JP3469290B2 - Absorbent articles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to absorbent articles, and more particularly to absorbent articles such as open-type diapers, pants or brief type disposable diapers (including those for incontinence) and so-called training pants.

[0002]

2. Description of the Related Art Conventionally, as absorbent articles such as pants or brief type disposable diapers, particularly training pants, elastic members are attached around the waist and legs, and an absorber is interposed between the top sheet and the back sheet. Things are known. In these absorbent articles, the top sheet and the back sheet do not have stretchability, or even if they have stretchability, they are not excellent. By providing a large number of gathers around the legs, workability of attachment / detachment to the body and fit to the body are obtained.

However, the absorbent article having the above structure,
Especially, the diaper has the following problems. Since the structure of the diaper becomes complicated, the number of manufacturing steps increases, resulting in poor production efficiency and high cost. Since the gathers are relatively large, the diaper becomes bulky and difficult to store and store in a compact mold. The use of the elastic member may be biased, and local pressure is applied to the body, leaving marks on the skin. The back sheet or the front sheet may cause tight spots, which may reduce the fit of the diaper. The reduced fit of the diaper may cause leakage of excrement. It is difficult to give accurate gathers, and the diaper may shift from the wearer.

Therefore, in order to solve the above-mentioned problems (1) to (3), a diaper having a structure using elastic members as the top sheet and the back sheet has been conventionally proposed. For example, JP-A-3-80859 and JP-A-3-2245.
59 and Japanese Patent Application Laid-Open No. 4-227260 describe a diaper in which a stretchable non-woven fabric is used as a surface material and a stretchable film is used as a back surface material, and both are joined.

Further, Japanese Patent Laid-Open No. 4-89050 discloses that
A diaper using an elastic elastic film as the back sheet and an elastic elastic nonwoven fabric as the surface sheet, or
A disposable diaper that is a composite sheet of a stretchable elastic film and a non-stretchable film is used as the back sheet, and a stretchable elastic nonwoven fabric and a non-stretchable nonwoven fabric are used as the top sheet. Have been described.

[0006]

However, although any of the above-mentioned constitutions solves some of the above problems, not all of them have been solved.

For example, in the diapers having the configurations described in the above-mentioned respective publications, since a stretchable elastic nonwoven fabric is used for the surface sheet, various physical properties of the nonwoven fabric used as the surface sheet may be limited. .

That is, the topsheet is a member that comes into direct contact with the wearer of the diaper, and the non-woven fabric used as the topsheet is soft to the touch, irritating to the skin, liquid permeable, liquid diffusible, and has a covering effect on the absorbent body. Although it is required to control many physical properties such as prevention of liquid return, it is difficult for the diaper having the configuration described in each of the above publications to satisfy all these physical properties.

When the stretchable elastic nonwoven fabric is stretched, the basis weight, the thickness, the thickness of the fibers, the openings between the fibers, or the interfibers when the stretched state is compared to the original non-stretched state. Physical properties such as distance may change, and the physical properties of the surface sheet of the diaper controlled by these physical properties may not be maintained. Further, since the entire diaper is stretchable, it fits well on the body, but in the case of a back sheet having no moisture permeability, there is a risk of causing stuffiness.

Therefore, an object of the present invention is to provide an absorbent article which makes full use of the advantages of the non-woven fabric which is usually used in disposable diapers and the advantages of using a film having elastic elasticity as a back sheet. To do.

[0011]

The present invention comprises a liquid-impermeable backsheet, a liquid-permeable topsheet, and a vertically elongated absorber disposed between the backsheet and the topsheet. in an absorbent article having a flexible film in which the back sheet is a stretchable elastic properties, on the flexible film, a nonwoven fabric having a plurality of fold portion stretchable is, are intermittently joined, the The absorber is
The front surface of the absorber is surrounded by at least both sides of the bottom surface of the absorber.
It is joined intermittently to the face sheet, and
The surface sheet located on the bottom surface is not
The above object is achieved by providing an absorbent article characterized by being joined intermittently (hereinafter, this invention will be referred to as the "first invention").

