JP4294045B2 - Absorbent articles - Google Patents

Description

The present invention relates to an absorbent article such as a disposable diaper or a sanitary napkin formed using a composite elastic member that can form a gather that is soft to the touch and has a beautiful appearance.

In an absorbent article such as a disposable diaper and a sanitary napkin, an elastic member is joined to a sheet material in an expanded state, and the elastic member is contracted to form a gather (an elastic part having a large number of wrinkles) on the sheet material. It is widely done.
However, the conventional gathered heel has a short length in the direction orthogonal to the expansion and contraction direction, and is not very beautiful in appearance.

  Patent Document 1 discloses an elastic stretchable sheet formed by bending a flat sheet material to form a large number of ridges that repeat peaks and valleys, and joining elastic members to the tops of a plurality of peaks of the ridges. . In this sheet, the wrinkle extends over a plurality of the elastic members and is relatively beautiful. On the other hand, the wrinkles are caused by the presence of the joint portion between the sheet material and the elastic member. The touch when touching the skin is not so good.

  Patent Document 2 discloses an elastic stretchable part having a sheet material made of nonwoven fabric and an elastic member sandwiched between two layers formed by folding the sheet material, in a direction perpendicular to the stretch direction of the elastic member. There is described a disposable diaper having a linear joint portion between extending sheet materials, and having an elastic stretchable portion formed by joining the elastic member to the sheet material at the joint portion. However, there is room for improvement in the elastic stretchable part of the disposable diaper in terms of softness and touch when in contact with the skin.

JP 2001-11769 A Registered Utility Model No. 2518953

An object of the present invention is to provide an absorbent article such as a disposable diaper or a sanitary napkin formed using a composite elastic member that can form a gather with a soft touch and a beautiful appearance.

The present invention is an absorbent article in which a stretchable part is formed using a composite stretchable member having a stretchable part composed of two sheet materials and a plurality of elastic members arranged between the two sheet materials, The two sheet materials are intermittently bonded to each other in the expansion / contraction direction of the expansion / contraction portion and the direction orthogonal thereto, and the elastic member is attached to the expansion / contraction portion so as not to pass through the connection portion between the two sheet materials. Are arranged and fixed to both sheet materials at both ends thereof, and each of the sheet materials forms a plurality of ridges extending continuously across the plurality of elastic members , The object is achieved by providing an absorbent article in which a waist stretchable part is formed by the composite stretchable member .

The present invention is an absorbent article in which a stretchable part is formed using a composite stretchable member having a stretchable part composed of two sheet materials and a plurality of elastic members arranged between the two sheet materials, The absorbent article is a disposable diaper having a fastening tape, and the two sheet materials are intermittently joined to each other in the expansion / contraction direction of the expansion / contraction section and the direction orthogonal thereto. The sheet material is disposed so as not to pass through the joint portion between the sheet materials, and is fixed to both sheet materials at both ends thereof, and each of the sheet materials spans a plurality of the elastic members. forms a plurality of pleats extending continuously Te, wherein the composite elastic member, said tape near stretchable part that expands and contracts in conjunction with the fastening tape is formed to provide an absorbent article It is obtained by achieving the above object by the.

The absorbent article of the present invention can form a gather (a stretchable part having a large number of wrinkles) that is soft to the touch and has a beautiful appearance .

Hereinafter, the present invention will be described with reference to the drawings.
FIG. 4 is a diagram showing a disposable diaper 20 as an embodiment of the present invention.
In the disposable diaper 20 shown in FIG. 4, the waist stretchable portion 22, the tape vicinity stretchable portion 23 that stretches in conjunction with the fastening tape 21, the waistline stretchable portion 24, and the stretchable portion formed on the skin contact surface of the leak-proof wall. 25 is formed of a specific composite elastic member.
Hereinafter, the composite elastic member that can be used for forming the elastic part in the absorbent article of the present invention will be described.
A composite elastic member 1 (hereinafter also referred to as a composite elastic member 1 of this embodiment) used in one embodiment (first embodiment) of the present invention is composed of two sheet materials 2, 3 as shown in FIG. The elastic member 10 includes a plurality of elastic members 4 disposed between the two sheet materials.
The stretchable part 10 is formed at the center of the composite stretchable member 1 in the direction in which the elastic member 4 extends. At both ends 11 (only one shown) of the composite stretchable member 1 in the same direction, the elastic member 4 is a sheet. Bonded to the material.

