JP2018164824A - Tape type disposable diaper and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tape type disposable diaper having a stretchable part.SOLUTION: A tape type disposable diaper has stretchable tapes that can expand and contract at both side parts of a back body of a paper diaper body. In the stretchable tape, an elastic film that can expand and contract at least in a longitudinal direction is laminated between a first sheet layer having no elasticity and a second sheet layer. The first sheet layer and the second sheet layer are joined directly or through the elastic film at a plurality of junctions with intervals. The stretchable tape 1 can be contracted by a contractive force of the elastic film and expanded by applying an external force in a width direction of an article. Because the junction area ratio occupied by the total area of the junctions included in a unit area is different between areas A, B, stretch stress differs between the areas A, B.SELECTED DRAWING: Figure 16

Description

  The present invention relates to a tape-type disposable diaper having elasticity and a method for producing the same.

  In a tape-type disposable diaper, in order to improve fit to the body surface, it is common to provide stretchability at appropriate positions such as around the legs, around the waist, and around the waist. As a method for imparting stretchability, conventionally, a method of fixing an elongated elastic stretchable member such as rubber thread in a stretched state in the longitudinal direction has been widely adopted, but it is desired to impart stretchability to a certain width. In such a case, a mode is adopted in which the rubber thread is fixed in a state of being arranged side by side with an interval in the width direction.

On the other hand, it is also known to make the body of the wearer follow the movement of the tape-type disposable diaper by imparting elasticity to the tape.
As an example, there is an elastic tape described in Patent Document 1. This is provided with a stretchable sheet in the middle, a non-stretchable sheet at one end and joined to the back diaper body, a nonstretchable sheet at the other end, and a fastener member (hook material) Is fixed and mechanically joined to the front target member on the ventral side.

  In the elastic tape of patent document 1, a level | step difference produces | generates between an elastic sheet and the non-elastic sheet of both ends, and the appearance is not favorable. In addition, three sheets are required excluding the fastener member (hook member), which is a factor of high cost due to the labor and time required for joining the sheets.

On the other hand, as a stretchable sheet, a stretch-bonded nonwoven fabric made of a mixture of elastic fibers and inelastic fibers is also known in which stretchability is imparted by breaking a part of the inelastic fiber layer with a gear (Patent Document 2). Paragraph 0066).
However, a large stretch force cannot be obtained with a nonwoven fabric.

JP 2009-55996 A JP2015-24050A

  Accordingly, a main object of the present invention is to provide a tape-type disposable diaper having a tape made of an elastic sheet that exhibits a sufficiently large elastic stress and has a low cost, and a method for manufacturing the same.

  The present invention that has solved the above problems is as follows.

(Basic form)
In a tape-type disposable diaper having stretchable tape that can be expanded and contracted in the width direction on both sides of the back body of the paper diaper
In the stretchable tape, a stretchable elastic film is laminated between a first sheet layer that does not have stretchability and a second sheet layer, and the first sheet layer and the second sheet layer are , Directly or via an elastic film, joined at a large number of spaced joints, the first sheet layer and the second sheet layer remain in the joint,
The elastic tape is contracted by the contraction force of the elastic film, and can be expanded by applying an external force in the width direction,
The joint area ratio occupied by the total area of the joints included in the unit area is different between the first region at the center and the two second regions adjacent to the first region in the width direction. The stretch stress of the region 1 is high, the stretch stress of the second region is low, or the second region is not stretched,
The second region on the proximal end side of the second region is coupled to the disposable diaper body, and the male material of the mechanical fastener is coupled to the second region on the other distal end side, and this male material is mechanically coupled to the front body. Is,
A tape-type disposable diaper characterized by that.
The tape type disposable diaper of this invention has the elastic tape which can be expanded-contracted in the width direction in the both sides.
In the stretchable tape, a stretchable elastic film is laminated between a first sheet layer that does not have stretchability and a second sheet layer, and the first sheet layer and the second sheet layer are The elastic tape is contracted by a contracting force of the elastic film and can be expanded by applying an external force in the width direction. Yes,
The joint area ratio occupied by the total area of the joints included in the unit area is different between the first region at the center and the two second regions adjacent to the first region in the width direction. The stretch stress of the region 1 is high, the stretch stress of the second region is low, or the second region is not stretched,
The second region on the proximal end side of the second region is coupled to the disposable diaper body, and the male material of the mechanical fastener is coupled to the second region on the other distal end side, and this male material is mechanically coupled to the front body. Is.

Since it is set as the structure where the expansion / contraction stress of a 2nd area | region is low or does not expand / contract, when couple | bonding with a paper diaper main body, it can couple | bond stably. Further, even when the stretchable tape is stretched with the diaper secured, the shape of the joint between the second region and the paper diaper main body is prevented from being deformed, and the shape stability is improved.
As the fastening member provided at the other end of the elastic tape and fastened to the front body, a male material of a mechanical fastener as a surface fastener can be provided from the viewpoint of the stability of repeated fastening.
To this end, the stretchable tape has a first region and two second regions adjacent to the first region, and the stretchable tape has one second region coupled to the paper diaper body and the other second region. The male material of a mechanical fastener is couple | bonded with the area | region of 2, and it can be set as the structure by which this male material is mechanically connected to the front body (for example, to a front target tape).
In accordance with the example of the present invention, the male material of the mechanical fastener is coupled to the other second region. Since it is set as the structure where the expansion / contraction stress of a 2nd area | region is low or does not expand-contract, when connecting the male material of a mechanical fastener, it can couple | bond stably. Further, even when the stretchable tape is stretched with the diaper fastened, the shape of the second region and the male material is stable, so that it can be stably fastened to the front body.

