JP4981539B2 - Method for producing high-density region-containing sheet and disposable diaper using high-density-containing sheet - Google Patents

Description

  The present invention relates to a method for producing a high-density region-containing sheet, a sheet member using the high-density region-containing sheet, and a disposable diaper using the sheet member. More particularly, the present invention relates to a high-density region-containing sheet having a high-density region and a low-density region, a sheet member obtained by joining a high-density region of the high-density region-containing sheet and an elastic member, and a disposable diaper using the sheet member for a chassis. .

  Conventional disposable absorbent articles include, for example, disposable diapers. Disposable diapers are widely used from infants and children to the elderly and the disabled, and have come to replace reusable cloth absorbent articles. In addition, in order to improve the adhesion to the wearer and the cushioning properties, two types of non-stretchable sheet members are stuck through stretched elastic members such as threads, nets, belts, sheets, etc. An elastic composite sheet that imparts elasticity to a sheet member such as a conductive nonwoven fabric is used.

  When the elastic member in the stretchable composite sheet is in a contracted state, each sheet member forms a large crease or crease, and cushioning properties can be obtained by the crease or crease. However, such large wrinkles and wrinkles occur irregularly on the nonwoven fabric with the random stiffness distribution of the nonwoven fabric, and when the wearer wears such disposable diapers, the adhesion to the wearer is poor. The contact feeling is also hard and the touch is not good.

  In recent years, if large folds or wrinkles continue to irritate the skin, it can affect the body as a tactile stimulus, causing not only discomfort, but also endocrine function, autonomic dysfunction, and even the development of intelligence. Has been reported, and it has become an urgent need to provide disposable diapers with smaller folds and folds.

For example, in Patent Document 1, the elastic yarn for body is disposed between the front exterior member and the back exterior member at 1-5 mm intervals in the body fit portion of the disposable pants and arranged in the circumferential direction. Disposable diapers are provided in which fine vertical gathers with a pitch of about 3 mm or less are formed throughout.
JP 2002-238934 A

  However, the above-described configuration in which the elastic yarn is sandwiched between the front exterior member and the back exterior member at intervals of 1 to 5 mm in the waist expansion / contraction portion is a unit per unit of the elastic member or adhesive. Increases in weight. For this reason, since the large and deep wrinkles are eliminated, even if the sense of stiffness is eliminated, the sense of contact with the skin may be deteriorated due to the high rigidity.

  On the other hand, there is a method using a stretchable nonwoven fabric, but stretchability is insufficient for use as a disposable diaper or the like, which may be costly.

  The present invention has been made in view of the above, and an object of the present invention is to provide a sheet member and a sheet member that have a flexible and uneven small wrinkle and can be used with good adhesion to the wearer. It is providing the manufacturing method of the used disposable diaper and the high-density area | region containing sheet | seat which is a constituent sheet | seat of this sheet | seat member.

  The present inventor has intensively studied to solve the above problems. As a result, by laminating two high-density region-containing sheets in which high-density regions and low-density regions are alternately formed via an elastic member, it has a soft and uneven small wrinkle and less skin irritation In addition, by using an external member laminated with a sheet member for a chassis of a disposable diaper, it is found that adhesion to a wearer is increased, there is no sense of incongruity, and there is little skin irritation, and the present invention is completed. It came to. More specifically, the present invention provides the following.

  According to the first embodiment of the present invention, the first sheet, the second sheet, and the thread, the net, the band, and the sheet disposed between the first sheet and the second sheet. And a plurality of high density regions and a plurality of low density regions are predetermined in the first sheet. The elastic member is formed in a direction in which the plurality of high-density regions and the plurality of low-density regions are alternately and continuously formed in a predetermined direction. The sheet member is arranged so as to be along, and at least a part of the plurality of high-density regions is joined to the elastic member in an expanded state.

  In the second embodiment of the present invention, the sheet member according to the first embodiment of the present invention, wherein at least the first sheet is formed in an uneven shape along the predetermined direction.

In the third embodiment of the present invention, the density of the high-density region for obtaining the first rigidity is 0.05 to 0.6 g / cm ^3. The first embodiment or the second embodiment of the present invention. The sheet | seat member as described in.

In the fourth embodiment of the present invention, the density of the low density region for obtaining the second rigidity is 0.01 to 0.05 g / cm ^3. First to third embodiments of the present invention The sheet | seat member in any one of.

  In the fifth embodiment of the present invention, the sheet member according to any one of the first to fourth embodiments of the present invention, wherein a length of the high-density region is 0.1 to 1.5 mm.

  In the sixth embodiment of the present invention, the length of the low density region is 0.5 to 3 mm. The sheet member according to any one of the first to fifth embodiments of the present invention.

  In the seventh embodiment of the present invention, when the adhesive is applied to the elastic member and bonded to the first sheet and the second sheet, the elastic member has a higher density than the low density region. The sheet member according to any one of the first to sixth embodiments of the present invention that is strongly bonded to the region.

（Ａは高密度領域の長さ、Ｃは低密度領域の長さ、およびＸは弾性部材の実質倍率である。） In the eighth embodiment of the present invention, the sheet member according to any one of the first to seventh embodiments of the present invention that satisfies the following mathematical formula 1.

(A is the length of the high density region, C is the length of the low density region, and X is the substantial magnification of the elastic member.)

