JP5779011B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as disposable diapers and sanitary napkins.

  In general, for example, spunbonded nonwoven fabrics are frequently used in absorbent articles such as disposable diapers because they are high in breaking strength, excellent in processing suitability, and economical. However, the spunbonded nonwoven fabric lacked a feeling of plumpness as a whole, and it was difficult to improve the touch. In particular, the so-called three-dimensional gathers arranged to prevent side leakage of body fluids such as urine and menstrual blood are parts that directly touch the wearer's skin, so it is desirable to improve the touch of the three-dimensional gathers while reducing costs. And there was a need.

For example, Patent Document 1 discloses a disposable diaper having a pair of three-dimensional gathers, and a flow inhibition made of a flocked fiber having a lower stool flow rate than a part of the inner surface of the three-dimensional gather. A disposable diaper with an attached member is described.
Further, Patent Document 2 discloses a disposable diaper provided with mechanical joining type fastening tape on both sides on the back side so that the fastening tape can be directly engaged with the surface of the outer back sheet when the diaper is mounted. In addition, a disposable diaper is described in which a raised treatment is applied to the fastening tape engaging region on the outer surface side of the outer back sheet.

JP 2009-136311 A WO2006 / 135011

  However, the cited documents 1 and 2 do not describe any disposable diaper with raised solid gathers. Moreover, when it is formed from the flocked fiber like the flow inhibiting member attached to the three-dimensional gather described in the cited document 1, it becomes hard due to the influence of the adhesive, and it is difficult to improve the touch and cost. It is difficult to suppress.

  Therefore, the subject of this invention is providing the absorptive article provided with the solid gathers which are good in touch, suppressing cost.

  The present invention includes a top sheet, a back sheet, and a vertically long absorber disposed between the sheets, and a pair of three-dimensional gathers are formed by arranging elastic members on both sides along the vertical direction. Each of the pair of three-dimensional gathers is formed by using a sheet that is raised from at least a part of a spunbond nonwoven fabric or a laminated nonwoven fabric of a spunbond layer and a meltblown layer. An absorbent article is provided.

  According to the absorbent article of the present invention, the three-dimensional gather is formed using a spunbonded nonwoven fabric or a sheet raised from a laminated nonwoven fabric of a spunbond layer and a meltblown layer, while suppressing costs. , The touch is improved.

Drawing 1 is a top view showing the state where the deployment type disposable diaper which is a 1st embodiment of the present invention was extended and expanded. 2 is a cross-sectional view taken along line x1-x1 of FIG. FIG. 3 is an enlarged perspective view of a main part for explaining a three-dimensional gather provided in the diaper shown in FIG. FIG. 4 is a perspective view showing an embodiment of a three-dimensional gather forming sheet for forming a three-dimensional gather provided in the diaper shown in FIG. FIG. 5 is a perspective view showing fibers in which the free end portion of the three-dimensional gather forming sheet shown in FIG. 4 is thick. FIG. 6 is a schematic view showing a suitable apparatus for producing the three-dimensional gather forming sheet shown in FIG. FIG. 7 is a schematic view showing a suitable apparatus for producing the three-dimensional gather forming sheet shown in FIG. FIG. 8 is a schematic diagram showing a method of measuring the tip fiber diameter of the three-dimensional gather forming sheet shown in FIG. FIG. 9 is a schematic view showing a method for measuring the number of fibers raised in the sheet for forming a three-dimensional gather shown in FIG. FIG. 10: is a top view which shows the state which expanded and expanded the sanitary napkin which is 2nd Embodiment of this invention. 11 is a cross-sectional view taken along line x2-x2 of FIG. Fig.12 (a) is an important section expanded sectional view explaining the solid gather of another form with which an absorptive article is provided, and Drawing 12 (b) is a key point explaining the solid gather of another form with which an absorptive article is provided. FIG.

  Hereinafter, an absorptive article of the present invention is explained based on the desirable 1st embodiment, referring to Drawings 1-5.

  The absorbent article according to the first embodiment is a disposable diaper, and the disposable diaper 1A according to the first embodiment (hereinafter also referred to as “diaper 1A”) includes a liquid-permeable top sheet 21 and a liquid-permeable surface. A back sheet 22 and a vertically long absorbent body 23 disposed between the sheets 21 and 22 are provided, and as shown in FIGS. 1 and 2, a pair is provided on both side portions 1s and 1s along the longitudinal direction (y direction). These three-dimensional gathers 3 and 3 are so-called unfolded disposable diapers formed by arranging elastic members 31. In addition, as shown in FIGS. 1 and 2, the diaper 1A has lateral sides (x direction) outward from the pair of three-dimensional gathers 3 and 3 on both sides 1s and 1s along the vertical direction (y direction). A pair of leg gathers 4, 4 is formed by arranging the elastic member 41. As shown in FIG. 1, the diaper 1A is formed symmetrically with respect to a center line CL extending in the longitudinal direction of the diaper 1A. The “y direction” shown in each figure is a direction parallel to the center line CL, and is also the same direction as the vertical direction of the diaper. The “x direction” shown in each figure is a direction orthogonal to the center line CL, and is also the same direction as the lateral direction of the diaper.

The diaper 1A will be described in detail. As shown in FIG. 1, the diaper 1A includes a topsheet 21, a backsheet 22, and an absorber 23 disposed between the sheets 21 and 22, as shown in FIG. A pair of fastening tapes 5 extending outward in the X direction from both side edges of the absorptive main body 2 divided into the ventral side A, the back side B and the crotch C, and the back side B of the absorptive main body 2 5 and the abdominal side A of the absorbent main body 2 have a target sheet 6 that engages with the fastening tape 5.
The ventral part A is a part located on the abdomen side of the wearer at the time of wearing, the dorsal part B is a part located on the dorsal side of the wearer at the time of wearing, and the crotch part C is a part of the ventral part A and the dorsal part. It is a part arranged between B.

  As shown in FIG. 1, the absorbent main body 2 has a shape that is long in the y direction and that both side edges extending in the y direction are inwardly bound in the center of the y direction, and both ends in the y direction. The width of the part is wider than the width of the central part in the y direction. As shown in FIG. 1, each of the topsheet 21 and the backsheet 22 forming the absorbent main body 2 covers the entire surface on the skin contact surface side and the non-skin contact surface side of the absorber 23, and absorbs it. It extends from the periphery of the body 23. Further, as shown in FIG. 2, the length of the top sheet 21 in the x direction is shorter than the length of the back sheet 22 in the X direction.

  Each of the pair of three-dimensional gathers 3 and 3 of the diaper 1 </ b> A is a sheet (hereinafter also referred to as a three-dimensional gather forming sheet 24) having raised at least a part of a spunbond nonwoven fabric or a laminated nonwoven fabric of a spunbond layer and a meltblown layer. Is used). Here, the “raised sheet” refers to a sheet in which the number of raised fibers is 5 / cm. The number of raised fibers is measured based on [Measured method of raised fibers] described later. As shown in FIG. 2, each of the pair of three-dimensional gathers 3 and 3 folds the three-dimensional gather forming sheet 24 into two or more layers, and has one or more stretched states in the vertical direction (y direction) between the folded sheets. An elastic member 31 is provided. More specifically, as shown in FIG. 1, the absorbent main body 2 of the diaper 1 </ b> A is provided with a three-dimensional gather forming sheet 24 via a surface sheet 21 on both side portions 1 s and 1 s along the y direction. . As shown in FIG. 1, the three-dimensional gather forming sheet 24 is disposed and fixed over the entire side portion in the y direction on the skin contact surface side of the topsheet 21. The inner end (near the center line CL) in the x direction of each three-dimensional gather forming sheet 24 is folded back to the topsheet 21 side along the fold line that forms the top of the free end side of the first three-dimensional gather 3 and overlaps two sheets. One or more elastic members 31 stretched in the vertical direction (y direction) are arranged between the two stacked sheets with an interval in the horizontal direction (x direction) between the folded sheets. The three-dimensional gather 3 is formed by fixing one or more elastic members 31 using an adhesive. In the three-dimensional gather 3 formed in this way, a portion having a predetermined width from the free end is separated from the surface sheet 21 due to the contraction of one or more elastic members 31 when worn, and laterally toward the skin side of the wearer. Stands inward (x direction) (centerline CL side). As described above, the three-dimensional gather 3 included in the diaper 1 </ b> A has one or more elastic members 31 arranged between the folded three-dimensional gather forming sheets 24, and is fixed using an adhesive. However, since the three-dimensional gather forming sheet 24 is raised, it is difficult for the wearer to feel the discomfort due to the fixation of the adhesive. The three-dimensional gather 3 may fix the one or more elastic members 31 between the folded sheets by applying a heat seal distributed in a dot shape in addition to fixing with an adhesive. Therefore, it is preferable to fix with an adhesive, particularly a hot melt adhesive.