The stretchable tape of the present invention can be formed by distinguishing the first region having a high stretch stress and the second region having a low stretch stress or not stretched by making the joint area ratio different between the regions.
Therefore, the stretchable tape of the present invention can basically be formed by a single stretchable sheet, and even when a fastening member is provided, the number of materials is two, which is compared with the conventional form of combining many materials. Thus, the elastic tape is low in cost.
Moreover, since the elastic film is interposed, it is possible to obtain a high stretch stress that cannot be obtained with a nonwoven stretch tape.

  In the elastic sheet constituting the elastic tape of the present invention, it is desirable that the first sheet layer and the second sheet layer remain in the joint portion. That is, a hole penetrating the first sheet layer and the second sheet layer is not formed. This point is different from the stretchable sheet shown in FIG. 5 or 7 of Japanese Patent No. 4562391.

The stretchable tape has a second region on the proximal end side and a first region on the distal end side, and a plurality of parts that have been manually broken or separated at the distal end of the first region. A configuration is proposed in which a male material of the mechanical fastener is coupled and this male material is mechanically coupled to the front body.
By separating the male material of the mechanical fastener into a plurality of parts, the first region in which these are arranged can expand and contract even at the tip.

The region outside the base end of the stretchable tape can be divided by a cut formed from the outer edge formed in the middle of the diaper in the front-rear direction.
This form is particularly effective in the case of diapers for adults, and since the divided one and the other can be fixed to different parts, the diaper can be stably held even by the movement of the wearer.

The joint part of the stretchable part of the present invention will be further described.
In a junction part, there exists the following example of a joining form, for example.
(1) A mode in which the first sheet layer and the second sheet layer are partially melted and joined to the elastic film, that is, the first sheet layer and the second sheet layer are joined via the elastic film.
(2) A mode in which the elastic film melts and moves into the first sheet layer and the second sheet layer, and the first sheet layer and the second sheet layer are directly joined without interposing the elastic film.
(3) It is an intermediate form between the form of (1) and the form of (2), and both surface portions of the elastic film melt and move into the first sheet layer and the second sheet layer, but elastic A form in which the first sheet layer and the second sheet layer are bonded via the remaining elastic film by partially remaining the film.

Among these forms, in particular, in the form (2) and the form (3), there is a difference in elastic film strength between the joined part and the non-joined part. Therefore, after the stretched state of the stretch sheet holding the extension is once opened and shrunk to make a product; or after the stretch sheet holding the stretch is combined with another member, the stretched state is once released and shrunk. When the product is stretched mechanically or manually in the expansion / contraction direction, breakage occurs at the boundary between the joined portion and the non-joined portion.
As a result, a through hole is formed.

  In the case where the through hole is formed, there is an advantage that air permeability is ensured. The through holes do not need to be formed in all the joints, and exhibit air permeability even if formed in some of the joints. The through hole may have a shape extending in the expansion / contraction direction from the edge of the joint portion, or the through hole may have a shape extending in both directions from the edge of the joint portion, and may have an annular shape around the joint portion in some cases.

As a preferred example of the joint portion, the area of the joint portion in the stretchable region is 0.14 to 3.5 mm ² , and the area of the opening of the through hole in the natural length state is 1 to 1 of the area of the joint portion. And the area ratio of the joint in the stretchable region is 1.8 to 22.5%.
Here, the “area ratio” means the ratio of the target portion to the unit area, and the total area of the target portion (for example, joints and openings of through holes) in the target region (for example, the stretchable region) is the area of the target region. In particular, the “joint area ratio” means the area ratio in a state of being stretched to the elastic limit in the stretching direction. In addition, the area of the opening of the through hole means a value in a state in which the stretchable structure is in a natural length, and the area of the opening of the through hole is not uniform in the thickness direction, such as different between the front and back of the elastic film. Means the minimum value.
The joint area ratio in the present specification can be selected by selecting the size, shape, separation interval, arrangement pattern in the roll length direction and roll circumferential direction, etc. of the protrusions of the anvil roll described later.

“Stretching stress” is measured by a tensile test according to JIS K7127: 1999 “Plastics—Test method for tensile properties—” with an initial chuck interval (distance between marked lines) of 50 mm and a tensile speed of 300 mm / min. It means “stress when stretched to 50% of elastic limit (N / 35 mm)”. When a test piece having a width of 35 mm cannot be cut out, the test piece is created with a width that can be cut out, and the measured value is set to a value converted into a width of 35 mm.
If the target area is small and sufficient specimens cannot be collected, a comparatively small specimen can be compared at least if it is a comparison of stretching stress.
In addition, since a plurality of stretching stresses are different within the region, how to collect the test piece becomes a problem. Therefore, apart from obtaining the absolute value of the stretching stress, for comparison of the stretching stress, a test piece is collected for each part of the stretchable sheet, and each test piece is 150% from the 100% length in the natural state. It is also possible to compare the magnitude by the stress when stretched to% length.

