dry state), it is sealed with a highly crystalline polyethylene thick film or saran resin film or other packaging material with a high gas barrier property. By doing so, the absorber made of pulp or the like can be made a hygroscopic substance made of a hygroscopic material satisfying the above-mentioned moisture absorption amount.

[0026]

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1 A mixed surfactant of alkyl phosphate and sorbitan fatty acid ester was 0.34
25 g / m ² basis weight using polyethylene / polypropylene composite fiber [NBF manufactured by Chisso Corporation] with wt%
2 of low-density polyethylene [Mitsui Petrochemical Industry Co., Ltd., ULTOZEX 15101C] is used as the dry heat-bonded nonwoven fabric of
The 5 μ-laminated product was subjected to heat-opening to obtain a surface sheet material having a formation density of recesses of 52 / cm ² .
The size of the side wall opening in this recess is 0.1 to 2 m.
It was m ² .

Using the obtained topsheet, a sanitary napkin shown in FIG. 1 was prepared. FIG. 1 is a partially broken perspective view showing a sanitary napkin which is one embodiment of the absorbent article of the present invention. In FIG. 1, the sanitary napkin 10 has a recess 14 formed of the surface sheet material. Having a top sheet 11, a back sheet 12 made of a polyethylene-laminated liquid-impermeable leak-proof sheet, and having a density of 0.
It is composed of an absorbent body 13 made of a pulp sheet having a thickness of 5 mm and an amount of 06 g / cm ² , a basis weight of 300 g / m ² , and a slip-preventing hot melt adhesive (not shown). After the sanitary napkin is placed in a vacuum oven, it is vacuum sucked all day and night (the above treatment is referred to as absolute drying treatment). After finishing the drying process,
The sanitary napkin was taken out of the oven, immediately put in a polyethylene bag having a thickness of 40 μ, and the open part of the bag was heat-sealed to obtain the product 1 of the present invention.

Example 2 As an absorber, the basis weight is 33 g /
With the use of an absorbent paper of m ² having a length of 175 mm and a width of 70 mm which is integrated by sandwiching 2 g of a highly absorbent polymer (moisture absorbing material) (Wonder Gel manufactured by Kao Co., Ltd.),
A sanitary napkin similar to that of Example 1 was prepared and the product 2 of the present invention was prepared.
Got

[Example 3] As an absorber, a density of 0.06
Use an absorbent body in which 3 g of silica gel (hygroscopic material) [manufactured by Wako Pure Chemical Industries, Ltd.], which has been previously dried in advance, is evenly dispersed on a pulp sheet having a weight of 5 g / cm ² , a basis weight of 300 g / m ² , A sanitary napkin having the same structure as that of Example 1 was prepared except that it was used. Then, the product was promptly placed in a polyethylene bag having a thickness of 40 μm, and the opening of the bag was heat-sealed to obtain the product 3 of the present invention.

Example 4 As an absorber, 1 g of lithium chloride (moisture absorbing material) was used as a moisture permeable film (moisture permeability of 1.7 g / 10).
0 cm ² · hr) enclosed with a hygroscopic body having a length of 175 mm, a width of 70 mm and a thickness of 1.5 mm, and a density of 0.06 g.
/ Cm ² , grammage of 300 g / m ² , thickness of 5 mm, a sanitary napkin was prepared in the same manner as in Example 1 except that an absorbent body integrally installed under the pulp sheet was used. Got 3.

[Embodiment 5] 1 g of lithium chloride (hygroscopic material)
A moisture-permeable film (moisture permeability 1.7 g / 100 cm ² · h
A hole having a diameter of 5 mm was randomly formed in the sheet having a length of 175 mm, a width of 70 mm, and a thickness of 1.5 mm, which was enclosed by r). At this time, the edges of the holes were heat-sealed to form a perforated hygroscopic body having a hole having a density of about 1.5 holes / cm ² as a whole and in which lithium chloride inside was not exposed to the outside. The perforated hygroscopic material was subjected to a density of 0.06 g / cm ² , a basis weight of 300 g / m ² ,
It was sandwiched by two pulp sheets having a thickness of 2.5 mm, and these were integrated to obtain an absorber. A sanitary napkin was prepared in the same manner as in Example 1 except that the obtained absorbent body was used.
The product 5 of the present invention was obtained.

Comparative Example 1 The sanitary napkin prepared in Example 1 before being subjected to the absolute dry treatment was designated as Comparative Product 1.

[Comparative Example 2] An absorbent body having a basis weight of 33 g /
Between the m ² absorbent paper, a super absorbent polymer [manufactured by Kao Corporation,
Wonder Gel] Length 175m with 0.2g sandwiched
Comparative product 2 was obtained by preparing a sanitary napkin similar to that in Example 1 except that an absorber having a width of m and a width of 70 mm was used.

Products 1 to 5 of the present invention obtained as described above
Also, with respect to Comparative Products 1 and 2, the moisture absorption amount per hour, the humidity control effect in the wearing and the texture were evaluated, respectively. As a result, {amount of moisture absorption A of hygroscopic material, amount of moisture absorption A'of sanitary napkin, humidity control effect in wearing (humidity h0 [% R immediately after wearing
H], humidity h1 [% RH] after 2 hours of wearing, and average value of humidity change δh [% RH] before and after), texture evaluation results [a] stickiness, b) stuffiness, ha) overall feeling of use ]}
Is shown in Table 1. The evaluation method is shown below.