  As shown in FIG. 1, the three-dimensional gather forming sheet 24 extends outward in the x direction on both sides 1 s and 1 s of the absorbent main body 2 of the diaper 1 </ b> A in each of the ventral side A and the back side B. The extending portion of the three-dimensional gather forming sheet 24 and the back sheet 22 are joined to form a side flap portion 25. Further, as shown in FIG. 1, on both side portions 1 s and 1 s of the absorbent main body 2, extending portions of the three-dimensional gather forming sheet 24 extending outward in the lateral direction (X direction) in the crotch portion C and A leg flap portion 26 is formed by joining the back sheet 22. An elastic member 41 for leg gather formation is disposed and fixed in the longitudinal direction (Y direction) in the crotch C at the leg flap portion 26. A gather 4 is formed.

  In the diaper 1A, as shown in FIGS. 2 and 3, the three-dimensional gather forming sheet 24 forming each three-dimensional gather 3 has raised one surface 31r opposite to the elastic member 31 and the other surface 31f on the opposite side. doing. In the diaper 1A, one or more elastic members 31 are arranged between the folded sheets of the three-dimensional gather forming sheet 24 in the three-dimensional gather forming sheet 24 forming each three-dimensional gather 3, as shown in FIG. Only the top region 3t is raised. Therefore, each three-dimensional gather 3 with which the diaper 1A is provided becomes a form which has a raising fiber in the top part corresponding to the top part 3t of the sheet | seat 24 for three-dimensional gathers formation, as shown in FIG.2, FIG.3. Thus, having raised fibers at the top portion of the three-dimensional gather 3 improves the touch, and can effectively prevent side leakage that leaks beyond the three-dimensional gather 3.

  In the diaper 1 </ b> A, the three-dimensional gather forming sheet 24 that forms each three-dimensional gather 3 is raised only in a region located in the crotch part C of the diaper 1 </ b> A. In other words, each three-dimensional gather 3 provided in the diaper 1 </ b> A is in a form having raised fibers at a portion corresponding to the crotch part C of the three-dimensional gather forming sheet 24. When the diaper 1A is worn, the crotch part C hangs down due to the weight of the diaper 1A, and a gap is likely to be formed between the wearer's skin and the top of the three-dimensional gather 3, but the region located in the crotch part C is raised. If so, the gap between the wearer's skin and the top of the three-dimensional gather 3 is reduced by the raised fibers, so that side leakage that leaks beyond the three-dimensional gather 3 can be effectively prevented. In the diaper 1A, the three-dimensional gather 3 is raised only in the region located in the crotch part C as described above, but may be raised from the abdominal side A to the back side B. Only either A or the back side B may be raised.

  The three-dimensional gather forming sheet 24 forming the three-dimensional gather 3 will be described in detail. As described above, the three-dimensional gather forming sheet 24 is based on a spunbond nonwoven fabric or a laminated nonwoven fabric of a spunbond layer and a meltblown layer. A part of the long fiber 7 constituting the spunbond nonwoven fabric or the laminated nonwoven fabric is broken, and only the one end portion 70a is fixed by the heat fusion portion 8 of the spunbond nonwoven fabric or the laminated nonwoven fabric, and the other end side is fixed. A fiber 71 having a thick free end 70b is provided. As shown in FIGS. 3 and 4, the three-dimensional gather forming sheet 24 is viewed in the orientation direction of the constituent fibers, and generally the MD direction along the fiber orientation direction is the Y direction, and the CD direction perpendicular thereto is X. Judge the direction. In the diaper 1A, the three-dimensional gather forming sheet 24 is arranged so that the Y direction (MD direction) of the three-dimensional gather forming sheet 24 matches the vertical direction (y direction) of the diaper 1A. The X direction (CD direction) of 24 is arranged to match the horizontal direction (x direction) of the diaper 1A. Therefore, in the following description in the state of the diaper 1A, the Y direction (MD direction) and the y direction mean the same direction, and the X direction (CD direction) and the x direction mean the same direction.

The three-dimensional gather forming sheet 24 will be described in detail. A spunbonded nonwoven fabric or a spunbonded layer and a meltblown in which the webs of long fibers 7 are intermittently pressed or fused with each other by the heat-sealing portion 8. It is formed based on the laminated nonwoven fabric with the layer. Hereinafter, this is also referred to as the original nonwoven fabric. The three-dimensional gather forming sheet 24 has a feeling of plumpness even in the case of a thin thickness as compared with a normal spunbonded nonwoven fabric because some of the long fibers are broken.
Here, the “long fibers” are fibers having a fiber length of 30 mm or more, and so-called continuous long fibers having a fiber length of 150 mm or more are preferable in that a nonwoven fabric having high breaking strength can be obtained.

The three-dimensional gather forming sheet 24 is preferably inexpensive and has a good feel, and the basis weight is preferably 5 to 100 g / m ² from the viewpoint of processing suitability, and 5 to 25 g / m. ² is more preferable.

  The three-dimensional gather forming sheet 24 preferably has a breaking strength value of 5 N / 50 mm or more, more preferably 8 to 30 N / 50 mm, from the viewpoint of prevention of tearing during use and processing suitability. . The value of the breaking strength of the original nonwoven fabric is preferably 7 N / 50 mm or more, and more preferably 10 to 50 N / 50 mm, from the viewpoint of achieving the breaking strength of the three-dimensional gather forming sheet 24. The value of the breaking strength of the three-dimensional gather forming sheet 24 manufactured by the raising method described later is less reduced from the value of the breaking strength of the original nonwoven fabric than other raising methods. It is preferable that the breaking strength of the three-dimensional gather forming sheet 24 and the original nonwoven fabric satisfy the above range in the X direction (CD direction). The ratio of the breaking strength between the three-dimensional gather forming sheet 24 and the original nonwoven fabric (the breaking strength of the three-dimensional gather forming sheet 24 / the breaking strength of the original nonwoven fabric) is preferably 0.5 to 1.0. More preferably, it is 7-1.0. The breaking strength is measured by the following method.

[Measurement method of breaking strength]
A rectangle with dimensions of 200 mm in the X direction (CD direction) and 50 mm in the Y direction (MD direction) from the three-dimensional gathering sheet 24 or the original non-woven fabric (for example, spunbonded non-woven fabric) in a 22 ° C. and 65% RH environment. Cut out the shape measurement piece. The cut out rectangular measurement piece is used as a measurement sample. The measurement sample is attached to a chuck of a tensile tester (for example, Tensilon tensile tester “RTA-100” manufactured by Orientec Co., Ltd.) so that the X direction is the tensile direction. The distance between chucks is 150 mm. The measurement sample is pulled at 300 mm / min, and the maximum load point until the sample breaks is defined as the breaking strength in the X direction. Further, a rectangular measurement piece having a size of 200 mm in the Y direction and 50 mm in the X direction is cut out and used as a measurement sample. This measurement sample is attached to the chuck of a tensile tester so that the Y direction is the tensile direction. The breaking strength in the Y direction is obtained by the same procedure as the method for measuring the breaking strength in the X direction described above.

The three-dimensional gather forming sheet 24 used for the diaper 1 </ b> A in this embodiment is also characterized by a good touch.
Conventionally, many characteristic values representing the touch are known, and in particular, the characteristic values in KES manufactured by Kato Tech Co., Ltd. are generally known (reference: texture evaluation standardization and analysis (second edition), author) Issued by Katsuo Kawabata, July 10, 1980). In particular, LC (linearity of compression load-compression strain curve), WC (compression work), and RC (compression resilience) of three characteristic values called compression characteristics are known to show a feeling of plumpness. These compression characteristics of 0.5~50gf / cm ² load is calculated characteristic values from deformation amount when the (sensitive measurement 0.5~10gf / cm ²⁾ applied. However, a very thin cloth such as a non-woven fabric having a small basis weight (5 to 25 g / m ² ) did not show a large difference, and the correlation with the touch was not large. Furthermore, the load when a human touches an absorbent article feels a very light load of around 1 g / cm ² , and a characteristic value in a range smaller than the conventional load is useful to express the original touch. As a result, a new characteristic value was found from the load between 0.3 gf / cm ² and 1 gf / cm ² and the amount of deformation at that time. This characteristic value is shown as a numerical value that clearly represents the difference in feel between the spunbond nonwoven fabric and the air-through nonwoven fabric, and the nonwoven fabric can be expressed as a new characteristic value that represents the feel of the spunbond nonwoven fabric.