  According to the ninth embodiment of the present invention, a high-density region-containing sheet in which a plurality of high-density regions and a plurality of low-density regions are formed by pressing the sheet with a shaping roll having a toothed region. The manufacturing method of the high-density area | region containing sheet | seat characterized by manufacturing this.

  In the tenth embodiment of the present invention, the method for producing a high-density region-containing sheet according to the ninth embodiment of the present invention, which produces a high-density region-containing sheet formed in an uneven shape along the longitudinal direction.

  In an eleventh embodiment of the present invention, the high-density region-containing sheet according to the ninth embodiment or the tenth embodiment of the present invention, wherein the sheet is squeezed between a pair of shaping rolls that rotate opposite to each other. Production method.

  In a twelfth embodiment of the present invention, the high-density region and the low-density region are alternately formed in the longitudinal direction of the sheet, and the high-density region according to the ninth embodiment or the eleventh embodiment of the present invention. Production method of containing sheet.

  In the thirteenth embodiment of the present invention, the shaping roll has at least one toothed region and at least one grooved region in the high-density region-containing sheet according to the twelfth embodiment of the present invention. Manufacturing method.

  In the fourteenth embodiment of the present invention, the grooved region is a method for producing a high-density region-containing sheet according to any one of the ninth to thirteenth embodiments of the present invention, wherein the grooved region is covered with a heat insulating material.

  According to a fifteenth embodiment of the present invention, there is provided a high-density region-containing sheet characterized by melting a low-density sheet, forming a part of the low-density sheet into a film, and adding a high-density region. Production method.

  According to the sixteenth embodiment of the present invention, the chassis includes a front waistline portion and a back waistline portion, and has a waistline opening portion and a pair of left and right leg opening portions in the crotch portion, and the chassis. A liquid-permeable top sheet disposed at least in part, a liquid-impermeable back sheet disposed on one side in the thickness direction of the liquid-permeable top sheet, the liquid-permeable top sheet, and the liquid A disposable diaper comprising a liquid retaining absorbent disposed between an impermeable back sheet and extending between the trunk opening and the leg opening in the chassis. A disposable diaper using the sheet member according to any one of the first to eighth embodiments of the present invention.

  According to the present embodiment, a sheet member that can be used by a wearer with satisfactory adhesion, and a disposable diaper using the sheet member can be provided.

  The present invention is characterized by producing a high-density region-containing sheet having a high-density region and a low-density region by pressing the sheet with a shaping roll having a toothed region. In addition, a flexible and uneven small pleat is formed by joining the high density region of the high density region-containing sheet with the stretched elastic member, and this is used as a chassis for disposable diapers. It is used. Hereinafter, although the manufacturing method of a high-density area | region containing sheet | seat of this invention, a sheet | seat member, and embodiment of a disposable diaper are demonstrated in detail, this invention is not limited to the following embodiment at all, The objective of this invention Within the range, it can be implemented with appropriate modifications. In addition, although description may be abbreviate | omitted suitably about the location where description overlaps, the meaning of invention is not limited.

[Method for producing high-density region-containing sheet]
Drawing 1 is a figure showing an example of a manufacturing method of a high-density field content sheet of the present invention. The sheet 1 is squeezed with a shaping roll 3 composed of a pair of embossing rolls as shown in FIG. 1, and the high density sheet 1 is stretched in advance to provide a low density area 22, thereby providing a high density area containing sheet 2. Manufacturing. The shaping roll 3 has a toothed region 31 having a plurality of teeth of a certain size, and the pair of shaping rolls 3 rotate opposite to each other and squeeze the sheet 1. The portion squeezed by the teeth in the toothed region 31 becomes the low-density region 22 when the fiber stretches, and the portion that is not squeezed becomes the high-density region 21. When the sheet 1 is passed through the pair of shaping rolls 3 and the shaping roll 3 is rotated, the places squeezed in the toothed region 31 as shown in FIG. 21 and a low density region 22 are formed. In addition, in FIG. 1, although the sheet | seat 1 is squeezed with a pair of shaping roll 3, when the sheet | seat 1 is high-density, it may be made to squeeze the sheet | seat 1 using only one shaping roll 3. FIG. Good.

  The high density region 21 and the low density region 22 are alternately formed at every tooth interval of the toothed region 31. That is, the sheet 1 is alternately formed in the longitudinal direction of the sheet 1, here, the conveying direction (MD) of the sheet 1 that passes the shaping roll 3. The length of the low density area 22 (the distance between the high density area 21 and the nearest high density area 21 and the tooth width of the toothed area 31) depends on the intended use of the high density area-containing sheet 2 to be obtained. Although it can change suitably, it is preferable that it is 0.5-3 mm. When the length of the low density region 22 is less than 0.5 mm, a sheet member with less skin irritation that forms a soft and uneven small wrinkle cannot be provided, although details will be described later. On the other hand, if the length of the low-density region 22 exceeds 3 mm, a sheet member with less skin irritation that forms a soft and uneven small wrinkle cannot be provided although details will be described later.

  Although the length of the high-density area | region 21 can be suitably changed according to the intended purpose etc. of the high-density area | region containing sheet 2 manufactured, it is preferable that it is 0.1-1.5 mm. If the length of the high-density region 21 is less than 0.1 mm, a sheet member with less skin irritation that forms a soft and uneven small wrinkle cannot be provided although details will be described later. On the other hand, if the length of the high-density region 21 exceeds 1.5 mm, a sheet member with less skin irritation that forms a soft and uneven small wrinkle cannot be provided although details will be described later.

