JP5336154B2 - Elastic composite sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retractility composite sheet which is superior in the permeability of a thickness direction and/or a horizontal direction, keeps the appearance of a surface irregularity favorable, and is easily manufactured. <P>SOLUTION: The retractility composite sheet includes a retractility sheet 10 and another sheet 2 which is laminated with the retractility sheet 10. The retractility sheet 10 includes a first domain 14 which has elastic retractility and a second domain 15 extensibility of which is inferior to that of the first domain 14, wherein the first and second domains 14, 15 are formed so as to respectively extend in one direction, and are interchangeably formed. Corresponding surfaces of the retractility sheet 10 and the another sheet 2 are joined by a large number of band-like joints 4 which extend in the cross direction which intersects the one direction and intermittent-arranged. The retractility composite sheet 1, as the composite sheet 1 whole, has at least retractility in the cross direction. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a stretchable composite sheet.

As an elastic sheet having a large number of wrinkles or wrinkles, an elastic sheet and a non-expandable sheet are intermittently bonded, and the elastic sheet contracts to form a wrinkle on the non-elastic sheet at the non-bonded portion. Are known.
Moreover, in patent document 1, the outermost sheet | seat which forms absorbent articles, such as a diaper, and the inner surface side sheet | seat fixed to the inner surface were fixed in the state which extended | stretched one sheet | seat rather than the other sheet | seat. Then, it is described that the outermost sheet and the inner sheet are opened, and the outermost sheet or the inner sheet is formed with ridges by the wrinkles generated by the one sheet. It is described that the bonding to the sheet is performed with an adhesive that is regularly applied at intervals.

  However, when two sheets are joined intermittently, and a portion where the sheets are not joined is deformed into a convex shape to obtain a concavo-convex sheet, the position of the joint between the sheets and the position of the recess between the convex parts Therefore, in order to manufacture an uneven sheet with a small pitch between the convex part and the concave part at a low cost, it is necessary to finely control the joint pitch and control it with high precision, and the adhesive coating device and control are complicated. There is a problem. Therefore, since the pitch of the joint portion is difficult to control, the pitch of the ridges may not be uniform, and the appearance is often poor.

JP 2007-111503 A

  An object of the present invention is to provide a stretchable composite sheet that is excellent in air permeability in the thickness direction and / or in the horizontal direction, has an excellent appearance of surface irregularities, and is easy to manufacture.

  A stretchable composite sheet having the stretchable sheet of the present invention and another sheet laminated with the stretchable sheet, wherein the stretchable sheet is inferior in extensibility to the first region having elastic stretchability and the first region. The first and second regions extend in one direction and are alternately formed in a direction perpendicular to the one direction, and the opposing surfaces of the stretchable sheet and the other sheet are Are joined by a plurality of intermittently arranged strip-like joints extending in the intersecting direction intersecting the one direction, and the stretchable composite sheet having stretchability in at least the intersecting direction as a whole composite sheet. By providing this, the above-mentioned object is achieved.

  The stretchable composite sheet of the present invention is excellent in air permeability in the thickness direction and / or in the horizontal direction, has an excellent appearance of surface irregularities, and is easy to manufacture.

The present invention will be described below based on preferred embodiments with reference to the drawings.
As shown in FIGS. 1 to 3, the stretchable composite sheet 1 of the present embodiment includes a stretchable sheet 10 and a non-stretchable sheet 2 (another sheet) laminated on the stretchable sheet 10.
As shown in FIG. 4, the stretchable sheet 10 includes a first region 14 having elastic stretchability and a second region 15 that is less extensible than the first region 14. The first and second regions 14 and 15 are formed to extend in the X direction in FIG.
The first and second regions 14 and 15 are alternately formed in the Y direction in FIG. The X direction in the figure is the direction in which the first and second regions 14 and 15 of the stretchable sheet 1 extend among the directions parallel to the front and back surfaces of the stretchable composite sheet 1, and the Y direction is a direction orthogonal thereto. It is.
The elastic sheet 10 has elasticity in the Y direction because each of the plurality of first regions 14 has elastic elasticity. The second region 15 of the stretchable sheet 10 has almost no stretchability.

The non-stretchable sheet 2 has substantially no stretchability. The stretchability referred to here is the stretchability of the sheet itself.
The non-stretchable sheet 2 preferably does not have stretchability in a direction (Y direction) orthogonal to the direction (X direction) in which at least the first and second regions extend, and is stretchable in both the X direction and the Y direction. It is preferable not to have.
The non-stretchable sheet 2 in this embodiment has substantially no stretchability in any of the X direction and the Y direction. The non-stretchable sheet 2 may not have stretchability in all directions parallel to the front and back surfaces.

The fact that the sheet is not substantially stretchable in a certain direction means that the sheet hardly stretches even when a force for pulling in the certain direction is applied to the sheet. For example, when a sample having a length of 15 cm and a width of 5 cm is pulled in the longitudinal direction with a material tensile tester such as Tensilon and the breaking elongation when the sample breaks is 10% or less, The sample is not substantially stretchable in the longitudinal direction.
The elongation at break can be calculated by (the sample length at break-the original length of the sample) / (the original length of the sample) × 100. The longitudinal direction of the sample is the same as the above-described “certain direction”.

  As shown in FIG. 5, the stretchable sheet 10 and the non-stretchable sheet 2 are joined by a large number of strip-like joining portions 4, 4. The belt-like joining portion 4 is respectively crossed with the one direction (X direction in the figure) in which the first and second regions 14 and 15 of the stretchable sheet 10 extend, more specifically, the one direction (in the figure). It extends in a direction (Y direction in the figure) orthogonal to the (X direction). Further, the strip-shaped joint portions 4, 4,... Are intermittently arranged at equal intervals in the X direction in the drawing, and each strip-shaped joint portion 4 is formed by bonding the opposing surfaces of the stretchable sheet 10 and the non-stretchable sheet 2 with an adhesive. It is formed by bonding with (for example, a hot-melt adhesive) 41. Between the adjacent belt-like joint portions, non-joint portions 5 are not joined between the stretchable sheet 10 and the non-stretchable sheet 2.

  The width W1 (see FIG. 5) of the belt-like joint 4 is preferably 20 to 200% of the width W2 (see FIG. 5) of the non-joint portion 5 between adjacent belt-like joints, and more preferably 50 to 150. %. By being in these ranges, the adhesive strength between the stretchable sheet 10 and the non-stretchable sheet 2 and the breathability as the stretchable composite sheet 1 can be maintained in a well-balanced manner.

Further, the width W1 (see FIG. 5) of the belt-like joint portion 4 is preferably 1 to 10 mm from the viewpoint of increasing the adhesive strength between the stretchable sheet 10 and the non-stretchable sheet 2 and preventing peeling, as described above. Preferably it is 3-5 mm.
On the other hand, the width W2 (see FIG. 5) of the non-joining part 5 is different from the viewpoint of forming a convex strip having a good appearance on the surface on the non-stretchable sheet 2 side, From the viewpoint of formation, it is preferably 0.5 to 50 mm, more preferably 2 to 10 mm.

