JP2020156989A - Underpants type paper diaper - Google Patents

Abstract

To provide a boxer-short type paper diaper which has enhanced fitness and preferable appearance.SOLUTION: A boxer-short type paper diaper 1 comprises an exterior body 10 and an interior pad 20, and is in a boxer-short shape when being worn. The boxer-short type paper diaper is configured to become in an underpants shape when a front bodice 11 and a rear bodice 12 are overlapped and both side parts in a width direction are deposited. The exterior body 10 is formed of a stretchable composite material obtained by sticking a nonwoven fabric 10a to both surfaces of a stretched elastic film 10b by deposition. In an expanded state before both side parts of the exterior body 10 are deposited, a circular hole 13 is provided on a lateral part of each side part of the interior pad 20 and in a vertical center of the underpants type paper diaper. A cut line K around a leg which extends to the front bodice 11 side and to the rear bodice 12 side at an equal angle (θ) from a horizontal line T from the circular hole 13 and a point S overlapping a surrounding of the circular hole 13 on a reverse side of the horizontal line T passing the vertical center of the underpants type paper diaper and the interior pad 20 side, is formed, and the angle (θ) is 5 degrees or greater and 35 degrees or smaller.SELECTED DRAWING: Figure 1

Description

The present invention relates to pants-type disposable diapers.

Boxer shorts-type disposable diapers with a covering around the legs have higher adhesion between the crotch than conventional pants-type disposable diapers, and the gap between the absorber and the body due to the movement of the legs is less likely to occur, and leaks are less likely to occur. is there.

Generally, as for the manufacturing method of pants-type disposable diapers, as illustrated in Patent Document 1, for example, a raw material sheet flowing in the product width direction of pants-type disposable diapers is processed to form a continuously developed shape, and then the final shape is obtained. Fold it into a diaper by side-sealing both sides of the front and back bodies, cutting and isolating both sides to make a pants-type disposable diaper.
A method of manufacturing a boxer shorts type disposable diaper by this manufacturing method has been conventionally known. The covering portion around the leg is not formed in a tubular shape, but is formed when worn by deforming the outer body near the leg circumference and the crotch portion when worn.

Pants-type disposable diapers are processed in the direction of the product width. Therefore, the elastic members are basically joined in a state of being stretched in the product width direction. Therefore, the expansion and contraction of disposable diapers is basically in the width direction. When rubber thread is used as the elastic member, it may be arranged diagonally to give elasticity in the diagonal direction, but since the rubber thread is arranged while meandering, the number of places and number of threads that can be used There is a limit.
Boxer shorts-type disposable diapers need to be devised to improve the fit in response to complex deformation when worn. As represented by Patent Documents 2 and 3, it is necessary to use more rubber threads than ordinary pants-type disposable diapers and to install the rubber threads in a complicated arrangement.

On the other hand, there is a method of using an elastic film instead of rubber thread as the elastic member. The major difference from the rubber thread is that the elastic film itself can expand and contract not only in the material flow direction (MD direction) but also in the direction perpendicular to the material flow direction (CD direction). The stretched elastic film and non-woven fabric are processed into a composite material (hereinafter referred to as stretchable non-woven fabric) that is bonded by ultrasonic welding or the like to form an exterior body, but the welding at that time limits the movement in the CD direction. However, since the expansion and contraction in an oblique direction is not greatly restricted depending on the selection of the pattern, it is most suitable as an exterior body of a boxer shorts type paper diaper that requires complicated expansion and contraction.

Japanese Unexamined Patent Publication No. 2010-35582 Japanese Unexamined Patent Publication No. 2010-82133 JP-A-2018-83019

However, there is no example of use in boxer shorts type disposable diapers using elastic non-woven fabric. The reason is that even if a stretchable non-woven fabric with optimal stretchability is used for the exterior body, the area of the crotch part that is joined to the interior pad and the stretchability becomes inactive is large, and the special properties cannot be utilized. is there.

Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a boxer shorts type disposable diaper having a high fit and a good appearance.

