JP6265332B2 - Pants-type disposable diaper - Google Patents

Description

  The present invention relates to a pants-type disposable diaper.

  The pants-type disposable diaper has an absorbent body interposed between the liquid-permeable top sheet and the back sheet, has leg gathers on both sides, and covers from the back side through the crotch to the abdomen side. And an exterior sheet that is affixed to the outer surface of the interior body and covers the waistline and the crotch, and includes both sides of the back body and both sides of the front body. Many of them have a pants type structure in which a side seal portion is formed by welding and joining by heat sealing or ultrasonic sealing, and a waist opening and a leg opening are formed in advance.

  In such a pants-type disposable diaper, when the diaper is removed after excretion or the like, the back body and the front body of the side seal are peeled off and removed from the body. For this reason, the side seal is required not only to have a seal strength that does not break during mounting, but also to be easily peeled off after use, and various techniques have been proposed in the past (for example, Patent Documents 1 to 10). reference). For example, the techniques described in Patent Documents 1 and 2 propose a seal pattern that takes into account the number of materials in the side seal portion.

  Among these, the dot pattern in which the dotted welds shown in FIG. 6 of Patent Documents 1 and 2 and Patent Document 5 are arranged in a staggered pattern is a straight line along the horizontal direction as shown in Patent Document 4 There is an advantage that it is easy to peel compared with a horizontal striped pattern in which welded portions having a long shape (a rectangular shape with long sides extending in the horizontal direction, etc.) are aligned in the vertical direction.

JP 2010-115424 A JP 2010-119577 A JP 2000-316898 A JP 2003-38573 A JP 2002-369842 A Japanese Patent Laid-Open No. 10-137287 Japanese Patent Laid-Open No. 2003-24381 JP 2002-272785 A JP 2003-144494 A JP-A-11-140706

  In the conventional pattern, it may be difficult to achieve both sufficient strength and ease of peeling during mounting. For example, if there is a part in which only a non-woven fabric of polypropylene (hereinafter also referred to as PP) or a copolymer thereof is laminated on a part or all of the side seal part, the seal strength at this part becomes very strong and difficult to peel off. . Furthermore, in this case, since the nonwoven fabric that is the material is flexible and easily stretched, if there is a region where the number of laminated nonwoven fabrics is small, when the force is applied to peel the side seal part, the side before the welded joint is peeled off. There is a possibility that the material of the seal portion is stretched and torn in an unintended direction (hereinafter also referred to as lateral tearing), which is also one of the reasons why it is difficult to peel off. In such a case, the strength can be reduced by reducing the area of one welded portion (dot) or reducing the number of welded portions.

  However, even if the area and number of welded portions in the conventional pattern are increased or decreased, it has been difficult to achieve both sufficient strength and ease of peeling during mounting.

  Therefore, the main problem of the present invention is to achieve both sufficient strength and ease of peeling during mounting.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
In a pants-type disposable diaper in which both sides of the front body and both sides of the back body are welded and joined to form a side seal, thereby forming a waist opening and a pair of left and right leg openings.
The side seal portion is formed in a dot pattern in which at least a part of the vertical direction has a plurality of rows of dotted welded portions arranged in rows in the vertical direction.
In this dot pattern:
In the row of welded portions at both ends in the lateral direction, an interval enlarged portion in which the longitudinal interval between adjacent welded portions is enlarged is provided every other welded portion,
The longitudinal range of the interval enlarged portion in the row of welded portions at one end in the horizontal direction does not overlap the longitudinal range of the interval enlarged portion in the row of welded portions at the other end in the horizontal direction, and the row of welded portions at one end in the lateral direction In the row of welded portions at both ends in the horizontal direction, the vertical range between adjacent gap enlarged portions and the vertical range between adjacent gap enlarged portions in the row of welded portions at the other end in the horizontal direction partially overlap. The interval enlarged portions of are arranged alternately,
In the longitudinal range of the interval enlarged portion, a plurality of welds are not lined up in the width direction.
A pants-type disposable diaper characterized by that.

(Function and effect)
Generally, in order to peel off the side seal part of a pants-type disposable diaper, put your hands from the waist opening to the front body side and the back body side respectively, grab the front body side and the back body side of the side seal part, By pulling away from the rear body, each welded portion constituting the side seal portion is peeled in order from the waist side. At this time, the seal strength becomes higher as the total area of the welded portions to be peeled at one time is larger.

  In the dot pattern of the present invention, the longitudinal range of the interval enlarged portion is a range in which a plurality of welds are not arranged in the width direction, that is, the seal strength is relatively weak. In addition, a vertical range between adjacent interval enlarged portions in the row of welded portions at one end in the horizontal direction partially overlaps a vertical range between adjacent interval enlarged portions in the row of welded portions at the other end in the horizontal direction. The overlapping range is a range where the welded portions in both rows are closer, that is, the seal strength is relatively strong, such as a plurality of welded portions arranged in the width direction. Therefore, in the dot pattern of the present invention, the strong seal range and the weak seal range are alternately formed in the vertical direction. Furthermore, in the case of the present invention, the interval enlarged portions of the rows at both ends are arranged alternately. According to such a pattern, the entire side seal part has continuity in the vertical direction and has a certain width, and further, a portion having a strong seal strength is arranged at a certain interval, so that sufficient strength during mounting is provided. Can be secured. Nevertheless, in the dot pattern of the present invention, the portions with weak seal strength are intermittently arranged, so that they are easy to peel off and even if the material is easy to stretch, it is difficult to tear laterally. Furthermore, the direction of the force at the time of peeling is not constant and changes due to the staggered arrangement of the gap expansion portions also contributes to prevention of lateral tearing.

<Invention of Claim 2>
The side seal part has a polypropylene region in which only a nonwoven fabric of polypropylene or a copolymer thereof is laminated,
The pants-type disposable diaper according to claim 1, wherein the dot pattern is formed in the polypropylene region.

(Function and effect)
Polypropylene or a copolymer non-woven fabric is a preferred material because it is easy to stretch and gives a soft touch. However, as described above, it is a material that is easy to stretch, and the sealing strength may be increased. The material of the seal part stretches and is easily torn in an unintended direction. Therefore, it is desirable to employ the dot pattern of the present invention in such a polypropylene region.

<Invention of Claim 3>
The side seal portion is a polypropylene region in which only the nonwoven fabric of polypropylene or a copolymer thereof is laminated in the entire longitudinal direction, the leg opening side region having the smallest number of nonwoven fabrics laminated, and the number of nonwoven fabrics laminated is the leg opening side. 1 to 2 more waist edge side regions than the region are aligned in the vertical direction,
The area of each welded portion in the leg opening side region is 1.1 times or more and less than 2.4 times the area of each welded portion in the waist edge side region,
The pants-type disposable diaper according to claim 1 or 2.

(Function and effect)
The number of laminated nonwoven fabrics to be welded is extremely important for the quality stability of the welded joint of the side seal portion. In the current general pants-type disposable diapers, the number of nonwoven fabrics laminated in the side seal part is not uniform in the vertical direction, and often varies, and different types of nonwoven fabrics are laminated from the viewpoint of cost and functionality. There are many things. In such a case, the strength varies depending on the type of laminated nonwoven fabric even with the same number of overlapping sheets, and it is extremely difficult to perform appropriate welding and joining to each region having a different number of laminated nonwoven fabrics. In order to achieve both ease of peeling, it is necessary to make the areas of the welded portions in each region greatly different. However, when performing the welding process of each region at the same time (performed at the same time in a general manufacturing process), if the area of the welded part differs greatly between the regions, stable processing is difficult, especially in the case of ultrasonic sealing. There is also a problem that a device failure is likely to occur. On the other hand, if the entire region of the side seal portion is a polypropylene region as described above, it will be composed of the same type of nonwoven fabric over the entire length, and the difference in strength due to the type of laminated nonwoven fabric will be reduced. It becomes difficult to be affected by the number of laminated nonwoven fabrics, and the area ratio of the welded portions can be reduced to 1.1 times or more and less than 2.4 times even in regions where the number of nonwoven fabric layers is different. It is possible to improve quality stability and reduce equipment failures.