A tape-type disposable diaper having stretchable elastic tapes on both sides of the back of the paper diaper main body can be manufactured by the following method.
A supply step of interposing an elastic film stretchable at least in the width direction between the first sheet layer not having stretchability and the second sheet layer not having stretchability;
In this supplying step, in a state where the elastic film is interposed between the first sheet layer and the second sheet layer in an expanded state, heat is applied from outside the first sheet layer and the second sheet layer. A thermal melting energy is applied to the elastic film by a plurality of thermal melting portions spaced by a melting device, the elastic film is melted, and the first sheet layer and the second sheet layer are directly or via an elastic film. A joining step of joining in a state where the first sheet layer and the second sheet layer remain in the joined portion by a large number of joined portions,
A stretchable sheet manufacturing stage for manufacturing a stretchable sheet, including:
A cutting step of cutting the stretchable sheet into a predetermined size;
A process of joining the cut elastic sheet as an elastic tape to both sides of the back body of the paper diaper main body,
Combining the elastic tape with the back of the diaper body;
It is a method including.

The elastic film needs to be stretched. The elastic film is passed through a nip roll step in which a pair of opposing nips are arranged in the front-rear direction, and between the front and rear nip roll steps, the peripheral speed of the front nip roll step is made faster than the peripheral speed of the rear nip roll step. Is provided to the supplying step in an expanded state.
Another method may be to pass only a pair of nip rolls while winding the elastic film around the drive roll in, for example, an S shape.

The heat melting apparatus has an anvil roll and an ultrasonic horn, and the anvil roll has a plurality of protrusions formed on the outer surface thereof spaced apart in the roll length direction and the outer peripheral direction. The aspect which comprises the said thermal fusion part with an ultrasonic horn is provided.
Instead of the ultrasonic heat melting apparatus, other heat melting means may be used.

The melting point of the elastic film is lower than the melting point of the first sheet layer made of nonwoven fabric and the melting point of the second sheet layer made of nonwoven fabric, higher than this melting point, and lower than the melting points of the first sheet layer and the second sheet layer. When the melting energy corresponding to the temperature is applied, the elastic film is melted by heat, while the first sheet layer and the second sheet layer are not melted at all or are partially melted. As a result, holes are formed in the entire joint region. The first sheet layer and the second sheet layer remain.
However, the line speed at the time of manufacturing the elastic sheet is high. Therefore, even if a melting energy corresponding to a temperature higher than the melting point of the first sheet layer and the second sheet layer is given, the first sheet layer and the second sheet layer are not melted at all or are partially melted. A form in which no hole is formed can be obtained.

From such a viewpoint, the melting point of the elastic film is preferably about 80 to 145 ° C, the melting point of the first sheet layer and the second sheet layer is about 85 to 190 ° C, particularly preferably about 130 to 190 ° C, The difference between the melting points of the first sheet layer and the second sheet layer and the melting point of the elastic film 30 exhibiting a lower melting point is preferably about 50 to 80 ° C.
As a suitable specific example, the melting point of the elastic film is 95 to 125 ° C., the melting point of the first sheet layer is more than 125 ° C. to 160 ° C., more preferably 130 to 160 ° C., and the melting point of the second sheet layer is 125. More than ℃ ~ 160 ℃, more preferably 130-160 ℃.

In the above method for producing a tape-type disposable diaper of the present invention, an existing method can be used as a method not described.
If the existing method is demonstrated, in the component formation process, the component which comprises a tape type disposable diaper will be formed. For example, an absorbent body is formed by laminating absorbent materials. An elastic sheet is formed and individually cut into an elastic tape.
In the component combination process, various materials such as an exterior sheet, an elastic tape, a back sheet, an absorber, and a top sheet are combined.
In the cutting process, the legs are cut and cut into individual articles.
Thereby, a tape type disposable diaper can be manufactured.

  As described above, according to the present invention, it is possible to obtain a tape-type disposable diaper having a tape made of an elastic sheet that exhibits a sufficiently large elastic stress and is low in cost.

It is a top view of the example of arrangement pattern of a joined part. It is a schematic plan view of the example from which a junction area ratio differs. It is a schematic plan view of the other example from which a junction area ratio differs. It is a schematic plan view of another example from which a junction area ratio differs. It is sectional drawing for description before joining of an elastic sheet. It is sectional drawing for description of the joining state of an elastic sheet. It is sectional drawing for description of the contracted state of an elastic sheet. It is sectional drawing for description of the joining state of the expansion-contraction sheet | seat in which a through-hole is formed. (A) (b) is a schematic diagram of an example of extension and joining means. It is a top view for description of the example of formation of a through hole. It is a top view for description of the formation example of the through-hole which differs in an aspect. It is a top view for description of the example of formation of a through hole. It is an expanded state outline top view of the tape type disposable diaper of the 1st example. It is an expansion state outline top view of a tape type disposable diaper of the 2nd example. It is an expansion state outline top view of a tape type disposable diaper of the 3rd example. It is a schematic explanatory drawing which shows the example of a manufacturing process of a disposable diaper. It is an expanded view of the example of another tape structure. It is an expanded view of another example of a tape structure. It is a top view of the example of a tape type disposable diaper. FIG. It is a 21-21 line arrow directional view. It is a 22-22 line arrow directional view. It is a top view which shows the various arrangement | sequence examples of a junction part.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The tape-type disposable diaper of the present invention is a product that absorbs and retains body fluids.
The tape-type disposable diaper of the present invention has stretchable elastic tapes on both sides of the back body of the paper diaper main body.