The rigidity of the low density region 22 can be appropriately changed according to the purpose of use and the like, but the density for obtaining a predetermined rigidity is preferably 0.01 to 0.05 g / cm ³ . When the density of the low density region 22 is less than 0.01 g / cm ³ , a sheet member with less skin irritation, which will be contracted too much by the elastic member to form a soft and uneven small wrinkle, as will be described in detail later. I can't. On the other hand, when the density of the low density region 22 exceeds 0.05 g / cm ³ , the rigidity becomes too high, and a sheet member with less skin irritation that forms a soft and uneven small wrinkle is described in detail later. Can not.

In order to obtain the predetermined rigidity of the high-density region 21, it is preferable to use the sheet 1 such that the density of the sheet 1 is 0.05 to 0.6 g / cm ³ . When the density of the high-density region 21 is less than 0.05 g / cm ³ , the sheet member has the same degree of rigidity as the low-density region 22, and will be described later in detail. Can not provide. On the other hand, when the density of the high-density region 21 exceeds 0.6 g / cm ³ , the rigidity becomes too high, and a sheet member with less skin irritation that forms a soft and uneven small wrinkle is described in detail later. I can't.

  The nonwoven fabric used for the sheet 1 can be appropriately changed according to the purpose of use, for example, spunbond nonwoven fabric, meltblown nonwoven fabric, heat roll nonwoven fabric, SMS nonwoven fabric combining spunbond nonwoven fabric and meltblown nonwoven fabric, air through Various known nonwoven fabrics such as a nonwoven fabric, a spunlace nonwoven fabric, and an airlaid nonwoven fabric can be used, and these may be used alone or in combination. It is more preferable to use an air-through nonwoven fabric, a heat roll nonwoven fabric, a spunlace nonwoven fabric, a spunbonded nonwoven fabric, or a melt blown nonwoven fabric in order to form a flexible wrinkle that is beautiful to the eye and feels good.

  Although the material of the fiber which comprises the nonwoven fabric used for the sheet | seat 1 can be suitably changed according to a use purpose etc., for example, polyethylene, polypropylene, polyester, acrylic, polyethylene / polypropylene, polyethylene / polyethylene terephthalate, polypropylene / Known fibers such as composite fibers such as polyethylene terephthalate, that is, fibers formed of core-sheath fibers and side-by-side fibers can be used, and these fibers may be used alone, but may be used in combination. Also good. The sheet 1 may have a single layer structure or a multilayer structure.

The basis weight of nonwoven fabric used for the sheet 1 is preferably 5 to 50 g / ^{m 2,} and more preferably 10 to 20 g / ^{m 2.} If the basis weight of the nonwoven fabric is less than 5 g / m ² , there is a possibility that a portion where the strength is reduced due to intense formation unevenness and tearing. On the other hand, if the basis weight of the nonwoven fabric exceeds 20 g / m ² , the air permeability is hindered, and if it is worn for a long time, it may be steamed.

  The elongation of the nonwoven fabric used in the sheet 1 is not particularly limited as long as it is 40% or more. If the elongation of the nonwoven fabric is less than 40%, there is a possibility that tearing may occur when a soft and uneven small wrinkle is formed.

  In addition to the method for producing the high-density region-containing sheet shown in FIG. 1, for example, the sheet may be produced as shown in FIG. Unlike the embodiment of FIG. 1, the shaping roll 3 has a toothed region 31 having a plurality of teeth of a certain size and a planar grooved region 32 having no teeth, and has a toothed region. 31 and the grooved region 32 are alternately installed in the shaping roll 3. When the sheet 1 is passed through the pair of shaping rolls 3 and the shaping roll 3 is rotated, the portion squeezed in the toothed region 31 extends the sheet 1 to form a low density region 22, As shown in FIG. 3, a high-density region having a portion where the high-density region 21 and the low-density region 22 are formed (shaped region) and a portion not formed by the grooved region 32 (groove region 23). The containing sheet 2 can be obtained. In addition, you may make it have the adhesive bond layer 24 for joining the high density area | region containing sheet | seat 2 with another member etc. as needed.

  The width of the toothed region 31 shown in FIG. 2 can be appropriately changed according to the purpose of use of the high-density region-containing sheet 2 to be manufactured, but is preferably 2 mm to 10 cm, and preferably 3 to 9 mm. It is more preferable. When the width of the toothed region 31 is less than 2 mm, the convex portion of the soft and uneven small ridge of the sheet member, which will be described in detail later, is crushed, and the shape of the flexible and uneven small ridge can be maintained. Disappear. On the other hand, when the width of the toothed region 31 exceeds 10 cm, a sheet member, which will be described later in detail, is stretched, and it becomes impossible to maintain the shape of a soft and uneven small ridge.

  Although the width | variety of the grooved area | region 32 shown in FIG. 2 can be suitably changed according to the intended purpose etc. of the high-density area | region containing sheet 2 manufactured, it is preferable that it is 0.5 mm-3 cm, More preferably, it is 5 mm. When the width of the grooved region 32 is less than 0.5 mm, the convex portion of the sheet member, which will be described later in detail, is crushed, and a flexible and uneven small wrinkle cannot be formed. On the other hand, when the width of the grooved region 32 exceeds 3 cm, the ratio of the entire groove region 23 that is soft and uneven and has no small wrinkles increases.

