JP2019058545A - Underpants type disposable wearing article - Google Patents

Abstract

To provide what is provided with a side seal part that has peel strength when worn which changes little in the whole vertical direction and peel strength after use, and can be smoothly peeled off.SOLUTION: In an underpants type disposable wearing article, a side seal part 13 is a part where a group 140 of welded parts in which three or more welded parts 14 are arranged toward sides at intervals in a diagonally downward direction are repeated in a vertical direction YD, areas of the welded parts 14 are all flush. Only one welded part 14 is provided in the same vertical direction position in the side seal part 13, and vertical direction gaps 14d of the welded parts 14 in the side seal part 13 are all identical. The number of welded parts of the group 140 of welded parts increases stepwise as it goes from a waist opening WO side to a leg opening LO side.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a pants-type disposable wearing article.

  Pants-type disposable diapers, pants-type disposable sanitary napkins, and pants-type disposable diaper covers are welded and joined by heat sealing and ultrasonic sealing on both sides of the front body and both sides of the back body. The waist opening and the leg opening are pre-formed by forming the side seal portion.

  In such a pants-type disposable diaper, when the diaper is removed after excretion, etc., the front and back bodies are peeled off at the side seal portions to remove the diaper from the body. For this reason, not only peel strength that does not tear during mounting but also ease of peeling after use is required for the side seal portion, and various techniques have been proposed conventionally (for example, Patent Documents 1 and 2) reference).

  In the following, the peel strength during mounting is referred to as the peel strength at mounting, and means the peel strength when the front and back body portions are pulled in the opposite direction by 180 degrees with the side seal portion interposed therebetween. In addition, the peel strength at the time of peeling off the side seal part after use is called peel strength after use, grasping the waist part of the front body and the waist part of the back body by hand with the side seal part in front, It means the peel strength when pulling away from the waist opening towards the leg opening as it opens (see arrow in FIG. 6). Further, as well known, the peeling (peeling) of the side seal portion includes not only interfacial peeling but also substrate breakage along the periphery of the welded portion.

  However, in the pattern described in Patent Document 1, for example, the direction of the peeling force and the inclination angle in the longitudinal direction of the weld substantially coincide with each other, so lateral tearing hardly occurs, but the unit area moves from the waist opening to the leg opening The welding area per contact increases. As a result, when sufficient peel strength at the time of wearing is secured on the waist opening side, the peel strength after use on the leg opening side becomes excessive, and there is a possibility that peeling off after use becomes difficult. On the other hand, if the peel strength on the leg opening side is suppressed by placing importance on peelability after use, the peel strength on the waist opening side may be insufficient, and the waist opening side may be broken during mounting.

  In this respect, in the case of Patent Document 2, since the welding area per unit area is substantially constant in the longitudinal direction of the side seal portion, the peel strength at the time of mounting becomes substantially constant in the longitudinal direction. However, in the case described in Patent Document 2, the elongated welds are arranged in a zigzag, and in a region where the welds are obliquely upward toward the side, the peeling force is obliquely downward toward the side. On the other hand, since the direction of progress of peeling is reversed, it becomes difficult to apply force, and not only it becomes difficult to smoothly peel off, but also it becomes easy to generate a lateral tear. In addition, in the area where the welded part is obliquely upward toward the side, the dimension of the welded part in the direction orthogonal to the peeling force becomes longer, so the necessary peeling force is also increased, which also makes smooth peeling difficult. Do.

JP, 2013-233383, A Unexamined-Japanese-Patent No. 2003-24381

  Therefore, the main object of the present invention is to provide a pants-type disposable wearing article provided with a side seal portion having peel strength at the time of wearing and peel strength after use with little change over the entire longitudinal direction and being able to be peeled off smoothly. It is to do.

The pants type disposable wearing article which solved the said subject is as follows.
<First aspect>
A pants-type disposable wearing article comprising a side seal portion in which welds between a front side and a back side are arranged, and a waist opening and a pair of left and right leg openings.
The said side seal part is a part which the welding part group in which three or more welding parts line up at intervals in a diagonally downward direction toward a side, and is repeated in the vertical direction,
The welds all have the same area,
Only one welding portion is provided at the same longitudinal position in the side seal portion,
The longitudinal intervals of the welded portions in the side seal portion are all the same,
The number of welds of the weld group is gradually increased from the waist opening toward the leg opening.
Pants-type disposable wearing article characterized in that.

(Action effect)
The dot pattern in the side seal portion of the present pants type disposable wearing article has the same area in all the welded portions, and only one is provided at the same longitudinal position in the side seal portion, and the welding in the side seal portion The longitudinal intervals of the parts are all the same. Therefore, since the welding area per unit area is substantially constant in the longitudinal direction of the side seal portion, the peel strength at the time of attachment becomes substantially constant in the longitudinal direction, and a break may occur due to weak peel strength at a specific location during attachment. It is difficult to do.
In addition, if the number of welds in the weld group (the total number of welds included in one weld group) increases stepwise from the waist opening toward the leg opening, the welds are connected at both ends. The acute side crossing angle between the direction and the width direction increases stepwise. Therefore, when the side seal part is pulled away from the waist opening toward the leg opening after use, the direction of the peeling force is close to the inclination angle in the longitudinal direction of the welded part group, and the force at peeling of the individual welded parts, time Since the change in the direction is small, not only the lateral tearing does not easily occur, but also the change in the peeling force is small, and the smooth peeling is possible.

<Second aspect>
The widthwise dimensions of all the weld groups are the same,
The 1st aspect pants type disposable wearing article.

(Action effect)
In this way, if the widthwise dimensions of all weld groups are the same, the side edges of the side seal become longitudinally straight, and after use, the side seal is pulled off from the waist opening toward the leg opening In this case, the change in the direction of the force when moving from one welded part group to another welded part group at the peeling position is reduced, and smoother peeling is possible, which is preferable.

<Third aspect>
The shape of the weld is circular,
The pants-type disposable wearing article according to the first or second aspect.