As shown in FIGS. 5 to 8, the stretchable tape has a first sheet layer 21 made of, for example, non-woven fabric that does not have stretchability, and a second sheet layer 22 made of, for example, non-woven fabric that does not have stretchability, The elastic film 30 that can be expanded and contracted in the front-rear direction is laminated, and the first sheet layer 21 and the second sheet layer 22 are directly or via the elastic film 30 with a large number of intervals. 40 is joined.
Here, “the first sheet layer 21 and the second sheet layer 22 are not stretchable” does not mean that the first sheet layer 21 and the second sheet layer 22 are not stretched at all. It means not.

At the time of joining, for example, as shown in FIG. 9A, the first sheet layer 21 and the elastic film 30 are disposed between an anvil roll 60 having a projection 60a formed in a predetermined pattern on the outer surface and an ultrasonic horn 61. Then, the second sheet layer 22 is supplied, and ultrasonic melting energy is applied by the ultrasonic horn 61, for example, mainly by melting the elastic film 30, thereby joining the first sheet layer 21 and the second sheet layer 22.
On the other hand, the embodiment shown in FIG. That is, the opposing roll 63 is disposed opposite to the anvil roll 60, and the driving roll 65 is provided to the opposing roll 63, and the nip roll sandwiches the elastic film 30.
In the structure of such an apparatus, after the elastic film 30 is circulated around the opposing roll 63, the nip position with the drive roll 65 is reached, and thereafter the anvil roll 60 is circulated.
At that time, by making the peripheral speed of the driving anvil roll 60 faster than the peripheral speed of the driving roll 65 (and thus the peripheral speed of the opposing roll 63), the elastic film 30 is stretched and the anvil roll 60 Joining is performed by the group of protrusions 60 a and the ultrasonic horn 61. According to this aspect, since the extension (stretching) length is shorter than that in the aspect of FIG. 9A, there is an advantage that neck-in can be suppressed.
In addition, about the example of a joining form, it explains in full detail later.

  The elongation rate in the manufacturing process of the elastic film 30 (based on a natural state length of 100%) is, for example, that the peripheral speed of the anvil roll 60 that is driven to rotate is made faster than the peripheral speed of the rear drive roll 62. It can be set by selecting the speed difference between the rolls. 63 is a guide roller.

  FIG. 6 schematically shows a cross section of the stretchable sheet after joining in the stretched state. When the stretched state of the stretchable tape (stretchable sheet) is released, as shown in FIG. 7 (schematic diagram), the stretchable film contracts due to the contraction force of the elastic film 30 and can be stretched when an external force is applied in the front-rear direction (left-right direction in FIG. 7). It is. Therefore, when the expansion / contraction direction of this stretchable tape is matched with, for example, the front / rear direction of the disposable diaper, the disposable diaper can be expanded / contracted in the front / rear direction.

  And since an elastic sheet can be manufactured with a predetermined area, when it is desired to apply a contracting force to the entire desired area, an elastic tape cut to the desired area may be applied.

On the other hand, in the above example, the first sheet layer 21 and the second sheet layer 22 are joined by melting the elastic film 30. In this case, (1) a mode in which the first sheet layer 21 or the second sheet layer 22 is joined on the surface of the elastic film 30, (2) the surface portion of the elastic film 30 is melted, and the first sheet layer 21 and the second sheet A mode of invading and joining between the respective fibers of the layer 22 (3) Almost all of the elastic film 30 is melted and invaded and joined between the respective fibers of the first sheet layer 21 and the second sheet layer 22. There are aspects. In the present invention, the bonding mode between the layers is not limited to these examples.
Among these aspects, in the aspect such as (3), it can be evaluated that the first sheet layer 21 and the second sheet layer 22 are joined directly, that is, without interposing an elastic film.
The above aspects (1) to (3) are cases where the melting point of the elastic film 30 is lower than the melting points of the first sheet layer 21 and the second sheet layer 22, but the melting point of the elastic film 30 is the first sheet layer. 21 and / or higher than the melting point of the second sheet layer 22. In this case, the elastic film 30 side surface portion of the first sheet layer 21 and / or the second sheet layer 22 is activated or melted and joined to the elastic film 30.
Furthermore, the elastic film 30 may be partly melted, and the first sheet layer 21 and / or the second sheet layer 22 may be joined by melting.
The 1st sheet layer 21 and / or the 2nd sheet layer 22 are nonwoven fabrics, and the fiber may have a core-sheath structure. In this case, for example, only the sheath component of the fiber can be melted and contribute to the joining.

  In the stretchable tape (stretchable sheet), the joint area ratio occupied by the total area of the joints included in the unit area is different between the first region and the second region adjacent thereto.

