JP5464791B2 - Pants-type disposable diapers - Google Patents

Description

  The present invention relates to a pants-type disposable diaper constructed by joining a front body sheet and a back body sheet in which a large number of elastic elastic members are arranged along the diaper width direction to an absorbent main body, and more specifically Further, the present invention relates to a pants-type disposable diaper that is excellent in preventing slippage by not interlocking the shift between the waist part and the waist part of the diaper, and that does not hinder the movement of the wearer's leg and improves the ease of flaking.

  Conventionally, in a pants-type disposable diaper, it is arranged in the waist part of the diaper, around the waist, and around the leg from the viewpoint of preventing the diaper from falling down and preventing the movement of the leg and making it easy to loosen. What adjusted the expansion-contraction stress of the elastic body made is known.

  For example, an elastic ribbon is widely arranged from the waistline opening part to the crotch area, and the elastic ribbon has a large elongation stress and expansion ratio in the waistline opening part and is made smaller in the crotch area (Patent Document 1 below), An elastic member in the front / rear side waist opening stretchable region and an elastic member in the upper, middle and lower portions of the front / rear side waistline stretchable region are arranged with an elongation stress having a predetermined relative relationship (Patent Document 2 below) ), A waist opening peripheral part, a trunk peripheral part, and a peripheral expansion / contraction stress of a leg opening peripheral part have a predetermined magnitude and relationship (Patent Document 3 below).

  In particular, in infant diapers, taking into account the large bulge of the abdomen, which is a characteristic of the infant's body shape, by increasing the stretching stress at the waist, waist, and legs around the abdomen (front body) Measures such as slipping prevention have been taken.

On the other hand, a two-part diaper whose exterior sheet is composed of a front body sheet and a back body sheet has less trim (excess disposal part) when punching out the leg opening at the time of manufacture, and the front body sheet and the rear body. There are advantages that each material of the body sheet can be individually selected and that there is no exterior sheet in the crotch portion, so that the breathability is excellent and the legs are easy to move.
JP-A-4-289201 JP-A-9-38134 Japanese Patent Laid-Open No. 11-253489

  However, in consideration of the influence of the swelling of the abdomen, increasing the stretching stress on the abdomen (front body side) increases the tightening of the abdomen and tends to cause skin marks and blurring. In addition, from the balance with the stretch stress on the abdomen (front body side), the stretch stress on the back side (rear body side) must be increased, and overall the stretch stress is high, making it a diaper that is difficult to break, Not only the pleats formed by the stretching stress are enlarged and the appearance is bad, but also the touch is bad.

  For this reason, in recent years, by suppressing the stretching stress around the waist, which is easily affected by changes in the swelling of the stomach during fasting, fullness, or breathing, and by increasing the stretching stress at the waist and legs. , Trying to prevent diaper slipping. However, although this measure is effective in terms of the difficulty of shifting the diaper, there are drawbacks such as obstructing the movement of the legs for infants who start to walk and move rapidly.

  Therefore, the main problem of the present invention is that it prevents slippage between the waistline and the waist and is excellent in slipping prevention, does not hinder the movement of the wearer's legs, improves ease of flaking, and diapers. It is providing the underpants type disposable diaper which improved the external appearance and the touch.

In order to solve the above-mentioned problem, as the present invention according to claim 1, an absorbent main body in which an absorbent body is interposed between a liquid-permeable top sheet and a back sheet, and a waist portion between two nonwoven fabrics and A large number of elastic elastic members are arranged along the waist part, and a large number of the waist part and the waist part are provided between the back body sheet joined to the back body side of the absorbent main body and the two nonwoven fabrics. The elastic body is arranged and is composed of a front body sheet joined to the front body side of the absorbent main body, and the back body sheet and the front body sheet in the product state are arranged at both side ends thereof. In a pants-type disposable diaper in which a waist opening and a pair of left and right leg openings are formed by being joined at the joint of
Each of the rear body sheet and the front body sheet is provided with a gap absorbing buffer band in which a distance between specific elastic elastic members is set to be larger than an interval between elastic elastic members in adjacent peripheral regions, and the front body The displacement absorbing buffer band provided in the front seat is biased to the crotch side relative to the displacement absorbing buffer band provided in the rear body sheet, and provided in the displacement absorbing buffer band and the back body sheet provided in the front body sheet. The gap absorption buffer band is not overlapped at all so that the gap absorption buffer band provided in the front body and the gap absorption buffer band provided in the back body have a discontinuity in the torso direction. A featured pants-type disposable diaper is provided.

  In the first aspect of the present invention, the gap absorption in which the interval between the specific elastic elastic members is set larger than the interval between the elastic elastic members in the adjacent peripheral region in each of the back body sheet and the front body sheet. By providing the buffer band, the shift between the waist portion and the waist portion does not interlock with each other. That is, the waist portion does not slide down due to the slipping of the waistline portion, and at the same time, the waistline portion does not slip down due to the slipping of the waist portion, thereby preventing the diaper slipping as a whole.

  Furthermore, the deviation absorbing buffer band provided on the front body sheet is biased to the crotch side with respect to the deviation absorbing buffer band provided on the rear body sheet. In other words, by providing the gap absorption buffer band provided in the front body and the gap absorption buffer band provided in the back body to have discontinuities in the waist circumference direction, the shift generated in the front body is It becomes difficult to interlock with the body, and the shift generated in the back body is difficult to interlock with the front body, so that the entire diaper is difficult to slide down.

  Since sliding of the diaper is prevented in this way, it is not necessary to increase the stretching stress in order to strengthen tightening at the waist part and the leg surrounding part to prevent sliding, and the movement of the wearer's leg is prevented. Therefore, the stretching stress can be kept low overall, and the ease of peeling is improved. Moreover, since the expansion / contraction stress of the whole diaper is low, the pleats formed on the sheet become finer, and the appearance and feel of the diaper are improved.