<Invention of Claim 4>
Each welded portion of the side seal portion is circular with a diameter of 0.7 to 2.0 mm,
In the leg opening side region, the rows of the welded portions are three rows, and in the waist edge side region, the rows of the welded portions are two rows,
In the leg opening side region, the horizontal interval between the rows of the adjacent welded portions is −1.5 to 2.4 mm,
In the leg opening side region, the longitudinal interval between adjacent welded portions in the row of welded portions is 0.0 to 5.0 mm,
In the waist edge side region, the horizontal interval between the adjacent welded portions is 0.7 to 5.6 mm,
In the waist edge side region, the longitudinal interval between adjacent welded portions in the row of welded portions is 0.0 to 5.0 mm.
The pants-type disposable diaper according to claim 3.

(Function and effect)
The size and the like of the dot pattern of the present invention can be determined as appropriate, but it is preferable to be within the above-mentioned range for infant use.

<Invention of Claim 5>
The pants-type disposable diaper according to claim 1 or 2, wherein the side seal part is entirely formed in the same dot pattern in the vertical direction.

(Function and effect)
As described above, the number of laminated nonwoven fabrics to be welded is extremely important for the quality stability of the welded joint of the side seal portion. In the current general pants-type disposable diapers, the number of nonwoven fabrics laminated in the side seal part is not uniform in the vertical direction, and often varies, and different types of nonwoven fabrics are laminated from the viewpoint of cost and functionality. There are many things. In such a case, the strength varies depending on the type of laminated nonwoven fabric even with the same number of overlapping sheets, and it is extremely difficult to perform appropriate welding and joining to each region having a different number of laminated nonwoven fabrics. In order to achieve both ease of peeling, it is necessary to make the areas of the welded portions in each region greatly different. However, when performing the welding process of each region at the same time (performed at the same time in a general manufacturing process), if the area of the welded part differs greatly between the regions, stable processing is difficult, especially in the case of ultrasonic sealing. There is also a problem that a device failure is likely to occur. On the other hand, in the present invention, only the characteristic arrangement of the dot pattern exhibits sufficient strength and anti-cracking property as described above. It is difficult to be affected by the type, and on the contrary, it has the great advantage of improved processing stability and reduced equipment failure.

<Invention of Claim 6>
Each welded portion of the dot pattern is circular with a diameter of 0.7 to 2.0 mm,
The welded portion has two rows,
The horizontal interval between the adjacent rows of welds is 0.7 to 5.6 mm,
The longitudinal interval between adjacent welded portions in the row of welded portions is 0.0 to 1.5 mm.
The pants-type disposable diaper according to claim 5.

(Function and effect)
Although the dimensions of the dot pattern of the present invention can be determined as appropriate, by making such dimensions, the welded portion becomes fine and sparse, so the side seal portion becomes flexible and the individual welded portions stand out. Disappear. Moreover, although the reason is not certain, the direction within this range is less susceptible to the number of nonwoven fabrics laminated and the type of nonwoven fabric.

<Invention of Claim 7>
The pants-type disposable diaper according to any one of claims 1 to 6, wherein the welding joining is performed by an ultrasonic seal.

(Function and effect)
Compared to heat seals, ultrasonic seals have little heat effect on the welded area, and the material of the side seal part is easy to stretch and finishes flexibly. It is difficult to peel off and lateral tearing easily occurs. Therefore, this invention is suitable when employ | adopting an ultrasonic seal.

  As described above, according to the present invention, there are advantages such as sufficient strength during mounting and ease of peeling at a higher level.

It is a top view in the state where the diaper was developed showing the inside of a pants type disposable diaper. It is a top view in the state where the diaper was developed showing the outer surface of a pants type disposable diaper. FIG. 3 is a 3-3 cross-sectional view of FIG. 1. FIG. 4 is a sectional view taken along the line 4-4 in FIG. 1. FIG. 5 is a sectional view taken along line 5-5 in FIG. 1. It is a top view in the state where the diaper was developed showing only the principal part of a pants type disposable diaper. It is sectional drawing which shows only the principal part of a pants type disposable diaper. It is a perspective view of a pants type disposable diaper. It is (a) principal part enlarged front view of a side seal part, and (b) sectional drawing. It is a principal part enlarged front view of a side seal part. It is (a) principal part enlarged front view of a side seal part, and (b) sectional drawing. It is a principal part enlarged front view of a side seal part. It is the schematic of an ultrasonic sealing apparatus. It is (a) principal part enlarged front view of a side seal part, and (b) sectional drawing. It is (a) principal part enlarged front view of a side seal part, and (b) sectional drawing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 to 8 show an example 100 of a pants-type disposable diaper. The pants-type disposable diaper 100 includes an exterior sheet 12 that forms the outer surface (rear surface) of the product and an interior body 200 that is attached to the inner surface of the exterior sheet 12. Symbol Y indicates the total length of the diaper in the deployed state (the length in the vertical direction from the edge of the waist opening WO of the front body F to the edge of the waist opening WO of the back body B), and symbol X indicates the diaper in the deployed state. The full width of is shown.

  The interior body 200 is a part that absorbs and holds excrement such as urine, and the exterior sheet 12 is a part that is worn by the wearer. In addition, the dot pattern part in sectional drawing has shown the junction part which joins each structural member, and is formed by solid, beads, curtains, summits, spiral application, etc., such as a hot-melt-adhesive. In addition, “front-rear direction” means a direction connecting the ventral side (front side) and the back side (rear side), “width direction” means a direction (left-right direction) perpendicular to the front-rear direction, and “up-down direction Is the wearing state of the diaper 100, that is, the direction perpendicular to the waistline direction when the diaper 100 is folded in two at the crotch so that both sides of the front body and the back body of the diaper 100 overlap each other, in other words It means the direction connecting the waist opening WO side and the crotch part side.

(Interior body)
The interior body 200 can take any shape, but is rectangular in the illustrated form. As shown in FIGS. 3 to 5, the interior body 200 includes a surface sheet 30 on the body side, a liquid-impermeable back sheet 11, and an absorbent element 50 interposed therebetween. It is the main body that takes up the absorption function. Reference numeral 40 denotes an intermediate sheet (second sheet) provided between the top sheet 30 and the absorbent element 50 in order to quickly transfer the liquid that has passed through the top sheet 30 to the absorbent element 50. Shows a three-dimensional gather 60 that stands on the body side and is provided on both sides of the interior body 200 in order to prevent excrement from leaking to both sides of the interior body 200.

(Surface sheet)
The top sheet 30 has a property of transmitting liquid, and examples thereof include a porous or non-porous nonwoven fabric, a porous plastic sheet, and the like. Of these, the nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. For example, if flexibility and drapeability are required, the spunbond method and spunlace method are preferable. If bulkiness and softness are required, the air-through method, point bond method, and thermal bond method are preferable processing methods. .

  Further, the top sheet 30 may be composed of one sheet or may be composed of a laminated sheet obtained by bonding two or more sheets. Similarly, the top sheet 30 may be composed of one sheet or two or more sheets in the planar direction.

  When providing the three-dimensional gather 60, both sides of the surface sheet 30 pass between the liquid-impermeable back sheet 11 and the three-dimensional gather 60 to the back side of the absorbent element 50 to prevent penetration of the liquid. It is preferable to adhere to the liquid-impermeable back sheet 11 and the three-dimensional gather 60 with a hot melt adhesive or the like.

(Intermediate sheet)
An intermediate sheet (also referred to as “second sheet”) 40 having a higher liquid permeation rate than the top sheet 30 can be provided to quickly transfer the liquid that has passed through the top sheet 30 to the absorber. This intermediate sheet 40 not only improves the absorption performance of the absorbent by quickly transferring the liquid to the absorbent body, but also prevents the “reversed” phenomenon of the absorbed liquid from the absorbent body, so that the top sheet 30 is always dried. It can be made into the state which carried out. The intermediate sheet 40 can be omitted.

Examples of the intermediate sheet 40 include the same material as the top sheet 30, spunlace, spunbond, SMS, pulp nonwoven fabric, mixed sheet of pulp and rayon, point bond, or crepe paper. In particular, an air-through nonwoven fabric is preferable because it is bulky. It is preferable to use a core-sheath composite fiber for 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 raw fiber of the nonwoven fabric is preferably 2.2 to 10 dtex. In order to make the nonwoven fabric bulky, it is also preferable to use an eccentric fiber, a hollow fiber, or an eccentric and hollow fiber that does not have a core at the center as the mixed fiber of all or part of the raw fiber.