As shown in FIGS. 1 to 3, the stretchable composite sheet 1 of the present embodiment is shrunk in the Y direction in a state where no external force is applied (natural state), and at least in the shrunken state, the stretchable composite sheet. 1 is formed with a large number of ridges 3, 3,... Extending along the X direction. The multiple ridges 3, 3,... Are formed so as to extend substantially parallel to the direction (X direction) in which the first and second regions 14, 15 extend. Further, the stretchable sheet 10 used in the present embodiment has a large number of ridges 3, 3,... Due to the first and second regions 14, 15 being formed at equal intervals in the Y direction. Are generally the same in height and width.
In addition, the stretchable composite sheet 1 of the present embodiment can be extended in the Y direction until the non-stretchable sheet 2 becomes substantially flat, and in this state, the ridge 3 disappears. And if it releases from the extended force, the elastic composite sheet 1 contracts and returns to the original state in which a large number of ridges 3 are formed. The multiple ridges 3 in the stretchable composite sheet 1 of the present embodiment are formed at least in a natural state.

  The pitch P (see FIG. 2) between the tops of the ridges 3 of the stretchable composite sheet 1 and the height T (see FIG. 2) of the ridges 3 are appropriately determined according to the use of the stretchable composite sheet 1. Although it is not particularly limited, in the case of constituting a part of the absorbent article (such as when used for a surface sheet forming a liquid-absorbing surface or an exterior body of a pants-type absorbent article (pants-type diaper, etc.)), The pitch P is preferably 0.5 to 5 mm, particularly 1 to 3 mm, and the height T is preferably 0.5 to 5 mm, particularly 1 to 3 mm. In the stretchable composite sheet 1, the pitch P between the tops of the ridges 3 is about twice the pitch of the first region 14 or the second region 15.

[Measuring method of the pitch P and the height T]
The pitch P and the height T are measured in a state where the stretchable composite sheet 1 does not apply an external force (a contracted state, a natural state). In this state, the distance between the tops of the adjacent ridges 3 and 3 adjacent to each other is defined as a pitch P, and the distance between the valley formed between the ridges 3 and 3 and the top of the ridges 3 is increased. It is assumed that T. The measurement can be performed using a laser displacement meter, or the sheet cross section can be measured by microscopic observation or photography.

When the stretchable sheet 10 is stretched in a direction (Y direction) orthogonal to the direction in which the first and second regions 14 and 15 extend, the sheet width in the direction orthogonal to the extension direction (X direction) becomes narrower. That is, it is preferable that the width is not easily reduced. When a material that does not easily cause width shrinkage is used, a beautiful ridge 3 that extends substantially parallel to the direction (X direction) in which the first and second regions 14 and 15 extend is formed on the surface of the non-stretchable sheet 2 side. It becomes easy.
For example, when the stretchable sheet 10 is stretched 2.0 times in the direction (Y direction) orthogonal to the direction (X direction) in which the first and second regions 14 and 15 extend, the ratio of the width shrinkage in the X direction is The width before elongation is preferably 70 to 100%, more preferably 80 to 100%, and still more preferably 90 to 100%.
The ratio (%) of width shrinkage can be obtained as a value obtained by dividing the width after expansion by the width before expansion [(width during expansion / width before expansion) × 100]. In the measurement, a sample having a length in the Y direction of 200 mm and a length in the X direction of 100 mm is cut out, and the width (length in the X direction) at both ends in the extending direction (Y direction) is maintained at 100 mm. This is done by extending it twice. The measurement position of the width after extension is the center.

In this embodiment, the stretchable sheet 10 shown in FIG. 4 is used as the stretchable sheet that is less likely to cause width shrinkage.
The elastic sheet 10 shown in FIG. 4 has a large number of elastic filaments 13 arranged so as to extend in one direction (the Y direction in FIG. 4) without crossing each other, and extend over their entire length in a substantially non-extended state. Bonded to possible non-woven fabrics 11 and 12.

  The arrangement pitch P13 of the elastic filaments (see FIG. 4) is not particularly limited, but is 30 to 300%, particularly 50 to 150% with respect to the width W1 of the strip-like joint portion 4, and also the non-joint portion. The width W2 of 5 is preferably 30 to 300%, more preferably 50 to 150%, from the viewpoints of stretchable physical properties and moldability of the ridges.

In the stretchable sheet 10, each elastic filament 13 is substantially continuous over the entire length of the stretchable sheet 10. The elastic filament 13 contains an elastic resin. The elastic filaments 13 are arranged so as to extend in one direction without crossing each other.
Such a sheet is extended in a direction (Y direction) orthogonal to the direction (X direction) in which the first and second regions 14 and 15 extend, compared to the stretchable sheet arranged in a state where the elastic fibers are entangled. The width shrinkage is less likely to occur.
However, the elastic filaments 13 are allowed to cross unintentionally due to inevitable fluctuations in the manufacturing conditions of the stretchable sheet 10. Each elastic filament 13 may extend linearly as long as it does not cross each other, or may extend while meandering.

The elastic filament 13 is bonded to the nonwoven fabrics 11 and 12 in a substantially non-stretched state. The elastic filament 13 can be a thread-like synthetic rubber thread or natural rubber. Alternatively, it may be obtained by dry spinning (melt spinning) or wet spinning. The elastic filament 13 is preferably obtained by direct melt spinning without winding it once. The elastic filament 13 is preferably obtained by drawing an undrawn yarn.
The elastic filament 13 is preferably formed by being stretched in a state where the elastic resin is melted or softened. By stretching the elastic resin in a melted or softened state, the elastic filament 13 can be bonded to the nonwoven fabrics 11 and 12 in a non-stretched state. Specific operations for stretching in the present embodiment are as follows: (a) A resin as a raw material of the elastic filament 13 is melt-spun to obtain an unstretched yarn, and the elastic filament of the unstretched yarn is heated again to soften the temperature. (B) Operation for stretching in a state higher than (hard segment glass transition temperature Tg), and (b) operation for directly stretching a molten fiber obtained by melt spinning a resin as a raw material of the elastic filament 13 . When the stretchable sheet 10 is manufactured according to a preferable manufacturing method described later, the elastic filament 13 is obtained by directly stretching a molten fiber obtained by melt spinning.

  The elastic filament 13 obtained by stretching preferably has a diameter of 10 to 200 μm, particularly 20 to 130 μm. The elastic filament 13 may have a circular cross section, but in some cases may have an elliptical cross section. The pitch of the adjacent elastic filaments 13 is preferably 0.1 to 5 mm, particularly preferably 0.4 to 1 mm, provided that the diameter of the elastic filaments 13 is in the above-described range.

  The elastic filament 13 is bonded to the nonwoven fabrics 11 and 12 over the entire length thereof. Here, “joining over the entire length” requires that all the fibers in contact with the elastic filament 13 (component fibers of the nonwoven fabrics 11 and 12) are joined to the elastic filament 13. In other words, it means that the elastic filament 13 and the constituent fibers of the nonwoven fabrics 11 and 12 are bonded to the elastic filament 13 in such a manner that there is no intentionally formed non-bonded portion. Since the elastic filament 13 is bonded to the nonwoven fabrics 11 and 12 over the entire length, the bonding force between the elastic strands 13 and the nonwoven fabrics 11 and 12 can be sufficiently increased.

  Examples of the bonding mode between the elastic filament 13 and the first and second non-woven fabrics 11 and 12 include fusion, bonding with an adhesive, and the like. It is also preferable that the elastic filament 13 is fused to the nonwoven fabric before the elastic filament 13 obtained by melt spinning is solidified. In this case, before bonding the nonwoven fabrics 11 and 12 and the elastic filaments 13, an adhesive can be applied as an auxiliary bonding means. Or after joining each nonwoven fabric 11 and 12 and the elastic filament 13, heat processing (steam jet, heat embossing), mechanical entanglement (needle punch, spunlace) etc. can also be performed as an auxiliary joining means. .