  According to a second aspect of the present invention, as the present invention, the displacement absorbing buffer band is provided in a flap portion where there is no absorbent body from the diaper longitudinal end of the absorbent body to the waist opening. A mold disposable diaper is provided.

  The present invention according to claim 2 shows a formation region of a deviation absorbing buffer band provided in the back body sheet and the front body sheet, and when a rigid absorber is located in the deviation absorbing buffer band, Since the function of the displacement absorbing buffer band that does not interlock the displacement will be significantly hindered, the displacement absorbing buffer band is located at the flap portion where the absorber does not exist from the longitudinal end of the absorber to the waist opening. It is preferable to provide them.

According to the third aspect of the present invention, the rear body seat is disposed within a double length range of the width L5 of the deviation absorbing buffer band from the deviation absorbing buffer band to the waist opening side and the crotch side. The pants-type disposable diaper according to any one of claims 1 and 2, wherein the arrangement pitch Pb of the elastic elastic members is a relationship of the following formula (1).

As the present invention according to claim 4, the elastic stress F8 of the first elastic elastic member disposed on the side of the waist opening from the deviation absorbing buffer band of the back body sheet, the second and subsequent waist openings Elastic stress F5 of the elastic elastic member on the side, elastic stress F7 of the first elastic elastic member disposed on the crotch side from the displacement absorbing buffer band, and elastic stress F6 of the elastic elastic member on the crotch side after the second one The pants-type disposable diaper according to any one of claims 1 to 3, which is in a relationship of the following formula (2):

  According to the third and fourth aspects of the present invention, in the back body sheet, the elastic elastic member disposed on both sides of the deviation absorbing buffer band and the elastic elastic member disposed in the vicinity of the deviation absorbing buffer band are preferable. Since the relative stress relationship is defined, it is possible to further ensure the effect of preventing the diaper from slipping in the deviation absorbing buffer zone.

As the present invention according to claim 5, the front body seat is disposed in a range twice as long as the width L6 of the shift absorbing buffer band from the shift absorbing buffer band of the front body sheet toward the waist opening side and the crotch side. The pants-type disposable diaper according to any one of claims 1 to 4, wherein the disposing pitch Pf of the elastic elastic members has a relationship of the following formula (3).

As the present invention according to claim 6, the elastic stress F3 of the first elastic elastic member disposed on the side of the waist opening from the displacement absorbing buffer band of the front body sheet, the second and subsequent waist openings Elastic stress F1 of the elastic elastic member on the side, elastic stress F4 of the first elastic elastic member disposed on the crotch side from the deviation absorbing buffer band, and elastic stress F2 of the elastic elastic member on the crotch side after the second one Is a pants-type disposable diaper according to any one of claims 1 to 5, which is in the relationship of the following formula (4).

  The present invention according to claims 5 and 6 is preferably a front body sheet comprising: an elastic elastic member disposed on both sides of the deviation absorbing buffer band; and an elastic elastic member arranged in the vicinity of the deviation absorbing buffer band. Since the relative stress relationship is defined, it is possible to further ensure the effect of preventing the diaper from slipping in the deviation absorbing buffer zone.

As the present invention according to claim 7, the elastic stress F1 of the second and subsequent elastic elastic members disposed on the waist opening side from the deviation absorbing buffer band of the front body sheet, and the back body sheet It is arranged on the crotch side from the deviation absorbing buffer band of the front body sheet and the relationship with the expansion / contraction stress F5 of the second and subsequent elastic elastic members arranged on the waist opening side from the deviation absorbing buffer band. The elastic stress F2 of the second elastic elastic member after the second and the elastic stress F6 of the elastic elastic member after the second arranged from the displacement absorbing buffer band of the back body sheet are expressed by the following formula (5 ) And the elastic stresses F7 and F8 of the first elastic elastic member disposed on both sides of the deviation absorbing buffer band of the rear body sheet and the deviation absorbing buffer band of the front body sheet. Expansion and contraction of the first elastic elastic member arranged on both sides Force F3, F4 and the pants type disposable diaper according to any one of claims 1 to 6, the relationship of the following equation (6) is provided.

  The present invention according to claim 7 includes an elastic elastic member disposed on both sides of and in the vicinity of the deviation absorbing buffer band in the back body sheet, and both sides of and in the vicinity of the deviation absorbing buffer band in the front body sheet. The relative stress relationship of the expansion / contraction stress with the elastic expansion-contraction member arrange | positioned in FIG. Overall, by setting the stretching stress on the back body side higher than the front body side, the front body sheet as a whole is pulled up toward the waist opening of the back body sheet, resulting in diaper slipping Can be prevented.

  As an aspect of the present invention according to claim 8, there is provided a pants-type disposable diaper according to any one of claims 1 to 7, wherein openings are provided in the nonwoven fabric of the deviation absorbing buffer band at predetermined intervals along the trunk circumference direction. Is done.

  The present invention according to claim 8 is characterized in that, in the displacement absorbing buffer zone in which the wearer's sweat easily collects because no stretch force is applied, the nonwoven fabric is provided with openings at predetermined intervals along the waist circumference direction. The air permeability is improved to prevent stuffiness.

  As described above in detail, according to the present invention, the slippage of the waist portion and the waist portion is not interlocked with each other, and it is excellent in slip-off prevention performance, does not hinder the movement of the wearer's leg, and improves ease of peeling, and It becomes possible to improve the appearance and feel of the diaper.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a product state external view of a disposable diaper according to the present invention, FIG. 2 is a development view thereof, and FIG. 3 is an exploded view thereof.