(Action effect)
It is preferable that the shape of the welded portion is circular, because changes in the force, time, and direction in peeling of the individual welded portions are particularly small.

<Fourth aspect>
The shape of the welded portion is an ellipse having a major axis along a direction connecting both end portions of the welded portion group,
The pants-type disposable wearing article according to the first or second aspect.

(Action effect)
If the shape of the welded portion is an elliptical shape having a long axis along the direction connecting both end portions of the welded portion group, the direction of the peeling force will be close to the advancing direction of peeling, so it is more difficult to cause lateral tearing. Instead, the change in the direction of the force when moving from one welded part to another welded part in the same welded part group is smaller, and smoother peeling is possible, which is preferable.

<Fifth aspect>
It has three or more welding part groups,
The number of welds in the weld group is increased stepwise by two or more steps from the waist opening toward the leg opening.
The pants type disposable wearing article according to any one of the first to fourth aspects.

(Action effect)
By thus providing a large number of welds and setting the number of welds in the welds to two or more, it is possible to peel off the side seal from the waist opening to the leg opening after use. It is preferable because the change in the direction of the force when moving from one weld group to another weld group is less, and smoother peeling is possible.

<Sixth aspect>
The shape of the welded portion is a circle or a regular polygon having an area of 0.7 to 1.5 mm ² ,
The longitudinal interval of the welded portion is 0.5 to 1 mm,
The width direction dimension of all the said welding part groups is the same, and is 3-5 mm,
The number of welds in the weld group is increased in three to six, seven, or eight steps in one to five steps from the waist opening toward the leg opening.
The pants-type disposable wearing article according to the first aspect.

(Action effect)
Although the dimension etc. of the dot pattern of a welding part can be determined suitably, it is preferable to be in the range of this aspect in general for infants and children use. Thereby, the acute angle side crossing angle between the direction connecting the both ends of the welded portion group and the width direction is approximately 37 to 45 degrees in the welded portion group closest to the waist opening, and 66 to 72 in the welded portion group closest to the leg opening Degree. As a result, when the side seal portion is pulled away from the waist opening toward the leg opening after use, the direction of the peeling force is particularly close to the inclination angle in the longitudinal direction of the welded portion group, and thus smoother peeling is possible. It becomes.

  As described above, according to the present invention, it is possible to provide a side seal portion having peel strength at the time of wearing and peel strength after use with little change throughout the longitudinal direction and being able to be peeled off smoothly, etc. Benefits are brought about.

It is a top view in the state where a diaper was developed which shows the inside of a pants type disposable diaper. It is a top view in the state where a diaper was developed showing the outer surface of a pants type disposable diaper. It is the 3-3 sectional drawing of FIG. It is 4-4 sectional drawing of FIG. (A) 5-5 sectional drawing of FIG. 1, (b) It is 6-6 sectional drawing of FIG. It is a perspective view of a pants type disposable diaper. It is a front view of a side seal part. It is an enlarged view of the code | symbol 7 part of FIG. It is a front view of a side seal part. It is an enlarged view of the code | symbol 8 part of FIG. It is an enlarged view of the code | symbol 9 part of FIG. It is a principal part enlarged front view of a side seal part.

  Hereinafter, a pants type disposable diaper as an example of a pants type disposable wearing article will be described in detail with reference to the attached drawings. 1 to 6 show a pants-type disposable diaper 100. FIG. The underpants type disposable diaper 100 includes an exterior body 12 forming an outer surface (back side) of the product and an interior body 200 attached to the exterior body 12. The symbol Y indicates the total length of the diaper in the unfolded state (longitudinal length from the edge of the waist opening WO of the front part F to the edge of the waist opening WO of the back part B), and the symbol X indicates the full width of the diaper in the unfolded state Is shown. The inner body 200 is a portion that absorbs and holds excrement such as urine, and the outer body 12 is a portion that supports the inner body 200 with respect to the body of the wearer.

  Each component member is joined to a member adjacent to at least one side of the front and back as required. Bonding between the members can be performed by a hot melt adhesive applied to one or both members. As an application pattern of the hot melt adhesive, an appropriate pattern such as a solid, bead, curtain, summit or spiral application, or a pattern coat (transfer of the hot melt adhesive in the letterpress system) can be adopted. Alternatively, or together with this, at the fixing portion of the elastic member, the hot melt adhesive can be applied to the outer peripheral surface of the elastic member by a comb gun, a sure wrap application or the like, and the elastic member can be fixed to the adjacent member. As the hot melt adhesive, for example, those of EVA type, adhesive rubber type (elastomer type), olefin type, polyester / polyamide type, etc. exist, but they can be used without particular limitation. As a joining means for joining the respective constituent members, means by material welding such as heat sealing or ultrasonic sealing can be used.

(Interior body)
The inner body 200 can have any shape, but is rectangular in the illustrated form. As shown in FIGS. 3 to 5, the inner body 200 is provided with the top sheet 30 on the body side, the liquid impermeable sheet 11, and the absorbent element 50 interposed therebetween. Yes, it is the main part that carries the absorption function. The code | symbol 40 has shown the intermediate sheet (second sheet) provided between the top sheet 30 and the absorption element 50, in order to make the liquid which permeate | transmitted the top sheet 30 transfer to the absorption element 50 rapidly, and 60 11 shows the rising gathers 60 provided on both sides of the inner body 200, which are provided on both sides of the inner body 200, in order to prevent leakage of excrement at both sides of the inner body 200.

(Top sheet)
The top sheet 30 has a property of transmitting a liquid, and can be exemplified by a non-porous or non-porous non-woven fabric, a porous plastic sheet, and the like. Moreover, among these non-woven fabrics, the raw material fibers are not particularly limited. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, regenerated fibers such as rayon and cupra, natural fibers such as cotton, etc., mixed fibers of which two or more are used, composite fibers Etc. can be illustrated. Furthermore, the non-woven fabric may be produced by any processing. Examples of the processing method include known methods such as spun lace method, spun bond method, thermal bond method, melt blown method, needle punch method, air through method, point bond method and the like. For example, if flexibility and drape are required, the spun bond method and spun lace method require bulkiness and softness, and the air through method, point bond method and thermal bond method are preferable processing methods. .