  The stretchable sheet 10 is stretchable in the same direction as the direction in which the elastic filament 13 extends. The stretchability of the stretchable sheet 10 is expressed due to the elasticity of the elastic filament 13. When the stretchable sheet 10 is stretched in the same direction as the elastic filament 13 extends, the elastic filament 13 and the first and second nonwoven fabrics 11 and 12 extend. When the stretching of the stretchable sheet 10 is released, the elastic filament 13 contracts, and the first and second nonwoven fabrics 11 and 12 return to the state before stretching with the contraction.

  For example, as shown in FIG. 6, the stretchable sheet 10 is drawn by drawing a large number of molten elastic filaments 13 spun from the spinning nozzle 16 at a predetermined speed, and stretching the elastic filaments 13 before the elastic filaments 13 are solidified. The elastic filaments 13 are fused to the nonwoven fabrics 11 and 12 so that the elastic filaments 13 are arranged in one direction without crossing each other, and then the nonwoven fabrics 11 and 12 (the original sheet of the stretchable sheet 10) ) Can be obtained by stretching the nonwoven fabrics 11 and 12 by stretching along the extending direction of the elastic filaments 13.

  FIG. 6 shows a state in which the stretchable composite sheet 1 is continuously manufactured after the stretchable sheet 10 shown in FIG. 4 is manufactured as an example of a preferable method for manufacturing the stretchable composite sheet 1.

  The spinning nozzle 16 is provided in the spinning head 17. The spinning head 17 is connected to an extruder. Resin can also be supplied to the spinning head 17 via a gear pump. The elastic resin melt-kneaded by the extruder is supplied to the spinning head 17. The spinning head 17 has a large number of spinning nozzles 16 arranged in a straight line. The spinning nozzle 16 is arranged along the width direction of the first and second nonwoven fabrics 11 and 12. The interval between the adjacent spinning nozzles 16 corresponds to the interval between the elastic filaments 13 in the stretchable sheet 10. The spinning nozzle 16 is usually circular, and its diameter affects the diameter of the elastic filament 13 and the draw ratio. From this viewpoint, the diameter of the spinning nozzle 16 is preferably 0.1 to 2 mm, particularly preferably 0.2 to 0.6 mm. For the purpose of increasing the bonding strength with the nonwoven fabrics 11 and 12, the purpose of increasing the spinnability of the elastic filament 13, and the purpose of improving the expansion / contraction characteristics of the elastic sheet 10, the elastic filament 13 is in a composite form (side-by-side, core sheath, sea-island structure). ). Specifically, it is preferable to combine a PP elastomer resin and a styrene elastomer resin.

  The melted elastic filaments 13 spun together with the first nonwoven fabric 11 and the second nonwoven fabric 12 fed from the original fabric at the same speed, and are sandwiched between the nonwoven fabrics 11 and 12 at a predetermined speed. Taken over. The take-up speed of the elastic filament 13 coincides with the feeding speed of both the nonwoven fabrics 11 and 12. The take-up speed of the elastic filament 13 affects the diameter and the draw ratio of the elastic filament 13. The tension generated in the elastic filament 13 by stretching prevents the elastic filament 13 from being disturbed due to wind or static electricity when the elastic filament 13 is bonded to the nonwoven fabrics 11 and 12. Thereby, the elastic filaments can be arranged in one direction without crossing each other. From these viewpoints, the drawing speed of the elastic filament 13 is 1.1 to 400 times, particularly 4 to 100 times, more preferably 10 to 80 times the resin discharge speed in the spinning nozzle hole. It is preferable to adjust.

  The elastic filament 13 merges with the first and second nonwoven fabrics 11 and 12 before solidification, that is, in a state capable of being fused. As a result, the elastic filament 13 is fused to the nonwoven fabrics 11 and 12 while being sandwiched between the first and second nonwoven fabrics 11 and 12. That is, the elastic filament 13 is pulled and stretched by fusing the elastic filament before solidification to the nonwoven fabrics 11 and 2 to be conveyed. When the elastic filament 13 is fused, heat is not applied to the first and second nonwoven fabrics 11 and 12 from the outside. That is, the elastic filament 13 and the nonwoven fabrics 11 and 12 are fused only by the heat of fusion caused by the elastic filament 13 that can be fused. As a result, among the constituent fibers of both the nonwoven fabrics 11 and 12, only the fibers existing around the elastic filament 13 are fused to the elastic filament, and the fibers present at a position further away from the elastic filament 13 are not fused. As a result, since the heat applied to both the nonwoven fabrics 11 and 12 is kept to a minimum, the good texture inherent to the nonwoven fabric itself is maintained. Thereby, the texture of the stretchable sheet 10 obtained becomes favorable.

  Until the spun elastic filament 13 joins the first and second nonwoven fabrics 11 and 12, the elastic filament 13 is stretched and molecules are oriented in the stretching direction. Also, the diameter is reduced. Due to the molecular orientation, an elastic filament 13 having a small strength going / return ratio (hysteresis) at 50% elongation can be obtained. From the viewpoint of sufficiently stretching the elastic filament 13 and spinning the yarn breakage of the elastic filament 13, wind of a predetermined temperature (hot air or cold air) is blown onto the spun elastic filament 13 to set the temperature of the elastic filament 13. You may adjust.

  The stretching of the elastic filament 13 is not limited to stretching in the molten state (melt stretching) of the elastic resin, but may be stretching in the softened state (softening stretching) in the cooling process. The molten state is a state in which the resin flows when an external force is applied. The melting temperature of the resin is measured as a peak temperature of Tan δ by viscoelasticity measurement (for example, measured by adding vibration strain in the rotational direction to a resin sandwiched between circular parallel plates). In order to prevent thread breakage during stretching of the elastic resin, it is preferable to secure a long stretching section. From this viewpoint, the melting temperature of the elastic resin is preferably 130 to 300 ° C. Further, from the viewpoint of heat resistance (molding temperature) of the elastic resin, the melting temperature is preferably 130 to 220 ° C. The softening temperature is measured as the Tg temperature in the viscoelastic property of the measurement sample of the elastic resin in sheet form. The range from the softening temperature to the melting temperature is called a softened state. The softening temperature is preferably 60 ° C. or higher, and more preferably 80 ° C. to 180 ° C., from the viewpoint of the growth of elastic resin crystals during storage of the stretchable sheet 10 and the decrease in stretchability of the stretchable sheet 10 due to body temperature.

  The temperature of the elastic filament 13 when the elastic filament 13 and the nonwoven fabrics 11 and 12 are joined is preferably 100 ° C. or higher in order to ensure fiber fusion. Further, from the viewpoint of obtaining the stretchable sheet 10 having a good stretchability by maintaining the shape of the elastic filament 13, the temperature of the elastic filament is preferably 180 ° C. or lower. More preferably, it is the range of 120-160 degreeC. The bonding temperature is observed using a film made of a modified polyethylene or a modified polypropylene having a melting point different from the melting point of the elastic resin constituting the elastic filament as a laminate base material to be bonded to the elastic filament 13. Can be measured. At this time, if the elastic filament and the laminate base material are fused, the joining temperature is equal to or higher than the melting point of the laminate base material.