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

(Impermeable liquid back sheet)
The material of the liquid-impermeable back sheet 11 is not particularly limited. For example, a plastic film made of an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric in which a plastic film is provided on the surface of the nonwoven fabric, or plastic Examples thereof include a laminated sheet in which a nonwoven fabric or the like is laminated on a film and joined. For the liquid-impermeable back sheet 11, it is preferable to use a liquid-impervious and moisture-permeable material that has been preferred in recent years from the viewpoint of preventing stuffiness. 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, forming a sheet, and then stretching in a uniaxial or biaxial direction. Is widely used. In addition, non-woven fabric using micro-denier fibers, leakproof reinforcement by reducing the voids of the fibers by applying heat or pressure, and methods such as applying a superabsorbent resin or hydrophobic resin or water repellent Accordingly, a sheet that is liquid-impermeable without using a plastic film can also be used as the liquid-impermeable back sheet 11.

  The liquid-impermeable back sheet 11 is preferably extended to both sides of the side surface 30 of the absorbent element 50 by wrapping around both sides of the absorbent element 50 in order to improve leakage resistance. The width of this extended portion is suitably about 5 to 20 mm on each of the left and right sides.

  Moreover, the excretion indicator from which a color changes by absorption of a liquid part can be provided in the inner side of the liquid-impermeable back sheet 11, especially the absorber 56 side surface.

(Three-dimensional gather)
The three-dimensional gather 60 is a belt-like member that extends over the entire front-rear direction along both side portions of the interior body 200, blocks urine and soft stool that move in the lateral direction along the top sheet 30, and prevents side leakage. It is provided for this purpose. The three-dimensional gather 60 of the present embodiment is provided so as to stand up from the side portion of the interior body 200, the base side portion rises obliquely toward the center in the width direction, and the tip side portion from the intermediate portion has a width. It stands up diagonally outward in the direction.

  More specifically, the three-dimensional gather 60 folds the belt-shaped gather sheet 62 having a length equal to the length in the front-rear direction of the interior body 200 in the width direction and folds it into two. In addition, a plurality of elongated elastic elastic members 63 are fixed along the longitudinal direction at intervals in the width direction. A base end portion (an end portion on the side opposite to the sheet folding portion in the width direction) located on the opposite side to the front end portion of the three-dimensional gather 60 is an attachment portion 65 fixed to the back surface of the side edge portion of the interior body 200. A portion other than the attachment portion 65 is a protruding portion 66 (a portion on the folded portion side) protruding from the attachment portion 65. The projecting portion 66 includes a base side portion that extends toward the center in the width direction, and a tip side portion that is folded back outward in the width direction from the tip of the base side portion. This form is a surface contact type three-dimensional gather, but a line contact type three-dimensional gather (not shown) that is not folded outward in the width direction can also be employed. And while it is set as the front-and-rear fixing | fixed part 67 fixed to the side part surface of the surface sheet 30 by the hot-melt-adhesive agent or the heat seal in the front-back direction both ends among the protrusion parts 66, between these, The intermediate portion in the front-rear direction is a non-fixed free part, and an elongated elastic member 63 along the front-rear direction is fixed to the free part in an extended state.

The gather sheet 62 is made of a spunbond nonwoven fabric (SS, SSS, etc.), SMS nonwoven fabric (SMS, SSMMS, etc.), a melt-blown nonwoven fabric with excellent uniformity and concealment, and water repellent with silicon as necessary. A treated product can be suitably used, and the fiber basis weight is preferably about 10 to 30 g / m ² . As the elongated elastic elastic member 63, rubber thread or the like can be used. When spandex thread rubber is used, the thickness is preferably 470 to 1240 dtex, more preferably 620 to 940 dtex. The elongation rate at the time of fixation is preferably 150 to 350%, more preferably 200 to 300%. The term “elongation rate” means a value when the natural length is 100%. Further, as shown in the drawing, a waterproof film 64 can be interposed between the gather sheets folded in two.

  2-6 are preferable and, as for the number of the elongate elastic expansion-contraction members 63 provided in the free part of the three-dimensional gather 60, 3-5 are more preferable. The arrangement interval 60d is suitably 3 to 10 mm. If comprised in this way, in the range which has arrange | positioned the elongate elastic expansion-contraction member 63, it will become easy to contact | abut with respect to skin. The elongated elastic elastic member 63 may be disposed not only at the distal end side but also at the base side.

  The fixing target of the attachment portion 65 of the three-dimensional gather 60 can be an appropriate member such as the top sheet 30, the liquid-impermeable back sheet 11, and the absorbent element 50 in the interior body 200.

  In the three-dimensional gather 60 thus configured, the contraction force of the elongated elastic elastic member 63 acts so that both ends in the front-rear direction are brought close to each other, but the both ends in the front-rear direction of the protruding portion 66 are fixed so as not to stand up. On the other hand, since they are non-fixed free portions, only the free portions stand up against the body side as shown in FIG. In particular, when the attachment portion 65 is positioned on the back surface side of the interior body 200, the three-dimensional gather 60 stands up so as to open outward in the width direction at the crotch portion and in the vicinity thereof. It comes in contact, and the fit is improved.

  The dimensions of the three-dimensional gather 60 can be determined as appropriate. In the case of an infant paper diaper, for example, as shown in FIG. 7, the standing height of the three-dimensional gather 60 (the length in the width direction of the protruding portion 66 in the unfolded state) W6 is It is preferably 15 to 60 mm, particularly 20 to 40 mm. In addition, the distance W3 between the folds located on the innermost side in a state where the three-dimensional gather 60 is folded flat so as to be parallel to the surface of the top sheet 30 is preferably 60 to 190 mm, particularly preferably 70 to 140 mm.

  Note that, unlike the illustrated embodiment, the three-dimensional gathers can be provided in double (two rows) on the left and right sides of the interior body 200.

(Absorption element)
The absorbent element 50 includes an absorbent body 56 and a packaging sheet 58 that wraps the entire absorbent body 56. The packaging sheet 58 can be omitted.

(Absorber)
The absorber 56 can be formed of an aggregate of fibers. As this fiber assembly, a filament assembly obtained by opening, as necessary, synthetic fiber tows (fiber bundles) such as cellulose acetate as well as short fibers such as cotton-like pulp and synthetic fibers Can also be used. The fiber basis weight can be set to, for example, about 100 to 300 g / m ² when cotton-like pulp or short fibers are stacked, and in the case of a filament aggregate, for example, about 30 to 120 g / m ^2. Can do. The fineness in the case of a synthetic fiber is 1-16 dtex, for example, Preferably it is 1-10 dtex, More preferably, it is 1-5 dtex. In the case of a filament aggregate, the filament may be a non-crimped fiber, but is preferably a crimped fiber. The crimped degree of the crimped fiber can be, for example, 5 to 75, preferably 10 to 50, and more preferably about 15 to 50 per inch. Further, a crimped fiber that is uniformly crimped is often used. It is preferable to disperse and hold superabsorbent polymer particles in the absorber 56.

  Although the absorbent body 56 may be rectangular, as shown in FIG. 6, as shown in FIG. 6, the hourglass has a front end portion, a rear end portion, and a narrow portion narrower than the front end portion and the rear end portion. When the shape is formed, it is preferable because the fit of the absorber 56 itself and the three-dimensional gather 60 around the legs is improved.

  Moreover, although the dimension of an absorber can be determined suitably, it is preferable to extend to the peripheral part of the interior body, or its vicinity in the front-back direction and the width direction. Reference numeral 56X indicates the width of the absorber 56.

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

  The material of the superabsorbent polymer particles can be used without any particular limitation, but those having a water absorption (JIS K7223-1996 “Test method for water absorption of superabsorbent resin”) of 40 g / g or more are preferable. High-absorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and sodium carboxymethylcellulose crosslinks. Or an acrylic acid (salt) polymer can be used. As the shape of the superabsorbent polymer particles, a commonly used granular material is suitable, but other shapes can also be used.

  As the superabsorbent polymer particles, those having a water absorption rate (JIS K7224-1996 water absorption rate test method for superabsorbent resin) of 40 seconds or less are preferably used. When the water absorption speed exceeds 40 seconds, so-called reversion in which the liquid supplied into the absorber 56 returns to the outside of the absorber 56 is likely to occur.

The basis weight of the superabsorbent polymer particles can be appropriately determined according to the amount of absorption required for the use of the absorber 56. Therefore, although it cannot be said unconditionally, it can be set to 50 to 350 g / m ² . If the amount of polymer is less than 50 g / m ^2, it is 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 spraying density or spraying amount in the plane direction of the absorber 56. For example, it is possible to increase the application amount of the liquid excretion site as compared to other sites. When gender differences are taken into account, men can increase the front spray density (amount), while women can increase the center spray density (amount). In addition, a portion where no polymer exists locally (for example, in a spot shape) in the planar direction of the absorber 56 can also be provided.