  The top sheet 30 may be formed of one sheet or may be formed of a laminated sheet obtained by laminating two or more sheets. Similarly, the top sheet 30 may be a single sheet or two or more sheets in the plane direction.

  When the rear gathers 60 are provided, both sides of the top sheet 30 pass through between the liquid impermeable sheet 11 and the rear gathers 60 and wrap around to the back of the absorbent element 50 to prevent the penetration of the liquid. It is preferable to adhere to the impermeable sheet 11 and the rising gather 60 by a hot melt adhesive or the like.

(Intermediate sheet)
In order to rapidly transfer the liquid that has permeated the top sheet 30 to the absorber, an intermediate sheet (also referred to as a “second sheet”) 40 can be provided, which has a higher liquid permeation rate than the top sheet 30. This intermediate sheet 40 not only allows the liquid to be rapidly transferred to the absorber to enhance the absorption performance by the absorber, but also prevents the phenomenon of "reversion" from the absorber of the absorbed liquid, and always dries on the top sheet 30 It can be in a state of The intermediate sheet 40 can be omitted.

As the intermediate sheet 40, materials similar to the top sheet 30, spun lace, spun bond, SMS, pulp nonwoven fabric, mixed sheet of pulp and rayon, point bond or crepe paper can be exemplified. In particular, an air through non-woven fabric is preferable because it is bulky. It is preferable to use a core-sheath composite fiber as the air-through nonwoven fabric. In this case, the resin used for the core may be polypropylene (PP), but polyester (PET) having high rigidity is preferable. Basis weight is preferably ^{20~80g / m 2, 25~60g / m} 2 is more preferable. The thickness of the non-woven material fiber is preferably 2.2 to 10 dtex. In order to make the nonwoven fabric bulky, it is also preferable to use eccentric fibers having no core in the center, hollow fibers, eccentric and hollow fibers as mixed fibers of all or part of the raw material fibers.

  The intermediate sheet 40 in the illustrated form is disposed shorter than the width of the absorbent body 56 in the center, but may be provided over the entire width. The longitudinal length of the intermediate sheet 40 may be the same as the length of the absorber 56, or may be within a short length range centered on the liquid receiving area.

(Liquid impervious sheet)
The material of the liquid impermeable sheet 11 is not particularly limited. For example, a plastic film made of an olefin resin such as polyethylene or polypropylene, a laminated non-woven fabric having a plastic film on the surface of a non-woven fabric, or a plastic film A laminated sheet etc. which overlapped and joined a nonwoven fabric etc. can be illustrated. For the liquid impermeable sheet 11, it is preferable to use a liquid-impervious and moisture-permeable material that is preferably used in recent years from the viewpoint of preventing bleeding. As a plastic film having moisture permeability, a microporous plastic film obtained by kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction Is widely used. In addition, non-woven fabric using microdenier fibers, reinforcement of leakproofness by reducing the voids of the fibers by applying heat and pressure, and methods of coating highly water-absorbent resin or hydrophobic resin or water repellent agent Thus, a sheet which is made liquid impermeable without using a plastic film can also be used as the liquid impermeable sheet 11.

(Get up and gather)
Uprising gathers 60 are belt-like members extending along the both sides of the inner body 200 in the front-rear direction, and block urine and loose stools moving laterally on the top sheet 30 to prevent side leakage. Provided for The rising gather 60 of the present embodiment is provided to stand up from the side portion of the inner body 200, the root side portion stands obliquely toward the width direction center side, and the tip side portion from the middle portion has a width It stands diagonally outward in the direction.

  More specifically, the rising gather 60 folds a band-shaped gather sheet 62 having a length equal to the longitudinal length of the inner body 200 in the width direction WD and folds it in two, and a sheet in the folded portion and its vicinity Between them, a plurality of elongated gather elastic members 63 are fixed in a stretched state along the longitudinal direction at intervals in the width direction WD. The base end (the end opposite to the sheet folding portion in the width direction WD) of the rising gather 60 is a mounting portion 65 fixed to the back of the side edge of the inner body 200. The portion other than the mounting portion 65 is a projecting portion 66 (portion on the folded portion side) protruding from the mounting portion 65. Further, the protruding portion 66 is composed of a root side portion toward the center in the width direction and a tip side portion folded back outward in the width direction from the tip of the root side portion. This form is a surface contact type rising gather, but a line contact type rising gather (not shown) which is not folded back in the width direction can also be adopted. The front and rear end portions of the projecting portion 66 are fixed to the side surface of the top sheet 30 with the hot melt adhesive or the heat seal in the laid-back state as the front and rear fixing portion 67, The front-rear direction intermediate portion located is a non-fixed free portion, and a gather elastic member 63 along the front-rear direction LD is fixed to the free portion in an extended state.

The gather sheet 62 is a flexible, uniform, high-masking non-woven fabric such as a spunbond non-woven fabric (SS, SSS, etc.), SMS non-woven fabric (SMS, SSMMS, etc.), melt-blown non-woven fabric, etc. The treated one can be suitably used, and the fiber basis weight is preferably about 10 to 30 g / m ² . As the gather elastic member 63, a thread rubber or the like can be used. When spandex thread rubber is used, the thickness is preferably 470 to 1240 dtex, and more preferably 620 to 940 dtex. 150 to 350% is preferable and 200 to 300% of the elongation rate at the time of fixation is more preferable. The term "extension rate" means a value when the natural length is 100%. Also, as shown, a waterproof film 64 can be interposed between the two-folded gather sheet.