  1 to 3, a pants-type disposable diaper 1 (hereinafter simply referred to as a diaper) includes an absorbent main body 10 and elastic elastic members 22, 22... Disposed on a waist part S 1 and a waist part S 2. The elastic elastic members 23, 23... Are arranged to form shearing, and the rear body sheet 20 joined to the rear body B side of the absorbent main body 10 and the elastic elastic members 32, 32. In addition, the elastic stretch members 33, 33,... Are arranged in the waist portion S2 to form shearing, and the front body sheet 30 is joined to the front body F side of the absorbent main body 10. And, in each of the rear body sheet 20 and the front body sheet 30, the interval between the specific elastic elastic members is more than the interval between the elastic elastic members 22, 23... 32, 33. The displacement absorbing buffer bands 2 and 3 that are set larger than the above are provided, and the displacement absorbing buffer band 3 provided on the front body sheet 30 is more than the displacement absorbing buffer band 2 provided on the rear body sheet 20. It is designed to be biased toward the crotch side.

  The said absorptive main body 10 consists of a perforated or non-porous nonwoven fabric, a perforated plastic sheet, etc. as shown in FIGS. 2-4, the liquid-permeable surface sheet 11 which covers the use surface side, and the outer surface side of the diaper Further, a side for forming an absorbent body 12 made of cotton-like pulp or the like having a certain degree of rigidity (for example, rectangular shape (or hourglass shape)) and a three-dimensional gather BS standing on the surface side on both sides around the legs of the diaper It is mainly composed of a gathered nonwoven fabric 13 and a leak-proof sheet 14 made of polyethylene or the like disposed so as to cover at least the entire area of the absorbent body 12 on the outer surface side of the absorbent body 12.

  As shown in FIGS. 3 and 5, the rear body sheet 20 includes two upper-layer nonwoven fabrics 21 </ b> A and lower-layer nonwoven fabrics 21 </ b> B made of nonwoven fabrics, and the waist portion S <b> 1 and the waist portion S <b> 2 in the horizontal direction therebetween. It is mainly composed of a plurality of elastic elastic member groups 22, 22..., 23, 23.

  As shown in FIGS. 3 and 6, the front body sheet 30 includes two upper-layer nonwoven fabrics 31 </ b> A and lower-layer nonwoven fabrics 31 </ b> B made of a nonwoven fabric, and the waist portion S <b> 1 and the waist portion S <b> 2 in the horizontal direction therebetween. It is mainly comprised from the some elastic elastic member group 32, 32 ..., 33, 33 ... adhere | attached along.

  Hereinafter, the absorbent main body 10, the back body sheet 20, and the front body sheet 30 will be described in detail.

(Structure of the absorbent main body 10)
First, an example of the structure of the absorbent main body 10 will be described in detail with reference to FIGS.

  As described above, the absorbent main body 10 includes an absorbent body 12 such as cotton-like pulp between the liquid-permeable surface sheet 11 made of a nonwoven fabric or the like and the liquid-impermeable leak-proof sheet 19 made of a plastic sheet or the like. The back sheet 14 which consists of a nonwoven fabric etc. is arrange | positioned in the outermost layer.

  In the illustrated example, the absorbent body 12 is formed in a substantially rectangular shape (or an hourglass shape, etc.), and its width dimension is a dimension that does not give the wearer a feeling of wrinkle by hitting the crotch part. It is wide. The absorbent body 12 is surrounded by crepe paper 16 in order to maintain the shape and improve the diffusibility of the body fluid that has passed through the liquid-permeable surface sheet 11. As the absorbent body 12, it is desirable to use an airlaid absorbent body that can reduce the bulk.

  As the liquid-permeable surface sheet 11 covering the surface side (skin contact surface side) of the absorbent body 12, a porous or non-porous nonwoven fabric or a porous plastic sheet is preferably used. The material fibers that make up the nonwoven fabric can be synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, and polyamides, recycled fibers such as rayon and cupra, and natural fibers such as cotton. A nonwoven fabric obtained by an appropriate processing method such as a spun bond method, a thermal bond method, a melt blown method, or a needle punch method can be used. Among these processing methods, the spunlace method is excellent in terms of flexibility and the spunbond method is excellent in drapeability, and the thermal bond method and the air-through method are excellent in terms of being bulky and soft. When a large number of through holes are formed in the liquid-permeable surface sheet 11, urine and the like are quickly absorbed, and the dry touch property is excellent. The liquid-permeable top sheet 11 extends to the back surface side of the absorbent body 12 around the side edge of the absorbent body 12.

  Examples of the back sheet 14 made of a nonwoven fabric exposed on the outer surface of the product include synthetic fibers such as polyethylene or polypropylene such as olefin, polyester, and polyamide, recycled fibers such as rayon and cupra, natural fibers such as cotton, and the like. Obtained by appropriate processing methods such as spunlace method, spunbond method, thermal bond method, melt blown method, needle punch method, air through method, SMS (spunbond / meltblown / spunbond), point bond method, etc. Produced nonwoven fabrics can be used. Among these processing methods, the spunlace method is excellent in terms of flexibility and the spunbond method is excellent in drapeability, and the thermal bond method and the air-through method are excellent in terms of being bulky and soft.

  The leak-proof sheet 19 that covers the back surface side (non-skin contact surface side) of the absorbent body 12 is made of a liquid-impervious plastic sheet such as polyethylene or polypropylene, but in recent years has moisture permeability from the viewpoint of preventing stuffiness. Those are preferably used. This water-impervious / breathable sheet is a microporous sheet obtained by, for example, melt-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. If the sheet thickness is the same, the rigidity is lower than that of the non-porous sheet, which is superior in terms of flexibility. In addition, it is desirable to use an opaque one so that brown color such as defecation and urine does not appear. As the opacification, a plastic film and a pigment and filler such as calcium carbonate, titanium oxide, zinc oxide, white carbon, clay, talc and barium sulfate are preferably used.