[0012]

[0013]

In the absorbent article of the present invention, the back sheet is made of a flexible film having elasticity, and the nonwoven fabric intermittently joined on the flexible film is also formed to be extensible. Since the non-woven fabric and the non-woven fabric are integrally stretchable, the non-woven fabric is stretchable in the waist circumference direction when worn by the user, and has a good fit to the body.

[0014]

EXAMPLES The absorbent article of the present invention will be described in more detail below with reference to examples. <Embodiment 1 (Embodiment of the first invention)> FIG.
(Invention) is a perspective view showing a pants-type disposable diaper showing an embodiment, FIG. 2 is a development view thereof, and FIG. 3 is a sectional view taken along line I-I in FIG. The absorbent article (pants-type disposable diaper) 1 of the present embodiment, as shown in FIGS. 1 to 3, is a liquid impermeable back sheet 2, a liquid permeable top sheet 3, the back sheet 2 and the back sheet 2. It is provided with a vertically long absorber 4 arranged between the surface sheets 3, and has both side portions 5a, 5a at the front portion (abdominal side portion) and both side portions 5b, 5b at the rear portion (back side portion). As shown in FIG. 1, the waist openings 12 are joined together.
And a pair of leg openings 13 and 13 are formed in a pants shape. Such a structure is similar to a known pants-type disposable diaper.

In the pants-type disposable diaper 1 of this embodiment, as shown in FIGS. 2 and 3, the back sheet 2 is a flexible film having elastic properties (hereinafter referred to as “flexible film” as appropriate). ), And the non-woven fabric 6 having a large number of stretchable folds is intermittently joined to the flexible film. Further detailed description of this embodiment,
As shown in FIG. 3, the non-woven fabric 6 has a corrugated cross-sectional shape in which convex ridges 6 ′ and concave ridges 6 ″ extending in the longitudinal direction of the absorbent body 4 are alternately arranged. A fold is formed by the portion 6 ′ and the recessed portion 6 ″, and the fold is extendable in the width direction of the absorbent body 4. And the non-woven fabric 6
Is intermittently joined to the back sheet 2 via a hot melt adhesive 7 at the outer surface apex of the recessed portion 6 ″, and the back sheet 2 is integrally formed with the nonwoven fabric 6 and the absorbent body 4. The width of the folds in the nonwoven fabric 6, that is, the ridges 6 ', 6'.
The interval L between them is 0.5 to 1.5 mm. The "range" in which the non-woven fabric 6 having a large number of folds can be stretched varies depending on the flexible film forming the back sheet 2 used, but the width of the non-stretched non-woven fabric 6 (width direction of the absorbent body 4). And non-woven fabric 6 stretched to a non-stretchable state
Ratio of width (the latter / the former) [(the latter; extension) / (the former;
Unstretched)] is particularly preferably in the range of 1.2 to 3.0.

The absorber 4 is made up of the topsheet 3
Is surrounded by both sides of the bottom surface of the absorber 4,
On the upper surface side of the absorber 4, the hot melt adhesive 7
Is joined to the surface sheet 3 by. In addition, the topsheet 3 is provided on both sides of the bottom surface of the absorber 4,
The ridge 6'of the non-woven fabric 6 by the hot melt adhesive 7
Is joined to the top end of the non-woven fabric 6 so as not to hinder the expansion of the nonwoven fabric 6.

As the constituent fibers forming the non-woven fabric 6, the following fibers are preferred. Polyolefin-based fibers such as polyethylene or polypropylene, polyester-based, amide-based or acrylic-based synthetic fibers, regenerated fibers such as rayon or cupra, and natural fibers such as cotton, linen or silk. As a method for processing the above fibers into a non-woven fabric, an ordinary processing method can be used, and examples thereof include heat roll bond, air through heat bond, spun bond, needle punch, spun lace or melt blown. be able to. In addition, the nonwoven fabric 6
Preferably has a basis weight of 10 to 40 g / m ² . If the grammage is less than 10 g / m ^2, it is difficult to obtain a uniform nonwoven fabric, and the physical properties of the surface sheet may vary. If it exceeds 40 g / m ² , the diaper becomes bulky and compact. It is not preferable because it becomes difficult to store and store.