  At the time of joining the elastic filament 13 and the nonwoven fabrics 11 and 12, the elastic filament 13 is substantially in a non-stretched state (a state in which it does not shrink when an external force is removed). In the bonding state between the two, at least a part of the fibers constituting the nonwoven fabrics 11 and 12 are fused to the elastic filaments, or both the elastic filament 13 and at least a part of the fibers constituting the nonwoven fabrics 11 and 12 are used. It is more preferable to fuse. This is because sufficient bonding strength can be obtained. The stretch properties of the resulting stretchable sheet 10 are affected by the density of the joint points between the elastic filament 13 and the nonwoven fabrics 11 and 12. In addition, the expansion / contraction characteristics can be adjusted by the joining temperature, the joining pressure, and the deviation of the joining point due to the stretching of the nonwoven fabrics 11 and 12 described later. By bonding the constituent fibers of the nonwoven fabrics 11 and 12 to the elastic filament 13, the bonding strength of each bonding point increases. Lowering the density of the joining points is preferable because the stretch inhibition by the nonwoven fabrics 11 and 12 is reduced and the stretch sheet 10 having sufficient joint strength is obtained.

  When the elastic filament 13 is merged with the first and second nonwoven fabrics 11 and 12, the elastic filaments 13 are arranged in one direction without crossing each other. Then, the elastic filament 13 is joined with the first and second nonwoven fabrics 11 and 12, and the elastic filament 13 is sandwiched between the nonwoven fabrics 11 and 12, and the three are sandwiched by a pair of nip rolls 18 and 18. Press. The condition of the clamping pressure affects the texture of the stretchable sheet 10 obtained. If the pinching pressure is too large, the elastic filament 13 is likely to bite into both the nonwoven fabrics 11 and 12, and the texture of the stretchable sheet 10 obtained due to this tends to be lowered. From this point of view, the clamping pressure by the nip rolls 18 and 18 is sufficient so that the elastic filament 13 contacts both the nonwoven fabrics 11 and 12, and an excessively high clamping pressure is not required.

  Another condition for the clamping pressure by the nip roll 18 is the temperature of the nip roll 18. As a result of the examination, it is possible to obtain the stretchable sheet 10 having a good texture by not heating (that is, whether to make it happen) or by holding the nip roll 18 while cooling, rather than holding the nip roll 18 in a heated state. Turned out to be. When cooling the nip roll 18, it is preferable to use a coolant such as cooling water and adjust the temperature so that the surface setting temperature of the nip roll 18 is 10 to 50 ° C.

In this way, a composite 19 in which the elastic filament 13 is sandwiched between the two nonwoven fabrics 11 and 12 is obtained. The nonwoven fabrics 11 and 12 in the composite 19 are not inherently stretchable, and the composite 19 is a raw sheet of the stretchable sheet 10.
And in order to form in this composite 19 the 1st area | region 14 which has elastic elasticity, and the 2nd area | region 15 which is inferior to a 1st area | region, the composite 19 containing this nonwoven fabric 11 and 12 is used. An operation of stretching along the extending direction of the elastic filament 13 is performed.
As shown in FIG. 6, in the method of the present embodiment, this stretching operation is performed using a stretching device 22 including a pair of tooth gap rolls 20, 21 in which teeth and roots are alternately formed in the circumferential direction. The composite 19 is stretched along the conveying direction, that is, along the direction in which the elastic filament 13 extends.

  The extending | stretching apparatus 22 has the well-known raising / lowering mechanism (not shown) which displaces the pivotal support part of one or both tooth space rolls 20 and 21 up and down, and the space | interval between tooth space rolls 20 and 21 becomes adjustable. ing. In this manufacturing method, each tooth gap roll 20 and 21 is inserted freely between the teeth of one tooth gap roll 21 and the tooth of the other tooth gap roll 21 is one tooth. It combines so that it may be loosely inserted between the teeth of the groove roll 20, and the composite body 19 is inserted between the both tooth groove rolls 20 and 21 of the state, and this is extended.

  In the stretching device 22, both the pair of tooth groove rolls 20 and 21 may be driven by a driving source (co-rotating roll), and only one tooth groove roll 20 or 21 is driven by the driving source. It may be like (rotating roll). In this manufacturing method, only the lower tooth gap roll 21 is driven by the drive source, and the upper tooth gap roll 20 is not connected to the drive source, and is driven as the tooth gap roll 21 rotates (accompanied). It is supposed to turn). The use of the follower roll is preferable because the first region 14 and the second region 15 are easily formed in a striped pattern on the stretchable sheet 10 after the stretching process. As the tooth profile of the tooth gap rolls 20 and 21, a general involute tooth profile and a cycloid tooth profile are used, and those having a narrowed tooth width are particularly preferable.

  FIG. 7 schematically shows a state in which the composite 19 is stretched. When the composite 19 passes between the tooth gap rolls 20 and 21, the composite 19 is in a region that contacts the teeth 23 and 24 of the tooth gap rolls 20 and 21 (between P 3 and P 2 and between P 1 and P 4). Is hardly stretched. On the other hand, in the region (between P2 and P1) pressed toward the tooth surface of the tooth 23 of the tooth space roll 20 that is the driven roll by the tooth surface of the tooth 24 of the tooth space roller 21 that is the driving roll. The two teeth 20 and 21 are greatly stretched. Further, in the region (between P4 and P3) that is separated from the tooth 23 of the tooth space roll 20 by the tip of the tooth 24 of the tooth space roll 21, it is not as large as the region (between P2 and P1), but is greatly stretched. The

  In addition, in the area | region (between P3-P2 and between P1-P4) in which the composite_body | complex 19 contact | abuts the front-end | tip part of the teeth 23 and 24 of the tooth space roll 20 and 21, although it extends as mentioned above, the teeth 23, Since the tip end portion 24 is pressed in the radial direction, that is, in the thickness direction of the composite 19, the thickness is reduced in the thickness direction. However, because the region (between P3 and P2) and the region (between P1 and P4) are in the opposite direction, the thinning direction is the opposite direction.

In the region (between P2 and P1 and between P4 and P3) in which the composite 19 is largely stretched by the stretching process, the nonwoven fabrics 11 and 12 are stretched with the constituent fibers themselves, the separation of the bonds between the fibers, Changes that allow the nonwoven fabrics 11 and 12 to be stretched, such as structural changes in the three-dimensional structure formed by the fibers of the book, breakage of the constituent fibers, etc., on the other hand, regions that are hardly stretched (between P3-P2 and P1-P4) In the meantime, such a change does not occur in both the nonwoven fabrics 11 and 12.
And the area | region (between P2-P1 and P4-P3) extended | stretched greatly becomes the 1st area | region 14 which has elastic elasticity, and the area | region (between P3-P2 and between P1-P4) hardly extended is 1st. It becomes the 2nd field 15 inferior to extensibility rather than field 14.

By the stretching process described above, the first and second regions 14 and 15 are alternately formed in the composite 19, and the stretchable sheet 10 is obtained.
In addition, the extending | stretching apparatus 22 is not restrict | limited to a roll shape like a present Example, For example, it comprised a pair of conveyor belt and formed the continuous stripe part extended in the direction orthogonal to a sheet | seat flow direction in each of them. A stretching device may be used.
In addition, a pair of concavo-convex plates having a plurality of ridges extending in a direction orthogonal to the sheet flow direction are provided on the mutually facing surfaces, and a cam mechanism is used so that the distance between the concavo-convex plates can be expanded or reduced. Thus, an apparatus for stretching the sheet by displacing it from a state of being separated from each other to a state of meshing may be used.