  On the other hand, as shown in FIG. 4, the gathered nonwoven fabric 13 that forms the three-dimensional gathered BS is a nonwoven fabric made into a double sheet by folding, and the side edges of the absorbent body 12 wound by the topsheet 11 are further provided. It winds up from the upper side and extends to the back side of the absorbent body 12 to be bonded. More specifically, the gathered nonwoven fabric 13 has a three-dimensional gather BS forming portion at the middle part in the longitudinal direction of the diaper, and a range from the middle part in the width direction to the back side of the absorbent body 12 is bonded by a hot melt adhesive or the like. Further, at the front and rear end portions in the longitudinal direction, the section from the intermediate portion in the width direction to the one side end edge is bonded in the range extending to the back surface side of the absorber 12, and the portion forming the three-dimensional gather BS is the absorber. 12 is bonded by a hot melt adhesive or the like while being folded at the upper surface portion.

  Inside the gathered nonwoven fabric 13 formed of the double sheet nonwoven fabric, a plurality of thread-like elastic elastic members 15, 15... The thread-like elastic stretch members 15, 15... Are for forming a three-dimensional gather BS by raising a nonwoven fabric portion protruding from the absorber side edge portion by elastic stretch force in a product state. In the present invention, since the absorbent main body 10, the back body sheet 20 and the front body sheet 30 are manufactured in separate steps and then bonded, the absorbent main body 10 is always provided with the elastic elastic member. The production line can be conveyed along the arrangement direction of 15, 15,..., And the operation such as rotating in the orthogonal direction is not necessary, and the production operation can be simplified.

  As the thread-like elastic elastic member 15, materials such as styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene, silicon, and polyester that are usually used can be used. Further, in order to make it difficult to see from the outside, the thickness is 1880 dtex or less, preferably 925 dtex or less, the tension is 100 to 350%, preferably 150 to 300%, and the interval is 10 mm or less, preferably 7 mm or less. . Instead of the thread-like elastic elastic member, a tape-like elastic elastic member having a certain width may be used.

  In the same manner as the liquid-permeable surface sheet 11, the material fiber constituting the gathered nonwoven fabric 13 is not limited to synthetic fibers such as polyethylene or polypropylene, such as olefins, polyesters, and polyamides, but also regenerated fibers such as rayon and cupra, Natural fibers such as cotton can be used, and suitable processing methods such as the spunbond method, thermal bond method, melt blown method, needle punch method, air through method, SMS (spunbond / meltblown / spunbond), point bond method, etc. The nonwoven fabric obtained can be used, but it is particularly preferable to use a nonwoven fabric excellent in air permeability by suppressing the basis weight in order to prevent stuffiness. Furthermore, with respect to the gathered nonwoven fabric 13, in order to prevent the transmission of urine and the like, to prevent fogging, and to improve the touch to the skin (dry feeling), a silicon-based, paraffin-metal-based, alkylchromic-chromoid water repellent It is desirable to use a water-repellent non-woven fabric coated with such as.

(Structure of rear body sheet 20)
The back body sheet 20 is, as shown in FIGS. 2, 3 and 5, a two-layer nonwoven fabric sheet composed of an upper nonwoven fabric 21A and a lower nonwoven fabric 21B, and the upper nonwoven fabric 21A and the lower nonwoven fabric 21B. Various elastic elastic members 22..., 23... Are arranged in the horizontal direction between them, and elasticity is given in the horizontal direction. The back body sheet 20 is adhered to the back body B side of the absorbent main body 10 and joined at the front body sheet 30 (described later) and joints 24 and 24 on both side ends thereof, thereby opening the waist opening and the left and right sides. A pair of leg openings are formed.

  As shown in the planar shape of FIG. 5, a concave leg-around cut line 29 is formed in a portion corresponding to the leg opening of the diaper. However, a rectangular sheet may be used in some cases.

  As shown in FIG. 5, the rear body sheet 20 has a waist along the horizontal direction with an interval in the vertical direction of the waist portion S1 and the waistline portion S2 between the upper nonwoven fabric 21A and the lower nonwoven fabric 21B. The elastic elastic members 22, 22... Are bonded to the plurality of elastic elastic members 23, 23.

  The waist elastic elastic members 22, 22... Are a plurality of elastic rubber elastic elastic members arranged in the vicinity of the waist opening edge (waist part S1) in the vertical direction, and around the waist part of the body. It is for attaching a diaper to the body by giving an expansion / contraction force so as to tighten. As the waist elastic elastic member 22, thread rubber is used in the illustrated example, but, for example, a tape-like elastic member may be used.

  The waist elastic elastic members 23, 23,... Extend in the horizontal direction with an interval in the vertical direction over the range (body waist portion S2) from the lower end of the waist portion S1 to the lower end of the seat 20 for the back body. It is an elastic elastic member in the form of a rubber thread, and is provided with waistline shirring that applies a horizontal expansion and contraction force to the waistline portion of the back body B, so that the diaper is in close contact with the body. The boundary between the waist elastic elastic members 22, 22... And the waist elastic elastic member groups 23, 23. For example, even if the number of elastic elastic members arranged horizontally in the vertical direction is not specified, some of the upper elastic members 22, 22... The elastic elastic member should just function as the waist elastic elastic member group 23,23 ....

  Further, the back body sheet 20 has the waist portion S1 and the waistline portion S2, and the tension (adhesion) between the waist elastic stretch members 22, 22... And the waistline elastic stretch members 23, 23. By adjusting the (elongation in time), the shearing strength can be varied.

  Particularly in the present invention, the back body sheet 20 is provided with a deviation absorbing buffer band 2 in which the interval between the specific elastic elastic members is set to be larger than the interval between the elastic elastic members 22, 23,. It has been. The displacement absorbing buffer zone 2 will be described in detail later.