As shown in FIG. 1, the joint area ratio is a percentage of the total area of the joints 40, 40... Included in the unit area S. The unit area S in this case is desirably set to a size that includes at least 10 joints (it is difficult to compare the stretching stress with a small number). In the example of FIG. 1, 13 joint portions are included. Moreover, the external shape which defines unit area S may be other shapes, such as a rectangle and a circle, besides a square.
An example of the joint 40 is a circle shown in FIG. Of course, the shape may be an ellipse or a rectangle. In FIG. 1, Lm is an arrangement interval length in the machine direction, Lc is an arrangement interval length in an orthogonal direction (cross direction) orthogonal to the machine direction, Pm is a machine direction (pitch length of MD (, and Pc is an orthogonal direction (cross direction: CD)). ) Pitch length.

The aspect in which the joint area ratio differs depending on the region in the stretchable tape is shown in FIGS.
In FIG. 2, for the regions A and B, the expansion stress is in the relationship of A> B by setting the joint area ratio to A <B.
For example, when the pitch length Pm and the pitch length Pc are long and A is compared with the case B when the pitch length Pm and the pitch length Pc are short, the case A (when the joint area ratio is low) is long. In the case where the pitch length Pm · Pc is short, the elongation ratio is larger than that in B (when the joint area ratio is high). As a result, the stretching stress has a relationship of A> B.
The form of FIG. 2 has different stretching stresses in the lateral direction of FIG. 2 for each region, and therefore the region A having a high stretching stress is made to correspond to the intermediate region in the width direction of the tape-type disposable diaper. Then, the B region having low expansion / contraction stress (so-called small expansion / contraction) is made to correspond to both outer sides of the A region.

  FIG. 3 shows an example in which B and B regions having low stretching stress are arranged before and after the A region in the middle in the width direction.

In the present invention, the difference in the joint area ratio can be achieved by changing the joint area in addition to the density of the arrangement pattern.
In order to understand this, FIG. 4 shows an example in which a large number of small junctions are arranged in the region C so as to have the same junction area as the region D. By setting the joint area to A <C = D, the stretching stress is in the relationship of A> C = D.

  By the way, the elastic film in the present invention may be stretchable only in the first direction (diaper width direction), but it is also possible to use a two-way stretchable film that stretches in a second direction orthogonal thereto.

  Physical properties such as the thickness, material, strain / stress characteristics, and melting point of the elastic film can be selected as appropriate. By selecting the relationship between this elastic film, the ultrasonic melting energy applied thereto, and the elongation rate of the elastic film at the time of manufacturing the stretchable sheet, as shown in FIG. 31 can be formed. When the first sheet layer 21 and the second sheet layer 22 are formed of, for example, a nonwoven fabric, the nonwoven fabric exhibits air permeability. However, the air permeability is considered to be lower than that of the sheet according to Japanese Patent No. 4562391.

  The reason why the ventilation through hole 31 is formed is not necessarily clear, but the elastic film 30 is melted by the ultrasonic melting energy, and the coupling portion 40 is thinned by the pressing by the projection 60 a of the anvil roll 60. At this time, the elastic film 30 is also thinned, the peripheral portion of the joint portion 40 reaches the breaking strength, the breakage starts due to the stretching stress acting on the stretched elastic film 30, shrinks to the balance point, and the hole is opened it is conceivable that.

  FIG. 10 schematically shows an example of forming the through hole 31 in the case of a circular through hole. A substantially crescent-shaped through hole 31 is formed on both sides of the connecting portion 40 in the machine direction (extension direction).

  The joint portion can be formed in a shape that is long in a direction (cross direction: CD direction) orthogonal to the machine direction (extension direction) of the stretchable sheet manufacturing. In this case, for example, as shown in FIG. 11, a semicircular through hole 31 having a large opening can be formed.

On the other hand, it is not essential for the through holes 31 to be formed in all the coupling portions. If it is required to reliably form the through-hole 31 or to open a large hole, the technique shown in FIG. 12 can be adopted.
That is, as shown in FIG. 12B, the stretchable sheet in which the coupling portion 40 is formed is passed between a pair of rolls 64 having ridges or protrusions 64a, and between adjacent protrusions 64a and 64a of one roll 64. The through-hole 31 can be formed by biting the protrusion 64a of the other roll 64 and applying a deformation force to the stretchable sheet.

(Application example for tape-type disposable diapers)
The stretchable sheet formed as described above is generally applied to tapes used in tape-type disposable diapers as follows. That is, as shown to FIGS. 13-15, it can apply as the elastic tape T couple | bonded with the both sides of the back body of tape type disposable diaper TD1.

  As shown in FIG. 14, the disposable diaper TD1 may be of a so-called “fundoshi” type in which the front body is wrapped with a long tape Ta.

  As shown in FIG. 15, a so-called “straight type” may be used. In the illustrated example, solid gathers G and G are formed on both outer sides of the elastic sheet 1 by elongated elastic elastic members 4G such as thread rubber. These three-dimensional gathers G and G are formed on the inner side from both side edges, and do not impair the shape retention of the exterior sheet.