  In the manufacturing method of the present embodiment, as shown in FIG. 6, the stretchable sheet 10 is conveyed in an expanded state, joined with the non-stretchable sheet 2 under the stretched state, and joined to the non-stretchable sheet 2. The stretched state here is different from the stretching of the composite 19 by the pair of tooth space rolls 20 and 21, that is, the stretching for alternately forming the first and second regions 14 and 15 in the composite 19. The stretchable sheet 10 after the first and second regions 14 and 15 are formed is a stretched state as compared with its natural state (shrinked state).

  The stretchable sheet 10 is non-stretchable in a state where it is stretched 1.1 to 4.0 times, more preferably 1.2 to 3.0 times, and even more preferably 1.5 to 2.5 times in the flow direction. Joining to the sheet 2 is preferable from the viewpoint of easiness of elongation and shrinkage as the stretchable composite sheet in the joined state. The expansion ratio of the stretchable sheet 10 is obtained by dividing the length in the stretched state by the length of the natural state (stretched state) before stretching.

The basis weight in the coating area of the adhesive (basis weight at the belt-like joint) is 0.2 to 20 g / m ² , more preferably 0.3 to 10 g / m ² , and still more preferably 0.5 to 5 g / m ^2. It is preferable that it is difficult to inhibit the stretchability and shrinkage of the stretchable composite sheet.
In the manufacturing method of the present embodiment, an adhesive (preferably hot melt adhesive) 41 is applied in a stripe shape by the adhesive application device 40 to the non-elastic sheet 2 just before joining the elastic sheet 10. That is, the adhesive 41 is continuously applied in the flow direction of the non-stretchable sheet 2, but is applied at a predetermined interval in the direction orthogonal to the flow direction.
Instead of applying the adhesive to the non-stretchable sheet 2, the adhesive may be applied to the stretchable sheet 10, or the adhesive may be applied to both sheets 10,2. The coating basis weight of the adhesive is the total amount of the adhesive applied to the stretchable sheet 10 and the adhesive applied to the non-stretchable sheet 2 in the stretchable composite sheet 1 in the natural state (shrinked state). .

The stretchable sheet 10 and the non-stretchable sheet 2 are pinched by a pair of nip rolls 41 and 42 at the time of joining or immediately after joining. In this way, the stretchable composite sheet 1 in which the stretchable sheet 10 and the non-stretchable sheet 2 are laminated and integrated is obtained.
If the stretchable composite sheet 1 is maintained in the stretched state of the stretchable sheet 10 when bonded to the nonstretchable sheet 2, the surface of the stretchable composite sheet 1 described above is formed on the surface of the nonstretchable sheet 2 as shown in FIG. Although the ridges 3, 3,... Do not occur, the ridges 3, 3,... As shown in FIG. In addition, in FIG. 8, the 2nd area | region 15 formed in contact with the front-end | tip part of the tooth | gear of one tooth space roll, and the 2nd area | region formed in contact with the front-end | tip part of the tooth of the other tooth space roll In order to distinguish 15, the elastic filament 13 in the second region 15 is bent in the upside down direction for convenience.

In the manufacturing method of the stretchable composite sheet 1 shown in FIG. 6, immediately after joining the stretchable sheet 10 and the non-stretchable sheet 2, the stretched state of the stretchable composite sheet 1 is relaxed and wound into a roll in that state. ing. By setting the stretchable composite sheet 1 in a non-or low stretched state, the stretchability of the stretchable sheet 10 and thus the stretchability of the stretchable composite sheet 1 and the formability of the ridges 3 are stably maintained. Is done.
When the stretchable sheet 10 before being bonded to the non-stretchable sheet 2 is shrunk alone, the stretchable sheet 10 is deformed as shown in FIG. The stretchable sheet 10 is regular on the front and back surfaces corresponding to the pitch of the first and second regions 14 and 15, and small convex portions are continuously formed along the Y direction. When a convex portion is formed in the second region 15 on one surface, a concave portion is formed in the same second region 15 on the opposite surface. Conversely, when a concave portion is formed in the second region 15 on one surface, a convex portion is formed in the same second region 15 on the opposite surface. In this way, the positions of the convex portions are alternately formed on the front and back surfaces.
Further, when the stretchable sheet 10 is shrunk from the state shown in FIG. 9, the non-stretchable sheet 2 itself is not shrunk, so that the part that cannot be shrunk is absorbed by deformation. Due to these actions, regular ridges 3, 3... Are formed in the stretchable composite sheet 1 according to the pitch of the first and second regions 14, 15.

In the stretchable composite sheet 1 in the contracted state, the above-mentioned regular ridges 3, 3... Are formed on the non-stretchable sheet 2 side surface, while the stretchable sheet 10 side surface is stretched. Unevenness having a shape different from the surface on the sheet 10 side is formed.
FIG. 10 is an enlarged view showing a part of the surface of the stretchable composite sheet 1 on the stretchable sheet 10 side.
As shown in FIG. 10, on the surface of the stretchable sheet 10 side, a portion corresponding to the groove 6 </ b> A between the ridges 3, 3 on the non-stretchable sheet 2 side is raised and extends in the X direction in the drawing. While the part 6 is formed, the part corresponding to the non-joining part 5 of the adjacent belt-like joining part 4 is also raised to form the second raised part 7. And while the 1st protruding part 6 and the 2nd protruding part 7 protrude, the part enclosed by them becomes the recessed part 8 relatively.
As described above, in the stretchable composite sheet 1 of the present embodiment, the airflow excellent in the direction parallel to the front and back surfaces of the sheet 1 due to the unevenness of the front and back surfaces due to the formation of uneven surfaces on the front and back surfaces. For example, when used as a constituent material of an absorbent article such as a disposable diaper, for example, a diaper exterior body or a surface sheet used in contact with the skin, excellent breathability and absorptivity are obtained. be able to.

Further, the stretchable sheet 10 and the non-stretchable sheet 2 are joined by an adhesive. Therefore, the stretchable composite sheet 1 is advantageous in that it is softer than the case of being bonded by heat sealing, embossing, or the like, and is excellent in touch. Further, since the stretchable sheet 10 and the non-stretchable sheet 2 are intermittently joined at the belt-like joining portion 4, softness and feel are further improved.
Further, when the breathable stretchable composite sheet 1 is obtained by using a breathable sheet for the stretchable sheet 10 and the non-stretchable sheet 2, it is intermittently joined at the belt-like joining portion 4, so that The air permeability can be further improved.

In the stretchable composite sheet 1 of the present embodiment, the adhesive 41 may be continuously applied in the flow direction of the stretchable sheet 10 and the non-stretchable sheet 2 in the manufacturing method described above. , It is not necessary to apply the adhesive intermittently according to the pitch of 3. Therefore, the adhesive coating apparatus and control are not complicated.
Examples of the adhesive coating apparatus include a coater-type coating apparatus, a spray-type coating apparatus, and the like that are alternately provided with an adhesive discharge portion and a non-discharge portion in the width direction of the sheet. Alternatively, by using a spiral gun, for example, a roll-type coating apparatus described in JP-A-9-299849, adhesive portions and non-adhesive portions that are uniformly bonded in a similar pattern may be alternately formed.