(Packaging sheet)
When the packaging sheet 58 is used, as the material, tissue paper, particularly crepe paper, non-woven fabric, polylaminated non-woven fabric, a sheet with small holes, or the like can be used. However, it is desirable that the superabsorbent polymer particles be a sheet that does not escape. When a nonwoven fabric is used in place of the crepe paper, a hydrophilic SMS nonwoven fabric (SMS, SSMMS, etc.) is particularly suitable, and the material can be polypropylene, polyethylene / polypropylene composite material, or the like. The basis 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 the superabsorbent polymer particles from the front and rear end edges, the cylinder is formed so as to surround the front and back surfaces and both side surfaces of the absorbent body 56. It is preferable that the front and rear edges of the absorbent body 56 are protruded from the front and back of the absorbent body 56, and the protruding portions are crushed in the front and back directions and joined by a joining means such as a hot melt adhesive.

(Exterior sheet)
The exterior sheet 12 has a part constituting the front body F extending from the crotch part to the ventral side and a part constituting the rear body B extending from the crotch part to the back side, and both sides of the front body F The side seal part 13 is formed by joining the side part and the both sides of the back body B, and as shown in FIG. 8, a waist opening WO for passing the wearer's torso and a pair of left and right legs for passing the leg An opening LO is formed. The crotch portion means 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 part and the back part thereof are the front body F and Each back body B is meant.

  The exterior sheet 12 includes a waistline T defined as a front-rear direction range extending from the waist opening WO to the upper end of the leg opening LO, and a front-rear direction range of the part forming the leg opening LO (the side seal portion 13 of the front body F). And an intermediate portion L defined as a front-rear direction region having the side seal portion 13 of the back body B. The waistline T can be divided into a “waist edge” W that conceptually forms the edge of the waist opening, and a “waist lower part” U that is a lower part than this. These lengths in the vertical direction vary depending on the size of the product and can be determined as appropriate. For example, the waist edge W may be 15 to 40 mm, and the waist lower portion U may be 65 to 120 mm. On the other hand, both side edges of the intermediate portion L are bundled along the circumference of the wearer's leg, and this is a portion into which the wearer's leg is put. As a result, the exterior sheet 12 has a substantially hourglass shape as a whole. The degree of tightness of the exterior sheet 12 can be determined as appropriate, and, as shown in FIGS. 1 to 8, the narrowest part may be narrower than the width of the interior body 200 in order to obtain a clean appearance. Although it is preferable, the narrowest part may be determined so as to be equal to or larger than the width of the interior body 200.

  As shown in FIGS. 3 to 5, the exterior sheet 12 is formed by bonding two sheet materials 12 </ b> S and 12 </ b> H with an adhesive such as a hot melt adhesive, and is an inner sheet material positioned on the inner side. Although 12H extends only to the edge of the waist opening WO, the outer sheet material 12S wraps around the edge on the waist side of the inner sheet material 12H and is folded inside, and the folded portion 12r is an interior body. It extends so as to cover up to 200 on the waist end.

  The sheet materials 12S and 12H can be used without particular limitation as long as they are sheet-like, but at least one, preferably both are nonwoven fabrics. The nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. In particular, when a non-woven fabric (hereinafter also referred to as PP-based non-woven fabric) of polypropylene (PP) or a copolymer thereof (for example, polyethylene or a copolymer blended with ethylene as a copolymer component) is used as the outer sheet material 12S, the outer surface is flexible. Therefore, it is preferable. Also, as the inner sheet material 12H, polyethylene sheath (PE / PP) with polyethylene (PE) as a sheath and polypropylene (PP) as a core component, polyethylene terephthalate (PET) with polyethylene (PE) as a sheath. A core-sheath fiber (PE / PET) made into a core component can be suitably used.

Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. When using a nonwoven fabric, the 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 .

Further, the total basis weight of the exterior sheet 12 (the total of the outer sheet material 12S and the inner sheet material 12H) is 20 to 60 g / m ² so that the design of the printing sheet 25 to be described later can be satisfactorily visually recognized through the exterior sheet 12. The total light transmittance defined in JIS K 7105 of the exterior sheet 12 is preferably 40% or more, particularly 50% or more.

  The exterior sheet 12 is provided with elongate elastic members 15 to 19 such as thread rubber between the sheet materials 12S and 12H at a predetermined elongation rate in order to improve fit to the waistline. As the elongated elastic elastic members 15 to 19, synthetic rubber or natural rubber may be used. For bonding the two sheet materials 12S and 12H of the exterior sheet 12 and fixing the elongated elastic elastic members 15 to 19 sandwiched between them, hot melt bonding or heat sealing or ultrasonic bonding by various coating methods is used. it can. If the entire exterior sheet 12 is firmly fixed, the texture of the sheet is impaired, which is not preferable. By combining these, it is preferable that the elongated elastic elastic members 15 to 19 are firmly bonded, and other portions are not bonded or bonded weakly.

More specifically, between the inner side surface of the inner sheet material 12H and the outer surface of the folded portion 12r of the outer sheet material 12S at the waist edge W of the rear body B and the front body F, the entire width direction is continuous. In addition, a plurality of waist edge elastic elastic members 17 are fixed in a state where they are extended along the width direction at a predetermined extension rate at intervals in the vertical direction. In addition, one or more of the waist edge elastic elastic members 17 disposed in a region adjacent to the waist lower portion U may overlap with the interior body 200 or may be overlapped with the interior body 200 in the width direction. You may each provide in the width direction both sides except a center part. As the waist edge resilient and elastic members 17, the thickness 155～1880Dtex, particularly about 310～1240Dtex (the case of synthetic rubber. Cross-sectional area in the case of natural rubber 0.05 to 1.5 mm ^2, in particular 0.1 the rubber thread of 1.0mm about ^2), 3 to 22 present approximately at intervals of 4 to 12 mm, respectively elongation from 150% to 400%, preferably fixed in particular about 220-320%. Further, the waist edge elastic elastic members 17 need not all have the same thickness and elongation rate. For example, the elastic elastic members may have different thicknesses and elongation rates at the upper and lower portions of the waist edge W. .

  Further, between the outer side surface of the inner sheet material 12H and the inner side surface of the outer sheet material 12S in the lower waist portion U of the front body F and the rear body B, except for the central portion in the width direction overlapping the interior body 200, the upper side thereof. A plurality of waist lower elastic elastic members 15 and 19 made of an elongated elastic elastic member are continuously provided in the respective parts on both sides in the width direction so as to be continuous over the entire width direction. It is fixed in the state extended | stretched along the width direction.

The waist lower elastic elastic members 15 and 19 have a thickness of 155 to 1880 dtex, particularly about 310 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, a cross-sectional area of 0.05 to 1.5 mm ² , particularly 0.1 It is preferable to fix the thread rubber of about 1.0 mm ² ) at an interval of 1 to 15 mm, particularly 3 to 8 mm, and about 5 to 30 at an elongation of 200 to 350%, particularly about 240 to 300%.

  Further, the width between the outer side surface of the inner sheet material 12H and the inner side surface of the outer sheet material 12S in the intermediate portion L of the front body F and the rear body B, except for the widthwise central portion overlapping the interior body 200, is the width. A plurality of intermediate elastic elastic members 16 made of an elongated elastic elastic member, which are continuous in the entire width direction at each part on both sides in the direction, spaced in the vertical direction and at a predetermined elongation rate in the width direction It is fixed in a stretched state.

The intermediate elastic elastic members 16 and 18 have a thickness of 155 to 1880 dtex, particularly about 310 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1 to It is preferable to fix the thread rubber of about 1.0 mm ² ) at an interval of 5 to 40 mm, particularly 5 to 20 mm, and about 2 to 10 at an elongation of 150 to 300%, particularly 180 to 260%.

  As shown in the figure, when the waist lower elastic elastic member and the intermediate elastic elastic members 15, 19, 16, 18 are respectively provided on both sides in the width direction except for the central portion in the width direction overlapping the interior body 200. The interior body 200 does not shrink more than necessary in the width direction, so that it does not look bad or absorbs. In this form, in addition to the form in which the elastic stretchable member exists only on both sides in the width direction, the elastic stretchable member exists from one side of the width direction to the other side across the interior body 200, but overlaps the interior body 200. At the center in the width direction, the elastic expansion / contraction member is finely cut, and the contraction force does not act (substantially equivalent to not providing the elastic expansion / contraction member), and only the both sides in the width direction are configured as the contraction force acting portions. Are also included. Of course, the arrangement of the waist lower elastic members 15, 19, 16, and 18 is not limited to the above example, and the waist lower portion so that the elastic force acts on the entire width of the waist lower U. A part or all of the elastic elastic member and the intermediate elastic elastic members 15, 19, 16, 18 can be provided across the interior body 200 from one side in the width direction to the other side.