1) Moisture absorption amount per hour When measuring the moisture absorption amount of a hygroscopic material, a balance capable of weighing up to 0.01 g (manufactured by METTLER CORPORATION, Electronic, in an environment variable chamber set at 35 ° C./75% RH) [Balance, PM4000] was installed, and after the balance was sufficiently adapted to the environment, a moisture absorbent that had been precisely weighed was placed and left for 2 hours. If the weight increase before and after this is w1 and the weight of the original hygroscopic material is w0, the moisture absorption amount A of this hygroscopic material can be calculated by the following formula. A [g / g ^* hr] = w1 [g] / w0 [g] ^* 2 [h
r] The hygroscopic amount A ′ of the sanitary napkin can be measured by the same method, but in this case, it can be determined by the following formula. A '[g / hr] = w1 [g] / 2 [hr]

2) Humidity control effect during wearing Sanitary napkin (taken just before measurement when enclosed in polyethylene bag as in Example 1)
Is attached to the crotch of the monitor, and the temperature / humidity sensor [Daiichi Kagaku Co., Ltd., T
HP 13] was inserted, and the humidity in the wearing internal environment was measured immediately after the wearing and 2 hours after the wearing. The same measurement was performed using 20 women as monitors, and the humidity h0 [% RH] immediately after wearing and the humidity h1 [% R 2 hours after wearing
H] and the average value of the humidity change δh [% RH] before and after wearing are respectively determined and used as a standard for the effect of controlling the humidity inside the wearing.

3) Evaluation of texture Sanitary napkin (taken immediately before evaluation when enclosed in polyethylene bag as in Example 1)
We asked the monitor to be worn on the monitor for 2 hours or more under normal usage conditions, and interviewed the usage feeling for items a) to c) below.

B) Stickiness 1-Stickiness 2-Slightly sticky 3-Neutral 4-Slightly non-sticky 5-Not sticky

B) Feeling stuffy 1-stuffy 2-somewhat stuffy 3-neutral 4-somewhat stuffy 5-no stuffiness

C) Overall feeling of use 1-Dislike 2-Slightly dislike 3-Neutral 4-Some likes 5-Some likes

In the survey, we asked each person to select a number corresponding to a word that is closest to their feelings for each item. This survey was conducted on 20 monitors, and the average value of the numbers selected for each item was obtained. This average value has the following meanings for each item.

A) The smaller the stickiness value, the stronger the stickiness is felt. Neutral around 3,
The larger it is, the less sticky it is. B) Feeling stuffy The smaller the value, the stronger the feeling of stuffiness. Neutral at around 3, the greater the value, the less stuffy. C) The smaller the overall usability value, the worse the usability. Neutral in the vicinity of 3, the greater the feeling, the better the feeling of use.

[0044]

[Table 1]

As is clear from the results shown in Table 1, the hygroscopic material having a moisture absorption per unit time of 0.2 g / g ^* hr or more allows the sanitary napkin to have a moisture absorption of 0.2 g.
/ ^* Hr or more. It can be seen that the sanitary napkin having a moisture absorbing function keeps the humidity environment inside the dressing low for a long period of 2 hours. Particularly, in the napkins (particularly Examples 2, 4, and 5) in which a large amount of a hygroscopic material having an excellent hygroscopic property such as a high-absorbency polymer and lithium chloride was used, the humidity environment in the wearing was 2 It can be seen that there is almost no change until the time has elapsed, and the texture immediately after applying the napkin continues until the sanitary napkin is removed. With a napkin that does not have a special moisture absorption function, the humidity after two hours has passed since it was attached is 80 to 90%, which is almost unbearable. Corresponding to these conditions, in Examples 2, 4 and 5, the sanitary napkins have very good touch, and the sanitary napkins that do not have a special moisture absorption function as in Comparative Examples have very soft touch. It's bad.
In order to exhibit at least a neutral feel or more, the hygroscopic amount of the sanitary napkin is 0.2 g / h as in Examples 1 and 3.
It can be seen that it is necessary to be r or more.

Although the sanitary napkin has been described in the present embodiment, the present invention is not limited to these, and other absorbent articles such as disposable diapers and incontinence pads are provided. You can also

[0047]

EFFECTS OF THE INVENTION According to the present invention, the humidity in the clothes when the absorbent article is used is effectively reduced, and there is no discomfort such as stuffiness and stickiness, and a comfortable texture, and it is
There is provided an absorbent article such as a disposable diaper, an incontinence pad, and a sanitary napkin that does not cause skin problems such as rash.

[Brief description of drawings]

FIG. 1 is a partially broken perspective view showing an embodiment of an absorbent article of the present invention.

[Simple explanation of symbols]

 10 Sanitary Napkins 11 Topsheet 12 Backsheet 13 Absorber 14 Recesses

Claims (3)

[Claims] 1. An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body located between these sheets, wherein the absorbent article comprises a moisture absorbent material, The moisture absorption of the absorbent article is 0.10 g / hr under the environment of 35 ° C / 75% RH.
The above is the absorbent article characterized by the above. 2. The absorbent article according to claim 1, wherein the hygroscopic material is a super absorbent polymer. 3. The amount of the superabsorbent polymer used is 1.0
The absorbent article according to claim 2, which is g or more.