[Compression characteristic value at minute load]
In the present specification, a compression characteristic value at a minute load is defined as a new characteristic value representing the touch under a 22 ° C. and 65% RH environment. The measurement was performed in an environment of 22 ° C. and 65% RH. KES FB3-AUTO-A (trade name) manufactured by Kato Tech Co., Ltd. was used for measurement of data that is a basis for calculating the compression characteristic value at the time of a minute load. Three solid gather forming sheets 24 are cut into 20 cm × 20 cm to prepare measurement samples. Next, one of the measurement samples is placed on the test stand with the raised surface facing upward (if not raised, or if both surfaces are raised, measure both and adopt the smaller one). Next, compression is performed between steel plates having a circular plane with an area of 2 cm ² . The compression speed is 20 μm / sec, the maximum compression load is 10 gf / cm ² , and the recovery process is also measured at the same speed. At this time, the amount of displacement between the steel plates is set to a (mm), the load is set to b (gf / cm ² ), and the position of the point where the load is detected is set to a = 0 and measured in the compression direction. The value of a increases as it is compressed.

The compression characteristic value at the minute load is calculated by extracting the deformation amount of the thickness at the minute load from the measured data (a, b). Specifically, the first load which is not a recovery process, the load between 0.30 gf / cm ² and 1.00 gf / cm ² and the deformation data at that time are extracted, and the relationship between a and b is approximated. A straight line is obtained by the least square method, and the slope at that time is defined as the characteristic value (unit (gf / cm ² ) / mm). Three points are measured with one measurement sample. A total of 9 points of 3 samples are measured. The characteristic values at each of the nine locations are calculated, and the average value is set as the compression characteristic value when the nonwoven fabric is subjected to a minute load.

It was found that the compression characteristic value at the time of a minute load has a correlation with the touch, and in particular, when the original nonwoven fabric is the same, there is a strong correlation. The compression characteristic value (at the time of a minute load) indicates that the lower the numerical value, the easier it is to be crushed with a small load, and the better the feeling of feeling the human touch (particularly plumpness). For example, the compression characteristic value of an original spunbonded nonwoven fabric having a normal basis weight of 5 to 25 g / m ² that has not been processed as described later is 20.0 (gf / cm ² ) / mm to 30.0 (gf / Cm ² ) / mm, the non-woven fabric 1 obtained by subjecting the spunbonded nonwoven fabric to processing described later tends to be crushed and becomes 18.0 gf / cm ² ) / mm or less. That is, from the viewpoint of the touch, the compression characteristic value of the nonwoven fabric 1 obtained by processing the original spunbonded nonwoven fabric of 5 to 25 g / m ² is 18.0 (gf / cm ² ) / mm or less, and 15. It is preferably 0 (gf / cm ² ) / mm or less, and more preferably 10.0 (gf / cm ² ) / mm or less from the viewpoint of providing a touch close to an air-through nonwoven fabric with a good touch. The lower limit of the compression characteristic value of the nonwoven fabric 1 obtained by processing the original spunbond nonwoven fabric having a basis weight of 5 to 25 g / m ² is not particularly limited, but from the viewpoint of production, 1.00 (gf / cm ² ) / Mm. In the conventional processing such as raising method, the original spunbond nonwoven fabric having a low basis weight of 5 to 25 g / m ² is processed so as to have such a characteristic value without significantly reducing the breaking strength. It was difficult to apply.

  The long fibers 7 constituting the three-dimensional gather forming sheet 24 (original fibers of the non-woven fabric) mainly contain a thermoplastic resin, and the thermoplastic resins include polyolefin resins, polyester resins, polyamide resins, and acrylonitrile resins. , Vinyl resins, vinylidene resins and the like. Examples of the polyolefin resin include polyethylene, polypropylene, and polybuden. Examples of the polyester resin include polyethylene terephthalate and polybutylene terephthalate. Nylon etc. are mentioned as a polyamide-type resin. Examples of the vinyl resin include polyvinyl chloride. Examples of the vinylidene resin include polyvinylidene chloride. One of these various resins can be used alone or in admixture of two or more, and modified products of these various resins can also be used. The long fiber 7 may be a fiber provided with a small amount of additives such as a fiber colorant, an antistatic property agent, a lubricant, and a hydrophilic agent. The fiber diameter of the long fibers 7 is preferably 5 to 30 μm and more preferably 10 to 20 μm before processing to be described later.

  The original nonwoven fabric for forming the three-dimensional gather forming sheet 24 is preferably formed from a polypropylene resin which is a polyolefin resin from the viewpoint of spinnability. As the polypropylene resin, from the viewpoint of smoothness and further improved touch and ease of breakage, at least one of random copolymer, homopolymer and block copolymer is 5 to 100% by weight, more preferably 25% by weight to A resin containing 80% by weight is preferred. Further, these copolymers and homopolymers may be mixed, or other resins may be mixed. However, it is difficult to break the yarn during molding, and mixing of polypropylene homopolymer and random copolymer is preferable. As a result, the raised fiber itself becomes soft and soft to the touch by reducing the crystallinity of the fiber, and it is possible to achieve both the strength of the nonwoven fabric and the raised fiber is easily cut at the fusion part such as embossing. Peeling at joints such as dots is eliminated, napped fibers are shortened, hairballs are difficult to form, and a good appearance is obtained. In addition, since the melting point distribution is widened, the sealing property is improved. Further, a copolymer copolymerized with ethylene or α-olefin as a random copolymer based on a propylene component is preferred, and an ethylene-propylene copolymer resin is particularly preferred. From the same viewpoint, the polypropylene resin is preferably a resin containing 5% by weight or more of an ethylene propylene copolymer resin, and more preferably a resin containing 25% by weight or more. The ethylene-propylene copolymer resin preferably contains an ethylene concentration of 1 to 20% by weight, particularly has no stickiness, is easy to stretch when stretched, has little fluff loss, and maintains breaking strength. And, it is more preferable that the ethylene concentration is 3 to 8%. The polypropylene resin is preferably a resin containing 25% by weight or more of recycled polypropylene resin, and more preferably a resin containing 50% by weight or more from the viewpoint of the environment. The same applies to the case where the three-dimensional gather forming sheet 24 is formed on the basis of a laminated nonwoven fabric of a spunbond layer and a meltblown layer.

From the viewpoint of touch and suitability for processing, the area of each heat-sealed portion 8 is preferably 0.05 to 10 mm ² , and preferably 0.1 to ¹ mm ^2. Further preferred. The number of heat-sealed portion 8 is preferably 10 to 250 pieces / cm ^2, more preferably 35 to 65 pieces / cm ^2. The distance between the centers of the heat fusion parts 8 adjacent in the X direction is preferably 0.5 to 10 mm, more preferably 1 to 3 mm, and the heat fusion parts 8 adjacent in the Y direction. The distance between the centers is preferably 0.5 to 10 mm, and more preferably 1 to 3 mm.

  The heat fusion part 8 was intermittently formed by thermocompression bonding by embossing (by using an embossed convex roll and a flat roll, etc.), by ultrasonic fusion, or intermittently hot-aired and partially fused. Things. Among these, the thermocompression bonding is preferable in that the fiber is easily broken. The shape of the heat fusion part 8 is not particularly limited, and may be any shape such as a circle, a rhombus, and a triangle. The ratio of the total area of the heat fusion part 8 to the surface area of the one surface of the three-dimensional gather forming sheet 24 is preferably 5 to 30%, and 10 to 20% in that it is difficult to produce pills. Further preferred.

  The three-dimensional gather forming sheet 24 of the diaper 1A is formed based on, for example, a spunbonded nonwoven fabric made of long fibers 7, a part of the long fibers 7 is broken, and only one end portion 70a is the heat-sealed portion 8. The fiber 70 fixed by the above is formed, and the fiber 70 includes a fiber 71 having a thick free end 70b. It is preferable that the tip is thick, and that the cross section at the tip is flat (ellipse or crushed shape). Thereby, the raised fiber of a soft tip is obtained and the nonwoven fabric with little irritation | stimulation to skin is obtained. As shown in FIG. 4, in the fiber 70 in which only one end portion 70a is fixed by the heat-sealing portion 8, the fiber 71 in which the free end portion 70b on the other end side is thick and the free end portion 70b are thick. It consists of fibers 72 that are not. Here, the “free end portion” means the “other end portion” of the fiber 70 in which only one end portion 70 a is fixed by the heat-sealing portion 8, in other words, the “tip end portion”. Whether or not the free end portion 70b is thick is determined by measuring the fiber diameter according to the following measurement method and calculating the increasing rate of the tip fiber diameter.