  The shaping roll 3 is covered with a heat insulating material such as a heat insulating tape in the grooved region 32 so that heat is not transmitted to other than the toothed region 31. By applying heat only to the portion of the sheet 1 to be shaped, damage to the high-density region-containing sheet 2 can be suppressed by heat, and deformation of the high-density region-containing sheet 2 is prevented from being deformed. Can do.

  In addition, after passing the sheet 1 through the shaping roll 3, the formed high-density region 21 of the produced high-density region-containing sheet 2 may be cooled as necessary in order to keep the formed high-density region 21.

  The manufacturing method described in FIGS. 1 and 2 includes meshing plates, embossing, thermoforming, high pressure hydraulic forming, injection molding, and the like. In addition to the manufacturing method shown in FIGS. 1 and 2, for example, when using a low-density nonwoven fabric such as a through-air nonwoven fabric, the nonwoven fabric is melted once by heat treatment or ultrasonic treatment, and formed into a film. Alternatively, a method of adding the high density region 21 may be used. In this case, the heat-treated portion forms the high density region 21, and the untreated portion becomes the low density region 22. Furthermore, for example, the high-density region 21 may be formed by an embossed linear or dot aggregate.

  According to the method for producing a high-density region-containing sheet of the present embodiment, the material can be prevented from being deformed, such as entering into the width of the material, or twisted, and the high-density region-containing sheet having the high-density region 21 and the low-density region 22 alternately. 2 can be produced efficiently. In addition, the high-density area | region containing sheet 2 obtained by embodiment is a flat sheet, and the high-density area | region 21 and the low-density area | region 22 are flexible and uneven | corrugated in a longitudinal direction (MD) by the difference in the pressure which squeezes the sheet | seat 1. Both sheets having small ridges alternately and continuously can be obtained, and can be properly used according to the purpose of use.

[Sheet material]
In the high density region-containing sheet 2 obtained by the manufacturing method shown in FIG. 1 or FIG. 2, the high density regions 21 and the low density regions 22 are alternately formed as shown in FIG. The sheet member 5 can be obtained by joining the high-density region-containing sheet 2 (first sheet or second sheet) and the elastic member 4 in a stretched state. The sheet may be the high-density region-containing sheet 2. Hereinafter, for convenience of explanation, a sheet member 5 in which two high-density region-containing sheets 2 and an elastic member 4 are joined will be described.

  FIG. 5 is a cross-sectional view of a sheet member 5 in which two high-density region-containing sheets 2 and an elastic member 4 are joined. The two high-density region-containing sheets 2 are joined via the elastic member 4. When joining the high density region containing sheet 2 to the elastic member 4, the adhesive is directly applied to the elastic member 4, and the high density region containing sheet 2 is joined in a state where the elastic member 4 is stretched. Since the low density region 22 has a low fiber density and is peeled off immediately after the elastic member 4 is bonded, only the high density region 21 is joined to the elastic member 4. Therefore, as shown in FIG. 5, only the elastic member 4 and the high-density region 21 are joined, and when the elastic member 4 contracts, the low-density region 22 also contracts, forming a soft and uneven small ridge.

When the high-density region-containing sheet 2 is flat, when the length A of the high-density region 21, the length C of the low-density region 22 and the substantial magnification of the elastic member 4 are X, the following formula 1 is satisfied. Only form pleats. If Expression 1 is not satisfied, even if the elastic member 4 of the sheet member 5 contracts, the low density region 22 does not contract regularly, and pleats cannot be formed.

  Similarly, when the high-density region-containing sheet 2 is uneven and the uneven pattern is continuously formed, the pleats are formed only when Expression 1 is satisfied. If Expression 1 is not satisfied, even if the elastic member 4 of the sheet member 5 contracts, the low density region 22 does not contract regularly, and pleats cannot be formed.

In addition, although the application quantity which apply | coats an adhesive agent directly to the elastic member 4 can be suitably changed according to the property etc. of the high-density area | region containing sheet | seat 2 etc., it applies by 0.02-0.2g / m < ² >. It is preferable. If the coating amount is less than 0.02 g / m ² , the high density region 21 and the elastic member 4 cannot be joined. On the other hand, if the coating amount exceeds 0.2 g / m ² , the low density region 22 is also bonded to the elastic member 4 and pleats cannot be formed.

  The method of joining the elastic member 4 and the high density region 21 can be appropriately changed according to the purpose of use of the sheet member 5, but the uniform convex portion 51 is formed without inhibiting the shrinkage of the low density region 22 itself. From the viewpoint of facilitating the positioning and the alignment of the adhesive coating position with the elastic member 4, for example, directly to the elastic member 4 such as V-slit coating, Ω coating, control seam coating, etc. It is preferable to fix the elastic member 4 by a coating method capable of coating.