A production example of the tape-type disposable diaper of the present invention will be described with reference to FIG.
That is, stretchable elastic tape is provided on both sides of the back body of the paper diaper main body.
As shown in FIGS. 5 to 7, the elastic sheet as the original sheet of the elastic tape 1 includes a first sheet layer 21 made of, for example, a non-woven fabric that does not have elasticity, and a second sheet made of, for example, a non-woven cloth that does not have elasticity. A supply step of interposing an elastic film 30 that is stretchable at least in the width direction between the layer 22 in an expanded state;
In the supplying step, the elastic film 30 is interposed between the first sheet layer 21 and the second sheet layer 22 in the stretched state, and the first sheet layer 21 and the second sheet layer 22 are From the outside, heat elastic energy is applied to the elastic film 30 by a plurality of heat melting portions spaced by a heat melting device, the elastic film is melted, and the first sheet layer 21 and the second sheet layer 22 are A joining step of joining in a state in which the first sheet layer 21 and the second sheet layer 22 remain in the joining portion 40 by a large number of joining portions 40 directly or via the elastic film 30;
A stretchable sheet is manufactured.

For example, for the continuous sheet in which the first region A and the second region B that are flowing along the line direction are alternately formed, the male material fu of the mechanical fastener is used as a hot melt adhesive in the flow process. Is coupled to the second region B.
Thereafter, the continuous sheet is cut in the second region B and individualized as the stretchable tape 1.

  The individualized elastic tape 1 is rotated 90 degrees from the line direction, chucked by a known vacuum means (not shown), etc., and other materials flowing along the line direction (for example, a liquid-impermeable back) A bonding step of positioning along the width direction of the article and bonding by a hot melt adhesive or a heat melting means.

  As described above, the stretchable sheet 1 has different stretch ratios in the first region A and the second region B in the center region in the width direction of the stretchable tape 1 as shown in FIGS. 17 to 19. Can do. In this case, both ends of the elastic tape 1 can be chucked by the vacuum means.

As the absorbent body in the tape-type disposable diaper of the present invention, an absorbent body mainly composed of cotton-like pulp or an absorbent body containing a polymer-absorbing polymer in a cotton-like pulp layer can be used.
Absorbers to be used, including the absorbers that will be described in more detail later, are known ones such as pulp fiber stacks, aggregates of filaments such as cellulose acetate, or non-woven fabrics as basic elements. What mixed an adsorbent polymer, adhering, etc. can be used. This absorbent body can be packaged with a packaging sheet having liquid permeability and liquid retention, such as crepe paper, if necessary, for holding the shape and polymer.
The shape of the absorbent body can be formed in an almost hourglass shape having a narrowed portion narrower than the front and rear sides at the crotch portion, and can also have an appropriate shape such as a rectangular shape.

<Specific examples of tape-type disposable diapers>
FIGS. 19-22 has shown an example of the tape-type disposable diaper, and this disposable diaper is an absorber between the inner surface of the liquid-impermeable back sheet 10 on the back side and the liquid-permeable top sheet 2. 3 is interposed.

  In order to make the outer appearance and feel like the outer surface of a cloth diaper, a back sheet 11 made of a nonwoven fabric or the like is provided on the back side of the liquid-impermeable back sheet 10 made of a sheet of polyethylene or the like. The outer peripheral edge of the diaper extends to the outer peripheral edge of the diaper. As the nonwoven fabric of the back sheet 11, a spunbond nonwoven fabric is suitable.

(Top sheet)
As the top sheet 2, a perforated or non-porous nonwoven fabric or a perforated plastic sheet is used. As the material fiber constituting the nonwoven fabric, synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters and amides, recycled fibers such as rayon and cupra, and natural fibers such as cotton can be used. Moreover, as a processing method of a nonwoven fabric, well-known methods, such as the spunlace method, the spun bond method, the SMS method, the thermal bond method, the melt blown method, the needle punch method, the air through method, the point bond method, can be used. The basis weight of the nonwoven fabric used for the liquid-permeable top sheet 2 is preferably 15 to 30 g / m ² , and the thickness is preferably 0.05 to 1 mm.

  The top sheet 2 extends outside the periphery of the absorbent body 3, and a portion extending outside the side edge of the absorbent body 3 is fixed to the liquid-impermeable back sheet 10 by, for example, a hot melt adhesive. Yes. In addition, the dot pattern in a figure represents the adhering part.

(3D gathering around the legs)
If necessary, a three-dimensional gather around the legs can be provided, and an example of the form is shown. The three-dimensional gather sheet around the legs can be made of various non-woven fabrics (spunbond non-woven fabrics are suitable), plastic films similar to those used for the back sheet, or stretchable sheets thereof. In this respect, a nonwoven fabric subjected to a water repellent treatment is preferable. The projecting portion on the center side in the width direction of the three-dimensional gather sheet around the legs is fixed to the inner surface of the article (in the illustrated form, the top sheet 2 surface) by means such as hot melt adhesive at the both ends in the front-rear direction, and is used as a lying portion. However, the intermediate part in the front-rear direction between them is a non-fixed free part, and the end part of this free part (end part on the center side in the width direction in the unfolded state) is elongated such as rubber thread. The elastic elastic member 4G is fixed with a hot-melt adhesive or the like in a state of extending along the front-rear direction. In the illustrated example, a plurality of the elongated elastic elastic members 4G are provided with a predetermined interval, but one may be used. As shown in FIG. 22, as a result of the contraction force of the elongated elastic expansion / contraction member 4G, this free part is a three-dimensional gather G around the leg that stands on the use surface of the diaper (the surface of the top sheet 2 in the illustrated embodiment). Configure.