Examples of the surface sheet 3 include polyolefin fibers such as polyethylene or polypropylene, polyester fibers, amide fibers or acrylic fibers, regenerated fibers such as rayon or cupra, and natural fibers such as cotton, hemp or silk. Can be used. As the absorbent body 4, it is preferable to use a high-molecular water-absorbing polymer in combination with defibrated pulp as a main material, and it is preferable to heat-treat a mixture of a thermoplastic resin, cellulose fibers and a high-molecular water-absorbing polymer.
The high-molecular water-absorbing polymer is the upper layer, the middle layer,
It may be present in any of the lower layers, or may be a mixture with pulp. Further, the high molecular weight water-absorbing polymer is preferably in the form of particles having a retaining property capable of absorbing and retaining a liquid 20 times or more its own weight and having a gelling property. Preferred examples include starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, crosslinked sodium carboxymethyl cellulose, and acrylic acid (salt) polymers.

Further, as the above-mentioned flexible film having stretchable and elastic properties which forms the back sheet 2, an elastomer film having moisture permeability is preferably mentioned. As the material of the elastomer film, for example, one that satisfies the required physical properties is selected from elastomers such as natural rubber, isoprene rubber, butadiene rubber, olefin rubber, urethane rubber, ester rubber or amide rubber. Further, an elastomer is preferable, in which after the elastomer is tensioned and stretched 100%, and when the tension is released, at least 70% of its elongation is recovered.

A method for imparting the above-mentioned moisture permeability to the back sheet 2 is, for example, Japanese Patent Laid-Open No. 4-279321.
On the dielectric roll, after the back sheet 2 is sandwiched between a diamond roll and a resin-coated receiving roll to form micron-order unpenetrated holes in the back sheet 2, It is possible to use a method in which a high-pressure discharge is generated and the unpenetrated hole is irradiated with an arc to form a penetrating hole. In this case, the back sheet 2
Has a moisture resistance of 2m or more and a moisture permeability of 1.0.
Preferably so as to be ~2.5g / 100cm ² · 1hr.

In the underpants type disposable diaper 1 of the present embodiment constructed as described above, the back sheet 2 is
The non-woven fabric 6 which is a flexible film having stretchability and which is intermittently joined to the flexible film is formed so as to be stretchable in the width direction of the absorbent body 4.
Since the non-woven fabric 6 and the non-woven fabric 6 expand and contract integrally, the non-woven fabric 6 can fully utilize the advantages of the non-woven fabric 6 such as texture, liquid permeability, and liquid return property, and the flexible film used as the back sheet 2 has The advantages such as fit can be fully utilized.

[0022]

[0023]

[0024]

[0025]

[0026] <Other Embodiment> FIG 4 is a sectional view showing a partially omitted of the onset Ming another embodiment, the pants-type disposable diaper of this embodiment,
Except that aspects of the surrounding of the absorbent body by the surface sheet is different <br/> as in Example 1 is constructed in the same manner as in Example 1.
That is, the pants-type disposable diaper 1 of the embodiment shown in FIG.
As shown in the figure, the absorber 4 is surrounded by the topsheet 3 up to both sides of the bottom surface of the absorber 4, and the topsheet side of the absorber 4 is joined to the topsheet 3 by a hot-melt adhesive 7. Has been done. Then, the surface sheet 3 is partially folded back to the opposite side of the absorbent body 4 on both sides of the bottom surface of the absorbent body 4, and in the folded back part, a non-woven fabric is formed by the hot melt adhesive 7 (Fig. It is joined to the top end of the ridge (not shown) so as not to hinder the elongation of the nonwoven fabric. Further, the nonwoven fabric 6 in Example 1 can be expanded only in the width direction of the absorbent body 4, but as the nonwoven fabric 6, only the longitudinal direction of the absorbent body 4 or the width of the absorbent body 4 is used. It may be stretchable in both the longitudinal and longitudinal directions.