  As shown in FIG. 6, the high-density regions 21 may be joined to the elastic member 4 in a state where every other high-density region 21 is stretched (hereinafter, for convenience of explanation, the high-density on the upper side of the elastic member 4 in FIG. 5). The region-containing sheet 2 is referred to as a high-density region-containing sheet on the front surface, and the high-density region-containing sheet 2 below the elastic member 4 is referred to as a high-density region-containing sheet on the back surface. By joining the plurality of high-density regions 21 to the elastic member 4 in a state where every other high-density region 21 is stretched, the high-density region 21 that is not joined to the elastic member 4 is separated from the elastic member 4 when the elastic member 4 contracts. As a result, as shown in FIG. 6, a soft and uneven small wrinkle is formed. The top of the convex part 51 and the bottom part of the concave part 52 of the soft and uneven small ridge are formed by the high density region 21, and the space between the top part of the convex part 51 and the bottom part of the concave part 52 is formed by the low density region 22. Yes. Even if the elastic member 4 contracts, the high density region 21 does not contract because the rigidity is high, and only the low density region 22 contracts, and a sheet member having a regular uneven pattern can be obtained. Moreover, since the low density area | region 22 is formed between the top part of the convex part 51, and the bottom part of the recessed part 52, the sheet | seat member 5 with little skin irritation which forms a soft and uneven | corrugated small wrinkle can be obtained. It should be noted that only the low density region 22 is contracted only when the condition of Equation 1 is satisfied, as in the case where all the high density regions 21 are bonded to the elastic member 4. In this case, A in Formula 1 is the length of the high-density region 21 at the bottom of the recess 52, C is the shrinkage capacity region of the low-density region 22, and X is the substantial expansion ratio of the elastic member 4.

  The height H of the convex portion 51 is substantially the same as the length of the low density region 22 (the distance between the high density region 21 and the nearest high density region 21 and the tooth width of the toothed region 31). As described above, the height H of the convex portion 51 can be appropriately changed according to the purpose of use of the sheet member 5 or the like, but is preferably 0.5 to 3 mm. When the height H of the convex portion 51 is less than 0.5 mm, it is not possible to provide a sheet member with less skin irritation that forms a soft and uneven small wrinkle. On the other hand, when the height H of the convex part 51 exceeds 3 mm, when wearing the wear using the sheet | seat member 5, adhesiveness with a wearer will weaken.

  Further, the length B of the top portion of the convex portion 51 and the length A of the bottom portion of the concave portion 52 are the same as the length of the high-density region 21. As described above, it can be appropriately changed according to the purpose of use of the sheet member 5, but is preferably 0.1 to 1.5 mm. When the length A of the bottom and the length B of the top are less than 0.1 mm, it is not possible to provide a sheet member with less skin irritation that forms a soft and uneven small wrinkle. On the other hand, when A and B exceed 1.5 mm, when wearing an article using the sheet member 5, the area in contact with the high-density region 21 increases, the contact feeling becomes hard, and the touch becomes worse.

  The height H of the concavo-convex pattern on the front surface and the back surface of the sheet member 5 in FIGS. 5 and 6 is the same, but the high density region-containing sheet 2 is different in the width of the high density region 21 and / or the low density region 22. Can be joined to the elastic member 4 to form a sheet member 5 having a height H on the front surface and a back surface, a length A on the bottom, a length B on the top, and the like.

  The form of the elastic member 4 is not particularly limited and can be appropriately changed according to the purpose of use. The member 5 may be configured, but the sheet member 5 may be configured in a plurality of forms.

  The pitch (interval) at which the elastic member 4 intervenes can be appropriately changed according to the purpose of use of the sheet member 5 and the like, but is preferably 1 to 30 mm, and more preferably 6 to 8.5 mm. . When the pitch is less than 1 mm, the linear pressure increases, and when wearing a wearing article using the sheet member 5, a rubber mark is given to the wearer. On the other hand, if the pitch exceeds 30 mm, the elastic member 4 cannot be affected, and when wearing a wear using the sheet member 5, the surface pressure on the wearer is lowered and the wear is shifted. .

  The thickness of the elastic member 4 can be appropriately changed according to the purpose of use of the sheet member 5, but is preferably 310 to 1440 denier, and more preferably 420 to 940 denier. If the thickness of the elastic member 4 is less than 310 denier, it is necessary to increase the number of the elastic members 4 in order to generate stress and increase the magnification. For this reason, when the wear which uses the sheet | seat member 5 wears a line pressure, it will give a rubber | gum trace to a wearer. On the other hand, when the thickness of the elastic member 4 exceeds 1440 denier, the line pressure is excessively increased, and when wearing an article using the sheet member 5, a rubber mark is given to the wearer.

  The material of the elastic member 4 can be appropriately changed according to the purpose of use of the sheet member 5, for example, synthetic rubber such as styrene-butadiene, butadiene, isoprene, neoprene, natural rubber, EVA, SIS, SEBS, Various known materials such as SEPS, stretchable polyolefin, and polyurethane can be used, and these may be used alone or in combination.

  The expansion ratio (substantial expansion ratio) of the elastic member 4 can be appropriately changed according to the purpose of use of the sheet member 5, etc., but is preferably 1.5 to 5 times, and preferably 1.5 to 3.0. More preferably, it is double. If the expansion ratio is less than 1.5, a regular uneven pattern cannot be obtained even if the elastic member 4 contracts. On the other hand, if the expansion ratio exceeds 5.0, the sheet member 5 is still contracted even when the low density region 22 is fully contracted, and the entire sheet member 5 contracts, and large wrinkles and wrinkles are generated.