  In addition, when the elongated elastic elastic members 15 to 19 of each part cross a printing sheet 25 described later, when rubber containing titanium oxide is used as the elongated elastic elastic members 15 to 19, the content of titanium oxide is It is preferable to use a low one (for example, 2% or less) or one containing no titanium oxide.

(Post-processing tape)
A post-processing tape 70 (fixing means) can be provided at the center in the width direction on the outer surface of the rear body B of the exterior sheet 12. The post-processing tape 70 is for fixing the diaper 100 in a state where the diaper 100 is rolled or folded so that the topsheet 30 is on the inside and the front body F is on the inside. As shown in FIG. 5, in the general post-processing tape 70, a base end portion 71 is fixed to the outer surface of the exterior sheet 12 with an adhesive or the like, and a portion on the front end side of the base end portion 71 is tri-folded. (Folded in a Z-shaped cross section) or folded in half, and the portion between the folded portions is fixed (temporarily fixed) by the temporary fixing adhesive 72 so as to be peelable. Moreover, while having the knob | pick part 73 colored in opaque colors, such as white, in the front-end | tip part, the part except this knob | pick part 73 is transparent or semi-transparent, Through the transparent or semi-transparent part in this post-processing tape 70, A design to be described later is visible from the outer surface side of the post-processing tape 70. Although a specific structure can be appropriately configured, in the illustrated embodiment, the whole is formed by connecting a plurality of transparent or semi-transparent substrates in the longitudinal direction, and a colored tape 74 is bonded to the knob 73. Is adopted.

  At the time of disposal, the diaper 100 is rolled or folded so that the topsheet 30 is on the inside and the front body F is on the inside, and then the folded portion of the post-processing tape 70 is peeled off and spread, and the diaper 100 is rolled or folded. The diaper 100 is fixed with an adhesive so as to be wound from the rear body B of the diaper 100 to the outer surface on the opposite side over the waist opening WO. The post-processing tape 70 is particularly preferably a tri-fold shape that can be folded compactly when not in use and can be expanded into a long shape when in use.

  Fixing means such as the post-processing tape 70 may be provided on the front body F or on both the back body B and the front body F.

(Print sheet)
Between the liquid-impermeable back sheet 11 and the exterior sheet 12 (including the interlayer of the exterior sheet 12), a print sheet 25 that is designed by printing is provided. The exterior sheet 12 may be omitted, and the print sheet 25 may be exposed on the outer surface. The printed sheet 25 in the illustrated example has a smaller area than the body on which the printed sheet 25 is disposed, and is provided separately for the front body F and the back body B, but passes through the crotch from the front body F. It can also be provided so as to continue to the back body B integrally.

  Although the size and shape of the printing sheet 25 are not particularly limited, it is preferable to sufficiently increase the area in order to make the function sufficient. For example, the width of the printing sheet 25 is 50 to 120 of the width of the absorber 56. The length of the printing sheet 25 is preferably about 15 to 30% of the total length Y of the article on at least one side of the stomach side and the back side. Further, the shape of the print sheet 25 is preferably a rectangle as shown in the figure in that trim loss does not occur. However, the print sheet 25 has a geometric shape such as a circle, an ellipse, a triangle, a hexagon, or a shape along the periphery of the design. You may cut it.

As a sheet material of the printing sheet 25, a plastic film, a nonwoven fabric, paper, or the like can be used, but a bulky material having high air permeability is preferable. When using a plastic film, it is desirable to have moisture permeability in order to prevent stuffiness. Nonwoven fabrics and paper are preferable because they have moisture permeability, and when performing design printing, it is preferable to use nonwoven fabrics that are smooth and easy to print, and papers that are high in strength and difficult to bleed ink. Particularly preferred are basis weight 15 to 35 g / m ² approximately, crepe paper having a thickness of about 0.1 to 0.3 mm (thin paper) and a basis weight 10 to 25 g / m ² approximately, a thickness of about 0.1 to 0.3 mm Non-woven fabrics (especially spunbond nonwoven fabrics and SMS nonwoven fabrics having a spunbond portion having a fineness of about 1.0 to 3.0 dtex). When crepe paper is used, the crepe rate is preferably about 5 to 20%, particularly about 5 to 15%. If the crepe rate is 20% or more, the amount of ink fixed increases, but blurring occurs and is not suitable for design printing. If the crepe rate is 5% or less, the amount of fixing is small because the ink hardly penetrates.

(Exterior sheet split structure)
In the above-described example, the front body F to the back body B are continuously covered with the integral exterior sheet 12, but the exterior sheet covers the stomach side of the wearer's waist and the back side The front end portion of the interior body is connected to the inner surface of the center portion in the width direction of the abdominal side exterior sheet with a hot melt adhesive or the like, and the center portion in the width direction of the back side exterior sheet. The rear end of the interior body is connected to the inner surface by a hot melt adhesive or the like, and the form in which the abdominal exterior sheet and the back exterior sheet are not continuous on the crotch side and are separated from each other may be adopted. it can. This separation distance can be about 150 to 250 mm. In this case, on the back surface of the liquid-impermeable back sheet in the interior body, so as to cover the entire back surface of the interior body, or so as to cover the entire portion exposed between the abdominal exterior sheet and the back exterior sheet, The crotch outer sheet can also be fixed. As the crotch outer sheet, the same material as that used for the outer sheet described above can be used. The crotch outer sheet also corresponds to the outer sheet of the present invention.

(Side seal part)
As shown in FIG. 9 and FIG. 10, the welding pattern of the side seal portion 13 is based on a dot pattern in which a plurality of rows of dotted welded portions 13s, 13b are arranged in the vertical direction. In the row of the welded portions 13s and 13b at both ends in the lateral direction, the interval enlarged portions 13d in which the longitudinal interval between the adjacent welded portions 13s and 13b is increased are provided at intervals of the welded portions 13s and 13b. And the longitudinal direction range of the space | interval enlarged part 13d in the row | line | column of welding part 13s, 13b of a horizontal direction end and the vertical direction range of the space | interval enlarged part 13d in the row | line | column of welding part 13s, 13b of a horizontal other end do not overlap. In addition, a longitudinal range 13y between adjacent enlarged portions 13d in the row of welded portions 13s and 13b at one end in the horizontal direction and an adjacent interval enlarged portion 13d in the row of welded portions 13s and 13b at the other end in the horizontal direction. The interval enlarged portions 13d of the rows of the welded portions 13s and 13b at both ends in the horizontal direction are alternately arranged so as to partially overlap with the vertical range 13y, and in the vertical range of the interval enlarged portion 13d, a plurality of welds are arranged in the width direction. The portions 13s and 13b have a pattern that does not line up.

  In this dot pattern, the vertical range of the interval enlarged portion 13d is a range in which the plurality of welded portions 13s and 13b are not arranged in the width direction, that is, the seal strength is relatively weak. Further, a longitudinal range 13y between adjacent enlarged portions 13d in the row of welded portions 13s and 13b at one end in the horizontal direction and an adjacent enlarged portion 13d in the row of welded portions 13s and 13b at the other end in the horizontal direction. The vertical direction range 13y partially overlaps, and the overlap range is such that a plurality of welded portions 13s and 13b are arranged in the width direction, for example, so that the welded portions 13s and 13b of both rows are closer, that is, the seal strength is relatively It becomes a strong range. Therefore, in the present dot pattern, a strong seal range and a weak seal range are alternately formed in the vertical direction. Furthermore, in this case, the interval enlarged portions 13d of the rows at both ends are alternately arranged. According to such a pattern, the side seal portion 13 as a whole is continuous in the vertical direction and has a certain width, and the portions having a strong seal strength are arranged at a certain interval, so that sufficient strength is provided during mounting. Can be secured. Nevertheless, in the present dot pattern, since the portions with weak seal strength are intermittently arranged, it is easy to peel off, and even if the material is easily stretched, it is difficult to tear laterally. Furthermore, due to the staggered arrangement of the gap expanding portions 13d, the direction of the force at the time of peeling is not constant, and changing also contributes to prevention of lateral tearing.