In order to solve the above problems, (1) the pants-type diaper of the present invention has an exterior body and an interior pad, and is a boxer pants-type paper diaper when worn, and the front body and the back body are overlapped and have a width. It has a structure that becomes a pants type by welding both sides in the direction, and the exterior body is an elastic composite material in which a non-woven fabric is bonded to both sides of a stretched elastic film by welding, and both sides of the exterior body. In the unfolded state before welding, it has circular holes formed in the vertical center of the pants-type disposable diaper and on both sides of the interior pad, and the circular holes and the vertical center of the pants-type disposable diaper. From the point where the horizontal line passing through the diaper and the circumference of the circular hole on the opposite side of the interior pad side overlap, the horizontal line extends from the horizontal line to the front body side and the back body side at the same angle (θ), respectively. It has a cut line for undercarriage, and the angle (θ) is 5 degrees or more and 35 degrees or less.

(2) In the configuration of (1), the interior pad has an absorber using an acetate tow carrying highly absorbent polymer particles at the time of fiber opening and a carrier sheet wrapping the acetate tow absorber, and the opening. The acetate tow absorber carrying the highly absorbent polymer particles in the fibering step is fixed to the carrier sheet with an adhesive only at both ends in the vertical direction, and the adhesive region fixed with the adhesive is a side seal. It is characterized in that it is located above each of the lower ends.

(3) In the configuration of (2), the interior pad has a liquid-permeable top sheet, and the carrier sheet and the liquid-permeable top sheet side are adhered to the acetate toe absorber and the carrier sheet. It is characterized in that it is adhered within the same region as the adhesive region that fixes the.

(4) In the configuration of (2), the interior pad is adhered in the same region as the adhesive region fixing the acetate tow absorber and the carrier sheet, and in the center of the interior pad in the vertical direction. The width of the central adhesive region is within one-third of the width of the interior pad.

According to the present invention, it is possible to provide a boxer shorts type disposable diaper having a high fit and a good appearance.

It is a development view of the pants-type disposable diaper which concerns on embodiment of this invention. It is an enlarged view of the cut line for the undercarriage of the pants type paper diaper which concerns on embodiment of this invention. It is a cross-sectional view of XX'of FIG. It is a completed drawing of the pants-type disposable diaper which concerns on embodiment of this invention. It is an enlarged view of the undercarriage of the pants type paper diaper which concerns on embodiment of this invention. It is a figure explaining the wearing state of the pants-type disposable diaper which concerns on embodiment of this invention. It is explanatory drawing of the undercarriage covering part of the pants type paper diaper which concerns on embodiment of this invention, (a) is the explanatory view of the outer thigh side, (b) is the explanatory view of the inner thigh side. It is explanatory drawing of the undercarriage covering part and the inner thigh side of the pants-type paper diaper which concerns on embodiment of this invention, (a) is the view seen from the front oblique view, (b) is the view seen from the rear oblique view. It is explanatory drawing about the welding pattern of the stretchable composite material used in the exterior body of the pants-type disposable diaper which concerns on embodiment of this invention. It is a figure explaining the acetate tow absorber used in the absorber of the pants-type disposable diaper which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, but these are listed for the purpose of exemplification and do not limit the present invention. The same elements are designated by the same reference numerals throughout the description of the embodiment.
In the explanatory text and FIGS. 1, 2, 4, and 5, the shape of the stretchable composite material in the contracted state will be described. When the stretchable composite material is cut in the stretched state in the manufacturing process, it is necessary to adjust the shape of the cut line disclosed in the present invention according to the stretching ratio.

FIG. 1 is a development view of a pants-type disposable diaper according to an embodiment of the present invention.
As shown in FIG. 1, the pants-type disposable diaper 1 according to the embodiment of the present invention has a boxer-type shape when worn, which is composed of an exterior body 10 and an interior pad 20.

The exterior body 10 is a stretchable composite material in which a non-woven fabric is bonded to both sides of a stretched elastic film by ultrasonic welding.
The interior pad 20 uses an acetate tow carrying highly absorbent polymer particles as an absorber during fiber opening.
The pants-type paper diaper 1 has a structure in which the front body 11 and the back body 2 are superposed and welded on both sides in the width direction to form a pants type.