[Measurement method of fiber diameter]
First, in a 22 ° C. and 65% RH environment, as shown in FIG. 8 (a), from the three-dimensional gather forming sheet 24 to be measured, the size is 2 cm in the X direction and 2 cm in the Y direction with a sharp razor. As shown in FIG. 8 (c), a measurement sample is cut out and mountain-folded at a fold line Z extending in the X direction passing through the plurality of heat-sealing portions 8 as shown in FIG. 8 (b). Then, it is placed and fixed on an aluminum sample stage for a scanning electron microscope (SEM) on which a carbon tape is placed. Next, from the SEM image magnified approximately 750 times, ten fibers 70 in which only one end portion 70a is fixed by the heat-sealing portion 8 are selected at random, and a photograph is taken near the tip of the free end portion of these fibers. To do. From the obtained photograph (see FIG. 5), the fiber diameter of the fiber 70 at a position 120 μm away from the tip of the free end portion 70b (the diameter 71a of the fiber 70 at a portion excluding the free end portion 70b) is measured. The inclination at the time of measurement of the diameter 71a of the fiber 70 in a portion excluding the free end portion 70b is translated as it is to the free end portion 70b side, and is sandwiched between the tip of the free end portion 70b and a position 20 μm away from the tip. The fiber diameter of the fiber 71 (the diameter 71b of the fiber 71 at the free end 70b) at the thickest position in the region is measured. When the tip is flat, the tip may not appear thick depending on the observation angle, but even in that case, the obtained photograph is measured as it is.

The fiber 71 having a thick free end portion 70b means that the fiber 70 at the free end portion 70b measured from each of the ten fibers 70 in the randomly selected ten fibers 70. From the diameter 71b and the diameter 71a of the fiber 70 at a portion excluding the free end portion 70b, the fiber satisfies the requirement that the value of the increase rate of the tip fiber diameter obtained by the following formula (1) is 15% or more. This means that the fiber cutting between the heat-sealed parts 8 (the fiber form part excluding the boundary between the heat-fused part 8 and the fiber) is suppressed, the decrease in breaking strength is suppressed, and the touch From the viewpoint of obtaining a good product, it is preferably 20% or more, more preferably 25% or more.
Increase rate of tip fiber diameter (%) = [(21b-21a) ÷ 21a) × 100] (1)

In the three-dimensional gather forming sheet 24, from the viewpoint of the balance between the touch and the breaking strength, the fiber 70 in which only one end portion 70a is fixed by the heat fusion portion 8 (the fiber 71 having a thick free end portion 70b and the free fiber 70). The ratio of the fibers 71 whose free end portions 70b are thick in the fibers 72) whose end portions 70b are not thick is preferably 20% or more, more preferably 30% or more, and 40% or more. It is particularly preferred that The ratio of the fiber 71 whose free end portion 70b is thick is the ratio of the increase in the tip fiber diameter from the SEM image obtained by enlarging the randomly selected ten fibers 70 by about 750 times in the fiber diameter measurement method described above. Each is calculated, and the ratio of the fibers 71 whose free end portion 70b is thick is calculated.
Further, the three-dimensional gather forming sheet 24 includes fibers cut at the peripheral portion of the heat-sealing portion 8. The heat fusion part 8 of the sheet | seat 24 for forming a three-dimensional gather is selected at random, and the peripheral part of the heat fusion part 8 (the range within 100 μm from the boundary between the heat fusion part 8 and the long fiber 7 to the outside and the inside, total 10 mm. ² minutes) is observed with an electron microscope. This fiber is cut when the traces of the fiber cut (the shape in which the fiber in the embossed part is crushed and the part in which the fiber shape is not crushed and is not continuous) are counted. When the number of traces is large, only the very surface is raised, and it is preferable that the nonwoven fabric is cut at three or more points in view of obtaining a nonwoven fabric with high breaking strength for the amount of raising, and more preferably 5 It is preferable that the nonwoven fabric is cut at 15 to 15 locations.

  As shown in FIG. 4, the three-dimensional gather forming sheet 24 has loop-shaped fibers 73 that stand in a loop shape between the heat-sealing portions 8 and 8. The standing “loop-like fiber 73” means that when the fiber diameter measurement method described above is observed as shown in FIG. 8C, the other end portion does not have the free end portion 70b, and the folded line It means a fiber standing up from Z by 0.5 mm or more. In the present embodiment, the loop-shaped fiber 73 refers to the standing loop-shaped fiber. The fibers constituting the three-dimensional gather forming sheet 24 are composed of the fibers 71 whose free end portions 70b are thick and the fibers 72 whose free end portions 70b are not thick, and only one end portion 70a is fixed by the heat fusion portion 8. In addition to the fibers 70, the fibers 70 and the loop-shaped fibers 73 that stand in a loop shape between the heat-sealing portions 8 and 8 are included. From the viewpoint that the three-dimensional gather forming sheet 24 is not caught on the skin, the discomfort is reduced and the touch is improved, only one end portion 70a of the fibers constituting the three-dimensional gather forming sheet 24 is the heat-sealed portion 8. The ratio of the loop-like fibers 73 to the total number of the fibers 70 and the loop-like fibers 73 fixed by the above is preferably less than 50%, more preferably 45% or less, and 40% or less. Is particularly preferred. The ratio of the loop-shaped fibers 73 is determined by selecting 10 fibers randomly from the SEM image enlarged approximately 50 times in the above-described fiber diameter measurement method, and only one end portion 70a from the 10 fibers randomly selected. Are extracted by a fiber 70 (fiber 71 having a thick free end 70b and fiber 72 having a free free end 70b) and a loop-shaped fiber 73, which are fixed by the heat-sealed portion 8. 71, the ratio of the fibers 73 (loop fibers) in the total number of the fibers 72 and 73 is calculated. In addition, a measured value calculates | requires a ratio similarly from 9 SEM images of another site | part, and calculates it by those 10-point average. In addition, when one loop-shaped fiber 73 is contained in ten fibers selected at random, the loop-shaped fiber 73 is counted as one.

  In the three-dimensional gather forming sheet 24, the gap between the fibers is filled by including the fibers having a relatively high degree of freedom, and the surface roughness is small and smooth. From the viewpoint of improving the touch, the fiber diameter distribution (dispersion degree) is preferably as wide as possible. However, from the viewpoint of the touch, if it is 0.33 or more, a sufficiently satisfactory effect is obtained. If it is 35 or more, a more satisfactory effect can be obtained. The fiber diameter distribution (dispersion degree) is not particularly limited, but is preferably 100 or less. More preferably, the fiber diameter distribution (dispersion degree) is preferably 0.33 to 0.9. The fiber diameter distribution (dispersion degree) here means the fiber diameter distribution (dispersion degree) of all the fibers constituting the three-dimensional gather forming sheet 24, and only one end portion 70 a is formed by the heat fusion part 8. The fixed fiber 70, the loop-shaped fiber 73, and both ends are fixed by the heat-sealing portion 8, and the entire fiber that is not raised in a loop shape (fiber that is not affected by the processing process described later) Distribution. The fiber diameter distribution (dispersion degree) is measured by the following method.

Fiber diameter measurement method [Fiber diameter distribution (dispersion degree) measurement method]
First, in a 22 ° C. and 65% RH environment, a measuring piece having a size of 2 cm in the X direction and 2 cm in the Y direction is cut out from the three-dimensional gather forming sheet 24 to be measured with a sharp razor, and a carbon tape is placed thereon. The sample is placed on the aluminum sample stage for scanning electron microscope (SEM) without being bent and fixed. Next, from the SEM image magnified approximately 750 times, ten fibers are randomly extracted, and each fiber diameter is measured at a portion excluding the free end portion 70b (note that the three-dimensional gather forming sheet 24 to be measured is When the spunbond layer and the meltblown layer are formed on the basis of a laminated nonwoven fabric, the fiber of the meltblown layer is not selected, and only the fiber of the spunbond layer is selected. Ten fiber diameters are measured on one aluminum sample stage as described above, the average value d _ave is determined from the measured _ten fiber diameters d ₁ to d 10, and the obtained ten fiber diameters are obtained. From the d _{1 to} d ₁₀ and the average value d _ave , the fiber diameter distribution of 10 randomly selected fibers is obtained by the following equation (2). The measurement unit is μm, and measurement is performed with a resolution of 0.1 μm. For the distribution of the fiber diameter of 10 fibers, for each one-dimensional gather forming sheet 24, the above-mentioned aluminum sample stage was prepared at 6 locations, and the average value of the fiber diameter distribution of 10 fibers obtained at each location. (Refer to the following formula (3)) is the fiber diameter distribution in the sheet 24 for forming a three-dimensional gather. In addition, the VARPA function in spreadsheet software excel2003 of Microsoft Corporation is used for calculation of the fiber diameter distribution of 10 fibers.
Fiber diameter distribution of 10 fibers = [(d ₁ −d _ave ) ² + (d ₂ −d _ave ) ² +... (D ₁₀ −d _ave ) ² )] / 10 (2)
Fiber diameter distribution (dispersion degree) in the three-dimensional gather forming sheet 24 = (sum of fiber diameter distributions of ten fibers obtained by the above formula (2)) / 6 (3)

  The three-dimensional gather forming sheet 24 is preferably 8 fibers / cm or more, and more preferably 12 fibers / cm or more, from the viewpoint of improving the touch. Further, from the viewpoint of obtaining sufficient breaking strength, the upper limit is preferably 100 / cm or less, more preferably 40 / cm or less from the viewpoint that the appearance is not fuzzy. The raised fiber is measured by the following measuring method.