(Manufacturing method of sheet 20 for back body)
Next, the manufacturing method of the said back body sheet | seat 20 is explained in full detail.

  The waist elastic elastic members 22, 22... Arranged in the waist S1 and the waist elastic elastic members 23, 23 arranged in the waist S2 are elastic elastic members 22 according to a conventionally known coating method. The hot melt adhesive is applied to the peripheral surfaces of the upper nonwoven fabric 21A and the lower nonwoven fabric 21B, and then fixed.

  In manufacturing the rear body sheet 20, as shown in FIGS. 7 and 8, the upper layer nonwoven fabric 21 </ b> A is supplied to the upper side of the nip roller portion 40, and the lower layer nonwoven fabric 21 </ b> B is supplied to the lower side. Various elastic elastic members (waist elastic elastic member 22 and waist elastic elastic member 23) having a hot melt adhesive applied to the peripheral surface by the peripheral surface coating device 41 are supplied between 21A and the lower layer nonwoven fabric 21B. Each is bonded to produce a continuous back body sheet 20 (see FIG. 8). Thereafter, the individual rear body sheets 20 are completed by cutting the continuous rear body sheet 20 at a predetermined position (broken line position).

  For example, as shown in FIG. 9 (A), the peripheral surface application to the elastic elastic members 22 ..., 23 ... is performed by supplying an adhesive to the bottom of the groove using a member 43a having a V-shaped groove. A method of applying with a comb gun 43 that passes the elastic expansion and contraction member through the groove while applying an adhesive by passing the elastic expansion and contraction member through the bending member 44 and applying an adhesive as shown in FIG. 9B. The control seam coating method, the omega coating method, or the sure wrap coating method. These control seam coating method, omega coating method, and sure wrap coating method are preferable because the peripheral surface coating with higher uniformity can be applied than the comb gun coating in which the adhesive is not easily applied.

  Examples of the hot melt adhesive include EVA type, adhesive rubber type (elastomer type), olefin type, polyester / polyamide type, etc., but in this disposable diaper, the adhesive rubber type (elastomer type) is used. It is desirable to use

(Structure and manufacturing method of front body sheet 30)
The front body sheet 30 has substantially the same structure as the back body sheet 20, and as shown in FIG. 3 and FIG. 6, is a two-layer nonwoven fabric sheet composed of an upper nonwoven fabric 31A and a lower nonwoven fabric 31B. Between the upper layer nonwoven fabric 31A and the lower layer nonwoven fabric 31B, a plurality of elastic elastic members 32, 33,... Are bonded by a hot melt adhesive along the horizontal direction of the waist portion S1 and the waist portion S2. Has been granted. Further, in the present invention, in particular, the gap absorbing buffer band 3 in which the interval between the specific elastic elastic members is set to be larger than the interval between the elastic elastic members 32, 33,. Is provided. The displacement absorbing buffer zone 3 will be described in detail later.

  As shown in the planar shape of FIG. 6, the front body sheet 30 according to the present invention is a rectangular sheet, but in some cases, a concave leg-hole cut is formed in a portion corresponding to the leg opening of the diaper. A line may be formed.

  The waist elastic elastic members 32 and the waist elastic elastic members 33 are elastically expanded and contracted by a conventionally known application method or the like, similar to the application of the peripheral surface to the elastic elastic members 22. It can adhere | attach by apply | coating an adhesive agent to the members 32 ..., 33 ....

(Configuration of gap absorption buffer bands 2 and 3)
As described above, the back body sheet 20 is provided with the displacement absorbing buffer band 2 in which the interval between the specific elastic elastic members is set larger than the interval between the elastic elastic members in the adjacent peripheral region, and the front body The shift sheet 30 is provided with a deviation absorbing buffer band 3 in which the interval between the specific elastic elastic members is set larger than the interval between the elastic elastic members in the adjacent peripheral region. In the present invention, in particular, the displacement absorbing buffer band 3 provided on the front body sheet 30 is biased to the crotch side relative to the displacement absorbing buffer band 2 provided on the rear body sheet 20. Here, the gap absorption buffer bands 2 and 3 are respectively flap portions where the absorber 12 does not exist from the end of the absorber 12 in the diaper longitudinal direction to the waist opening (in the range of L3 and L4 in FIG. 2). Is preferably provided.

Next, the preferred embodiment of the displacement absorbing buffer band 2 provided on the rear body seat 20 will be described in detail. As shown in FIG. 2, the waist opening side of the rear body seat 20 from the displacement absorbing buffer band 2 is shown. And the disposition pitch Pb of the elastic elastic members 22... 23 disposed respectively in the double length range of the width L5 of the displacement absorbing buffer band 2 toward the crotch side is expressed by the following equation (1). It is desirable to be.

  When the arrangement pitch Pb of the elastic elastic members 22 ..., 23 ... is larger than L5 / 2 in the vertical length range from the deviation absorbing buffer band 2 within the double length L5 of the deviation absorbing buffer band 2 The displacement of the waist portion or the waistline portion cannot be absorbed by the displacement absorption buffer zone 2 without the effect of the displacement absorbing buffer zone being exhibited, and the displacement of the waist portion and the waistline portion are interlocked. Therefore, it is not preferable. On the other hand, since the influence of the deviation absorbing buffer band 2 is not affected in the range of the length L5 or more of the width L5 of the deviation absorbing buffer band 2, the arrangement pitch of the elastic elastic members 22 ..., 23 ... is arbitrarily set. be able to.