FIG. 2 is an enlarged view of a cut line for the undercarriage of a pants-type disposable diaper according to an embodiment of the present invention.
As shown in FIGS. 1 and 2, in the unfolded state before welding both sides of the exterior body 10, circular holes 13 and pants on both sides of the interior pad 20 at the center in the vertical direction of the pants pattern diaper 1. From the horizontal line T passing through the vertical center of the pattern diaper 1 and the point S that overlaps the circumference of the circular hole 13 on the side opposite to the interior pad 20 side, from the horizontal line T to the front body 11 side and the back body 12 There is a straight cut line K for undercarriage extending at the same angle (θ) with respect to each side.
The angle (θ) is preferably 5 degrees or more and 35 degrees or less.
The circular hole 13 includes not only a perfect circle but also an elliptical circle.

FIG. 3 is a cross-sectional view taken along the line XX'of FIG. As shown in FIG. 3, the interior pad 20 has a liquid-permeable top sheet 21, a liquid-impermeable back sheet 22, an acetate tow absorber 23, a carrier sheet 24, and a three-dimensional gather 25.
The acetate tow absorber 23 carrying SAP in the step of opening the fibers is fixed to the carrier sheet 24 only at both ends in the vertical direction with an adhesive, and the adhesive layer is indicated by reference numeral 26.
The adhesive region 26a of the adhesive layer 26 is preferably above the lower end F of the side seal 18 in FIG.
The adhesive between the carrier sheet 24 and the liquid-permeable top sheet 21 side is adhered within the same region as the adhesive region where the acetate tow absorber 23 and the carrier sheet 24 are fixed. This adhesive layer is indicated by reference numeral 27'.

The interior pad 20 is adhered at an adhesive region 28 in the same region as the adhesive region 26 fixing the acetate tow absorber 23 and the carrier sheet 24 and an adhesive region 29 at the center in the vertical direction of the interior pad. The width of the central adhesive region is within one-third of the width of the interior pad 20. The adhesive layer between the interior pad 20 and the exterior body 10 is indicated by reference numeral 28. The adhesive layer between the carrier sheet 24 and the back sheet 22 is indicated by reference numeral 27.
The exterior body 10 is an elastic composite material in which a non-woven fabric 10a is bonded to both sides of an elastic film 10b in a stretched state by welding.

FIG. 4 is a completed view of a pants-type disposable diaper according to an embodiment of the present invention. FIG. 5 is an enlarged view of the undercarriage of the pants-type disposable diaper according to the embodiment of the present invention. FIG. 6 is a diagram illustrating a wearing state of a pants-type disposable diaper according to an embodiment of the present invention. The pants-type disposable diaper according to the present embodiment will be described with reference to FIGS. 4 to 6.
Before wearing the pants-type disposable diaper 1 of the present invention, the tubular foot covering portion, which is a feature of the boxer shorts type, is not formed.

When worn, the vertical crotch part of the pants-type disposable diaper 1, the part AA'in FIG. 6, is centered near the center of AA' along the shape of the wearer's crotch, and A and A'are outside. Bend toward you.
As shown in FIG. 6, when the area from the bent points A and A'to the base of the leg becomes the covering part around the leg inside the thigh, and the line is cut along a straight line from point B to point C. Since the exterior body wraps around the leg from the point A on the inside of the leg, the suspension covering portion 15 is formed. If the cut line K around the leg starts from point B with a large inclination toward the upper part and then changes to a gentle inclination toward the side, the leg circumference covering portion is not formed. Therefore, the initial inclination of the cut line K is important when designing the abdominal portion 15 around the leg.

In the pants-type disposable diaper 1 of the present embodiment, it is desirable to set θ from 5 degrees to 35 degrees. If it is larger than 35 degrees, the boxer shorts type will disappear. On the other hand, as θ becomes larger, the leg opening in the natural length state becomes larger, which makes it easier to wear. Therefore, it is desirable that θ is 5 degrees or more.
The more optimal angle is 10 degrees or more and 25 degrees or less.

In the present embodiment, the linear cut line K starting from the point B may have a shape that reaches the point D of the side seal region as it is, but by making the line draw an arc upward from the point C in front of it, It is preferable because the slit portion 16 is formed under the side seal 18 when worn. The presence of the slit portion 16 can prevent the movement of the foot from being suppressed due to excessive tightening by the covering portion around the leg.