[Measurement method of raised fibers]
FIG. 9 is a schematic view showing a method for measuring the number of fibers raised among fibers constituting the three-dimensional gathering sheet 24 under a 22 ° C. and 65% RH environment. First, a 20 cm × 20 cm measurement piece is cut out from the nonwoven fabric to be measured with a sharp razor, and as shown in FIG. 9A, the measurement sample 104 is formed by folding the measurement piece on the raised surface. . Next, this measurement sample 104 is placed on an A4 size black mount, and as shown in FIG. 9 (b), an A4 size black mount in which holes 107 of 1 cm in length and 1 cm in width are further formed. Put on. At this time, as shown in FIG. 9B, the fold 105 of the measurement sample 104 is arranged so that it can be seen from the hole 107 of the upper black mount. For both mounts, “Kenran (black) continuous weight 265 g” of Fuji Kyowa Paper Co., Ltd. was used. Thereafter, a weight of 50 g is placed on each side of the upper mount hole 107 at a position spaced 5 cm outward along the fold line 105 so that the measurement sample 104 is completely folded. Next, as shown in FIG. 9 (c), the inside of the mount 107 is observed at a magnification of 30 times using a microscope (VHX-900 manufactured by KEYENCE), and the measurement sample 104 has a fold 105 to 0. Measure the number of fibers per 1 cm above the imaginary line 108 formed at the position translated by 2 mm above. Nine points are measured, and the average value (rounded to the second decimal place) is taken as the number of raised fibers.

  Further, when counting the number of raised fibers, for example, there is a fiber that crosses the virtual line 108 that is 0.2 mm above the fold 105 twice, such as a fiber 106a shown in FIG. 9C. The fiber counts as two. Specifically, in the example shown in FIG. 9C, there are four fibers that cross the virtual line 108 once and one fiber 106a that crosses the virtual line 108 twice, but there are 2 fibers 106a that cross the virtual line 108 twice. Counted as a book, the number of raised fibers is 6.

  From the viewpoint of improving the touch, the three-dimensional gather forming sheet 24 has an average fiber diameter of the raised fibers (fibers crossing the imaginary line 108), and the surface fibers (the imaginary lines 108 crossing the imaginary line 108) of the non-raised portion of the same surface. The average fiber diameter of the fibers not reaching the imaginary line 108) is preferable. The average fiber diameter refers to a fiber diameter obtained by measuring the fiber diameters of 12 raised fibers and 12 non-raised fibers with a microscope (such as an optical microscope or SEM). The fiber diameter of the raised fiber is preferably 97% to 40% of the non-raised fiber, and more preferably 90% to 40% because it is excellent in the touch.

  In addition, the three-dimensional gather forming sheet 24 is less likely to become pills, hard to come off, looks soft on the appearance, and the height of the raised fibers is 1.5 mm or less. Preferably, it is 0.8 mm or less. From the above viewpoint, the lower the better, the better. However, if it is 0.2 mm or more, a sufficiently satisfactory touch can be obtained. In addition to the above, more preferably, the height of the raised fiber is 1.5 mm or less, and the raised fiber is preferably 8 fibers / cm or more for coexistence with the breaking strength. . Further, the height of the raised fibers is 0.5 mm or less and the number of raised fibers is 15 fibers / cm or more, because it is difficult to cling to the skin and the touch is preferable. Here, unlike the fiber length, the fiber height means the fiber height in a natural state without pulling the fiber during measurement. When the value of the length of the raised fiber is large or the rigidity of the fiber is high, the height of the raised fiber tends to increase. The height of the raised fiber is measured by the following measurement method.

  The height of the raised fibers is measured simultaneously when the number of raised fibers is measured. Specifically, as shown in FIG. 9C, the inside of the hole 107 of the mount is observed, and a line is drawn in parallel from the fold 105 to a point where the raised fibers do not intersect every 0.05 mm. Next, compared to the number of raised fibers measured as described above (determined from the imaginary line 108 above 0.2 mm), select a parallel line that halves the fibers that intersect the parallel line, and from there The distance to the crease is the raised height. Three sheets are measured for the nonwoven fabric for measuring the above operation, and an average of nine places in three places and three pieces per piece is taken as the height of the raised fiber.

  It is preferable that the height of the raised fibers and the bulk softness of the three-dimensional gather forming sheet 24 in addition to the raised fibers is 8.0 cN or less from the viewpoint of obtaining a flexible product and excellent touch. . Furthermore, it is preferable that it is 0.5-3.0 cN at the point which becomes a supple thing like a baby's or infant's vestibule. Bulk softness is measured by the following measurement method.

[Measurement method of bulk softness]
For the bulk softness of the three-dimensional gather forming sheet 24, the three-dimensional gather forming sheet 24 is cut out 150 mm in the MD direction and 30 mm in the CD direction, and the end is stopped at two upper and lower positions using a stapler in a 45 mm diameter ring shape. At this time, the stapler core is elongated in the MD direction. Using a tensile tester (for example, Tensilon tensile tester “RTA-100” manufactured by Orientec Co., Ltd.), the ring is placed in a cylindrical shape on the sample stage, and the compression speed is 10 mm on a flat plate substantially parallel to the stage from above. Measure the maximum load when compressing at a speed of / min. Next, a ring is produced by changing the MD direction and the CD direction, and the bulk softness in the MD direction is similarly measured. Two rings are produced and measured in each of the MD direction and the CD direction, and the average value of the CD direction and the MD direction is defined as the bulk skewness of the three-dimensional gather forming sheet 24.

If the softener is kneaded or applied to the original nonwoven fabric for forming the three-dimensional gather forming sheet 24, the effect of the present invention is more effective. As the softening agent, for example, a wax emulsion, a reactive softening agent, a silicone type, a surfactant or the like can be used. In particular, amino group-containing silicones, oxyalkylene group-containing silicones, and surfactants are preferably used. As surfactants, carboxylate anionic surfactants, sulfonate anionic surfactants, sulfate ester anionic surfactants, phosphate ester anionic surfactants (especially alkyl phosphates). Acid ester salts) and the like; polyhydric alcohol monofatty acid esters such as sorbitan fatty acid ester, diethylene glycol monostearate, diethylene glycol monooleate, glyceryl monostearate, glyceryl monooleate, propylene glycol monostearate, N- (3-oleyloxy-2-hydroxypropyl) diethanolamine, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbit beeswax, polyoxyethylene sorbitan sesquistearate, polyoxyethylene monooleate Such as polyoxyethylene sorbitan sesquistearate, polyoxyethylene glyceryl monooleate, polyoxyethylene monostearate, polyoxyethylene monolaurate, polyoxyethylene monooleate, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, Nonionic surfactants: Cationic surfactants such as quaternary ammonium salts, amine salts or amines; aliphatic derivatives of secondary or tertiary amines containing carboxy, sulfonate, sulfate, or heterocyclic Zwitterionic surfactants such as aliphatic derivatives of secondary or tertiary amines can be used. Moreover, a well-known chemical | medical agent can be added to the softening agent of this invention as a secondary additive (small component) as needed.
By including the softening agent, the touch is good, the fluff is less, the skin friction on the surface is low, the breaking strength is high, and the effect is particularly high in the present invention.
The softening agent is preferably used in combination with the random copolymer described in paragraph [0028] in that the effect is further increased, and the softening agent reduces the slime feeling caused by the random copolymer in the raised fiber. It is particularly preferable in that it can be obtained and a smooth skin can be obtained.