  The number of gathered elastic members 63 provided in the free portion of the rising gather 60 is preferably 2 to 6, and more preferably 3 to 5. The arrangement interval 60d is suitably 3 to 10 mm. With this configuration, the skin can be easily hit in the area where the gather elastic member 63 is disposed. The gather elastic member 63 may be disposed not only on the tip side but also on the root side.

  The fixing target of the mounting portion 65 of the rising gather 60 can be an appropriate member such as the top sheet 30, the liquid impermeable sheet 11, and the absorbent element 50 in the inner body 200.

  The rising gather 60 having the above-described configuration works such that the contraction force of the gather elastic member 63 brings the both ends in the front and rear direction closer, but the both ends in the front and rear direction of the projecting portion 66 are fixed so as not to stand up. Since the space between them is a non-fixed free part, only the free part stands up to abut on the body side as shown in FIG. In particular, when the mounting portion 65 is located on the back side of the interior body 200, it rises up in the crotch and its vicinity and stands up so that the gathers 60 are opened outward in the width direction. It will come in contact and the fit will be improved.

  The size of the rising gather 60 can be appropriately determined, but in the case of an infant paper diaper, for example, as shown in FIG. 3, the rising height of the rising gather 60 (the width direction length of the projecting portion 66 in the unfolded state) W6 is It is preferably 15 to 60 mm, in particular 20 to 40 mm. Further, it is preferable that the separation distance W3 between the folds positioned at the innermost side in the flatly folded state is 60 to 190 mm, particularly 70 to 140 mm, in the flat folded state so that the rising gather 60 is parallel to the surface of the top sheet 30.

(Absorbent element)
The absorbent element 50 has an absorbent body 56 and a packaging sheet 58 which wraps the whole of the absorbent body 56. The packaging sheet 58 can also be omitted.

(Absorber)
The absorber 56 can be formed by an assembly of fibers. As this fiber assembly, a filament assembly obtained by opening as needed a fiber (a fiber bundle) of synthetic fibers such as cellulose acetate in addition to those obtained by stacking short fibers such as cotton-like pulp and synthetic fibers Can also be used. The fiber weight may be, for example, about 100 to 300 g / m ² in the case of stacking cotton-like pulp or short fibers, and in the case of filament aggregate, for example, about 30 to 120 g / m ^2. Can. The fineness in the case of a synthetic fiber is, for example, 1 to 16 dtex, preferably 1 to 10 dtex, and more preferably 1 to 5 dtex. In the case of a filament assembly, the filaments may be non-crimped fibers, but are preferably crimped fibers. The crimp degree of the crimped fiber can be, for example, about 5 to 75, preferably 10 to 50, and more preferably 15 to 50 per 2.54 cm. In addition, crimped fibers that are uniformly crimped can be used. It is preferable that the superabsorbent polymer particles be dispersed and held in the absorbent body 56.

  The absorber 56 may have a rectangular shape, but as also shown in FIGS. 1 and 2, the front end, the rear end and a narrow portion located between them and narrower than the front end and the rear end It is preferable that the hourglass has an hourglass shape, because the fit of the absorber 56 itself and the rising gather 60 around the legs is improved.

  Although the size of the absorber can be determined as appropriate, it is preferable that the absorber extends in the front-rear direction LD and the width direction WD to the periphery of the inner body or in the vicinity thereof. Reference numeral 56X indicates the width of the absorber 56.

(Superabsorbent polymer particles)
The absorbent body 56 may contain superabsorbent polymer particles in part or all thereof. The superabsorbent polymer particles include "powder" in addition to "particles". As the super-absorbent polymer particles 54, those used for absorbent articles of this kind can be used as they are, for example by sieving (shake for 5 minutes) using a standard sieve of 500 μm (JIS Z8801-1: 2006) The proportion of particles remaining on the sieve is preferably 30% by weight or less, and the proportion of particles remaining on the sieve by sieving (shake for 5 minutes) using a standard sieve (JIS Z8801-1: 2006) of 180 μm Is preferably 60% by weight or more.

  The material of the superabsorbent polymer particles can be used without particular limitation, but a material having a water absorption amount (JIS K 7223-1996 “Method of testing water absorption of highly water-absorbent resin”) of 40 g / g or more is preferable. Examples of the superabsorbent polymer particles include starch-based, cellulose-based and synthetic polymer-based particles, such as starch-acrylic acid (salt) graft copolymer, saponified starch-acrylonitrile copolymer, and crosslinked sodium carboxymethyl cellulose. A thing, an acrylic acid (salt) polymer, etc. can be used. The shape of the superabsorbent polymer particles is preferably in the form of commonly used powdery particles, but other shapes may also be used.

  As the superabsorbent polymer particles, those having a water absorption rate (a method of testing the water absorption rate of JIS K 7224-1996 superabsorbent polymer) of 40 seconds or less are suitably used. When the water absorption speed exceeds 40 seconds, it becomes easy to generate so-called reversion in which the liquid supplied into the absorber 56 returns out of the absorber 56.

  Further, as the superabsorbent polymer particles, those having a gel strength of 1000 Pa or more are suitably used. Thereby, even in the case of the bulky absorber 56, it is possible to effectively suppress the sticky feeling after liquid absorption.

The basis weight of the superabsorbent polymer particles can be appropriately determined in accordance with the absorption required for the application of the absorber 56. Therefore, although it can not generally say, it can be 50-350 g / m < ² >. If the basis weight of the polymer is less than 50 g / m ² , it will be difficult to secure the absorption amount. When it exceeds 350 g / m ² , the effect is saturated.

  If necessary, the superabsorbent polymer particles can adjust the spray density or the spray amount in the planar direction of the absorber 56. For example, it is possible to increase the spray amount of the fluid excretory site from other sites. When considering gender differences, males can increase the spray density (amount) on the front side, and females can increase the spray density (amount) in the center. In addition, it is possible to provide a portion where no polymer is present locally (for example, in the form of a spot) in the planar direction of the absorber 56.