  According to the sheet member 5 of the present embodiment, the elastic member 4 in a stretched state and the high-density region 21 of the high-density region-containing sheet 2 are joined, so that when the elastic member 4 contracts, the high-density region 21 becomes rigid. Since it is high, it does not shrink, and only the low density region 22 shrinks. As a result, a stretchable nonwoven fabric having regular pleats can be obtained.

[Disposable diapers]
Hereinafter, although the disposable diaper using the sheet member 5 described above will be described in detail, the side of the disposable diaper that is directed to the wearer's body is the skin contact surface side, and the side opposite to the skin contact surface side is non-skin The contact surface side.

  FIG. 7 (A) is a front view of the disposable diaper of the present invention. As shown in FIG. 7 (A), the disposable diaper main body forms an outer shape of the disposable diaper main body, and includes a chassis 9 including a front waistline portion 91 and a back waistline portion 92 that are formed into a pants shape when worn. The liquid permeable top sheet 6 that is provided on the skin contact surface side of the chassis 9 and is formed in a substantially vertically long shape constituting the surface layer, and the non-skin contact of the chassis 9 that is one side of the liquid permeable top sheet 6 A liquid-impermeable back sheet 7 provided on the surface side and formed in a substantially vertically long shape constituting the back layer, and a liquid-permeable top sheet between the liquid-permeable top sheet 6 and the liquid-impermeable back sheet 7 6 and a chassis 9, and a liquid-retaining absorbent 8 that is formed in a substantially vertically long shape and constitutes an absorption layer. Here, “substantially vertically long” includes a substantially rectangular shape having a longitudinal direction LD and a short direction, that is, a width direction WD, and a part of both sides of the longitudinal direction LD is depressed in the center direction in the longitudinal direction LD. Including the thing which protruded in the direction opposite to the center direction. That is, the absorbent body 8 includes a part of the longitudinal direction LD of the absorbent body 8 that has a different length in the width direction WD. Moreover, the absorber 8 may be arrange | positioned so that it may become vertically long in the width direction WD, and may be arrange | positioned so that it may become vertically long in the up-down direction.

  The absorbent body 8 may be arranged in a state of being wrapped in a tissue (not shown) or a hydrophilic nonwoven fabric (not shown). Moreover, when wrapped in a hydrophilic nonwoven fabric, a configuration in which the liquid-permeable top sheet 6 is not used or a configuration in which the liquid-permeable top sheet 6 is partially used may be used. Thereby, for example, it is possible to reduce the production cost. Furthermore, the liquid-impermeable back sheet 7 may be a non-skin contact surface side of the liquid-impermeable back sheet 7 bonded with a nonwoven fabric or the like. It is preferable to bond a non-woven fabric or the like to the non-skin contact surface side of the liquid-impermeable back sheet 7 because the touch when worn by the wearer is improved. Moreover, when a film is used for the liquid-impermeable back sheet 7, it is preferable to bond a non-woven fabric or the like to the film, for example, because it is possible to prevent generation of unpleasant sounds resulting from film rubbing.

  The chassis 9 includes a front waistline portion 91, a back waistline portion 92, and a crotch portion 93 formed between the front waistline portion 91 and the back waistline portion 92 when worn. The chassis 9 is formed in a pants shape by joining the front waistline portion 91 and the back waistline portion 92 at the joint 10 that is a predetermined position between the front waistline portion 91 and the back waistline portion 92. Yes. That is, it has the trunk periphery opening part 11 located in a wearer's abdomen circumference | surroundings, and a pair of leg periphery opening part 12 located in each of a wearer's both legs. Here, the predetermined positions of the front waistline portion 91 and the back waistline portion 92 are the front waistline portion 91 and the back waistline in a direction (hereinafter referred to as a width direction WD) perpendicular to the vertical direction in the wearing state. Of the both end sides of the part 92, the part except the leg periphery opening part 12 is said. Moreover, the front waistline part 91 and the back waistline part 92 include what is distinguished by the centerline of the width direction WD which bisects the longitudinal direction LD of a disposable diaper main body, for example.

  FIG. 7B is a partially enlarged view of the front waistline portion 91. The front waistline portion 91 is composed of the sheet member 5 described above. When the elastic member 4 is contracted by joining the two high-density region-containing sheets 2 having the high-density region 21 and the low-density region 22 with the elastic member 4 stretched, That is, pleats are formed. The sheet member 5 is configured such that the concavo-convex pattern of the high-density region-containing sheet 2 is formed such that convex portions and concave portions are alternately and continuously formed in a direction parallel to the waistline opening 1, and the elastic member 4 is also high. It arrange | positions so that the unevenness | corrugation of a density area | region containing sheet | seat may be followed. Further, the sheet member 5 is disposed between the waist opening 11 and the pair of leg openings 12. Although not shown, the rear waistline portion 92 is also composed of the sheet member 5 described above, and thus a plurality of uneven patterns are formed in the same manner as the front waistline portion 91. The concavo-convex pattern extends substantially orthogonally in the vertical direction and extends substantially straight in the vertical direction. Furthermore, the concavo-convex patterns are arranged at substantially equal intervals in the trunk periphery direction.