  Further, when the non-stretchable sheet 2 is fully stretched (see FIG. 8), a so-called stretch stop occurs in the stretchable composite sheet 1. Therefore, for example, when the elastic composite sheet 1 is used for an absorbent article such as a sanitary napkin or a diaper, the material flow direction (corresponds to the Y direction of the elastic composite sheet 1) when the absorbent article is continuously manufactured. ) Can be suppressed, so that there are advantages such as excellent material transportability, high-speed productivity, and high-precision processing.

  The constituent materials of the first and second nonwoven fabrics 11 and 12 and the elastic filament 13 constituting the stretchable sheet 10 will be described. Examples of the fibers constituting each of the nonwoven fabrics 11 and 12 include fibers made of polyethylene (PE), polypropylene (PP), polyester (PET or PBT), polyamide, and the like. The fibers constituting each of the nonwoven fabrics 11 and 12 may be short fibers or long fibers, and may be hydrophilic or water repellent. Further, core-sheath type or side-by-side composite fibers, split fibers, irregularly shaped cross-section fibers, crimped fibers, heat-shrinkable fibers, and the like can also be used. These fibers can be used singly or in combination of two or more. Each non-woven fabric 11, 12 can be a continuous filament or short-fiber non-woven fabric. In particular, from the viewpoint of making the stretchable sheet 10 thick and bulky, the nonwoven fabrics 11 and 12 are preferably short-fiber nonwoven fabrics. When the stretchable sheet 10 is used as a member that comes into contact with the skin, a short fiber nonwoven fabric with good texture may be used on the skin contact side, and a high-strength continuous filament nonwoven fabric may be used on the opposite surface.

  Each of the nonwoven fabrics 11 and 12 preferably has two or more constituent fibers of a low melting point component and a high melting point component. In that case, the constituent fibers are bonded to each other at the fiber intersection by heat fusion of at least the low melting point component. As the core-sheath type composite fiber composed of two or more components of a low melting point component and a high melting point component, those having a core of high melting point PET, PP and a sheath of low melting point PET, PP, PE are preferable. In particular, the use of these composite fibers is preferable because the fusion with the elastic filaments 13 becomes strong and peeling between the two hardly occurs.

  The elastic filament 10 is made of, for example, a thermoplastic elastomer or rubber. In particular, when a thermoplastic elastomer is used as a raw material, melt spinning using an extruder is possible in the same manner as a normal thermoplastic resin, and the filament thus obtained is easily heat-sealed. It is suitable for the elastic sheet. Examples of the thermoplastic elastomer include SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS (styrene-ethylene-butadiene-styrene), and SEPS (styrene-ethylene-propylene-styrene). And olefin-based elastomers (ethylene-based α-olefin elastomers, propylene-based elastomers copolymerized with ethylene / butene / octene), polyester-based elastomers, and polyurethane-based elastomers. These can be used individually by 1 type or in combination of 2 or more types. A core-sheath type or side-by-side type composite fiber made of these resins can also be used. In particular, use of a styrene-based elastomer, an olefin-based elastomer, or a combination thereof is preferable in terms of moldability, elastic properties, and cost of the elastic filament 13.

  A suitable combination of the elastic filament 13 and the fibers constituting the nonwoven fabric 11, 12 uses SEBS resin or SEPS resin for the elastic filament 13, and PP / PE core-sheath type composite fiber or PET / PE for the constituent fibers of the nonwoven fabric 11, 12. A combination using PE core-sheath type composite fibers. By adopting this combination, fusion can be performed firmly. In addition, since the melting point of the core is high, the fiber is not completely melted at the time of fusion (the core remains), and the stretchable sheet 10 having a high maximum strength is obtained.

The constituent material of the non-stretchable sheet 2 will be described.
As the non-stretchable sheet 2, nonwoven fabrics produced by various production methods are preferably used, and examples thereof include spunbond nonwoven fabrics, air-through nonwoven fabrics, and needle punched nonwoven fabrics. Among these, a spunbond nonwoven fabric is preferable. The spunbonded nonwoven fabric preferably has a fiber orientation direction that is the same as the direction in which the elastic filament extends.
As the constituent fibers of the nonwoven fabric used as the non-stretchable sheet 2, the first and second nonwoven fabrics 11 and 12 include fibers made of polyethylene (PE), polypropylene (PP), polyester (PET or PBT), polyamide, or the like. Can be mentioned. The fibers constituting the nonwoven fabric used as the non-stretchable sheet 2 may be short fibers or long fibers, and may be hydrophilic or water repellent. Further, core-sheath type or side-by-side composite fibers, split fibers, irregular cross-section fibers, and the like can also be used. These fibers can be used singly or in combination of two or more. The nonwoven can be a continuous filament or short fiber nonwoven. In particular, it is preferably a continuous filament nonwoven fabric.

In the stretchable composite sheet 1 of the present embodiment, the stretchable sheet 10 and the non-stretchable sheet 2 are joined intermittently in which irregularities having different shapes are formed on the stretchable sheet 10 side surface and the non-stretchable sheet 2 side surface. Therefore, it has excellent characteristics such as easy to ensure air permeability, good texture and softness, and good stretch physical properties.
Utilizing one or more of these, the stretchable composite sheet 1 of the present embodiment can be utilized for various applications.
For example, the elastic composite sheet 1 can be used as a sheet constituting a part of the absorbent article. In addition to these uses, it can also be used for various uses such as surgical clothing and cleaning sheets. In particular, it is preferably used as a constituent material of absorbent articles such as disposable diapers, incontinence pads, sanitary napkins, panty liners and the like. As the constituent material, for example, a surface sheet that is a liquid-permeable sheet (including sublayers) located on the skin side of the absorbent body, a sheet that constitutes the outer surface of the disposable diaper, a waistline part and a waist part, Examples thereof include a sheet for imparting elastic stretchability to the leg periphery and the like. Moreover, it can be used as a sheet or the like for forming a stretchable wing of a napkin. Moreover, even if it is another site | part, it can be used for the site | part etc. which want to provide a stretching property.
In addition, when comprising the elastic composite sheet 1 as a part of absorbent article, you may take in part or all of the manufacturing method of an elastic composite sheet as a part in the manufacturing process of an absorbent article.

  As a sheet constituting the outer surface of the disposable diaper, for example, an underpants type comprising an absorbent main body and an exterior body that is positioned on the non-skin contact surface side of the absorbent main body and fixes the absorbent main body It is preferably used as a sheet constituting an exterior body of an absorbent article (pants-type disposable diaper or pants-type sanitary napkin). In this case, the entirety of the exterior body may be composed of a composite stretchable sheet, and the exterior body is disposed on the abdomen side of the wearer, the back side part disposed on the back side, You may comprise only a stomach side part, only a back side part, or only a stomach side part and a back side part at the time of dividing into the crotch part distribute | arranged to a crotch with a composite elastic sheet. The absorbent main body is generally composed of a liquid-permeable top sheet, a liquid-holding absorber, and a liquid-permeable back sheet. Further, in order to reinforce the tightening force of the outer periphery of the waist opening and the periphery of the leg opening, elastic members such as thread rubber and flat rubber can be separately fixed to the periphery of the opening. The pants-type absorbent article, in which a part or all of the exterior body is made of the stretchable composite sheet according to the present invention, except that a composite stretchable sheet is used as a sheet constituting a part or the whole of the exterior body. Can be produced according to conventional methods. Moreover, the manufacturing process of a composite elastic sheet can also be integrated in the manufacturing process of an absorbent article.