  Each welded portion 13s, 13b is not particularly limited as long as it is point-shaped, such as a polygonal shape such as a triangular shape, a semicircular shape, a star shape, or an elliptical shape, but is preferably a circular shape as shown in the figure.

  The dimensional design of each part can be performed as appropriate, but the overlapping length (vertical direction) of the vertical range 13y in the row at one end in the horizontal direction and the vertical range 13y in the row at the other end in the horizontal direction is larger than the interval enlarged portion 13d. If the length is shorter, the side seal portion 13 becomes flexible, the apparent welding width becomes narrower, and the respective welding portions 13s and 13b become inconspicuous, which is preferable.

  In the illustrated embodiment, the leg opening side region A2 having the least number of nonwoven fabrics laminated (four in the illustrated example) includes a leg opening side region A2 and a region in which the number of nonwoven fabrics laminated is one or two more than the leg opening side region A2. Since A1 and A1 are arranged in the vertical direction, it is desirable to make the patterns of the leg opening side area A2 and the waist edge side area A1 different from each other on the basis of the arrangement condition. However, even in this case, in consideration of the quality stability of the welding process, as shown in the figure, the lateral welding width s of the leg opening side region A2 and the lateral welding of the waist edge side region A1. It is desirable to make the width s equal and match the lateral position.

Although the dimensions and positions in the dot pattern can be determined as appropriate, in the illustrated embodiment, in the case of infant use, it is preferably within the following range.
-Number of rows of welded portions 13s in the waist edge side region: 2 to 4 rows, especially 2 rows-Horizontal length g of each welded portion 13s in the waist edge side region A1: 0.6 to 3.0 mm (especially 0.8-1.5mm)
-Vertical length h of each welded portion 13s of the waist edge side region A1: 0.6 to 2.0 mm (particularly 0.8 to 1.5 mm)
In the waist edge side region A1, the horizontal interval q between adjacent welded portions 13s: +1.0 mm to +4.0 mm (in addition, + (plus) indicates the lateral position of the welded portions 13s and 13b in the adjacent rows. (It means the case where they do not overlap.)
In the waist edge side region A1, the longitudinal interval k between adjacent welded portions 13s in the row of welded portions 13s: 0.5 to 5.0 mm (particularly 0.8 to 1.5 mm)
-The longitudinal length n of the non-welded portion 13n in the waist edge side region A1 is 0.0 to 2.0 mm (particularly 0.1 to 1.0 mm).
-Spacing enlargement portion 13d in the waist edge region A1: 2.0 to 4.0 mm
In the waist edge side region A1, the length in the vertical direction between the gap enlarged portions 13d (longitudinal range 13y): 3.5 to 8.0 mm
In the waist edge side region A1, the ratio of the longitudinal range 13y between the interval enlarged portions 13d to the longitudinal length of the interval enlarged portion 13d is 0.16 to 0.60 times. Number of rows of welded portions 13b: More than the number of rows of waist edge side region A1, particularly 3 to 6 rows. Horizontal length i of each welded portion 13b of leg opening side region A2: 0.9 to 4.0 mm (Especially 0.9 to 2.0 mm)
The longitudinal length j of each welded portion 13b in the leg opening side area A2: 0.9 to 2.5 mm (particularly 0.9 to 2.0 mm)
In the leg opening side area A2, the horizontal interval r between adjacent welded portions 13b is 0.0 mm to +1.5 mm (“− (minus)” indicates the horizontal direction of the adjacent welded portions 13s and 13b. (It means the case where the positions overlap, and + (plus) means the case where the lateral positions of the welded portions 13s, 13b in the adjacent rows do not overlap.)
In the leg opening side region A2, the vertical interval m between adjacent welded portions 13b in the row of welded portions 13b: 2.0 to 5.0 mm (particularly 2.5 to 3.5 mm)
In the leg opening side region A2, the length p in the longitudinal direction of the non-welded portion 13n is 0.05 to 3.0 mm (particularly 0.3 to 1.5 mm).
-Space | interval enlarged part 13d in leg opening part side area | region A2: 4.0-8.0 mm
In the leg opening side area A2, the length in the vertical direction between the gap enlarged portions 13d (longitudinal range 13y): 6.0 to 12.0 mm
In the leg opening side area A2, the ratio of the vertical range 13y between the interval enlarged portions 13d to the vertical length of the interval enlarged portion 13d is 0.15 to 0.70 times. The horizontal direction of the side seal portion 13 Length s (maximum welding width): 2.0 to 7.0 mm

  In addition, since the characteristic arrangement of the dot pattern of the present invention is not easily affected by the number of nonwoven fabrics laminated and the type of nonwoven fabric, even when regions with different numbers of nonwoven fabrics are lined up in the vertical direction (of course, the number of nonwoven fabrics laminated and the number of nonwoven fabrics Even if the types are the same in the vertical direction), the same dot pattern can be formed in the entire vertical direction as shown in FIG. It goes without saying that this makes it possible to improve processing stability and reduce equipment failures. In the example shown in FIG. 14, the pattern of the waist edge side region A1 of the example shown in FIG. 9 is extended to the leg opening side region A2, and the entire longitudinal range is made the same pattern. The pattern of the part side area A2 can be extended to the waist edge part side area A1, and the entire longitudinal range can be made the same pattern.

The dimensions and positions in the case where the entire range in the vertical direction is the same dot pattern can be determined as appropriate. However, in the case of infant use in the illustrated embodiment, it is preferably within the following range.
-Number of rows of welded portions 13s: 2 to 4 rows, especially 2 rows-Horizontal length g of each welded portion 13s: 0.6 to 3.0 mm (especially 0.8 to 1.5 mm)
・ Vertical length h of each welded portion 13s: 0.6 to 2.0 mm (particularly 0.8 to 1.5 mm)
-Horizontal interval q between rows of adjacent welded portions 13s: +1.0 mm to +4.0 mm (Note that + (plus) means a case where the horizontal positions of welded portions 13s and 13b in adjacent rows do not overlap.)
-Vertical interval k between adjacent welded portions 13s in the row of welded portions 13s: 0.5 to 5.0 mm (particularly 0.8 to 1.5 mm)
・ Vertical length n of the non-welded portion 13n: 0.0 to 2.0 mm (particularly 0.1 to 1.0 mm)
-Spacing enlargement portion 13d: 2.0 to 4.0 mm
-Length in the vertical direction between the gap enlarged portions 13d (longitudinal range 13y): 3.5 to 8.0 mm
The ratio of the vertical range 13y between the interval enlarged portions 13d to the vertical length of the interval enlarged portion 13d: 0.16 to 0.60 times The horizontal length s (maximum welding width) of the side seal portion 13 : 2.0 to 7.0 mm

  Further, as shown in the figure, even if a slight amount of the welded portion 13n is formed on both sides in the longitudinal direction of the welded portions 13s and 13b, the gap between the convex portions for forming the welded portion in the sealing device is small. It becomes difficult for the fiber scraps of the nonwoven fabric to adhere to each other, and it becomes easy to remove the adhered fiber scraps. That is, in the pants-type disposable diaper, since the side seal portion 13 is formed while transferring the diaper in the lateral direction, a groove for forming the non-welded portion 13n in the sealing device (for forming the welded portion) even if fiber waste is generated. It is discharged through between the convex portions) and hardly stays between the convex portions for forming the welded portion. Specifically, the time for collecting the fiber waste is equivalent to that of a conventional general horizontal stripe pattern. In addition, even if fiber waste accumulates between the convex portions for forming the welded portion after a long time, the grooves between the convex portions are continuous in the line flow direction, so only the brush is applied in the line flow direction. Can easily remove the fiber waste.

  Further, if the entire longitudinal direction of the side seal part is a polypropylene region in which only a nonwoven fabric of polypropylene or a copolymer thereof (hereinafter also referred to as a PP nonwoven fabric) is laminated, it is difficult to be affected by the number of laminated nonwoven fabrics. The area ratio of the welded portions (the ratio of the area of each welded portion of the waist edge side region to the area of each welded portion of the leg opening side region) can be reduced even in a region with different areas, and as a result It is possible to improve the quality stability of the joint and reduce equipment failures. The area ratio is preferably 1.1 times or more and less than 2.4 times, and more preferably 1.1 times or more and less than 1.3 times. In order to obtain such a structure, if both the outer sheet material 12S and the inner sheet material 12H of the exterior sheet 12 are PP nonwoven fabrics, not only the above-described advantages but also the flexibility of the exterior sheet 12 is improved. preferable.