[0027] Note that in other embodiments of the above, for the points not specifically described, the description is applied to definitive in Example 1.

Next, show a manufacturing example of the onset light of the absorbent article, but further illustrate the invention, the absorbent article of the present invention is not intended to be limited to these Production Examples. <Manufacturing Example 1> This Manufacturing Example 1 is a manufacturing example of the pants-type disposable diaper of the first embodiment. The nonwoven fabric 6 having a large number of stretchable folds in Example 1 has a larger area than the area of the back sheet 2 in a state where no tension is applied to the back sheet 2 (so-called free tension state) [fold processing. A non-woven fabric (hereinafter, referred to as a non-woven fabric N means a non-folded non-woven fabric)]. Specifically, the non-woven fabric N is subjected to a fold process (crepe process) in advance by a method such as a Miclex process, the non-woven fabric N, and the back sheet 2 stretched in one direction to have the same area as the non-woven fabric N.
A method in which the nonwoven fabric N is pleated by intermittently joining and is mentioned.

As a method of joining the non-woven fabric 6 having the folds formed by the above method and the back sheet 2 to each other, there is a method of using an adhesive such as a hot melt adhesive. An adhesive is applied to the outer surface apex of the crease 6 ″ of the folds. Further, the non-woven fabric 6 formed by the above method and the back sheet 2 are joined together without using the adhesive. Alternatively, a thermoplastic elastomer may be used as the material, and the thermoplastic elastomer 2 may be brought into contact with the top end of the outer surface of the concave streak portion 6 ″ of the fold portion of the nonwoven fabric 6, and then the both may be subjected to composite processing.

As a method for joining the nonwoven fabric N and the back sheet 2 when forming the fold-containing nonwoven fabric 6 by the above method, a joining method using an adhesive such as a hot melt adhesive, heat sealing or A joining method using ultrasonic embossing or the like may be used. In the above method, when the above hot melt adhesive is used, the hot melt adhesive is patterned on the back sheet (flexible film) 2 or the non-woven fabric N in a dot shape or a linear shape. Among these patterns, the dot pattern is particularly preferable. In this case, the application of the adhesive may be performed before or after stretching the back sheet (flexible film). Also,
In the above method, when a method such as heat sealing or ultrasonic embossing is used, the back sheet 2 and the non-woven fabric N are joined intermittently by forming the roll pattern into a dot-shaped or linear-shaped pattern. can do.

According to the above method, the stretching direction of the back sheet (flexible film) 2 may be only in the width direction of the absorber 4, only in the longitudinal direction of the absorber 4, or in both directions. However, when the above linear pattern is used as the pattern of the adhesive or the like, the extension direction of the back sheet 2 is the width direction of the absorbent body 4, and in this case, the linear direction of the linear pattern. And the stretching direction of the back sheet are orthogonal to each other.

In the above method, when bonding is performed using an adhesive pattern such as a dot shape or a linear shape, the size and the distance between them are the expansion and contraction required for the construction of the pants-type disposable diaper and the absorbent article described later. It is preferable to appropriately select in consideration of the rate, and when joining using a linear pattern, it is preferable to apply intermittently. When the pattern is dot-shaped, the dot-shaped area is 0.05 ~
3.0 mm ^2, preferably 0.6 to 1.0 mm ^2, the interval distance between each dot 3.0～7.0Mm, preferably 3.0 to 5.0 mm. When the pattern has a linear shape, its width is preferably 0.5 to 1.5 mm.
Is. In addition, these numerical values are numerical values in the bonded sheet after the non-woven fabric N and the back sheet (flexible film) are bonded and then the back sheet returns to the unstretched state.

When the back sheet 2 and the nonwoven fabric 6 are joined by the above method, the area ratio of the back sheet 2 (the flexible film having elastic properties) and the nonwoven fabric N in the free tension state (free). Is the area of the backsheet 2 in tension: the area of the non-woven fabric) the same as the required expansion / contraction rate of the backsheet 2 when tension is applied to the backsheet 2 in the width direction or the longitudinal direction of the absorber 4. It is preferably larger than that. The area ratio is preferably 1 to 1.1: 5.0,
The ratio is more preferably 1 to 1.2: 3, and is preferably set as appropriate according to the method of joining the back sheet 2 and the nonwoven fabric or the designing method.