The distance between points C and D in the width direction is preferably 20 mm or less, preferably 10 mm or less. If it is larger than 20 mm, the width of the slit portion 16 becomes too wide, and not only the fit of the leg circumference covering portion 15 is impaired, but also the appearance is deteriorated. The vertical distance between points C and D is preferably 15 mm or less, preferably 10 mm or less. If it is larger than 15 mm, the length of the slit portion 16 is too long and the fit of the leg circumference covering portion 15 is impaired.
Further, in the diagram of the explanation of the present embodiment, points B to C are shown by straight lines, but there is no problem even if a curve is included so as to fit the line of the body more. Even in that case, the angle θ is set by drawing a virtual line from point B to point C.

As shown in FIG. 6, when the leg circumference covering portion 15 is configured, the portion closer to the leg circumference is accompanied by a complicated deformation in which the exterior body 10 is stretched not only in the width direction but also in the vertical direction. Therefore, in the present embodiment, as shown in FIG. 3, it is optimal to use an elastic composite material in which the elastic film 10b and the non-woven fabric 10a are bonded to each other.

7A and 7B are explanatory views of a suspension covering portion of a pants-type disposable diaper according to an embodiment of the present invention, in which FIG. 7A is an explanatory view of the outer thigh side and FIG. 7B is an explanatory view of the inner thigh side. 8A and 8B are explanatory views of the undercarriage covering portion and the inner thigh side of the pants-type disposable diaper according to the embodiment of the present invention, in which FIG. 8A is a view seen from an oblique front and FIG. Is.
The present embodiment is characterized in that a circular hole 13 is provided at the base of the cut line K of the leg portion, as described with reference to FIGS. 4 to 6. When there is no circular hole 13 and a linear cut line K is provided starting from the point A, the opening opens in a triangular shape starting from the point A as shown in FIG. 7A. At this time, a pulling force acts on both sides at point A.

As will be described later, the elastic composite material has an elastic film 10b and a non-woven fabric 10a bonded together at a large number of welding points. At the welding point, the non-woven fabric 10a is melted, and the elastic film 10b is perforated by melting or breaking. Since the welding point acts like a perforation, it is easy to break. Therefore, when a straight cut line is provided directly from the point A, the point A may be a trigger for tearing. When the circular hole 13 is first provided as in the embodiment of the present invention, it spreads as shown in FIG. 8, and the force is dispersed and does not tear.
Further, when a straight cut line is provided directly from point A, the end portion becomes a line that draws a curve from point A to point C, but in the present invention, the portion of the circular hole 13 is formed when worn. After opening in a semi-circular shape, it becomes a horizontal line from there, making it more like a boxer type.

The diameter of the circular hole 13 is determined by whether the final product is for men or women and the size, but 20 mm or more and 40 mm or less is appropriate. If it is less than 20 mm, the diameter is too small and it is difficult to obtain the desired effect. If it is larger than 40 mm, the opening on the inner crotch side formed by the circle when worn becomes too large. The appropriate distance G (FIG. 1) from the end of the interior pad 20 to the circle is 5 mm or more and 20 mm or less. If the distance G is narrower than 5 mm, it is difficult to control during manufacturing. If the distance G is wider than 25 mm, the inner or side of the leg circumference covering portion 15 becomes too long.

(Stretchable composite material)
As shown in FIG. 3, the stretchable composite material of the exterior body 10 is laminated with a non-woven fabric 10a on the front and back surfaces of the stretched elastic film 10b. Ultrasonic welding is desirable as a method of laminating the non-woven fabric 10a on the front and back of the elastic film 10b. The stretch ratio of the elastic film 10b at the time of bonding is preferably 2.5 to 4 times, and more preferably 3 to 3.5 times. Since the elastic film 10b stretched at the time of laminating remains a permanent strain, it does not return to its original length even if it has a natural length.