  Further, the three-dimensional gather forming sheet 24 is formed based on a laminated nonwoven fabric of a spunbond layer and a meltblown layer, which will be described later, and the spunbond layer of the laminated nonwoven fabric is composed of a plurality of layers. -When using a meltblown-spunbond laminated nonwoven fabric, a spunbond-spunbond-meltblown-spunbond laminated nonwoven fabric, etc., it is preferable to knead the softener only in one spunbond layer, It may be kneaded into a layer. When a softening agent is kneaded into a single layer of spunbond, if the layer side is subjected to the processing described below and the fibers have thickened free ends, the feel is good and the breaking strength is also good. It is preferable at a high point. As described above, the sheet 24 for forming a three-dimensional gather is based on a laminated nonwoven fabric of a spunbond layer and a meltblown layer rather than forming a spunbond nonwoven fabric alone because it is easy to adjust the touch and breaking strength. It is more preferable to form it.

  Next, the suitable manufacturing method of the sheet | seat 24 for three-dimensional gather formation used for 1 A of diapers is demonstrated, referring FIG. 6, FIG. Manufacturing apparatuses that are preferably used in the method for manufacturing the three-dimensional gather forming sheet 24 are roughly classified into a pre-processing unit 200 and a raised processing unit 300 disposed on the downstream side of the pre-processing unit 200.

  As shown in FIG. 6, the pre-processing unit 200 includes a steel matching embossing roller 230 including a pair of rolls 210 and 220 each having a convex portion 211 and a concave portion 221 that mesh with each other. As shown in FIG. 6, in the steel matching embossing roller 230, a plurality of convex portions 211 provided on the peripheral surface of the roll 210 and a plurality of concave portions 221 provided on the peripheral surface of the roll 220 are engaged with each other. The plurality of convex portions 211 are uniformly and regularly arranged in the rotation axis direction and the circumferential direction of the roll 210. The pair of rolls 210 and 220 are engaged with each other and rotated when a driving force from a driving means (not shown) is transmitted to one of the rotating shafts. Moreover, the pre-processing part 200 is provided with the conveyance rolls 250 and 260 which convey the raw material sheet 240 in the upstream and downstream of the steel matching embossing roller 230, for example, as shown in FIG.

Each protrusion 211 of the roll 210 preferably has a height from the peripheral surface of the roll 210 to the apex of the protrusion 211 of 1 to 10 mm, and more preferably 2 to 7 mm. The distance (pitch) between the convex portions 211 adjacent in the rotation axis direction is preferably 0.01 to 20 mm, more preferably 1 to 10 mm, and the distance between the convex portions 211 adjacent in the circumferential direction ( The pitch) is preferably 0.01 to 20 mm, and more preferably 1 to 10 mm. There is no restriction | limiting in particular in the shape of the top surface of each convex part 211 of the roll 210, For example, circular, a polygon, an ellipse etc. are used, The area of the top surface of each convex part 211 is 0.01-500 mm < ² >. It is preferable that it is 0.1 to 10 mm ² . Each concave portion 221 of the roll 220 is disposed at a position corresponding to each convex portion 211 of the roll 210. The depth of engagement between each convex portion 211 of the roll 210 and each concave portion 221 of the roll 220 (the length of the portion where each convex portion 211 and each concave portion 221 overlap) is 0.1 to 10 mm. Preferably, it is 1-5 mm.

  As illustrated in FIG. 7, the raised processing unit 300 includes a convex roll 310 having a convex portion 311 provided on the peripheral surface, and a conveying roll 320 that conveys the raw material sheet 240 to the upstream side and the downstream side of the convex roll 310, 330 is provided. The convex roll 310 rotates when a driving force from a driving means (not shown) is transmitted to its rotating shaft.

Each convex portion 311 of the convex roll 310 preferably has a height from the peripheral surface of the convex roll 310 to the apex of the convex portion 311 of 0.001 to 3 mm, and preferably 0.001 to 0.1 mm. Further preferred. The distance (pitch) between the protrusions 311 adjacent to each other in the rotation axis direction is preferably 0.1 to 50 mm, more preferably 0.1 to 3 mm, and the distance between the protrusions 311 adjacent to each other in the circumferential direction. The distance (pitch) is preferably 0.1 to 50 mm, and more preferably 0.1 to 3 mm. There is no restriction | limiting in particular in the shape of the top surface of each convex part 311 of the convex roll 310, For example, circular, a polygon, an ellipse etc. are used, and the area of the top surface of each convex part 311 is 0.001-20 mm < ² >. It is preferable that it is 0.01-1 mm < ² >.

  In the manufacturing apparatus including the pre-processed portion 200 and the raised processing portion 300 having such a configuration, first, for example, a strip-shaped spunbond nonwoven fabric (raw material sheet 240), which is a raw material of the three-dimensional gather forming sheet 24, is rolled (non-coated). The raw material sheet 240 is unwound from the illustrated roll and conveyed between the pair of rolls 210 and 220 of the steel matching embossing roller 230 by the conveying rolls 250 and 260. In the pre-processing part 200, as shown in FIG. 6, the raw material sheet 240 is pinched between a pair of rolls 210 and 220, and the raw material sheet 240 is damaged. The pair of rolls 210 and 220 of the steel matching embossing roller 230 does not actively heat or constitute the raw material sheet 240 from the viewpoint of not causing heat fusion between the constituent fibers of the spunbond nonwoven fabric when giving damage. The steel match embossing is preferably performed at a temperature equal to or lower than the melting point of the component having the lowest melting point among the components of the fibers to be processed, particularly at a temperature lower by 70 ° C. or more than the melting point.

  Next, the damaged raw material sheet 240 ′ is conveyed by the conveying rolls 320 and 330 to the convex roll 310 having the convex portion 311 provided on the peripheral surface. In the raised processing part 300, the surface of the damaged raw material sheet 240 ′ is processed by the convex roll 310, and a part of the long fibers 7 constituting the spunbonded nonwoven fabric is broken, and only one end part 70a is spunbonded. A three-dimensional gather forming sheet 24 having fibers 70 fixed by the non-woven heat fusion part 8 is formed (see FIG. 4). From the viewpoint of breaking a part of the long fiber 7 and efficiently forming the fiber 70 shown in FIG. 4, it is preferable to rotate the rotation direction of the convex roll 310 in the direction opposite to the conveying direction of the raw material sheet 240 ′. The convex roll 310 is preferably rotated at a speed of 0.3 to 10 times the conveying speed of the raw material sheet 240 ′. Moreover, when rotating in the circumferential direction (forward direction with respect to the conveyance direction), it is preferable to rotate the convex roll 310 at a speed of 1.5 to 20 times. Here, the speed of the convex roll 310 means the peripheral speed on the peripheral surface of the convex roll 310.

  From the viewpoint of breaking a part of the long fiber 7 more efficiently and forming the fiber 70 shown in FIG. 4 more efficiently, the position of the transport roll 330 is set higher than the convex roll 310 as shown in FIG. Is preferably in contact with the contact surface of the convex roll 310 at a holding angle α of 10 to 180 °, and is in contact with a holding angle α of 30 to 120 °, Since the width reduction by the neck-in of a nonwoven fabric is suppressed, it is still more preferable.

  In addition, when forming the fiber 70 in which only the one end portion 70 a is fixed by the heat-sealing portion 8 on both surfaces of the three-dimensional gather forming sheet 24, it is different from the surface of the raw material sheet 240 ′ processed by the convex roll 310. It can be obtained by processing the front surface (back surface) with another convex roll 310.