In the underpants type disposable diaper 1, the area ratio is set to be small in a part where a high expansion / contraction rate is not required, and in a part where a high expansion / contraction rate is required,
Although it is preferable to set the area ratio to a large value, the expansion / contraction rate required for the absorbent article is 1.1 to 5 in the width direction or the longitudinal direction of the absorbent body 4 at the portion to which the elasticity is to be imparted. It is preferably set to be 0.0 times. If the expansion / contraction ratio is less than 1.1 times, the pants-type disposable diaper 1 becomes difficult to apply, and if it exceeds 5.0 times, the ratio of the folds of the nonwoven fabric 6 when the back sheet 2 is in the free tension state. Is increased, which may adversely affect the absorbability and diffusibility of excrement, which is not preferable.

Thus, in this Production Example 1, the hot-melt adhesive is stretched in the width direction of the absorber 4 on the back sheet 2 or the nonwoven fabric N, and the absorber 4 in FIG.
Is applied linearly (linearly) in the width direction of the absorbent body 4 at regular intervals in the longitudinal direction. Then, by joining these and releasing the stretched state of the back sheet (flexible film), folds are formed in the nonwoven fabric N in the width direction of the absorbent body 4 (the ridges of the folds). The portion and the concave streak portion are formed along the longitudinal direction of the absorber 4). Then, the absorbent body 4 surrounded by the topsheet 3 in advance is placed on the non-woven fabric 6 joined to the backsheet in this manner, and the topsheet 3 and the nonwoven fabric 6 are combined at the top end of the ridge 6 '. Join intermittently at. After that, a pant-type diaper is formed by a conventional method.

[0036]

[0037] The present invention is not limited to the above embodiments and the above Production Examples, for example, as a non-woven fabric 6 in the first embodiment, as possible out also be used those produced by the above method. Needless to say, other changes can be made without departing from the spirit of the present invention. The absorbent article of the present invention is preferably a pants-type disposable diaper as shown in FIG. 1, but is an open-type diaper or a flat-type disposable diaper (including incontinence) and a so-called training pants. Is also good.

[0038]

INDUSTRIAL APPLICABILITY The absorbent article of the present invention can make full use of the advantages of a stretchable nonwoven fabric and the advantage of using a film having stretchable elastic properties as a back sheet.

[Brief description of drawings]

FIG. 1 is a perspective view showing a pants-type disposable diaper showing an embodiment of the present invention (first invention).

2 is a development view of the pants-type disposable diaper shown in FIG. 1. FIG.

3 is a cross-sectional view taken along line I-I in FIG.

FIG. 4 is a sectional view showing a part of another embodiment of the present invention (first invention).

[Explanation of symbols]

1 absorbent article 2 Back sheet 3 surface sheet 4 absorber 5 Extension 6 non-woven fabric 7 Hot melt adhesive

Continuation of front page (56) References JP-A-53-273 (JP, A) JP-A-2-152450 (JP, A) JP-A-5-245961 (JP, A) Actual Kaihei 6-7925 (JP , U) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61F 13/15-13/84 A61F 5/44

Claims (2)

(57) [Claims] 1. An absorbent article comprising a liquid-impermeable backsheet, a liquid-permeable topsheet, and a vertically long absorber disposed between the backsheet and the topsheet, wherein: a flexible film backsheet having a stretchable elastic properties, on the flexible film, a nonwoven fabric having a plurality of fold portion stretchable is being intermittently bonded, the absorber, by the topsheet At least the suck
Enclosed up to both sides of the bottom of the container and intermittently with the top sheet
On the bottom surface of the absorber
An absorbent article in which the surface sheet is intermittently joined to the non-woven fabric . 2. The absorbent article according to claim 1, wherein the nonwoven fabric is extensible in a width direction and / or a longitudinal direction of the absorbent body.