As shown in FIG. 2, the two sheet materials 2 and 3 constituting the expansion / contraction part 10 intermittently heat each other in each of the expansion / contraction direction (X direction) of the expansion / contraction part 10 and the direction orthogonal to the expansion direction (Y direction). It is fused (joined).
The plurality of elastic members 4 in the present embodiment are arranged in parallel with each other, and are arranged so as to extend along the longitudinal direction of the composite elastic member 1.
In the case where a plurality of elastic members are arranged parallel to each other as in the present embodiment, the expansion / contraction direction of the expansion / contraction part 10 is the same direction as the direction in which the elastic member 4 extends. In addition, the expansion / contraction direction of the expansion / contraction part when the plurality of elastic members 4 are not arranged in parallel to each other is a direction orthogonal to the direction in which the ridges of the ridges (described later) extending over the plurality of elastic members extend. .

FIG. 2 is a diagram illustrating a formation pattern of the heat-sealed portions (joined portions) 5 between the two sheet materials 2 and 3. In the present embodiment, the heat-fused portions 5 are staggered as illustrated. Is formed.
Expansion / contraction of the expansion / contraction part 10 in a state in which the expansion / contraction part is extended (the state shown in FIGS. 2 and 3, when the expansion / contraction part is extended) from the viewpoint of reliably forming the flange 6 extending continuously over the plurality of elastic members 4. In the direction (X direction), the pitch P1 (see FIG. 2) of the heat fusion part 5 is preferably 1 to 30 mm, particularly 6 to 20 mm, and the length L1 of each heat fusion part 5 (see FIG. 2). Is preferably 0.1 to 5 mm, particularly preferably 0.2 to 1.5 mm, and the ratio of the pitch P1 to the length L1 (P1 / L1) is 1.1 to 300, particularly 4 to 100. Is preferred.

It is preferable that the two sheet materials 2 and 3 in the stretchable part 10 are not joined to each other at a part other than the heat-sealed part 5.
Each elastic member 4 is disposed on the stretchable portion 10 so as not to pass through the heat-sealing portion 5 between the two sheet materials, and is fixed to the two sheet materials 2 and 3 only at both ends of the elastic member 4. Both end portions of the elastic member 4 are fixed between both sheet materials at both end portions 11 (only one is shown) of the composite elastic member 1 while being sandwiched between the sheet materials 2 and 3. The both end portions 11 may be formed to be extendable.

The heat-sealed portions 5 between the sheet materials are formed so as to form a line (form a seal line) in the expansion / contraction direction (X direction) of the expansion / contraction portion 10 and the direction orthogonal to the expansion direction (Y direction). One heat fusion part 5 constituting a row in the direction to be formed is formed for every two elastic members.
A region where the heat-sealing portion 5 does not exist extends between both ends 11 (only one is shown) of the stretchable portion 10 between the stretchable direction (X direction) row and the row adjacent thereto. The elastic member 4 is arranged in a non-bonded state in the region. In addition, the position of the heat-fusion part 5 has shifted | deviated by a half pitch (P1 / 2) with the row | line | column of the expansion-contraction direction (X direction) of the expansion-contraction part 10 and the row | line | column adjacent to it.

  In the composite stretchable member 1 of the present embodiment, the elastic member 4 contracts in its natural state (a state in which no external force is applied), so that each of the two sheet materials 2 and 3 is, as shown in FIG. A plurality of flanges 6 and 6 extending continuously over the plurality of elastic members 4 are formed.