(Packaging sheet)
When the packaging sheet 58 is used, tissue paper, in particular, crepe paper, non-woven fabric, polylaminated non-woven fabric, a sheet with small holes, or the like can be used as the material. However, it is desirable that it is a sheet from which the superabsorbent polymer particles can not escape. When non-woven fabric is used instead of crepe paper, hydrophilic SMS non-woven fabric (SMS, SSMMS, etc.) is particularly preferable, and polypropylene, polyethylene / polypropylene composite material, etc. can be used as its material. The coating weight is preferably 5 to 40 g / m ² , particularly 10 to 30 g / m ² .

  The packaging form of the packaging sheet 58 can be determined as appropriate, but from the viewpoint of ease of manufacture and prevention of leakage of superabsorbent polymer particles from the front and rear edges, a cylinder is used to surround the front and back and both sides of the absorber 56. It is preferable that the sheet is wound in a shape and the front and rear edges thereof are ejected from the front and back of the absorber 56, and the extruded part is crushed in the front and back direction and joined by joining means such as a hot melt adhesive.

(Exterior body)
The exterior body 12 has a portion forming a front body F extending from the crotch to the ventral side and a portion forming a back body B extending from the crotch to the back. The side seal 13 is formed by joining the rear part B and both sides of the rear body B, and as shown in FIG. 6, a waist opening WO for passing the trunk of the wearer and a pair of left and right leg openings for passing the legs. LO is formed. The crotch refers to the center in the front-rear direction from the waist edge of the front body F to the waist edge of the back body B in the unfolded state, and the front side portion and the rear side portion thereof are the front body F and Back body B means respectively.

  The exterior body 12 has a waist portion T defined as a longitudinal range extending from the waist opening WO to the upper end of the leg aperture LO, and a longitudinal range of a portion forming the leg aperture LO (the front and rear sides having the side seal portion 13 of the front body F) It has an intermediate portion L defined as the direction area and the front-rear direction area having the side seal portion 13 of the back body B). The waist T can be divided into a “waist” W that conceptually forms an edge of the waist opening and a “waist lower” U that is a lower part of the waist. In general, when there is a boundary (for example, the thickness and the elongation rate of the elastic member change) in the waist area T in which the stretching stress in the width direction WD changes, the waist opening WO side is closer to the waist than the boundary closest to the waist opening WO If there is no such boundary, the part extending to the side of the waist opening WO from the absorber 56 or the inner body 200 becomes the waist part W. The dimension of these longitudinal directions LD changes with sizes of a product, and can be set suitably, but if an example is given, waist part W can be 15-40 mm and waist lower part U can be 65-120 mm.

  Both side edges of the middle portion L in the exterior body 12 are U-shaped or curvilinearly narrowed along the circumference of the adherend's leg, and this is a portion along the circumference of the wearer's leg. The degree of constriction of the exterior body 12 can be appropriately determined, and in order to obtain a clear appearance, it is preferable to make the width of the exterior body 12 narrower than the width of the interior body 200 at the narrowest portion. Even a narrow portion may have a width equal to or greater than the width of the inner body 200.

  The exterior body 12 is formed by laminating two sheets of sheet materials 12S and 12H with an adhesive such as a hot melt adhesive as shown in FIGS. Although 12H extends only to the edge of the waist opening WO, the outer sheet material 12S wraps around the waist side edge of the inner sheet material 12H and is folded back inside, and this folded portion 12r is the interior body 200. It extends so as to cover up to the waist side end of.

  As sheet materials 12S and 12H, although it is a sheet-like thing, it can be used without limitation, but a nonwoven fabric is used for at least one, preferably both. The non-woven fabric is not particularly limited as to its raw material fiber. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, regenerated fibers such as rayon and cupra, natural fibers such as cotton, etc., mixed fibers of which two or more are used, composite fibers Etc. can be illustrated. In particular, when a non-woven fabric of polypropylene (PP) or a copolymer thereof (eg, polyethylene or a copolymer containing ethylene as a copolymerization component) (hereinafter, also referred to as a PP non-woven fabric) is used as the outer sheet material 12S, the touch on the outer surface is soft. It is preferable because In addition, as the inner sheet material 12H, polyethylene (PE) as a sheath, core-sheath fibers (PE / PP) having polypropylene (PP) as a core component, and polyethylene (PE) as a sheath, polyethylene terephthalate (PET) Core-sheath fibers (PE / PET) made into a core component can be suitably used.

Furthermore, the non-woven fabric may be produced by any processing. Examples of the processing method include known methods such as spun lace method, spun bond method, thermal bond method, melt blown method, needle punch method, air through method, point bond method and the like. When using a non-woven fabric, the fineness of the fiber is preferably about 1.7 to 2.8 dtex, and the basis weight is preferably about 10 to 30 g / m ² .

  Then, in the outer package 12, elongated elastic members 15 to 19 such as thread rubber are provided between the two sheet members 12S and 12H at a predetermined elongation rate in order to enhance fit to the waist. As the elastic members 15 to 19, synthetic rubber or natural rubber may be used. Hot-melt adhesion, heat sealing, or ultrasonic bonding using various coating methods can be used to bond the two sheet materials 12S and 12H of the package 12 and fix the elastic members 15 to 19 sandwiched therebetween. It is not preferable to firmly fix the entire surface of the exterior body 12 because the texture of the sheet is impaired. It is preferable that these be combined and the adhesion of the elastic members 15 to 19 be strong, and that the other parts be not adhered or be adhered weakly.