Further, since it is fixed to the non-woven fabric 10a at the welding point, it cannot be stretched more than it was stretched at the time of laminating. Therefore, the stretching ability of the processed elastic composite material is lower than the stretching rate at the time of laminating. Therefore, when stretched less than 2.5 times during laminating, the stretchable composite material has only about twice the capacity, which is low for use as an exterior body.

On the other hand, the higher the stretch ratio at the time of laminating, the larger the neck-in of the elastic film. The elastic film 10b fixed to the non-woven fabric 10a at the welding point in the neck-in state does not easily return to the original width even in the natural length state, and may wrinkle between the upper and lower non-woven fabrics, resulting in the finish of the elastic composite material. Is not flat and has swells.

Therefore, it is desirable that the stretch ratio of the elastic film at the time of laminating is 4 times or less.
The elastic film 10b and the non-woven fabric 10a can be welded by a method such as heat or ultrasonic waves, but ultrasonic welding is suitable because the finished product is soft to the touch. Lamination by ultrasonic welding is performed by passing the stretched elastic film 10b and the non-woven fabric 10a between the vibration from the horn and the anvil roll having the convex portion provided in the same shape as the welding pattern. Therefore, the performance of the stretchable composite material is determined by the stretch ratio and the welding pattern of the elastic film 10b during the treatment.

FIG. 9 is an explanatory diagram of a welding pattern of an elastic composite material used in an exterior body of a pants-type disposable diaper according to an embodiment of the present invention. In the present invention, the welding pattern is not particularly limited, but as shown in FIG. 9, the zigzag pattern is desirable because the elasticity of the staggered pattern does not decrease after lamination and the thickness of the elastic composite material becomes thin at a small number of welding points.
Further, it is desirable to have an inclination of an angle θ'with respect to the anvil roll axis direction because the durability of the device can be improved. If there is no inclination, the impact is large because the horn repeats when it is in contact with the convex portion of the anvil roll and when it is not. On the other hand, when the horn is tilted, the horn is always in contact with the convex portion of the anvil roll, so that the load due to the impact on the horn is reduced.

The distance D between the welding points in the laminating treatment direction affects the thickness of the stretchable composite material. When a softer and warmer texture such as a towel is desired, the distance D between welding points may be increased and the height of the waves of the non-woven fabric formed on the elastic composite material may be increased. In that case, the distance D between welding points is preferably 2 mm or more and 4 mm or less. On the contrary, when it is desired to make the texture flatter and more like cotton, the distance D between welding points is preferably 1.5 mm or less and 0.8 mm or more.
The interval in the width direction of the welding points can be appropriately determined after setting the distance D between the welding points. If the distance between the welding points in the width direction is too narrow, the area ratio of the welding points becomes high, and the treatment conditions at the time of ultrasonic welding require high energy, which is not preferable. If the distance between the welding points in the width direction is too wide, vertical wrinkles may occur due to the return of the elastic film 10b from the neck-in generated during ultrasonic welding.
From the above, the distance D between welding points can be selected from 0.8 mm to 4 mm, which has a good balance between processing conditions and finish.

FIG. 10 is a diagram illustrating an acetate tow absorber used in the absorber of the pants-type disposable diaper according to the embodiment of the present invention, in which (a) is a non-deformed acetate tow absorber and (b) an acetate tow absorber. Shows the time of transformation of. In the embodiment of the present invention, an acetate tow carrying SAP at the time of opening the fiber is used as the absorber 23. A plasticizer such as triacetin can be used for fixing the SAP to the acetate tow.

Compared to fluff pulp, which is widely used as a carrier for SAP, acetate tow has a low ability to retain urine by itself, but on the contrary, it is characterized by excellent diffusion of urine inside. Moreover, since it is a long fiber, it does not collapse, and has elasticity to return even if both ends are pulled, for example. In the embodiment of the present invention, such a feature of long fibers of acetate tow is utilized. The acetate tow absorber 23, which is a rectangular shape of acetate carrying SAP while being opened, is wrapped with a carrier sheet 24.
At this time, as shown in FIG. 10, only both ends of the acetate tow are fixed with an adhesive. The adhesive layer made of this adhesive is indicated by reference numeral 26. The acetate tow absorber 30 fixed in this way can be freely deformed between the adhesive regions.