  Each ridge 6 of both sheets 2 and 3 is formed so as to protrude on both surfaces of the composite elastic member 1, and a convex curved surface having an arcuate cross section is formed at the tip in the protruding direction of each ridge 6. Yes. The convex curved surface continuously extends in a direction (Y direction) orthogonal to the expansion / contraction direction of the expansion / contraction part. In the present embodiment, two ridges 6 are formed between the heat fusion portions 5 and 5 adjacent to each other in the expansion / contraction direction (X direction) of the expansion / contraction portion 10, and these ridges 6 are elastic members. 4 is continuously divided in a direction (Y direction) orthogonal to the expansion / contraction direction of the expansion / contraction part without being divided at a portion overlapping with 4.

  In the composite elastic member 1 of the present embodiment, each of a large number of flanges 6, 6 formed by contraction of the elastic member 4 continuously extends in a direction (Y direction) perpendicular to the expansion / contraction direction of the expansion / contraction part 10. Because it looks very beautiful. On the other hand, when the sheet materials 2 and 3 are continuously joined along the elastic member 4 (thermal fusion, adhesion with an adhesive, etc.), the flange 6 (particularly the top) is connected to the elastic member 4. In addition to being broken and divided at the overlapping points, random wrinkles are formed and the appearance is not only impaired, the degree of freedom of deformation of the wrinkles 6 with respect to external force is reduced, and the flexibility of the touch is also reduced.

Further, in the composite elastic member 1 of the present embodiment, the elastic member 4 in the elastic part 10 has a trough between the flange 6 and the flange 6 in one sheet material 2 and the flange 6 and the flange 6 in the other sheet material 4. Exists in a state of being sandwiched between the valleys between the two and the sheet materials 2 and 3 including a portion sandwiched between the valleys. In addition, since both the sheet materials 2 and 3 in the stretchable portion 10 are not continuously joined in any of the stretchable direction of the stretchable portion 10 and the direction orthogonal thereto, an increase in rigidity can be prevented and an external force can be prevented. The degree of freedom of deformation of the heel 6 is improved. Moreover, the tip of the ridge forms a convex curved surface.
Therefore, the volume is increased in the thickness direction of the sheet material, the touch when the surface of the composite elastic member 1 is touched is extremely soft, and the touch is very good.

  Further, since the elastic member in the stretchable part 10 is present in a state where it is not joined to both the sheet materials 2 and 3, the amount of adhesive used can be suppressed to zero or a small amount, particularly as in this embodiment. When the two sheet materials 2 and 3 are joined together by heat fusion, the effect of reducing the amount of adhesive used is more remarkable. Since there is little hot melt, air permeability and moisture permeability are not impaired.

The material for forming the composite elastic member 1 of this embodiment will be described.
Examples of the sheet materials 2 and 3 include nonwoven fabrics, woven fabrics, knitted fabrics, resin films, and the like produced by various manufacturing methods such as air-through nonwoven fabric, heat roll nonwoven fabric, spunlace nonwoven fabric, spunbond nonwoven fabric, and meltblown nonwoven fabric. A sheet material obtained by stacking and integrating the above can be used.
Both sheet materials or one sheet material (especially a sheet material that forms a skin-side surface when used for making a composite elastic member abut on the skin) from the viewpoint of forming a beautifully pleasing and comfortable feel. The forming material is preferably an air-through nonwoven fabric, a heat roll nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, a meltblown nonwoven fabric, or the like.

  The sheet is deformed with respect to the contraction of the elastic member, thereby forming the ridge. That is, the rigidity of the seat is one of the factors that determine the formability and cushioning properties of the composite elastic member. Stiffness can be represented by the buckling strength of the sheet material. The buckling strength of the nonwoven fabric used in the present invention is preferably 100 cN or less, particularly preferably 70 cN or less. Here, the buckling strength is measured by a compression test mode of a Tensilon universal testing device (Orientec Co., Ltd.) as shown below.