Further, as shown in FIG. 2, the elastic stress of each elastic expansion / contraction member with respect to the deviation absorbing buffer band 2 is the first that is disposed on the waist opening side from the deviation absorbing buffer band 2 of the rear body seat 20. The elastic force of the first elastic elastic member is F8, the elastic stress of the elastic elastic member on the waist opening side after the second is F5, and the first elastic elastic member disposed on the crotch side from the displacement absorbing buffer band 2. When the expansion / contraction stress of the expansion / contraction member is F7 and the expansion / contraction stress of the second and subsequent inseam elastic expansion / contraction members is F6, it is preferable that the following relationship (2) is satisfied.

  That is, except for F7 = F8, due to the difference in elastic stress between the upper and lower displacement absorbing buffer bands 2, the elastic elastic member having the smaller elastic stress is pulled by the elastic elastic member having the larger elastic stress, and the contracting force of the elastic elastic member having the larger elastic stress is hindered. In addition, the desired stretching stress in the displacement absorbing buffer band cannot be obtained, and the difference in stretching stress causes irregularities in the crease formed in the displacement absorbing buffer zone 2, resulting in poor appearance and feel. Moreover, when F8 is smaller than F5 or F7 is smaller than F6, the shift of the waist or the waistline portion cannot be absorbed by the displacement absorbing buffer band 2, and the shift may develop to the waistline portion or the waist portion. This is not preferable. Further, the second and subsequent elastic elastic members from the displacement absorbing buffer band 2 cause an action force to pull up the front body sheet 30 toward the waist opening of the rear body sheet 20, so that the waist extends from the crotch side (F 6). It is preferable to increase the stretching stress disposed on the opening side (F5).

Next, the preferred embodiment of the deviation absorbing buffer band 3 provided in the front body sheet 30 will be described in detail. As shown in FIG. 2, the waist opening side of the front body sheet 30 from the deviation absorbing buffer band 3 is shown. Further, it is desirable that the arrangement pitch Pf of the elastic elastic members arranged in the double length range of the width L6 of the displacement absorbing buffer band 3 toward the crotch side has the relationship of the following formula (3). .

Further, the elastic stress of the elastic elastic member in the vicinity of the deviation absorbing buffer band 3 is similar to that of the deviation absorbing buffer band 2, as shown in FIG. 2, from the deviation absorbing buffer band 3 of the front body sheet 30. The elastic stress of the first elastic elastic member disposed on the waist opening side is F3, the elastic stress of the elastic elastic member on the waist opening side after the second is F1, from the displacement absorbing buffer band to the crotch side It is desirable that the relationship expressed by the following equation (4) is satisfied, where F4 is the expansion / contraction stress of the first elastic expansion / contraction member and F2 is the expansion / contraction stress of the elastic expansion member on the crotch side after the second one.

Next, the relationship between the elastic stress of the elastic member of the rear body sheet 20 and the elastic stress of the elastic member of the front body sheet 30 will be described in detail. From the displacement absorbing buffer band 3 of the front body sheet 30 The elastic stress F1 of the second and subsequent elastic elastic members disposed on the waist opening side and the second and subsequent elastic fibers 2 disposed on the waist opening side from the displacement absorbing buffer band 2 of the rear body sheet 20 Relation with the elastic stress F5 of the elastic elastic member, the elastic stress F2 of the second and subsequent elastic elastic members disposed on the crotch side from the displacement absorbing buffer band 3 of the front body sheet 30, and the rear body The expansion stress F6 of the second and subsequent elastic members disposed on the crotch side from the displacement absorbing buffer band 3 of the sheet 30 is in the relationship of the following equation (5), and the displacement absorption of the rear body seat 20 is as follows: The first one disposed on both sides of the buffer band 2 The elastic stresses F7 and F8 of the elastic elastic member and the elastic stresses F3 and F4 of the first elastic elastic member disposed on both sides of the displacement absorbing buffer band 3 of the front body sheet 30 are expressed by the following equation (6). It is desirable that

  That is, the elastic elastic member having a relative relationship with the displacement absorbing buffer bands 2 and 3 generally sets the expansion stress on the back body side to be high. As a result, an effect of pulling up the front body sheet 30 as a whole through the joints 24 and 24 is produced, so that the diaper slipping can be effectively prevented against the swelling of the abdomen, which is a feature of the infant body shape. become. More specifically, in order to more reliably prevent the above-described slipping-down, it is preferable that the stretching stress of the waist part on the back body side is set to be the highest among the diapers.

  The distances L1 and L2 from the waist opening ends of the displacement absorbing buffer bands 2 and 3 are in the range of 10 to 50 mm and L2 in the range of 20 to 60 mm, respectively, considering the specific size of the diaper. Is desirable.

  Further, the relative difference (L2−L1) between the displacement absorbing buffer bands 2 and 3 is 5 to 30 mm, preferably 10 to 25 mm, more preferably 15 to 20 mm, and the displacement absorbing buffer bands 2 and 3 overlap. In the case of separation, the separation distance is preferably 15 mm or less, and more preferably 10 mm or less. By setting it as such a relative difference, the effect which pulls up the whole front body sheet | seat 30 to the waist opening part direction of the sheet | seat 20 for back body parts by the shift | offset | difference absorption buffer bands 2 and 3 comes to be exhibited more.

  On the other hand, the dimensions of the widths L5 and L6 of the displacement absorbing buffer bands 2 and 3 are 10 to 30 mm, preferably 10 to 20 mm in consideration of the specific size of the diaper.

  By the way, in the shift | offset | difference absorption buffer belts 2 and 3, since the stretching force is not provided, a wearer's skin and upper layer nonwoven fabric 21A, 31A are easy to closely_contact | adhere, and a wearer's sweat tends to accumulate. For this reason, it is preferable to provide openings in the upper layer nonwoven fabrics 21A and 31A and / or the lower layer nonwoven fabrics 21B and 31B at predetermined intervals along the circumference of the trunk. Thereby, the air permeability of the deviation absorbing buffer bands 2 and 3 is improved, and the stuffiness can be prevented.