When the diaper is processed and sandwiched between the groins, not only the entire absorber 23 but also the place where the diaper comes to the crotch can be bent as shown in FIG. 6 and can be shrunk in the width direction, so that the diaper fits more flexibly. In addition, since tension is applied to both fixed ends, a force is generated to return when the legs are opened even when sitting, so that the absorber 23 can be fitted according to the movement of the wearer's body. .. In order to generate such a feature, the adhesive regions 26a (FIG. 1) at both ends are provided above the lower end F of the side seal 18.

Since the region below the lower end F of the side seal 18 is a region that moves in a complicated manner in order to form the foot circumference covering portion 15, it is necessary to prevent the adhesive region 26a from overlapping there. Further, the adhesive layer 27 of the carrier sheet 24 and the back sheet 22 and the adhesive layer 28 of the interior pad 20 and the exterior body 10 must also be performed in the adhesive region 26a. If the inner pad 20 and the outer pad 10 are adhered only to the areas at both ends, the outer body 10 and the inner pad 20 may move differently in the crotch and may be displaced. Therefore, it is necessary to bond the interior pad 20 at the center of the exterior body 10 in the vertical direction, but the width of the bonded region at this time is within one-third of the width of the exterior body.
Here, the reason why both ends of the interior pad 20 are not fixed is that the exterior body 10 needs to be deformed in a complicated manner in this region as described above, and the movement is suppressed when the interior pad 10 is fixed at the full width. .. Therefore, the fixing of the interior pad 20 in the adhesive region 29 needs to be a minimum area. On the other hand, the lower limit of the width of the adhesive region 29 is preferably 20 mm because it needs to be sufficiently fixed.

According to the present embodiment, by using the stretchable non-woven fabric for the exterior body 10 and the acetate tow for the absorber 23, the fit is high and the appearance becomes more like underwear.

Although the present invention has been described above using the embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope described in the above-described embodiments and examples. It will be apparent to those skilled in the art that various changes or improvements can be made to the above embodiments. Further, it is clear from the description of the scope of claims that such a modified or improved form may be included in the technical scope of the present invention.

1 Pants type disposable diaper 10 Exterior body 10a Non-woven fabric 10b Elastic film 13 Circular hole K Cut line 20 Interior pad 21 Top sheet 22 Back sheet 23 Absorbent 24 Carrier sheet

Claims (4)

It has an exterior body and an interior pad, and when worn, it is a boxer shorts type disposable diaper.
The front body and back body are overlapped, and the width direction and both sides are welded to form a pants type.
The exterior body is an elastic composite material in which a non-woven fabric is bonded to both sides of an elastic film in a stretched state by welding.
In the unfolded state before welding both sides of the exterior body, there are circular holes formed in the vertical center of the pants-type paper diaper and on both sides of the interior pad, and the circular holes and the pants. The horizontal line passing through the vertical center of the pattern trousers overlaps with the circumference of the circular hole on the side opposite to the interior pad side, so the horizontal line is the same for the front body side and the back body side, respectively. It has a cut line for undercarriage that extends at an angle (θ),
A pants-type disposable diaper having an angle (θ) of 5 degrees or more and 35 degrees or less. The interior pad has an absorber that uses an acetate tow carrying highly absorbent polymer particles at the time of opening, and a carrier sheet that wraps the acetate tow absorber.
The acetate tow absorber carrying the highly absorbent polymer particles in the opening step is fixed to the carrier sheet with an adhesive only at both ends in the vertical direction.
The pants-type disposable diaper according to claim 1, wherein the adhesive regions fixed with the adhesive are located above the lower ends of the side seals. The interior pad has a liquid permeable top sheet and
The second aspect of the present invention is that the carrier sheet and the liquid permeable top sheet side are adhered within the same region as the adhesive region fixing the acetate tow absorber and the carrier sheet. The described pants pattern diaper. The interior pad is adhered in the same region as the adhesive region fixing the acetate tow absorber and the carrier sheet, and in the center of the interior pad in the vertical direction.
The pants-type disposable diaper according to claim 2, wherein the width of the central adhesive region is within one-third of the width of the interior pad.

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