Buckling strength test method (CD):
Take a rectangular test piece of 150 mm in the machine flow direction (MD) and 30 mm in the direction perpendicular to the machine flow direction (CD), make a cylinder with a diameter of 45 mm, and measure the upper and lower ends of the overlapping parts with staples etc. A sample. This is measured at a measurement environment of 20 ° C., 65% RH, and measurement conditions of a compression speed of 10 mm / min and a measurement distance of 20 mm in the compression test mode of the Tensilon universal testing device. The maximum strength when the sample is compressed by 20 mm is measured for each sample, the average value is obtained, and this is defined as the buckling independence.
As described above, a non-woven cloth is preferably used as the sheet material. The basis weight of the nonwoven fabric is preferably 5 to 50 g / m ² , particularly preferably 18 to 30 g / m ² . The buckling strength of the nonwoven fabric having such a basis weight is preferably 50 cN or less, particularly preferably 30 cN or less in the CD direction, and preferably 70 cN or less, particularly preferably 50 cN or less in the MD direction.

Further, from the viewpoint of facilitating bonding by heat fusion, the sheet material is preferably made of a heat-fusible resin as a forming material (fiber in the case of a nonwoven fabric, film material of a resin film). Examples of the adhesive resin include polyethylene and polypropylene. The fiber constituting the nonwoven fabric or the like may be a core-sheath type composite fiber or the like made of a resin whose surface is only heat-fusible.
The forming material may be the same or different between one sheet material and the other sheet material of the two sheet materials.

  The two sheet materials in the present invention are not limited to two separate sheets, but one sheet material is bent to form two opposing surfaces, and a portion constituting one surface is defined as 1 One sheet material and the part constituting the other surface may be another sheet material.

  As a material for forming the elastic member 4, various known elastic materials used for absorbent articles such as disposable diapers and sanitary napkins can be used without particular limitation. Synthetic rubber such as neoprene, natural rubber, EVA, stretchable polyolefin, polyurethane, etc. Alternatively, a multifilament type thread or the like can be used.

Another factor that determines the moldability of the composite elastic member is the expansion ratio and elastic stress of the elastic member. In order to make the cross-sectional shape of the ridge convex, the required expansion ratio and elastic stress of the elastic member are required. The elastic member is preferably applied to the sheet material in a stretched state of 20 to 1000%, particularly preferably 50 to 400%. Then, the elastic member contracts, and the non-woven fabric of the contracted portion is left, and the wrinkles are formed by deforming outwardly in the direction opposite to the bonding surface of the heat-sealing group into a convex cross section.
As described above, the height of the ridge is important when considering formability and cushioning properties, and can be arbitrarily designed by selecting the joint pattern and interval, the material, and the elastic member. The height of the ridge is preferably about 1 to 15 mm on one side. In order to increase the wrinkles, the distance between adjacent joints is secured by a predetermined size, and the expansion and contraction magnification and the convex wrinkles are sufficient to close the gap, thereby creating a soft composite stretch with a sense of volume. A member can be formed. When making one with a height of h on one side, the distance between the joints must be at least 2 × h, and the elastic members are adjacent to each other when the distance is 2 × h. It is necessary to shrink so that the joining part to adjoin is adjacent.

One preferred elastic member is natural rubber (or synthetic rubber). Natural rubber (synthetic rubber) has a thickness of 0.05 to 1.5 mm, a width of 0.2 to 5 mm, and a typical cross-sectional area of 0.91 mm with a thickness of 0.35 mm depending on the cross-sectional area. A low modulus elastic member having a stress at the time of 100% elongation of a single yarn having a width of about 1 to 70 gf, preferably about 1 to 40 gf, particularly preferably about 1 to 30 gf is desired. A plurality of sex members having such stress characteristics are used for the composite stretchable member.
Another preferred elastic member is polyurethane spandex elastic fiber. A single yarn having a size of 10 to 3360 denier, particularly preferably 70 to 1120 denier is used. Denier is a unit representing the thickness of a yarn, and a yarn of 1 g at 9000 m is called 1 denier. A plurality of spandex elastic fibers that are stretched to 30 to 500% are used.
By disposing a plurality of the above-mentioned single yarns of the elastic member having a low modulus at a high elongation ratio of preferably 100% or more, particularly preferably 200% or more, a composite stretchable member having a beautiful fold that softly stretches is obtained. be able to.