  In the present embodiment, as shown in FIG. 8, the front waistline portion 91 and the back waistline portion 92 are joined at a predetermined joint portion 10, whereby the waistline opening portion 11 and the pair of leg-hole openings. Although the disposable diaper which has the part 12 and is formed in a pants type is demonstrated, in this invention, it is not limited to this. For example, you may use for the deployment-type disposable diaper which can be worn by locking the front waistline part 91 and the back waistline part 92 with a locking member etc. FIG. In addition, for example, a hook-and-loop fastener that can be re-locked as used in a deployable disposable diaper at a predetermined joint 10 of the front waistline portion 91 and the back waistline portion 92 of a disposable diaper formed in a pants shape, etc. Even if it is a pants-type disposable diaper, the pants-type disposable diaper can be easily unlocked and the pant-type disposable diaper can be deployed and re-locked. Good.

  Note that the entire chassis 9 may be configured by the sheet member 5. For example, the portion on the absorber 8 or the trim cut portion of the leg opening 12 does not use the sheet member 5, and is a normal one. Nonwoven fabrics may be used.

  Furthermore, in this invention, the leak-proof wall formed using the elastic member 4 and a leak-proof sheet, what is called leg gathers (not shown) is arrange | positioned along the both ends of the width direction WD of the absorber 8 of a disposable diaper. May be. Specifically, a leak-proof sheet is provided so as to extend in the width direction WD of the absorbent body 8 from between the absorbent body 8 and the chassis 9 or the liquid-impermeable back sheet 7, and the width direction of the leak-proof sheet At least one elastic member 4 may be disposed at the WD end portion and fixed with a hot melt adhesive or the like. The leak-proof sheet may be in a state of extending in the width direction WD of the absorbent body 8, and by folding back in the center direction in the width direction WD of the absorbent body 8, the folded portion becomes the skin contact of the absorbent body 8. You may make it arrange | position to a contact surface side.

  As shown in FIGS. 7A and 8, the disposable diaper main body is formed by joining the front waistline portion 91 and the rear waistline portion 92 at a predetermined joint portion 10, so The leg-shaped opening 12 is formed in a pants shape.

  Moreover, when using a disposable diaper for children, the length of the up-down direction of the disposable diaper main body for children in the state before wearing formed in the underpants type can illustrate 200 mm to 300 mm, for example. Moreover, the maximum length between each junction part 10 in the expansion | deployment state of the width direction WD of the disposable diaper main body for children can illustrate 300 mm to 450 mm, for example.

  In addition, although the liquid-impermeable back sheet 7 is arrange | positioned at a wearer's non-skin contact surface side, in this invention, it is not restricted to this, Between the absorber 8 and the chassis 9, or the chassis 9 May be provided between the sheets in the case of being formed from a plurality of sheets.

  Here, the liquid-permeable top sheet 6 and the absorbent body 8 are joined so that each is bonded by a hot melt adhesive. Moreover, the liquid-permeable top sheet 6 and the absorber 8 and the chassis 9 are joined so that each is bonded together by a hot melt adhesive. Similarly, the chassis 9 and the liquid-impermeable back sheet 7 are joined so that each is bonded with a hot melt adhesive.

Examples of the coating pattern for hot melt bonding include spiral coating, control seam coating, coater coating, curtain coater coating, and summit gun coating. The basis weight of the adhesive in hot melt bonding is preferably 1 g / m ² to 30 g / m ² , and more preferably 3 g / m ² to 10 g / m ² . In the case of a pattern in which the adhesive is coated in a linear shape, the wire diameter is preferably 30 μm to 300 μm.

  The front waistline portion 91 and the back waistline portion 92 are intermittently joined at the joint 10 by ultrasonic sealing. Moreover, as another joining method in a joining part, joining by a heat seal, a hot-melt adhesive agent, etc. can be illustrated.

  As shown in FIGS. 7A and 8, in the disposable diaper main body, a plurality of thread-like elastic members 4 are arranged in the peripheral region of the waistline opening 11. The elastic member 4 may be a belt-shaped member. The elastic member 4 may be an elastic sheet having elasticity such as a stretchable nonwoven fabric (such as a nonwoven fabric formed from a mixed fiber of polyurethane and polypropylene) or a stretchable film.

  The sheet member 5 obtained by laminating the high-density region-containing sheet 2 obtained by the manufacturing method as shown in FIG. 2 has a groove region 23, thereby forming a stretch-free region. For this reason, it is possible to promote the formation of fine uneven patterns at regular intervals in the shaping region in which the high-density region 21 and the low-density region 22 are always formed.

  According to the disposable diaper using the sheet member of this embodiment, when the elastic member contracts due to the sheet member on which the concavo-convex pattern is formed, a large number of flexible and concavo-convex small wrinkles are generated. As a result, even if the elastic member is in either an expanded state or a contracted state, the convex portion of the concavo-convex pattern comes into contact with the wearer's skin, so that the wearer's skin has increased adhesion to the wearer. It is now possible to provide disposable diapers that are comfortable to wear. Moreover, since it has many flexible and uneven | corrugated small ridges, the clearance gap between a wearer and a disposable diaper can be reduced, and leakage of excrement etc. can be prevented now. Furthermore, since it has many soft and uneven small ridges, the surface area is increased and the heat insulating property is improved.

  Examples of the present invention will be described below. However, these examples are merely examples for suitably explaining the present invention, and do not limit the present invention.