  Further, as shown in FIG. 10, the displacement absorbing buffer bands 2 and 3 are provided with elastic elastic members in the displacement absorbing buffer bands 2 and 3 along the waistline direction in the manufacturing process, You may form an elastic expansion-contraction member by cutting | disconnecting at predetermined intervals along the trunk periphery direction with the upper layer nonwoven fabrics 21A and 31A and / or the lower layer nonwoven fabrics 21B and 31B of the gap absorption buffer bands 2 and 3. After the cutting, the cut portion is formed with an opening by contraction of the elastic elastic member, thereby improving air permeability and preventing stuffiness. The cutting dimension is 3 to 20 mm, preferably 5 to 10 mm in the diaper longitudinal direction in consideration of the width of the displacement absorbing buffer bands 2 and 3. The cutting interval is 5 to 40 mm in the diaper width direction, preferably 10 to 20 mm.

(Diaper assembly procedure)
As shown in FIGS. 1 to 3, the absorbent main body 10, the back body sheet 20, and the front body sheet 30 are non-body-side surfaces of the absorbent body 10, the back body B side and the front body. On the front F side, the back body sheet 20 and the front body sheet 30 are bonded and integrated by a hot melt adhesive or the like.

  Moreover, the said back body sheet | seat 20 and the front body sheet | seat 30 can also be adhere | attached on the body side surface of the absorptive main body 10, as FIG. 11 shows. When configured in this manner, a pocket-like portion surrounded by the liquid-permeable surface sheet 11, the back body sheet 20, and the front body sheet 30 can be formed in the front and back portions of the absorbent main body 10. Therefore, there is an effect that leakage of excrement such as urine can be prevented.

[Other examples]
(1) In the above embodiment, the displacement absorbing buffer bands 2 and 3 are provided on the back body sheet 20 and the front body sheet 30 one by one, but the back body sheet 20 and the front body sheet A plurality of stages 30 may be provided. In this case, the displacement absorbing buffer bands 2 and 3 provided in the uppermost stages of the back body sheet 20 and the front body sheet 30 are in the above positional relationship, that is, the displacement absorbing buffer band 3 provided in the front body sheet 30 is What is necessary is just to have the positional relationship biased to the crotch side rather than the shift | offset | difference absorption buffer band 2 provided in the sheet | seat 20 for back body parts.

(2) In the above embodiment, the waist elastic portions 23, 23,... Of the back body sheet 20 are arranged over the entire width of the back body sheet 20, but as shown in FIG. In addition, in the central part where the absorbent main body 10 is joined, it is possible to cut the waist elastic elastic member 23... is there. For example, as shown in Japanese Patent Application Laid-Open No. 2000-26015 and Japanese Patent Application Laid-Open No. 2002-273808, discontinuation of the elastic elastic member is performed by arranging various elastic elastic members on the lower layer nonwoven fabric 21B, and then embossing cutter roll and anvil roll. The lower layer non-woven fabric 21B is allowed to pass between the two, and the elastic stretchable member existing within a predetermined range may be finely cut by pressing or heating with the embossing cutter roll.

(3) In the above embodiment, the absorbent main body in which the absorbent body 12 is interposed between the liquid-permeable top sheet 11 and the leak-proof sheet 19 and the back sheet 14 made of a nonwoven fabric is disposed in the outermost layer. 10 and two non-woven fabrics (upper layer non-woven fabric 21A, lower layer non-woven fabric 21B), a plurality of elastic elastic members 22 ..., 23 ... are disposed along the waist portion S1 and the waist portion S2, and the absorbent main body 10 Between the back body sheet 20 joined to the back body B side and two nonwoven fabrics (upper layer nonwoven fabric 31A, lower layer nonwoven fabric 31B), a number of elastic elastic members 32 along the waist portion S1 and the waistline portion S2,. 33 is arranged and is composed of a front body sheet 30 joined to the front body F side of the absorbent main body 10, and the back body sheet 20 and the front body sheet 30 in a product state, Joint edge at both ends The pants-type disposable diaper 1 in which a waist opening and a pair of left and right leg openings are formed by being joined together in the present invention is a type that is not divided into the rear body sheet 20 and the front body sheet 30. It is possible to apply to the same way.

Specifically, as shown in FIG. 13 , an absorbent main body 10 in which an absorbent body 12 is interposed between a liquid-permeable top sheet 11 and a leak-proof sheet 19, and an outer surface side of the absorbent main body 10. And elastic elastic members 62 along the waist part S1 and the waist part S2 on the front body F side and the back body B side between the two nonwoven fabrics (upper nonwoven fabric 61A, lower nonwoven fabric 61B). , 63... Are arranged, and the back body B and the front body F of the exterior sheet 60 are joined at the joining edge portions at both ends in the product state. In a pants-type disposable diaper having a structure in which an opening and a pair of left and right leg openings are formed, each of the rear body B and the front body F has a space between adjacent elastic stretch members adjacent to each other. The displacement absorbing buffer bands 2 and 3 set larger than the interval between the elastic stretch members are provided, and the displacement absorbing buffer band 3 provided in the front body F is replaced by the displacement absorbing buffer band 2 provided in the rear body B. Also try to bias the crotch side. In addition, the manufacturing method of the said exterior sheet | seat 60 can be manufactured by the method similar to the sheet | seat 20 for back bodies, and the sheet | seat 30 for front bodies mentioned above.