  Further, the nonwoven fabric of the side seal portion 13 is made of a non-woven fabric material (such as an air-through nonwoven fabric) having a compressive restoring force, or the number of laminated nonwoven fabrics of the side seal portion 13 is increased. 13s and 13b are buried in the nonwoven fabric or close to it and become inconspicuous, and even if the surface is touched, the welded portions 13s and 13b are less likely to hit the skin, so that the touch is improved. Instead of or together with this, when the elastic elastic members 15 to 19 positioned in the side seal portion 13 are fixed to the side seal portion 13 in an extended state by a hot melt adhesive or the like, the nonwoven fabric of the side seal portion 13 is elastic. By contracting together with the expansion and contraction member, the periphery of the welded portions 13s and 13b projects over the welded portions 13s and 13b, and the welded portions 13s and 13b are hidden or close to each other. Therefore, also in this case, the welded portions 13s and 13b become inconspicuous, and even if the surface is touched, the welded portions 13s and 13b are less likely to hit the skin, so that the touch is improved.

Although welding joining at the side seal portion 13 can be performed by heat sealing, when an ultrasonic seal is used, there is almost no thermal influence on the periphery of the welding portion compared to heat sealing, and the material of the side seal portion 13 is expanded. It is preferable because it is easy and flexible. However, in the case of ultrasonic sealing, the ease of elongation of the material of the side seal portion 13 is damaged, and compared with the same seal pattern, it is more difficult to peel off, and lateral tearing is likely to occur. Therefore, this invention is suitable when employ | adopting an ultrasonic seal. The ultrasonic sealing apparatus 100 is not specifically limited, For example, what is shown in FIG. 13 can be used. The ultrasonic sealing device 100 includes an anvil 110 that is pivotally supported so as to be rotationally driven about a horizontal axis 111, and an ultrasonic horn 120 that faces the outer peripheral surface of the anvil 110. A seal projection 115 is formed on the outer peripheral surface of the anvil 110 with a predetermined seal pattern, and among the workpiece 101 passed between the anvil 110 and the ultrasonic horn 120, the seal protrusion 115 and the ultrasonic horn on the outer peripheral surface of the anvil 110. The portion sandwiched between 120 is melt-sealed with frictional heat generated by ultrasonic vibration transmitted from the ultrasonic horn 120. In addition, the force pressure in the ultrasonic seal can be about 700 to 2000 N. In particular, as described above, the area ratio is reduced so that the force pressure is about 800 to 1500 N and the unit pressure is 13 N / cm ² or more per unit area. Is desirable.
In addition, a force pressure means the pressure added to processing objects, such as a nonwoven fabric, from an ultrasonic horn in an ultrasonic sealing installation. The ultrasonic seal equipment transmits vibration energy from the tip of the ultrasonic horn in contact with the workpiece to the workpiece and welds the workpiece with frictional heat. The welding shape is almost the same as the shape of the contact surface of the horn tip. It will be. It is preferable that the ultrasonic horn is a part in contact with the material of the side seal portion 13 and has an area of 20 to 60 cm ² . The vibration frequency of the ultrasonic horn is preferably 5 to 50 kHz, and the amplitude is preferably 100 μm or less. Moreover, it is preferable that the line speed at that time is 100-400 m / min.

  As Examples 1 to 3, the pants-type disposable diaper provided with the side seal portion 13 of the dot pattern shown in FIGS. 9 and 10 and the side seal portion 13 of the dot pattern shown in FIG. Compared with a pants-type disposable diaper provided with a side seal portion shown in FIG. 10 and a non-woven fabric laminated structure), and a pants-type disposable diaper provided with a dot seal side seal portion 13 shown in FIG. As Examples 1 to 4, pants-type disposable diapers each including a side seal portion 13 (reference numeral 13W is a welded portion) having a dot pattern shown in FIGS. 11 and 12 were manufactured, and the following tests and evaluations were performed. The side seal portion 13 was formed by an ultrasonic seal device.

  In addition, the dimension of each part of the side seal part 13 in Examples 1-7 and Comparative Examples 1-4 was as follows. Further, Example 1 and Example 2 differ only in the force pressure of the ultrasonic sealing device, and Comparative Examples 1 to 3 also differ only in the force pressure of the ultrasonic sealing device.

(Examples 1-4)
-Shape of each welding part 13s, 13b: Circular shape-Diameter (lateral direction length g and vertical direction length h) of welding part 13s of waist edge side area | region A1: 1.0 mm
-Diameter (horizontal length i and vertical length j) of welded portion 13b of leg opening side region A2: 1.4 mm
-Area ratio of welded portion 13b of leg opening side region A2 and welded portion 13s of waist edge side region: 1.2 times-Number of rows of welded portion 13s of waist edge side region A1: 2 rows-Leg opening Number of rows of welded portions 13b in the side region A2: 3 rows ・ Vertical interval k between adjacent welded portions 13s in the row of welded portions 13s in the waist edge side region A1: 1.2 mm
-Vertical interval m between adjacent welded portions 13b in the row of welded portions 13b in the leg opening side region A2: 3.0 mm
-Vertical length n of the non-welded portion 13n in the waist edge side region A1: 0.1 mm
-Vertical length p of non-welded portion 13n in leg opening side region A2: 0.8 mm
-Spacing in the horizontal direction q of the welded portion 13s in the waist edge side area A1: +2.5 mm (+ (plus) means the case where the lateral positions of the welded portions 13s and 13b in the adjacent rows do not overlap. )
・ Lateral spacing r of rows of welded portions 13b in the leg opening side region A2: 0 mm
-Lateral length s of the side seal portion 13 (maximum welding width): 7 mm
-Spacing enlargement part 13d in the waist edge side area A1: 3.4 mm
In the waist edge side region A1, the length in the vertical direction between the gap enlarged portions 13d (longitudinal range 13y): 7.6 mm
In the leg opening side area A2, the interval enlarged portion 13d: 7.4 mm
In the leg opening side region A2, the length in the vertical direction between the gap enlarged portions 13d (longitudinal range 13y): 10.2 mm
Outer sheet material 12S: Polypropylene copolymer (copolymerization component is ethylene) SSS nonwoven fabric (laminated nonwoven fabric with three spunbond layers) having a basis weight of 17 g / m ²
Inner sheet material 12H: Polypropylene copolymer (copolymerization component is ethylene) SSS nonwoven fabric (laminated nonwoven fabric with three spunbond layers) having a basis weight of 17 g / m ²

(Examples 5-7)
-Shape of each welded portion 13s: circular-Diameter of welded portion 13s (lateral length g and longitudinal length h): 1.0 mm
-Number of rows of welded portions 13s: 2-Vertical interval k between adjacent welded portions 13s in the row of welded portions 13s: 1.2 mm
・ Vertical length n of non-welded portion 13n: 0.1 mm
-Horizontal interval q of the rows of welded portions 13s: +2.5 mm (Note that + (plus) means a case where the lateral positions of the welded portions 13s, 13b in the adjacent rows do not overlap.)
-Lateral length s of the side seal portion 13 (maximum welding width): 7 mm
-Spacing enlarged portion 13d: 3.4mm
-Length in the vertical direction between the gap enlarged portions 13d (longitudinal range 13y): 7.6 mm
Outer sheet material 12S: Polypropylene copolymer (copolymerization component is ethylene) SSS nonwoven fabric (laminated nonwoven fabric with three spunbond layers) having a basis weight of 17 g / m ²
Inner sheet material 12H: Polypropylene copolymer (copolymerization component is ethylene) SSS nonwoven fabric (laminated nonwoven fabric with three spunbond layers) having a basis weight of 17 g / m ²

(Comparative Examples 1-3)
-Shape of each welding part 13s, 13b: Circular shape-Diameter (lateral direction length g and vertical direction length h) of welding part 13s of waist edge side area | region A1: 1.0 mm
-Diameter (horizontal length i and vertical length j) of welded portion 13b of leg opening side region A2: 1.4 mm
-Area ratio of welded portion 13b of leg opening side region A2 and welded portion 13s of waist edge side region: 1.96 times-Number of rows of welded portion 13s of waist edge side region A1: 2 rows-Leg opening Number of rows of welded portions 13b in the side region A2: 5 rows ・ Vertical interval k between adjacent welded portions 13s in the row of welded portions 13s in the waist edge side region A1: 1.2 mm
-Vertical interval m between adjacent welded portions 13b in the row of welded portions 13b in the leg opening side region A2: 3.0 mm
-Vertical length n of the non-welded portion 13n in the waist edge side region A1: 0.1 mm
-Vertical length p of non-welded portion 13n in leg opening side region A2: 0.8 mm
-Spacing in the horizontal direction q of the welded portion 13s in the waist edge side area A1: +2.5 mm (+ (plus) means the case where the lateral positions of the welded portions 13s and 13b in the adjacent rows do not overlap. )
・ Lateral spacing r of rows of welded portions 13b in the leg opening side region A2: 0 mm
-Lateral length s of the side seal portion 13 (maximum welding width): 7 mm
Outer sheet material 12S: Polypropylene copolymer (copolymerization component is ethylene) SSS nonwoven fabric (laminated nonwoven fabric with three spunbond layers) having a basis weight of 17 g / m ²
Inner sheet material 12H: Polypropylene copolymer (copolymerization component is ethylene) SSS nonwoven fabric (laminated nonwoven fabric with three spunbond layers) having a basis weight of 17 g / m ²
(Comparative Example 4)
Inner sheet material 12H: Polypropylene (core) / polyethylene (sheath) bicomponent fiber nonwoven fabric with a basis weight of 18 g / m ^2. Others are the same as those in Comparative Examples 1 to 3.