Further, in the pant-type absorbent article in which part or all of the exterior body is made of the stretchable composite sheet according to the present invention, the non-stretchable sheet side surface of the stretchable composite sheet is directed to the inner surface side of the exterior body. However, the surface on the non-stretchable sheet side may be directed to the outer surface side.
When the surface of the stretchable composite sheet on the non-stretchable sheet side is located on the inner surface side of the exterior body, the ridges 3 hit the skin, and a space is formed between the valleys between the ridges 3 and the skin. Therefore, air can easily pass and air permeability is good. Moreover, since the part which contacts skin is excellent in cushioning properties, tactile feeling is also good.
On the other hand, when the surface of the stretchable composite sheet on the non-stretchable sheet side is located on the outer surface side of the exterior body, the appearance of the diaper is improved by the regularly formed convex strips 3 existing on the outer surface of the diaper. There are advantages such as.

FIG.11 and FIG.12 is a figure which shows an example of the underpants type disposable diaper which comprises the exterior body using the elastic composite sheet of this invention.
A pants-type disposable diaper 50 (hereinafter also referred to as a diaper 50) shown in FIGS. 11 and 12 is located on the non-skin contact surface side of the absorbent main body 52 including the absorbent core 51 and the absorbent main body 52. And an exterior body 53 that fixes the absorbent main body 52. As shown in FIGS. 11 and 12, the exterior body 53 has an abdominal side A, a crotch C, and a back side B, and both side edges A 1, A 2 of the abdominal side A of the exterior body 53 and Both side edge portions B1 and B2 of the back side portion B are joined together to form a pair of side seal portions 54 and 54, a waist opening portion 55, and a pair of leg opening portions 56 and 56.

  The absorbent main body 52 includes a liquid-permeable surface sheet 57, a liquid-impermeable or water-repellent leak-proof sheet (not shown), and a liquid-retaining absorbent core 51 disposed between the two sheets. ing. As a surface sheet, a leak-proof sheet, and an absorptive core, the thing similar to what was conventionally used for this kind of diaper can be used, respectively. On both sides in the longitudinal direction of the absorbent main body 52, a leak-proof cuff forming sheet 59 having an elastic member 58 at the free end is arranged, and a side leak-proof cuff 60 is formed.

  The exterior body 53 is entirely composed of the stretchable composite sheet according to the present invention, more specifically, the stretchable composite sheet 1 described above. In the stretchable composite sheet 1, the direction in which each of the first and second regions 14 and 15 extends (the X direction in FIGS. 1 to 5) is the diaper longitudinal direction (the longitudinal direction of the outer package 53, in FIG. 12). Same as vertical direction). The exterior body 53 is composed of a single stretchable composite sheet 1 that extends continuously from the abdominal side A, the crotch C, and the back side B. At the opening periphery of each of the waist opening 55 and the pair of leg openings 56, 56, the stretchable composite sheet 1 is folded back to the inner side of the diaper, and the waist elastic member 61 and the leg portion are placed inside the folded portion. The elastic member 62 is fixed. Examples of the material of the elastic members 58, 61, and 62 include synthetic rubbers such as styrene-butadiene, butadiene, isoprene, and neoprene, natural rubber, EVA, stretchable polyolefin, polyurethane, and the like. As a form, a thread-like (thread rubber or the like) or string-like (flat rubber etc.) having a rectangular, square, circular, or polygonal cross section, a multifilament type thread-like thing, or the like can be used.

In the stretchable composite sheet 1 constituting the exterior body 53 of the present diaper 50, the surface on the non-stretchable sheet 2 side described above is directed to the outer surface side of the diaper. For this reason, a large number of the above-described protruding strip portions 3 are formed on the outer surface of the diaper 50 in a worn state, and the appearance of the diaper is excellent. In that case, since the unevenness described above is also formed on the surface of the stretchable sheet 10 side, the touch of the skin is good and a space is formed between the valley and the wearer's skin. It is hard to give a rare touch.
In the pants-type disposable diaper according to another embodiment of the present invention, the stretchable composite sheet 1 constituting the exterior body 53 has the aforementioned non-stretchable sheet 2 side surface directed toward the wearer's skin side, On the inner surface side of the diaper 50 in a worn state, a large number of the above-mentioned protruding strip portions 3 are formed. In that case, a space is formed between the valleys between the ridges 3 and the wearer's skin, the air permeability is good, and the ridges 3 are in contact with the skin, so that the touch is good. It is hard to give a rare touch. Moreover, since the unevenness | corrugation mentioned above is formed also in the surface at the side of the elastic sheet 10, the external appearance of a diaper becomes unique.

When the stretchable composite sheet 1 having a configuration in which the non-stretchable sheet 2 and the stretchable sheet 10 are laminated and integrated with an adhesive is used for the exterior body 53, from the viewpoint of giving the exterior body 53 good air permeability, The basis weight of the adhesive existing between the stretchable sheet 2 and the stretchable sheet 10 is preferably 20 g / m ² or less, more preferably 10 g / m ² or less, and even more preferably 5 g / m ² or less. The basis weight of the adhesive here is the amount (g) per 1 m ² of the elastic composite sheet 1 in the natural state (contracted state) of the adhesive existing between the non-expandable sheet 2 and the elastic sheet 10. is there.

It is preferable that the exterior body 53 is comprised from the composite elastic sheet 1 which has the structure mentioned above at least the part which has fixed the absorptive main body 52. FIG. The portion of the exterior body 53 that fixes the absorbent main body 52 often has low air permeability and flexibility due to an adhesive or the like that fixes the absorbent main body 52. The non-elastic sheet 2 and the elastic sheet 10 are joined to the portion by an intermittent belt-like joint part 4 or have unevenness on the front and back surfaces, whereby the composite elastic sheet 1 having excellent air permeability is obtained. By being present, it is possible to improve the air permeability and flexibility of the portion where the absorbent main body 52 is fixed.
The exterior body 53 may have a different coating basis weight between a certain part and another part. For example, the coating basis weight of the abdominal part A and the back side part B of the exterior body 53 is lowered from the viewpoint of improving air permeability, and the coating basis weight of the crotch part C ensures the adhesion of the leg elastic member 62. From the viewpoint of performing the above, the coating basis weight of the ventral side A and the back side B may be increased.

As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, the elastic sheet 10 used in the above embodiment has a structure in which a large number of elastic filaments 13 are sandwiched between two nonwoven fabrics 11 and 12, but instead of this, on the surface of one nonwoven fabric. The elastic sheet may be formed by joining a large number of elastic filaments.
The stretchable sheet may have a structure in which an elastic film, an elastic nonwoven fabric, an elastic net-like material, or the like is sandwiched between the two nonwoven fabrics 11 and 12 in place of a large number of elastic filaments 13. . In the case where such an elastic sheet is used, as an elastic sheet, the width of the first and second regions extends in addition to the one that has little width shrinkage when extended in the direction orthogonal to the direction in which the first and second regions extend. It is also possible to use a material that has a large width shrinkage when stretched in an orthogonal direction. For example, as an elastic sheet, the one described in JP 2007-177384 A can also be used.

  In the stretchable composite sheet 1 in the above-described embodiment, the pitch P between the tops of the ridges 3 is about twice the pitch of the first region 14 or the second region 15. 3 may be substantially the same as the pitch of the first region 14 or the second region 15. The pitch P can also be adjusted by changing the pitch of the tooth gap roll.