(Fastening tape)
An elastic tape 1A (fastening tape T) that protrudes from the side edge is attached to the side flap portion of the back portion Ba, and the front target tape 6 extends along the width direction on the waist portion surface of the ventral portion F. When attached to the body, with the diaper applied to the body, the elastic tapes 1A on both sides are turned from each side of the waist to the ventral side outer surface to the front target tape 6 with male material (hook material) fu. Fasten through. The front target tape 6 can be omitted. In this case, the fastening tape T is directly hooked and fixed to the nonwoven fabric on the outer surface of the diaper. 1a is a break.

One example of the elastic tape 1A according to the present invention is, as shown in FIG. 17, the region outside the base end of the elastic tape is cut from the outer edge formed in the middle of the diaper in the front-rear direction. It is a form that can be divided by a cut 1a such as a perforation.
This form is particularly effective in the case of diapers for adults, and since the divided one and the other can be fixed to different parts, the diaper can be stably held even by the movement of the wearer.

As another example of the elastic tape 1B shown in FIG. 18, the second region B is formed on the proximal end side, the first region A is formed on the distal end side, and the 1b line is formed on the distal end portion of the first region A. A configuration is proposed in which the male materials fu, fu of a plurality of mechanical fasteners that are broken or separated manually by the human hand are joined together and mechanically connected to the front body.
By separating the male material of the mechanical fastener into a plurality of parts, the first region A expands and contracts even at the tip portion.

Although the constituent material of the 1st sheet layer 21 and the 2nd sheet layer 22 can be used without a limitation especially if it is a sheet form, it is preferable to use a nonwoven fabric from a viewpoint of air permeability and a softness | flexibility. The nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. When using a nonwoven fabric, the basis weight is preferably about 10 to 25 g / m ² .

By the way, the shape in the natural length state of each joint part 40 and the through-hole 31 is arbitrary, such as a perfect circle, an ellipse, polygons, such as a rectangle (including a linear or rounded thing), a star shape, a cloud shape, etc. It can be made into the shape. The size of each joint 40 may be determined as appropriate, but if it is too large, the effect of the hardness of the joint 40 on the feel will increase, and if it is too small, the joint area will be small and the materials will not be sufficiently bonded together. Therefore, in the normal case, the area of each joint 40 is preferably about 0.14 to 3.5 mm ² . The opening area of each through hole 31 may be equal to or larger than the joint portion because the joint portion is formed through the through hole 31, but is preferably about 1 to 1.5 times the area of the joint portion.

Moreover, as a junction part of this invention, although you may transfer directly from a main expansion-contraction part to a non-expandable area | region, the transition expansion / contraction part of the intermediate | middle can also be formed.
In general, the area and the area ratio of each joint 40 in each region are preferably set as follows.
(Non-stretchable area)
Area of the joint 40: 0.14 to 3.5 mm ² (particularly 0.25 to 1.0 mm ² )
Area ratio of the joint 40: 16 to 45% (especially 25 to 45%)
(Main elastic sheet 1)
Area of the joint 40: 0.14 to 3.5 mm ² (particularly 0.14 to 1.0 mm ² )
Area ratio of the joint 40: 1.8 to 19.1% (particularly 1.8 to 10.6%)
(Transition expansion / contraction part)
Area of the joint 40: 0.14 to 3.5 mm ² (particularly 0.25 to 1.0 mm ² )
Area ratio of the joint 40: 8 to 22.5% (particularly 12.5 to 22.5%)

  The plane arrangement of the joints 40 and the through-holes 31 can be determined as appropriate, but a plane arrangement that is regularly repeated is preferable, such as an oblique lattice shape as shown in FIG. 23 (a) or as shown in FIG. 23 (b). Hexagonal lattice shape (these are also called staggered shapes), square lattice shape as shown in FIG. 23 (c), rectangular lattice shape as shown in FIG. 23 (d), and parallel shape as shown in FIG. 23 (e). Body lattice (in the form shown in the figure, two groups are provided so that a large number of groups of parallel diagonal rows cross each other), etc. (in which these are inclined at an angle of less than 90 degrees with respect to the expansion / contraction direction) In addition, the group of joints 40 (group unit arrangement may be regular or irregular, and may be a pattern or a character shape) is repeated regularly. You can also. The arrangement form of the joint portion 40 and the through hole 31 may be the same in the main stretchable sheet 1, the transition stretchable portion, and the non-stretchable region, or may be different.

The elastic film 30 is not particularly limited, and can be used without particular limitation as long as it is a resin film having its own elasticity. For example, a styrene-based elastomer, an olefin-based elastomer, a polyester-based elastomer, a polyamide-based elastomer, and a polyurethane-based film can be used. A product obtained by processing one or two or more blends of thermoplastic elastomers such as elastomers into a film by extrusion molding such as a T-die method or an inflation method can be used. Further, as the elastic film 30, in addition to a non-porous film, a film in which a large number of holes and slits are formed for ventilation can be used. In particular, the tensile strength in the stretching direction is 8 to 25 N / 35 mm, the tensile strength in the direction perpendicular to the stretching direction is 5 to 20 N / 35 mm, the tensile elongation in the stretching direction is 450 to 1050%, and the direction perpendicular to the stretching direction. It is preferable that the elastic film 30 has a tensile elongation of 450 to 1400%. Note that the tensile strength and tensile elongation (breaking elongation) were JIS K7127 except that a tensile tester (for example, AOUTGRAPHAGS-G100N manufactured by SHIMADZU) was used and the test piece was a rectangular shape having a width of 35 mm and a length of 80 mm. According to 1999 “Plastics—Testing Method for Tensile Properties”, it means a value measured with an initial chuck interval of 50 mm and a tensile speed of 300 mm / min. Although the thickness of the elastic film 30 is not specifically limited, It is preferable that it is about 20-40 micrometers. The basis weight of the elastic film 30 is not particularly limited, but is preferably about 30 to 45 g / m ² , particularly preferably about 30 to 35 g / m ² .