The composite elastic member 1 described above can be produced efficiently and economically, for example, by the following method.
First, a plurality of elastic members 4 are arranged on one sheet material 2 so as to be parallel to each other in an extended state, and then on the surface of the sheet material 2 on which the elastic members 4 are arranged. The other sheet material 3 is laminated.

  Next, the portions of the laminated sheet materials where the elastic member 4 is not disposed are partially heat-sealed by heat embossing or ultrasonic embossing. The heat embossing or the ultrasonic embossing is laminated between an embossing roll having a convex portion of a pattern corresponding to a formation pattern (see FIG. 2) of the heat-sealing portion 5 and a receiving roll facing the roll, for example. It can be carried out by inserting both sheet materials in the state.

  Next, an integration process for fixing the elastic member 4 to both the sheet materials 2 and 3 is performed on the portions of the both sheet materials in the state where the elastic member 4 is sandwiched between them in the direction in which the elastic member 4 extends. The integration process is a process capable of joining the elastic member to both the sheet materials 2 and 3, and a heat embossing process or an ultrasonic embossing process can be used. The other integration process may be a process of applying an adhesive to one or both of the sheet material and / or the elastic member and pressurizing a site where the adhesive is applied. The adhesive in this case is, for example, one sheet material 2 before the elastic member 4 is disposed, the other sheet material 3 before being stacked on the sheet 2, before being disposed on the sheet material 2 or after being disposed. Apply to the elastic member 4 or the like.

  And the predetermined location in both the sheet materials 2 and 3 of the state which pinched | interposed the elastic member 4 is cut | disconnected so that the site | part which performed the integration process may be located in the both ends of the direction where the elastic member 4 is extended. Then, the elastic member 4 is contracted to form a plurality of wrinkles on each of the sheet materials 2 and 3, whereby the composite stretchable member 1 having the above-described configuration is obtained.

Next, a composite stretchable member 1 ′ (hereinafter also referred to as a composite stretchable member 1 ′ of the second embodiment) used in another embodiment (second embodiment) of the present invention will be described. About the composite elastic member 1 ' of 2nd Embodiment, a different point from the composite elastic member 1 of 1st Embodiment is demonstrated, About the same point, the same code | symbol is attached | subjected and description is abbreviate | omitted. The description of the composite stretchable member 1 described above is appropriately applied to points that are not particularly described.

As shown in FIG. 3, in the composite elastic member 1 ′ of the second embodiment, the heat fusion part 5 between the sheet materials 2 and 3 has an expansion / contraction direction (X direction) of the expansion / contraction part 10 and a direction (Y) Are formed so as to form rows in the direction), and the heat-sealing portions 5 constituting the rows in the orthogonal direction are formed between the elastic members 4.
Also in the composite elastic member 1 ′ of the second embodiment, the elastic member 4 contracts in the natural state (a state where no external force is applied), and each of the two sheet materials 2 and 3 is the same as that of the first embodiment. Similarly, a plurality of ridges (gathers) 6 and 6 that continuously extend over the plurality of elastic members 4 are formed, and therefore, the same operational effects as those of the composite elastic member 1 described above can be obtained. .

  In the composite stretchable member 1 ′ of the second embodiment, a single collar 6 is formed between the heat fusion portions 5 and 5 adjacent to each other in the stretchable direction (X direction) of the stretchable portion.

  From the viewpoint of reliably forming the flange 6 extending continuously over the plurality of elastic members 4, the pitch P <b> 2 of the heat fusion part 5 in the expansion / contraction direction (X direction) of the expansion / contraction part 10 when the expansion / contraction part 10 extends. (See FIG. 3) is preferably 1 to 20 mm, particularly 3 to 10 mm, and the length L2 (see FIG. 3) of each heat-sealing part 5 is 0.1 to 5 mm, particularly 0.2 to 1.5 mm. It is preferable that the ratio (P2 / L2) of the pitch P2 and the length L2 is 1.1 to 200, particularly 2 to 50.