  The present inventor stretches the spunbond nonwoven fabric (raw material sheet 240) with the steel matching embossing roller 230, forms a weakening point in the heat-sealed portion 8 of the spunbond nonwoven fabric (raw material sheet 240), and then uses the convex roll 310. It is presumed that the long fiber 7 is broken from the weakening point of the very surface of the non-woven heat-sealed portion 8 and a fiber cut from the heat-fused portion 8 is formed. The inventor presumes that the fiber cut from the heat-sealed portion 8 is a fiber 71 having a thick free end portion 70b. Further, the inventor uses the convex roll 310 to peel the long fibers 7 from the weakening point of the heat-sealing portion 8, and the fibers peeled from the heat-sealing portion 8 are between the heat-sealing portions 8, 8. It is presumed that a loop-like fiber 73 standing in the form of a loop is formed. Moreover, when this inventor processes the surface with the convex roll 310, the long fiber 7 is fractured | ruptured between the heat-fusion parts 8 and 8, and the fiber 72 with which the free end part 70b is not thick is formed. I guess. The nonwoven fabric manufactured by the suitable manufacturing method of the sheet | seat 24 for three-dimensional gathers mentioned above has few ratios of the loop-shaped fiber 73 and the fiber 72 which is not thick compared with the nonwoven fabric manufactured by the conventional raising method. Is a feature. When there are many fibers 72 that are not thick like a nonwoven fabric produced by a conventional raising method, the fibers are broken between the heat-sealed portions 8 such as between the embossed portions and the embossed portions, and the heat-fused portions 8 So-called breaks (fissures, holes) can be made between them. As a result, the base fibers that are not raised can be raised without damaging them, and a high breaking strength can be obtained. On the other hand, if you try to raise the hair without a weakening point, the fiber will be hard to brush unless you rub the fiber surface with a stronger force, and even the base fibers other than the non-raised surface will be damaged at the time of raising. Therefore, the whole nonwoven fabric is easily broken and the breaking strength is not easily maintained. On the other hand, since the nonwoven fabric manufactured by the suitable manufacturing method of the sheet | seat 24 for three-dimensional gather formation of this invention mentioned above has few ratios of the fiber 72 which is not thick, it can hold | maintain breaking strength. Furthermore, a nonwoven fabric with high punch-through strength is thereby obtained. Moreover, when raising in the state in which the weakening point is not formed, fiber peeling from the heat-sealed portion occurs, and the number of raised fibers tends to decrease and the raised height tends to increase. For this reason, problems such as being prone to fluff tend to occur.

The three-dimensional gather forming sheet 24 used in the diaper 1A corresponds to a predetermined portion, for example, a crotch part C of a diaper, on a raw material sheet 240 made of a spunbond nonwoven fabric or a laminated nonwoven fabric of a spunbond layer and a meltblown layer. The position, the region corresponding to the top region of the three-dimensional gather 3, and the like are formed by processing using the apparatus having the pre-processing unit 200 and the raised processing unit 300 described above.
The diaper 1A manufactures a strip-shaped member of the three-dimensional gather 3 in which one or more elastic members 31 extending in the transport direction are arranged in the folded region of the three-dimensional gather forming sheet 24 formed in this way. In this process, it can be manufactured in the same manner as in the conventional manufacturing method of a so-called longitudinal flow type deployment type disposable diaper. Specifically, the absorbent main body 2 including a continuous body of the top sheet 21, a continuous body of the back sheet 22, and a plurality of absorbent bodies 23, 23,. After the one or more elastic members 41 extending in the transport direction are arranged on each of the continuum of the absorbent body 2 along the both sides of the transport body in the transport direction, the above-described three-dimensional gather forming belt-like shape is manufactured in advance. A pair of fastening tapes 5 and 5 are arranged for each absorbent body 23 included in the continuous body of the absorbent main body 2 so as to protrude members in the width direction of the continuous body of the absorbent main body 2. The diaper 1A can be continuously manufactured by manufacturing a continuous body and cutting the continuous body. Regarding the manufacturing method of the diaper 1A, points that are not particularly described can be manufactured in the same manner as in the conventional manufacturing method of the deployable disposable diaper of the longitudinal flow method.

The material for forming the diaper 1A of the present embodiment will be described.
As the surface sheet 21, the back sheet 22, and the absorbent body 23 constituting the absorbent main body 2, any one can be used without particular limitation as long as it is usually used for absorbent articles such as disposable diapers. For example, a hydrophilic and liquid-permeable non-woven fabric can be used as the top sheet 21, and a liquid-impermeable or water-repellent resin film or a laminate of a resin film and a non-woven fabric is used as the back sheet 22. As the absorbent body 23, an aggregate of fibers such as pulp fibers (which may be a nonwoven fabric) or an absorbent core formed by holding particles of a water-absorbing polymer in the fiber core is used. The thing coated with the core wrap sheet which consists of can be used. As the elastic member 31 for forming a three-dimensional gather and the elastic member 41 for forming a leg gather, natural rubber, polyurethane, polystyrene-polyisoprene copolymer, polystyrene-polybutadiene copolymer, polyethylene-α such as ethyl acrylate-ethylene, etc. A thread-like stretchable material made of an olefin copolymer or the like can be used.

  The engagement protrusion of the fastening tape 5 and the target sheet 6 can be used without particular limitation as long as they are normally used for absorbent articles such as disposable diapers. For example, as the engagement protrusion, “Magic Tape (registered trademark)” (manufactured by Kuraray Co., Ltd.), “Quicklon (registered trademark)” (manufactured by YKK), “Majikurosu (registered trademark)” (manufactured by Kanebo Bell Touch) The male member etc. in etc. can be used. As the target sheet 6, a target sheet that can fasten the engaging protrusion by pressing the engaging protrusion can be used without particular limitation. For example, the female member in the various well-known mechanical hook-and-loop fastener mentioned above and the nonwoven fabric rich in engagement can be used.

  For fixing the top sheet 21, the back sheet 22, the three-dimensional gathering sheet 24, the fastening tape 5 and the target sheet 6, usually, an adhesive, heat embossing, ultrasonic embossing, high frequency used for absorbent articles such as disposable diapers are used. A fusing means such as embossing is used.

The effect at the time of using the diaper 1A of embodiment of this invention mentioned above is demonstrated.
The diaper 1A is formed using the three-dimensional gather forming sheet 24 in which the three-dimensional gather 3 provided in the diaper 1A is raised from a spunbond nonwoven fabric or a laminated nonwoven fabric of a spunbond layer and a meltblown layer. The touch is improved while keeping costs down. In particular, the three-dimensional gather 3 included in the diaper 1A is formed by using the three-dimensional gather forming sheet 24 having the raised surface 31r side of the top region 3t as shown in FIGS. It is difficult to cause leakage from the top of the three-dimensional gather 3 due to the raised fibers. In particular, in the three-dimensional gather forming sheet 24 forming the three-dimensional gather 3 provided in the diaper 1A, as shown in FIGS. 3 and 4, a part of the long fiber 7 is broken and only one end portion 70a is a heat-sealed portion. The fiber 70 fixed by 8 is formed. Since such a fiber 70 is formed, the three-dimensional gather forming sheet 24 can be given a plump feeling as a whole. Moreover, since only a part of the long fibers 7 is broken, the breaking strength can be kept high similarly to the original spunbonded nonwoven fabric. Further, the fiber 70 of the three-dimensional gather forming sheet 24 forming the three-dimensional gather 3 included in the diaper 1A includes a fiber 71 having a thick free end 70b as shown in FIG. 70b does not tingle, is not easily caught on the skin, and feels good. Further, the fiber 71 having a thick free end portion 70b is easy to sag on the free end portion 70b side and is smooth, so that the touch is good.

  Next, the absorbent article of this invention is demonstrated based on the preferable 2nd Embodiment, referring FIG.

  The absorbent article of the second embodiment is a sanitary napkin, and the sanitary napkin 1B (hereinafter also referred to as “napkin 1B”) of the second embodiment is different from the disposable diaper 1A of the first embodiment. Will be described. The point which is not demonstrated especially is the same as that of the diaper 1A, and description of the diaper 1A is applied suitably.

  As shown in FIGS. 10 and 11, the napkin 1 </ b> B is a sanitary napkin having a pair of wing portions 9 and 9, and is arranged between the top sheet 21, the back sheet 22, and the sheets 21 and 22. It is substantially vertically long with the absorber 23. As shown in FIGS. 10 and 11, the napkin 1 </ b> B is formed by arranging a pair of three-dimensional gathers 3 and 3 on both side portions 1 s and 1 s along the longitudinal direction (y-direction) and disposing elastic members 31. Yes. As shown in FIGS. 10 and 11, the napkin 1 </ b> B is provided with a three-dimensional gather forming sheet 24 over substantially the entire length in the vertical direction (y direction) on both side portions 1 s and 1 s. As shown in FIGS. 10 and 11, the three-dimensional gather forming sheet 24 of the napkin 1 </ b> B has a side portion near the center line CL overlapped with a side portion of the absorber 23, and is disposed above the absorber 23. The entire surface 31r is raised over the top region 3t where the one or more elastic members 31 are arranged. As shown in FIG. 11, each of the pair of three-dimensional gathers 3 and 3 folds the three-dimensional gather forming sheet 24 into two or more layers, and has one or more stretched states in the vertical direction (y direction) between the folded sheets. An elastic member 31 is provided. Accordingly, each three-dimensional gather 3 included in the napkin 1B is in a form having raised fibers on the entire surface corresponding to the entire one surface 31r of the three-dimensional gather forming sheet 24, as shown in FIG.