<Explanation of terms in the specification>
The following terms in the specification have the following meanings unless otherwise specified in the specification.
“Elongation rate” means a value when the natural length is 100%.
・ "Weight" is measured as follows. After the sample or test piece is pre-dried, it is left in a test room or apparatus in a standard state (the test place is temperature 20 ± 5 ° C. and relative humidity 65% or less) to obtain a constant weight. Pre-drying refers to making a sample or test piece constant in an environment where the relative humidity is 10 to 25% and the temperature does not exceed 50 ° C. In addition, it is not necessary to perform preliminary drying about the fiber whose official moisture content is 0.0%. A sample with a size of 200 mm × 250 mm (± 2 mm) is cut out from the test piece in a constant weight using a rice-basis plate (200 mm × 250 mm, ± 2 mm). Measure the weight of the sample, multiply it by 20, calculate the weight per square meter, and use it as the basis weight.
-"Thickness" is automatically measured using an automatic thickness measuring instrument (KES-G5 handy compression measurement program) under the conditions of load: 10 gf / cm ² and pressure area: 2 cm ² .
・ If there is no description about the environmental conditions in the test and measurement, the test and measurement shall be performed in a test room or equipment in the standard condition (test location is temperature 20 ± 5 ℃, relative humidity 65% or less). .

  INDUSTRIAL APPLICABILITY The present invention can be used for all types of tape-type disposable diapers including an elastic tape.

  A ... 1st area | region, B ... 2nd area | region, C-D ... area | region, Ba ... Back body, Fr ... Front body, T, Ta ... Tape, TD ... Tape type disposable diaper 1, 1A, 1B ... Expansion / contraction Sheet, 2 ... Top sheet, 3 ... Absorber, 10 ... Back sheet, 11 ... Exterior sheet, 21 ... First sheet layer, 22 ... Second sheet layer, 30 ... Elastic film, 31 ... Through hole, 40 ... Joint .

Claims (3)

In a tape-type disposable diaper having stretchable tape that can be expanded and contracted in the width direction on both sides of the back body of the paper diaper body,
In the stretchable tape, a stretchable elastic film is laminated between a first sheet layer that does not have stretchability and a second sheet layer, and the first sheet layer and the second sheet layer are , Directly or via an elastic film, joined at a large number of spaced joints, the first sheet layer and the second sheet layer remain in the joint,
The elastic tape is contracted by the contraction force of the elastic film, and can be expanded by applying an external force in the width direction,
The joint area ratio occupied by the total area of the joints included in the unit area is different between the first region at the center and the two second regions adjacent to the first region in the width direction. The stretch stress of the region 1 is high, the stretch stress of the second region is low, or the second region is not stretched,
The second region on the proximal end side of the second region is coupled to the disposable diaper body, and the male material of the mechanical fastener is coupled to the second region on the other distal end side, and this male material is mechanically coupled to the front body. Is,
A tape-type disposable diaper characterized by that.   The tape-type disposable diaper according to claim 1, wherein a region outside the base end portion of the stretchable tape can be divided by a cut formed from an outer edge formed in the middle of the diaper in the front-rear direction. When manufacturing a tape-type disposable diaper having stretchable tape that can be stretched in the width direction on both sides of the back body of the paper diaper body,
A supply step of interposing a stretchable elastic film in an expanded state between the first sheet layer not having stretchability and the second sheet layer not having stretchability;
In this supplying step, in a state where the elastic film is interposed between the first sheet layer and the second sheet layer in an expanded state, heat is applied from outside the first sheet layer and the second sheet layer. A thermal melting energy is applied to the elastic film by a plurality of thermal melting portions spaced by a melting device, the elastic film is melted, and the first sheet layer and the second sheet layer are directly or via an elastic film. A joining step of joining in a state where the first sheet layer and the second sheet layer remain in the joined portion by a large number of joined portions,
A stretchable sheet manufacturing stage for manufacturing a stretchable sheet, including:
A cutting step of cutting the stretchable sheet into a predetermined size;
A joining step of joining the cut elastic sheet as an elastic tape to both sides of the back body of the paper diaper main body,
Combining the elastic tape with the back of the body of the disposable diaper body,
The elastic tape is
The joint area ratio occupied by the total area of the joints included in the unit area is different between the first region at the center and the two second regions adjacent to the first region in the width direction. The region 1 has a high stretching stress, the second region has a low stretching stress or the second region does not stretch, and
The male material of the mechanical fastener is coupled to the second region on the distal end side of the second region, and the male material is mechanically coupled to the front body. In the coupling step, the proximal end of the second region The second region on the side is joined to the disposable diaper body,
A method for producing a tape-type disposable diaper characterized by the above.

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