More specifically, between the inner surface of the inner sheet material 12H in the waist portion W of the back body B and the front body F and the outer surface of the folded portion 12r of the outer sheet material 12S, the entire width direction is continuous. A plurality of waist elastic members 17 are fixed in a state in which they are extended along the width direction WD with a predetermined extension ratio at intervals in the front-rear direction LD. In addition, one or more of the waist elastic members 17 disposed in the area adjacent to the lower waist U may overlap the interior body 200 or a width direction central portion overlapping the interior body 200 It may be provided on both sides in the width direction except for. The waist elastic member 17 has a thickness of 155 to 1880 dtex, particularly about 310 to 1240 dtex (in the case of a synthetic rubber. In the case of a natural rubber, a cross-sectional area of 0.05 to 1.5 mm ² , particularly 0.1 to 1. It is preferable to fix thread rubber of about 0 mm ^{2 at} about 3 to 22 threads at intervals of 4 to 12 mm with an elongation of about 150 to 400%, and particularly about 220 to 320%. Further, the waist elastic member 17 does not have to have the same thickness and the same extension rate. For example, the thickness and the extension rate of the elastic member may be different between the upper portion and the lower portion of the waist portion W.

  Further, between the outer surface of the inner sheet material 12H in the lower waist portion U of the front body F and the rear body B and the inner surface of the outer sheet material 12S, except for the widthwise central portion overlapping with the inner body 200, the upper side A plurality of lower waist elastic members 15 and 19 are spaced apart from each other in the longitudinal direction LD along the width direction WD so as to be continuous over the entire width direction at each region on both sides in the width direction It is fixed in a stretched state.

The waist lower elastic members 15 and 19 have a thickness of 155 to 1880 dtex, particularly about 310 to 1240 dtex (in the case of a synthetic rubber. In the case of a natural rubber, a cross-sectional area of 0.05 to 1.5 mm ² , particularly 0.1 to 1). It is preferable to fix a rubber thread of about 0. 0 mm ^{2 at} an interval of 1 to 15 mm, particularly 3 to 8 mm, at about 5 to 30 and at an elongation rate of 200 to 350%, especially about 240 to 300%.

  Further, between the outer surface of the inner sheet material 12H and the inner surface of the outer sheet material 12S in the middle portion L of the front body F and the rear body B, except for the width direction central portion overlapping with the inner body 200, the width A plurality of intermediate elastic members 16 and 18 are extended along the width direction WD at a predetermined extension ratio at a plurality of intervals in the longitudinal direction LD so as to be continuous over the entire width direction at each region on both sides of the direction. It is fixed in the

The intermediate elastic members 16 and 18 have a thickness of 155 to 1880 dtex, particularly about 310 to 1240 dtex (in the case of a synthetic rubber. In the case of a natural rubber, a cross-sectional area of 0.05 to 1.5 mm ² , particularly 0.1 to 1). the rubber thread .0mm about ^2), 5 to 40 mm, in particular 2 to 10 present approximately at intervals of 5 to 20 mm, respectively elongation 150-300%, preferably fixed in particular from 180 to 260%.

  As illustrated, the waist lower elastic members 15 and 19 and the middle elastic members 16 and 18 have a width direction middle (preferably the inner body 200) including a part or all of a portion overlapping the absorber 56 in the width direction WD. Provided that the inner body 200 is not shrunk more than necessary in the width direction WD if it is respectively provided on both sides in the width direction except for the entire bonding area between the housing 12 and the exterior body 12). There is no decrease in absorbency. In this embodiment, in addition to the embodiment in which the elastic members are present only on both sides in the width direction, the elastic members are present across the interior body 200 from one side to the other side in the width direction. In the central part, the elastic member is finely cut at one or more places, and the contraction force does not act (substantially equivalent to the absence of the elastic member), and only the widthwise sides have contraction force acting portions The form comprised as is also included. Of course, the arrangement form of the lower waist elastic member and the middle elastic members 15, 19, 16 and 18 is not limited to the above-described example, and a waist lower elastic member is applied so that the stretching force acts over the entire lower waist U width direction. And a part or all of middle part elastic member 15, 19, 16, 18 can also be provided across the interior body 200 from the width direction one side to the other side.

(Exterior body division structure)
In the above-mentioned example, the front body F to the back body B are continuously covered by the integral outer package 12, but the outer package is a belly side outer package that covers the belly side of the wearer's waist and the back The front end portion of the inner body is connected to the inner surface in the width direction central portion of the ventral outer body by a hot melt adhesive or the like, and the widthwise center of the back outer body is divided. Use a form in which the rear end of the inner body is connected to the inner surface of the inner body by a hot melt adhesive or the like, and the ventral exterior body and the dorsal exterior body are not continuous on the crotch side and are separated. Can. This separation distance can be about 150 to 250 mm. In this case, the back of the liquid-impervious sheet in the interior body covers the entire back surface of the interior body, or the entire exposed portion between the ventral exterior body and the dorsal exterior body. It is also possible to fix a part exterior body. As the crotch outer package, the same material as that used for the above-described package can be used. The crotch outer package also corresponds to the package of the present invention.

(Side seal part)
The side seal portion 13 is a portion in which the welds 14 between the side portions of the front body F and the side portions of the rear body B are arranged. The processing of the welded portion 14 can also be performed by heat sealing, but when ultrasonic sealing is used, the heat influence on the periphery of the welded portion 14 is less than heat sealing, and the side seal portion 13 is finished softly. preferable.

  Characteristically, in the examples shown in FIG. 7 and FIG. 8 and in the examples shown in FIG. 9 to FIG. The welding part group 140 spaced apart and lined up is a part repeated in the longitudinal direction YD. Further, all the welded portions 14 have the same area, and only one welded portion 14 is provided at the same longitudinal position in the side seal portion 13, and all the longitudinal intervals 14d of the welded portions 14 in the side seal portion 13 are the same It has become. As a result, the welding area per unit area becomes substantially constant in the longitudinal direction YD of the side seal portion 13. Therefore, the peeling strength at the time of wearing becomes almost constant in the longitudinal direction YD, and it is hard to occur the situation where the peeling strength at a specific place is weak during wearing due to the weak.