It is an external view which shows the product state of the underpants type disposable diaper 1 which concerns on this invention. It is the development view. It is an exploded view of the underpants type disposable diaper. It is IV-IV sectional drawing of FIG. It is an expanded view of the sheet | seat 20 for back body parts. It is an expanded view of the sheet | seat 30 for front body parts. It is a schematic diagram which shows the assembly point of the sheet | seat 20 for back body parts. It is a principal part top view (IIIV-IIIV arrow of FIG. 7) of FIG. It is a figure which shows the example of an application | coating procedure (A) (B) of an adhesive agent. It is an external view of the underpants type disposable diaper 1 which shows the formation method of the shift | offset | difference absorption buffer zone which concerns on another form example. It is an external view of the underpants type disposable diaper 1 which concerns on another form example. It is an expanded view of the underpants type disposable diaper 1 which concerns on the other form example. It is an exploded view of the underpants type disposable diaper which concerns on the other example of a form.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Pants type disposable diaper, 2.3 ... Shift absorption buffer zone, 10 ... Absorbent main body, 11 ... Liquid-permeable surface sheet, 12 ... Absorber, 13 ... Gathered nonwoven fabric, 14 ... Back sheet, 15 ... Thread-like elastic expansion and contraction Member: 16 ... Crepe paper, 19 ... Leakproof sheet, 20 ... Sheet for back body, 21A ... Upper layer nonwoven fabric, 21B ... Lower layer nonwoven fabric, 22 ... Waist elastic elastic member, 23 ... Girth elastic elastic member, 24 ... Joint , 29 ... leg circumference cut line, 30 ... front body sheet, 31A ... upper layer nonwoven fabric, 31B ... lower layer nonwoven fabric, 32 ... waist elastic elastic member, 33 ... waist elastic elastic member, 40 ... nip roller, 41 ... circumference Surface coating device, 43 ... Comb gun, F ... Front body, B ... Back body, S1 ... Waist part, S2 ... Trunk circumference part

Claims (8)

An absorbent main body in which an absorbent body is interposed between the liquid-permeable top sheet and the back sheet, and a plurality of elastic elastic members are disposed between the two nonwoven fabrics along the waist portion and the waistline portion, A large number of elastic elastic members are disposed along the waist portion and the waistline portion between the back body sheet joined to the back body side of the absorbent body and the two nonwoven fabrics, and the front body side of the absorbent body A front opening sheet and a pair of left and right waist openings by joining the back body sheet and the front body sheet in a product state at the joints on both side ends thereof. In a pants-type disposable diaper with a leg opening,
Each of the rear body sheet and the front body sheet is provided with a gap absorbing buffer band in which a distance between specific elastic elastic members is set to be larger than an interval between elastic elastic members in adjacent peripheral regions, and the front body The displacement absorbing buffer band provided in the front seat is biased to the crotch side relative to the displacement absorbing buffer band provided in the rear body sheet, and provided in the displacement absorbing buffer band and the back body sheet provided in the front body sheet. The gap absorption buffer band is not overlapped at all so that the gap absorption buffer band provided in the front body and the gap absorption buffer band provided in the back body have a discontinuity in the torso direction. Characteristic pants-type disposable diapers.   2. The pants-type disposable diaper according to claim 1, wherein each of the gap absorption buffer bands is provided in a flap portion where no absorber exists from a longitudinal end portion of the diaper of the absorber to a waist opening. Arrangement pitches of the elastic expansion and contraction members respectively arranged within a double length range of the width L5 of the deviation absorbing buffer band from the deviation absorbing buffer band of the back body sheet toward the waist opening side and the crotch side. The pants-type disposable diaper according to claim 1, wherein Pb has a relationship represented by the following formula (1).

The elastic stress F8 of the first elastic elastic member disposed on the waist opening side from the displacement absorbing buffer band of the back body sheet, and the elastic stress F5 of the elastic elastic member on the waist opening side after the second one. The elastic stress F7 of the first elastic elastic member disposed on the crotch side from the displacement absorbing buffer band and the elastic stress F6 of the elastic elastic member on the crotch side after the second are expressed by the following equation (2). The underpants type disposable diaper in any one of Claims 1-3.

Arrangement pitches of the elastic expansion and contraction members arranged in the double length range of the width L6 of the deviation absorbing buffer band from the deviation absorbing buffer band of the front body sheet toward the waist opening side and the crotch side. Pf is the relationship of following Formula (3), The underpants type disposable diaper in any one of Claims 1-4.

The elastic stress F3 of the first elastic elastic member disposed on the waist opening side from the displacement absorbing buffer band of the front body sheet, and the elastic stress F1 of the elastic elastic member on the waist opening side after the second one The elastic stress F4 of the first elastic elastic member disposed on the crotch side from the displacement absorbing buffer band and the elastic stress F2 of the elastic elastic member on the crotch side after the second are expressed by the following equation (4): The underpants type disposable diaper in any one of Claims 1-5.

The elastic stress F1 of the second and subsequent elastic elastic members disposed on the waist opening side from the deviation absorbing buffer band of the front body sheet, and the waist opening from the deviation absorbing buffer band of the rear body sheet Of the second and subsequent elastic elastic members disposed on the side, and the second and subsequent elastic elastic members disposed on the crotch side from the displacement absorbing buffer band of the front body sheet. The stretch stress F2 and the stretch stress F6 of the second and subsequent elastic stretch members disposed on the crotch side from the displacement absorbing buffer band of the back body sheet have the relationship of the following formula (5), and the rear Elastic stresses F7 and F8 of the first elastic elastic member disposed on both sides of the displacement absorbing buffer band of the body sheet, and the first one disposed on both sides of the displacement absorbing buffer band of the front body sheet. The elastic stresses F3 and F4 of the elastic elastic member of Pants type disposable diaper according to any one of claims 1 to 6 in.

  The underpants type disposable diaper in any one of Claims 1-7 by which the opening is provided in the nonwoven fabric of the said shift | offset | difference absorption buffer zone at predetermined intervals along the trunk periphery direction.

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