<Peel strength test>
Of the left and right side parts of the interior body 200 in the pants-type disposable diaper, a part having a width of 25 mm from the edge of the waist opening WO toward the leg opening LO (hereinafter also referred to as the upper part), and the upper end of the leg opening LO A portion having a width of 25 mm (hereinafter also referred to as a lower portion) is cut from the waist opening WO side to produce a sample. The front body F side and the back body B side of the sample are placed on a tensile tester (for example, AUTOGRAPH AGS-G100N manufactured by SHIMADZU) so that the direction (circumferential direction of the diaper) perpendicular to the side seal portion 13 of the sample is the pulling direction. ), And a tensile test was performed at room temperature under conditions of 50 mm between chucks and a tensile speed of 500 mm / min, and the breaking strength was measured as the seal strength. Measurement was performed on 20 diapers, and an average value, 3σ, and the like were calculated.

  The test results are shown in Table 1. As shown in Table 1, in Examples 1 to 7, compared with Comparative Examples 1 to 4, the upper seal strength was lowered, and the upper and lower variations were small (3σ was small).

<Sensory evaluation>
The test subjects (48 in Examples 1 and 2 and 20 in Comparative Examples 1 to 4) gave a score of 5 points (5 points: very satisfied, 4 points: somewhat satisfied) 3 points: Neither can be said, 2 points: somewhat dissatisfied, 1 point: very dissatisfied), and the average value was taken as the evaluation value. The test results are shown in Table 1. Examples 1-7 were evaluated as being much easier to peel off than Comparative Examples 1-4. From the results of these sensory evaluations and peel strength tests, the peel strength is preferably 0.8 to 3.0 kgf, and the peel strength difference between the waist edge and the leg opening is 0.5 kgf or less. It turns out that it is preferable.

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

(Weight)
The basis weight is measured as follows. After the sample or test piece has been pre-dried, it is left in a test room or apparatus in a standard state (test location is temperature 20 ± 5 ° C., relative humidity 65% or less) to obtain a constant weight. Pre-drying refers to making a sample or test piece constant in an environment where the relative humidity is 10 to 25% and the temperature does not exceed 50 ° C. In addition, it is not necessary to perform preliminary drying about the fiber whose official moisture content is 0.0%. A sample with a size of 200 mm × 250 mm (± 2 mm) is cut out from the test piece in a constant weight using a rice-basis plate (200 mm × 250 mm, ± 2 mm). Measure the weight of the sample, multiply it by 20, calculate the weight per square meter, and use it as the basis weight.

(Thickness)
The thickness is automatically measured using an automatic thickness meter (KES-G5 handy compression measurement program) under the conditions of load: 10 gf / cm ² and pressure area: 2 cm ² .

(Crepe rate)
The crepe rate of the crepe paper means the elongation rate when wet, measured as follows. That is, a sample having a dimension of 100 mm in the MD direction × 25 mm in the CD direction (MD direction, CD direction is a direction during paper manufacture) is cut out from the test piece. After wetting the sample with a brush wet with water, pull it in the MD direction to the extent that it does not break and stretch the heel. After removing excess moisture from the sample, the length in the MD direction is measured. The crepe rate (elongation rate) is calculated by the following formula.
Crepe rate = {(length after stretching) −100} / 100 × 100

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

  DESCRIPTION OF SYMBOLS 11 ... Impervious back sheet, 12 ... Exterior sheet, 12r ... Folded part, 12S ... Outer sheet material, 12H ... Inner sheet material, 13 ... Side seal part, 13s, 13b ... Welded part, 13s ... Waist edge side Welded part of the region, 13b ... welded part on the side of the leg opening, 13n ... non-welded part, 13d ... spacing extension part, 25 ... printed sheet, 200 ... interior body, 30 ... top sheet, 40 ... intermediate sheet, 50 ... Absorbing element, 56 ... absorber, 58 ... packaging sheet, 60 ... solid gather, 62 ... gather sheet, F ... front body, B ... back body, W ... waist edge, WO ... waist opening, LO ... leg opening , A1 ... waist edge side area, A2 ... leg opening side area.

Claims (7)

In a pants-type disposable diaper in which both sides of the front body and both sides of the back body are welded and joined to form a side seal, thereby forming a waist opening and a pair of left and right leg openings.
The side seal portion is formed in a dot pattern in which at least a part of the vertical direction has a plurality of rows of dotted welded portions arranged in rows in the vertical direction.
In this dot pattern:
In the row of welded portions at both ends in the lateral direction, an interval enlarged portion in which the longitudinal interval between adjacent welded portions is enlarged is provided every other welded portion,
The longitudinal range of the interval enlarged portion in the row of welded portions at one end in the horizontal direction does not overlap the longitudinal range of the interval enlarged portion in the row of welded portions at the other end in the horizontal direction, and the row of welded portions at one end in the lateral direction In the row of welded portions at both ends in the horizontal direction, the vertical range between adjacent gap enlarged portions and the vertical range between adjacent gap enlarged portions in the row of welded portions at the other end in the horizontal direction partially overlap. The interval enlarged portions of are arranged alternately,
In the longitudinal range of the interval enlarged portion, a plurality of welds are not lined up in the width direction.
A pants-type disposable diaper characterized by that. The side seal part has a polypropylene region in which only a nonwoven fabric of polypropylene or a copolymer thereof is laminated,
The pants-type disposable diaper according to claim 1, wherein the dot pattern is formed in the polypropylene region. The side seal portion is a polypropylene region in which only the nonwoven fabric of polypropylene or a copolymer thereof is laminated in the entire longitudinal direction, the leg opening side region having the smallest number of nonwoven fabrics laminated, and the number of nonwoven fabrics laminated is the leg opening side. 1 to 2 more waist edge side regions than the region are aligned in the vertical direction,
The area of each welded portion in the leg opening side region is 1.1 times or more and less than 2.4 times the area of each welded portion in the waist edge side region,
The pants-type disposable diaper according to claim 1 or 2. Each welded portion of the side seal portion is circular with a diameter of 0.7 to 2.0 mm,
In the leg opening side region, the rows of the welded portions are three rows, and in the waist edge side region, the rows of the welded portions are two rows,
In the leg opening side region, the horizontal interval between the rows of the adjacent welded portions is −1.5 to 2.4 mm,
In the leg opening side region, the longitudinal interval between adjacent welded portions in the row of welded portions is 0.0 to 5.0 mm,
In the waist edge side region, the horizontal interval between the adjacent welded portions is 0.7 to 5.6 mm,
In the waist edge side region, the longitudinal interval between adjacent welded portions in the row of welded portions is 0.0 to 5.0 mm.
The pants-type disposable diaper according to claim 3.   The pants-type disposable diaper according to claim 1 or 2, wherein the side seal part is entirely formed in the same dot pattern in the vertical direction. Each welded portion of the dot pattern is circular with a diameter of 0.7 to 2.0 mm,
The welded portion has two rows,
The horizontal interval between the adjacent rows of welds is 0.7 to 5.6 mm,
The longitudinal interval between adjacent welded portions in the row of welded portions is 0.0 to 1.5 mm.
The pants-type disposable diaper according to claim 5.   The pants-type disposable diaper according to any one of claims 1 to 6, wherein the welding joining is performed by an ultrasonic seal.

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