  In the above-described composite stretchable member 1, 1 ′ (particularly the composite stretchable member 1), the pitch P3 (see FIGS. 2 and 3) of the heat-sealed portion 5 in the direction (Y direction) orthogonal to the stretchable direction of the stretchable portion 10. ) Is preferably 1 to 40 mm, particularly preferably 2 to 15 mm, and the length L3 (see FIGS. 2 and 3) of each heat-sealing part 5 is preferably 0.5 to 20 mm, particularly preferably 1 to 10 mm. The ratio (P3 / L3) between the pitch P3 and the length L3 is preferably 1.05 to 80, and more preferably 1.05 to 15.

As mentioned above, although preferable embodiment of this invention was described, this invention is not restrict | limited to embodiment mentioned above.
For example, the wrinkles in the composite elastic members 1 and 1 ′ described above are continuous between two elastic members located at both ends in the Y direction, but the elastic members in the vicinity of the Y elastic end portions of the composite elastic members. May exist in a state of being bonded to the sheet materials 2 and 3. However, it is preferable that the wrinkles are continuous over at least three, preferably half, particularly preferably 70% or more of the total number of elastic members. Further, the end portion of the elastic member 4 joined to both the sheet materials 2 and 3 is present inside the end portion of the composite stretchable member 1 in the X direction instead of being present at the end portion of the composite stretchable member 1. You may do it. In addition, although the number of the elastic members in a composite elastic member can be suitably determined according to the dimension and application of a composite elastic member, it can be 5-30, for example. Further, the joint portion between the sheet materials may be an adhesive portion in which the sheet materials are bonded together using a hot melt adhesive or the like instead of the heat fusion portion.
Moreover, the formation pattern of a heat-fusion part can be changed suitably, and the shape of each heat-fusion part can also be made into appropriate shapes, such as a rectangle, an ellipse, a circle, and a rhombus.

Examples of the absorbent article of the present invention include disposable diapers and sanitary napkins . Each composite elastic member described above is used good Mashiku for stretch-forming of the absorbent article. In that case, after completion of the composite elastic member, it may be fixed to the absorbent article to form an elastic part, but the manufacturing process of the composite elastic member is incorporated into the manufacturing process of the absorbent article, the absorbent article of the incorporated state as possible out also to be produced.

It is a perspective view which shows the composite elastic member used for one Embodiment of this invention partially fractured | ruptured. It is a top view which shows the state which extended the expansion-contraction part of the composite expansion-contraction member of FIG. It is a figure (figure 2 equivalent figure) which shows the composite elastic member used for other embodiment of this invention. It is a top view which shows the disposable diaper which has a fastening tape which is one Embodiment of the absorbent article of this invention.

Explanation of symbols

20 Disposable diapers (absorbent articles)
1, 1 'composite elastic member 2 sheet material 3 sheet material 4 elastic member 5 heat fusion part (joint part)
6 襞

Claims (3)

An absorbent article in which a stretchable part is formed using a composite stretchable member having a stretchable part composed of two sheet materials and a plurality of elastic members arranged between the two sheet materials,
The two sheet materials are intermittently joined to each other in the expansion / contraction direction of the expansion / contraction portion and the direction orthogonal thereto,
The elastic member is arranged in the stretchable part so as not to pass through the joint part between both sheet materials, and is fixed to both sheet materials only at both ends thereof, and each of the two sheet materials includes a plurality of each Forming a plurality of ridges extending continuously over the elastic members,
An absorptive article in which a waist elastic part is formed by the composite elastic member.   The absorbent article according to claim 1, further comprising a waist elastic part formed by the composite elastic member. An absorbent article in which a stretchable part is formed using a composite stretchable member having a stretchable part composed of two sheet materials and a plurality of elastic members arranged between the two sheet materials,
The absorbent article is a disposable diaper having a fastening tape,
The two sheet materials are intermittently joined to each other in the expansion / contraction direction of the expansion / contraction portion and the direction orthogonal thereto,
The elastic member is arranged in the stretchable part so as not to pass through the joint part between both sheet materials, and is fixed to both sheet materials only at both ends thereof, and each of the two sheet materials includes a plurality of each Forming a plurality of ridges extending continuously over the elastic members,
An absorptive article in which a tape stretchable part that stretches and contracts in conjunction with the fastening tape is formed by the composite stretchable member.

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