  Furthermore, the number of welds of weld group 140 gradually increases from the side of the waist opening WO toward the side of the leg opening LO. As a result, the acute angle side crossing angle θ between the direction connecting the both ends of the welded portion group 140 and the width direction WD increases stepwise. Therefore, when the side seal portion 13 is pulled away from the waist opening WO toward the leg opening LO after use, the direction of the peeling force (indicated by a white arrow in FIG. 7) is the inclination angle θ of the welded portion group 140 in the longitudinal direction. By being close to the above, and the change in force, time, and direction in peeling of the individual welds 14 is small, not only the lateral tearing is hard to occur, but also the change in peeling force is small, and smooth peeling becomes possible.

  The widthwise dimension 140w of the welding portion group 140 may be different for each welding portion group 140, but as in the illustrated example, if the widthwise dimensions 140w of all the welding portion groups 140 are the same, The side edge of the side seal portion becomes straight in the longitudinal direction, and when the side seal portion 13 is peeled away from the waist opening WO toward the leg opening LO after use, the welded portion group 140 where the peeling position is located It is preferable because the change in the direction of the force when moving to 140 is smaller, and smoother separation is possible.

  In the welding part group 140, the welding parts 14 are preferably arranged linearly as shown in the example shown in the drawing, but as long as they are arranged diagonally downward toward the side, they are arranged along a curved direction such as an arc. It may be

  The shape of each welded portion 14 can be appropriately determined, and is not particularly limited, such as a polygon such as a triangle, particularly a regular polygon, a semicircle, a star, an ellipse, etc., but the smaller the ratio of the minor axis to the major axis is Preferably, for example, the major axis is 1.5 times or less the minor axis. In particular, it is preferable that the shape of the welded portion 14 is circular as in the illustrated example, because changes in the force, time, and direction in peeling of the individual welded portions 14 are particularly small. Moreover, although it is preferable that all the welding parts 14 are the same shape and the same dimension, as long as all the areas are the same, the welding part 14 of multiple types of shape may be provided. For example, the shape of the welded portion 14 can be different for each of the one or more welded portion groups 140.

  Moreover, as shown in FIG. 12, it is also preferable that the shape of the welding part 14 is an ellipse which has a long axis along the direction (direction shown by the dashed-two dotted line in the figure) which ties the both ends of the welding part group 140. In this case, the direction of the peeling force is close to the direction of peeling, so that not only lateral tearing is less likely to occur, but also when the welding portion 14 in the same welding portion group 140 moves from one welding portion 14 to another welding portion 14 There is less change in the direction of force, and smoother separation is possible.

  Assuming that the increase step number of the number of welds in the weld group 140 is n, the minimum number of welds 140 is n + 1, and when a plurality of welds 140 having the same number of welds are provided, the minimum number of welds 140 is 2n + 1 It becomes. As the number of stages of increase in the number of welds in the weld group 140 increases, when peeling off the side seal part 13 from the waist opening WO toward the leg opening LO after use, another weld group from the weld group 140 having a peeling position There is less change in the direction of force when moving to 140, and a smoother separation is possible. Therefore, as in the example shown in FIGS. 7 and 8, it is also simple and preferable that the number of welds in weld group 140 is increased by one step in the middle area when the side seal part 13 is divided into three in YD. As shown in FIGS. 9 to 11, the number of stages of increase in the number of welds in the weld group 140 is 2 or more (in the illustrated example, the number of welds 14 is increased from 3 to 7 and is four). Is also preferred.

The dimension etc. of the dot pattern of the welded portion 14 can be appropriately determined, but the acute angle side intersection angle θ between the direction connecting the both ends of the welded portion group 140 and the width direction WD is the welded portion group 140 closest to the waist opening WO. It is desirable that the temperature be set to about 37 to 45 degrees, and to be about 66 to 72 degrees in the welded portion group 140 closest to the leg opening LO. As a result, when the side seal portion 13 is pulled away from the waist opening WO toward the leg opening LO after use, the direction of the peeling force is particularly close to the longitudinal inclination angle θ of the welded portion group 140, and thus smoother. Peeling is possible. Such dot patterns are made possible by the following size ranges in disposable diapers for infants and toddlers.
Shape of welded portion 14: circular or regular polygonal area of welded portion 14: 0.7 to 1.5 mm ²
Longitudinal distance 14d of welded portion: 0.5 to 1 mm
Width direction dimension 140 w of welds (same for all welds 140): 3 to 5 mm
Number of welds in weld group 140: increase from 1 to 5 steps from 3 to 6, 7 or 8

The dimensions of the example shown in FIGS. 7 and 8 are as follows.
Shape of weld 14: circular (diameter 1.0 mm)
Area of welded part 14: 0.79 mm ²
Longitudinal distance 14d of welds: 0.75 mm
Arrangement of welds 14 in welds 140: linear widthwise dimension 140w of welds (identical for all welds): 4.5 mm
Number of welds in weld group 140: increase from 1 to 3 in 1 step Weld group 140 with 3 welds
・ The width direction center interval 14x of the welding part: 1.75 mm
· An acute angle side intersection angle θ between a direction connecting both ends of the welded portion group and the width direction: 45 ° A welded portion group 140 having 7 welded portions
・ The width direction center interval 14x of the welding part: 0.580 mm
· Acute angle side intersection angle θ between the direction connecting the two ends of the welded portion and the width direction: 72 degrees

The dimensions of the example shown in FIGS. 9 to 11 are as follows.
Shape of weld 14: circular (diameter 1.0 mm)
Area of welded part 14: 0.79 mm ²
Longitudinal distance 14d of welds: 0.75 mm
Arrangement of welds 14 in weld 140: linear widthwise dimension 140w of welds (identical for all welds 140): 4.5 mm
Number of welds in weld group 140: increase in 4 steps from 3 to 7. Weld group 140 with 3 welds
・ The width direction center interval 14x of the welding part: 1.75 mm
· An acute angle side intersection angle θ between a direction connecting both ends of the welded portion group and the width direction: 45 ° A welded portion group 140 with four welded portions
· Width direction center distance 14x of welds: 1.17 mm
· An acute angle side intersection angle θ between a direction connecting both ends of the welded portion group and the width direction: 56 degrees A welded portion group 140 with five welded portions
· Width direction center distance 14x of welded part: 0.875 mm
· An acute angle side intersection angle θ between a direction connecting both ends of the welded portion group and the width direction: 63 degrees A welded portion group 140 having 6 welded portions
The widthwise center interval 14x of the welded portion: 0.700 mm:
· An acute angle side intersection angle θ between a direction connecting both ends of the welded portion group and the width direction: 68 degrees A welded portion group 140 having 7 welded portions
The widthwise center interval 14x of the welded portion: 0.580 mm:
· Acute angle side intersection angle θ between the direction connecting the two ends of the welded portion and the width direction: 72 degrees

<Explanation of terms in the specification>
The following terms in the specification have the following meanings unless otherwise indicated in the specification.