  As shown in FIGS. 10 and 11, each of the pair of wing portions 9, 9 included in the napkin 1 </ b> B is formed by extending a three-dimensional gather forming sheet 24, and extending the three-dimensional gather forming sheet 24. At least part of the region is also raised. More specifically, as shown in FIG. 11, in the napkin 1B, the back sheet 22 extends outward in the x direction from the top sheet 21 in the crotch part C. The three-dimensional gather forming sheet 24 extends outward in the x direction so as to cover, and the extended back sheet 22 and the three-dimensional gather forming sheet 24 are fixed to form the wing portion 9. In order to fix the napkin 1B to shorts or the like, an adhesive is applied to the lateral direction (x direction) center portion of the back sheet 3 of the napkin 1B and the outer surface of the extending portion of the back sheet 22 of the wing portion 9, respectively. A fixing portion (not shown) is formed. As shown in FIG. 11, the entire surface 31r of the three-dimensional gather forming sheet 24 is raised in the pair of wing portions 9 provided in the napkin 1B.

  A material for forming the napkin 1B of the second embodiment will be described. About the napkin 1B of 2nd Embodiment, it is the same as that of the formation material of 1 A of disposable diapers of 1st Embodiment.

The effect at the time of using the napkin 1B of 2nd Embodiment of this invention mentioned above is demonstrated.
About the effect of the napkin 1B of 2nd Embodiment, a different point from the effect of the disposable diaper 1A of 1st Embodiment is demonstrated. The point which is not demonstrated especially is the same as the effect of 1 A of disposable diapers of 1st Embodiment, and description of the effect of 1 A of disposable diapers of 1st Embodiment is applied suitably.

  As shown in FIGS. 10 and 11, the napkin 1 </ b> B has raised not only the three-dimensional gather 3 but also the wing portion 9, so that the touch is good and side leakage of body fluid can be prevented. Further, when the wing portion 9 is folded and used when worn, the folded top portion becomes soft and does not rub against the skin.

  The absorbent article of the present invention is not limited to the disposable diaper 1A of the first embodiment described above and the sanitary napkin 1B of the second embodiment, and can be appropriately changed. Moreover, each component in the disposable diaper 1A of the above-mentioned 1st Embodiment and the sanitary napkin 1B of 2nd Embodiment can be implemented suitably combining in the range which does not impair the meaning of this invention.

  For example, the three-dimensional gather 3 of the disposable diaper 1A of the first embodiment and the sanitary napkin 1B of the second embodiment is raised on the one surface 31r side of the three-dimensional gather forming sheet 24 as shown in FIGS. However, as shown to Fig.12 (a), the other surface 31f side may be brushed. Thus, if the other surface 31f side of the three-dimensional gather forming sheet 24 is raised, an effect that the top of the three-dimensional gather 3 to be formed becomes soft is exhibited. The three-dimensional gather 3 of the disposable diaper 1A of the first embodiment and the sanitary napkin 1B of the second embodiment has a three-dimensional gather forming sheet 24 folded in two as shown in FIGS. The elastic member 31 is formed in the folded two-layer portion. However, as shown in FIG. 12B, the elastic member 31 is folded into three layers, and the elastic member 31 is formed in the folded portion. May be formed.

  The sanitary napkin napkin 1B of the second embodiment described above includes a pair of wing portions 9 and 9 having raised fibers, but if the three-dimensional gather 3 having raised fibers is provided, the wing portions 9 and 9 are provided. It does not need to be provided, and even if it has the wing parts 9 and 9, it does not need to have raised fiber.

In the present invention, the elastic members 31 and 41 may be thread rubber or flat rubber. In addition, an elastic sheet (elastic sheet, non-stretch sheet bonded sheet, non-elastic sheet (non-woven film, film, paper) and elastic material) that integrates an elastic member and non-woven cloth to make it feel better A composite with a sheet) may be used for the three-dimensional gather 3.
In the present invention, the raised part may be the top of the three-dimensional gather 3, the entire surface of the three-dimensional gather 3, or the part of the leg gather 4 in the three-dimensional gather forming sheet 24. It is preferable that the portion where the skin is strongly hit by the elastic member is raised.
The manufacturing method of the three-dimensional gather 3 included in the manufacturing method of the absorbent article of the present invention includes three stages of forming a three-dimensional gather, forming a II sheet partially, and raising a III sheet in any order. In addition, the partial stretching process of II may be omitted. From the point that the hardness of the three-dimensional gather 3 is softened by partial stretching and the point that the specific part is easily raised, it is preferably performed in the order of I, II, and III. Furthermore, it is more preferable to process in the order of II, III, and I from the viewpoint that the raised height is low, the number of raised hair is increased, and a product having a good touch is obtained.

  The absorbent article of the present invention may be an unfolded disposable diaper, a pants-type disposable diaper other than a sanitary napkin, a liner or the like. When the absorbent article of the present invention is a disposable diaper, the disposable diaper may be a disposable diaper for infants or adults. Further, the side flap portion may be a panel type diaper having a separate member.

DESCRIPTION OF SYMBOLS 1A Disposable diaper 1B Sanitary napkin 1s Side part 2 Absorbent main body 21 Top sheet 22 Back sheet 23 Absorbent body 24 Three-dimensional gather formation sheet 25 Side flap part 26 Leg flap part 3 Three-dimensional gather 31 Elastic member 4 for three-dimensional gather formation Gather 41 Elastic member 5 for forming leg gathers Fastening tape 6 Target sheet 7 Long fiber 70 Fiber having only one end fixed by heat-sealed portion 8 70a One end, 70b Free end 71 Free end 70b is thickened The fiber 71a The diameter of the fiber 71 at the portion excluding the free end 70b 71b The diameter of the fiber 71 at the free end 70b 72 The fiber with the free end 70b not thick 73 The loop-shaped fiber 8 The heat fusion part 200 Pre-processed part 210, 220 A pair of rolls 211 Convex part 230 Steel Rumatching embossing roller 250, 260 Conveying roll 300 Raising processing part 310 Convex roll 311 Convex part 320, 330 Conveying roll 240, 240 'Raw material sheet 104 Measurement sample 105 Fold 106a Fiber 107 crossing twice Hole 108 Virtual line A Back side part, B ventral side, C inseam

Claims (10)

An absorbent article comprising a top sheet, a back sheet, and a vertically long absorbent disposed between the sheets, and a pair of three-dimensional gathers arranged on both sides along the longitudinal direction by arranging elastic members. Because
Each of the pair of three-dimensional gathers is formed by using a sheet that has raised at least a part of a spunbond nonwoven fabric or a laminated nonwoven fabric of a spunbond layer and a meltblown layer ,
In the raised sheet, a part of long fibers constituting the spunbond nonwoven fabric or the laminated nonwoven fabric is broken, and only one end is fixed by the heat-bonded portion of the spunbond nonwoven fabric or the laminated nonwoven fabric. An absorbent article comprising fibers having a thickened free end on the other end side . Each of the pair of three-dimensional gathers is formed by folding the raised sheet into two or more layers, and arranging one or more elastic members in the longitudinal direction between the folded sheets,
The absorbent article according to claim 1, wherein the raised sheet is raised on one surface side facing the elastic member and / or the other surface opposite to the one surface.   The absorbent article according to claim 2, wherein the raised sheet is raised only in a top region where one or more elastic members are disposed between the folded sheets.   The absorbent article according to claim 2 or 3, wherein each of the pair of three-dimensional gathers is formed by fixing one or more elastic members between the folded sheets using an adhesive or a heat seal.   The absorbent article according to any one of claims 1 to 4, wherein the raised sheet is raised only in a region located in a crotch portion of the absorbent article. The absorbent article according to any one of claims 1 to 5 , wherein the raised sheet is made of a polypropylene resin, and the polypropylene resin contains 50% by weight or more of recycled polypropylene resin. The absorbent article according to any one of claims 1 to 6 , wherein the absorbent article is a disposable diaper. The absorbent article is a sanitary napkin provided with a pair of wing parts,
Each pair of the wing portions, said formed to extend sheet being brushed, according to claim 1 to 6, also at least a region extending in the sheet that the standing hair is brushed The absorbent article according to any one of the above. It is a manufacturing method of the absorptive article according to claim 1,
A method for producing an absorbent article, comprising: subjecting the spunbond nonwoven fabric or the laminated nonwoven fabric to partial stretching and then raising the constituent fibers of the nonwoven fabric to produce the raised sheet. . The manufacturing method of the absorbent article of Claim 9 which fixes the said elastic member with an adhesive agent or a heat seal, after giving a raising process to the said spun bond nonwoven fabric or the said laminated nonwoven fabric.

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