[Preparation of high-density region-containing sheet 2]
Teeth as next 0.45mm length of the high-density region 21 with respect to the polypropylene spunbond of (PPSB) 19g / ^{m 2} and SMS nonwoven 15 g / ^{m 2,} the length of the low-density regions 22 becomes 1.65mm It squeezed with the shaping roll 3 which has the attachment area | region 31, and the high density area | region containing sheet 2 was obtained. The density of the high-density region 21 for obtaining the first rigidity is 0.07 g / cm ³ , and the density of the low-density region 22 for obtaining the second rigidity is 0.034 g / cm ³ . there were.

[Production of Sheet Member 5]
The sheet member 5 was prepared by laminating the high-density region-containing sheet 2 prepared in advance through the elastic member 4 of 620 denier in a state of being stretched twice as much as that during normal contraction. The pitch of the elastic members 4 was set to 5 mm (hereinafter referred to as sample 1).

[Bending characteristics test]
A non-woven fabric bending property tester (KES FB-2 manufactured by Kato Tech Co., Ltd.) was set so that a 100 mm x 100 mm sample 1 was bent perpendicular to the MD direction, and a KES test was performed to measure bending stiffness and hysteresis. It was. The CD direction was also measured in the same manner.

As a comparative example with Sample 1, Comparative Example 1 and Comparative Example 2 were similarly measured for bending stiffness and hysteresis (bending recovery rate). In Comparative Example 1, and 19 g / ^{m 2} and SMS nonwoven 15 g / ^{m 2} of PPSB, by joining the elastic member 4 of 620 denier in a state of being stretched to twice than the normal contractions, the further embossing process Made by doing. Moreover, the comparative example 2 was produced by joining PPSB with 19 g / m ² and SMS nonwoven fabric 15 g / m ² and the elastic member 4 with 620 denier in a state where the PPSB was stretched twice as much as normal shrinkage.

Table 1 shows the test results.

  From Table 1, it can be seen that the bending stiffness of Sample 1 shows the smallest value and is softer than Comparative Example 1 and Comparative Example 2. Similarly, the sample 1 shows the smallest value of the hysteresis, and it can be seen that the recovery rate is good as compared with Comparative Example 1 and Comparative Example 2. Thereby, it turns out that the sample 1 forms a soft and uneven small wrinkle, and there is little skin irritation.

[Sensitivity test]
Sample 1 and Comparative Example 1 and Comparative Example 2 were touched by a tester, and each absolute evaluation was performed. The results of the sensory test are shown in Table 2 below.

  As can be seen from Table 2, Sample 1 was evaluated as being softer than Comparative Example 1 and Comparative Example 2. Therefore, it can be seen that Sample 1 is more comfortable to touch and has less skin irritation than Comparative Example 1 and Comparative Example 2.

It is a figure which shows the manufacturing method of the high-density area | region containing sheet | seat of this invention. It is a figure which shows another embodiment of the manufacturing method of the high-density area | region containing sheet | seat of this invention. It is a top view of the high-density area | region containing sheet | seat obtained by embodiment shown in FIG. It is sectional drawing of a planar high-density area | region containing sheet | seat. It is sectional drawing of the sheet | seat member of this invention. It is sectional drawing of another embodiment of the sheet | seat member of this invention. FIG. 7 (A) is a front view of a disposable diaper using the sheet member of the present invention, and FIG. 7 (B) is a partially enlarged view of a front waistline portion. It is a perspective view of a disposable diaper using the sheet member of the present invention.

Explanation of symbols

1 Sheet 2 High Density Region Containing Sheet 21 High Density Region 22 Low Density Region 23 Groove Region 24 Adhesive Layer 3 Shaping Roll 31 Toothed Region 32 Grooved Region 4 Elastic Member 5 Sheet Member 51 Convex Part 52 Concave Part 6 Liquid Permeability Top sheet 7 Liquid impervious back sheet 8 Absorber 9 Chassis 91 Front waistline part 92 Rear waistline part 93 Crotch part 10 Joint part 11 Trunk circumference opening part 12 Leg circumference opening part

Claims (5)

By compressing the sheet with a shaping roll having at least one toothed region and at least one grooved region covered with a heat insulating material, a plurality of high density regions and a plurality of low density regions are formed. A method for producing a high-density region-containing sheet, comprising producing a high-density region-containing sheet. Method for producing a high-density region-containing sheet according to claim 1 for producing a high-density region-containing sheet being formed in an uneven shape along the longitudinal direction. The manufacturing method of the high-density area | region containing sheet | seat of Claim 1 or 2 which squeezes between the said shaping rolls which rotate the said sheet | seat mutually facing. The method for producing a high-density region-containing sheet according to any one of claims 1 to 3, wherein the high-density region and the low-density region are alternately formed in a longitudinal direction of the sheet. A chassis comprising a front waistline portion and a back waistline portion, and having a waistline opening portion and a pair of left and right leg opening portions in the crotch portion;
A liquid permeable topsheet disposed on at least a portion of the chassis;
A liquid-impermeable backsheet disposed on one side in the thickness direction of the liquid-permeable topsheet;
A disposable diaper comprising a liquid-retaining absorbent disposed between the liquid-permeable top sheet and the liquid-impermeable back sheet,
Of the chassis, a disposable diaper using the high-density-containing sheet produced by the production method according to any one of claims 1 to 4 over between said waist opening portion and the leg opening .

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