  "Longitudinal (longitudinal) direction" means a direction connecting the ventral side (front side) and back side (rear side), and "width direction" means a direction (horizontal direction) orthogonal to the longitudinal direction.

  ・ "Front side" means one closer to the wearer's skin when wearing a pants-type disposable diaper, and "back side" means one farther from the wearer's skin when wearing a pants-type disposable diaper .

  ・ "Surface" means the side closer to the skin of the wearer when wearing the pants-type disposable diaper of the member, and "back side" means the skin of the wearer when wearing the pants-type disposable diaper It means the far side.

  "Stretch rate" means the value when natural length is 100%.

  "Gel strength" is measured as follows. Artificial urine (urea: 2 wt%, sodium chloride: 0.8 wt%, calcium chloride dihydrate: 0.03 wt%, magnesium sulfate heptahydrate: 0.08 wt%, and ion-exchanged water: 97.09 wt% To 49.0 g of the mixture), 1.0 g of the superabsorbent polymer is added, and the mixture is stirred by a stirrer. The formed gel is left in a constant temperature and humidity chamber at 40 ° C. × 60% RH for 3 hours and then returned to normal temperature, and the gel strength is measured with a curd meter (manufactured by I. techno Engineering: Curdmeter-MAX ME-500).

  ・ "Age" is measured as follows. After the sample or test piece is predried, it is left in a test room or apparatus under standard conditions (test place: temperature 23 ± 1 ° C., relative humidity 50 ± 2%) to be in a constant weight state. Pre-drying refers to bringing a sample or test piece to a constant weight in an environment at a temperature of 100 ° C. In addition, it is not necessary to perform preliminary drying about the fiber whose official moisture percentage is 0.0%. From a test piece in a constant weight state, using a template for sampling (100 mm × 100 mm), cut out a sample of 100 mm × 100 mm in size. The weight of the sample is measured, multiplied by 10 to calculate the weight per square meter, and taken as the basis weight.

- "thickness" is used automatic thickness measuring instrument (KES-G5 Handy Compression measurement program), load: 0.098 N / cm ^2, and the pressure area: automatically measured under the conditions of 2 cm ^2.

  The amount of water absorption is measured according to JIS K 7223-1996 “Test method of water absorption of highly water-absorbent resin”.

  -Water absorption rate is defined as "time to end point" when JIS K 7224-1996 "Water absorption rate test method for super absorbent polymer" using 2 g of highly absorbent polymer and 50 g of physiological saline. .

  "Expanded state" means a flat state without contraction or slack.

  -Unless otherwise indicated, the dimension of each part means the dimension in the unfolded state, not the natural length state.

  ・ If there is no description about the environmental conditions in the test or measurement, the test or measurement shall be performed in the test room or equipment under the standard condition (test place: temperature 23 ± 1 ° C, relative humidity 50 ± 2%) Do.

  The present invention can be used for a pants-type disposable wearing article having a side seal portion.

  11: Liquid impermeable sheet, 12: Outer body, 12r: Folded portion, 12S: Outer sheet material, 12H: Inner sheet material, 13: Side seal portion, 14: Welded portion, 14d: Longitudinal spacing, 14x: Width Direction center distance, 140 ... welded portion, 200 ... interior body, 30 ... top sheet, 40 ... intermediate sheet, 50 ... absorbent element, 56 ... absorbent body, 58 ... packaging sheet, 60 ... rising gather, 62 ... gather sheet, F: front body, B: rear body, W: waist portion, WO: waist opening, LO: leg opening, WD: width direction, LD: longitudinal direction, YD: longitudinal direction, θ: acute angle side cross angle

Claims (6)

A pants-type disposable wearing article comprising a side seal portion in which welds between a front side and a back side are arranged, and a waist opening and a pair of left and right leg openings.
The said side seal part is a part which the welding part group in which three or more welding parts line up at intervals in a diagonally downward direction toward a side, and is repeated in the vertical direction,
The welds all have the same area,
Only one welding portion is provided at the same longitudinal position in the side seal portion,
The longitudinal intervals of the welded portions in the side seal portion are all the same,
The number of welds of the weld group is gradually increased from the waist opening toward the leg opening.
Pants-type disposable wearing article characterized in that. The widthwise dimensions of all the weld groups are the same,
The pants-type disposable wearing article according to claim 1. The shape of the weld is circular,
The pants-type disposable wearing article according to claim 1 or 2. The shape of the welded portion is an ellipse having a major axis along a direction connecting both end portions of the welded portion group,
The pants-type disposable wearing article according to claim 1 or 2. It has three or more welding part groups,
The number of welds in the weld group is increased stepwise by two or more steps from the waist opening toward the leg opening.
The pants type disposable wearing article according to any one of claims 1 to 4. The shape of the welded portion is a circle or a regular polygon having an area of 0.7 to 1.5 mm ² ,
The longitudinal interval of the welded portion is 0.5 to 1 mm,
The width direction dimension of all the said welding part groups is the same, and is 3-5 mm,
The number of welds in the weld group is increased in three to six, seven, or eight steps in one to five steps from the waist opening toward the leg opening.
The pants-type disposable wearing article according to claim 1.

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