  In the stretchable composite sheet of the present invention, another sheet laminated with the stretchable sheet is a stretchable sheet (a sheet having stretchability but not stretchability) or a second stretchable sheet different from the stretchable sheet. It may be a sheet. Further, as the second stretchable sheet used for another sheet, the same stretchable sheet 10 can be used with a different stretch rate. When an extensible sheet or a second stretchable sheet is used as another sheet, the elongation rate is preferably less than 1.1 times, and the natural state (contracted state) is most preferable. Further, when an extensible sheet or a second stretchable sheet is used as another sheet, the elongation at break when the other sheet is stretched in the direction orthogonal to the direction in which the first and second regions of the stretchable sheet 10 extend. The degree is preferably 10% or more, more preferably 50% or more, and most preferably 100% or more.

Moreover, also in the manufacturing method of embodiment mentioned above, the sheet | seat which joins and joins the elastic sheet 10 in the expansion | extension state is not limited to the non-elastic sheet 2. FIG. Another sheet side that joins and joins the stretchable sheet 10 under the stretched state by joining a stretchable sheet or stretched sheet in a natural state (shrinked state) with the stretchable sheet 10 instead of the non-stretchable sheet 2 A large number of ridges are formed in.

  The stretchable composite sheet of the present invention may have a portion where only one of the stretchable sheet and the non-stretchable sheet overlaps, in addition to the portion where the stretchable sheet and the non-stretchable sheet overlap. Moreover, it may replace with the whole part which the elastic sheet and the non-elastic sheet have overlapped, and the protruding item | line part may be formed only in part. When forming the ridges only on a part of the stretchable composite sheet, the opposing surfaces of the stretchable sheet and the non-stretchable sheet are joined at the above-described band-like joints only in the range where the ridges are formed. Also good. As an example of forming the ridges only on a part, when providing a part that does not form the ridges on the peripheral part of the stretchable composite sheet, the ridges are provided on parts other than the peripheral part of the stretchable composite sheet. When providing the part which does not form, the case where the part which forms a protrusion part in the flow direction of an elastic composite sheet, and the part which does not form a protrusion part are provided alternately, etc. are mentioned. When the stretchable composite sheet is provided with a region where the ridges are not formed, the stretchable sheet and the non-stretchable sheet in the region may be joined by a non-band-like joining portion or may not be joined to each other. .

  The range having the structure shown in FIGS. 1 to 5 is preferably such that at least the dimensions of the first and second regions extend and the natural state dimensions in the direction perpendicular thereto are 1 cm or more, particularly 2 cm or more, The number of ridges formed in the range is preferably 3 or more, particularly 6 or more.

FIG. 1 is a perspective view showing an embodiment (natural state) of the stretchable composite sheet of the present invention. FIG. 2 is a vertical cross-sectional view (cross-sectional view at a belt-like joint portion) in a natural state along the X direction of the stretchable composite sheet shown in FIG. 1. FIG. 3 is a vertical cross-sectional view (cross-sectional view at a non-joining portion) in a natural state along the X direction of the stretchable composite sheet shown in FIG. 1. FIG. 4 is a partially broken perspective view showing the stretchable sheet constituting a part of the stretchable composite sheet shown in FIG. 1 in an expanded state. FIG. 5 is a partially broken perspective view showing a part of the stretchable composite sheet shown in FIG. 1 in an expanded state. FIG. 6 is a schematic view showing an apparatus suitably used for producing the stretchable composite sheet shown in FIG. FIG. 7 is a schematic view showing a state in which the raw sheet of the stretchable sheet is stretched by the apparatus shown in FIG. FIG. 8 is a longitudinal sectional view of the stretchable composite sheet shown in FIG. 1 in a state of being stretched in the X direction. FIG. 9 is a longitudinal sectional view in a contracted state along the direction in which the elastic filament of the stretchable sheet shown in FIG. 4 extends. FIG. 10 is a partially enlarged perspective view schematically showing a part of the elastic sheet side surface of the elastic composite sheet shown in FIG. 1 in the natural state. FIG. 11: is a perspective view which shows the outline of the underpants type disposable diaper which is one Embodiment of the absorbent article of this invention. FIG. 12 is a developed plan view showing a developed and extended state of the diaper shown in FIG.

Explanation of symbols

1 Stretchable composite sheet 2 Non-stretchable sheet (another sheet)
DESCRIPTION OF SYMBOLS 3 Projection part 4 Strip | belt-shaped joining part 5 Non-joining part 6 1st protruding part 7 2nd protruding part 8 Recessed part 10 Elastic sheet 11 1st nonwoven fabric 12 2nd nonwoven fabric 13 Elastic filament 14 1st area | region (it has elastic elasticity) region)
15 2nd area (area that is inferior in elongation than the 1st area)
20,21 Tooth gap roll 50 Pants-type disposable diaper (absorbent article)
52 Absorbent body 53 Exterior body

Claims (10)

An elastic composite sheet having an elastic sheet and another sheet laminated with the elastic sheet,
The stretchable sheet has a first region having elastic stretchability and a second region that is less extensible than the first region, and the first and second regions are formed to extend in one direction and the one direction. It is formed alternately in the orthogonal direction,
The opposing surfaces of the stretchable sheet and the other sheet are joined by a plurality of strip-like joints arranged intermittently extending in the intersecting direction intersecting the one direction,
As a whole composite sheet, it has elasticity in at least the crossing direction ,
The another sheet is a non-stretchable sheet,
A stretchable composite sheet in which a number of ridges extending along the one direction are formed on the surface on the other sheet side in a natural state. In natural state, the surface of the stretchable sheet side, recess surrounded on all sides by the raised portion is formed, stretchable composite sheet according to claim 1, wherein.   When the stretchable sheet is stretched 2.0 times in the direction orthogonal to the direction in which the first and second regions extend, the ratio of width shrinkage ((width at stretch / width before stretch) × 100) The stretchable composite sheet according to claim 1, which is 70 to 100% of the width before stretching. The width W1 of the strip-shaped junction, 20 to 200% of the width W2 between the strip junctions adjacent stretchable composite sheet according to any one of claims 1-3. The stretchable sheet is formed by extending the stretched sheet between a pair of concavo-convex surfaces alternately having protrusions and grooves and engaging the first and second regions. it is obtained by forming a stretchable composite sheet according to any one of claims 1-4. The elastic sheet has a large number of elastic filaments bonded to an extensible nonwoven fabric over the entire length thereof in a substantially non-extended state, and the first region is a region formed by being largely stretched. There, the second region, the first compared to the area which is an area that was hardly stretched, stretchable composite sheet according to any one of claims 1-5. The stretchable composite sheet according to any one of claims 1 to 6, wherein the non-stretchable sheet and the stretchable sheet as the other sheets are joined together under the stretched state of the stretchable sheet. Absorbent articles in part from stretchable composite sheet is formed according to item 1 to claim 1-7. The absorbent article is a pants-type absorbent article comprising an absorbent main body and an exterior body that is positioned on the non-skin contact surface side of the absorbent main body and fixes the absorbent main body,
Wherein at least a part or all of the exterior body, the absorbent article according to claim 8, wherein the comprises a composite stretchable sheet according to any one of claims 1-7. The absorbent article according to claim 9 , wherein at least a portion of the exterior body that fixes the absorbent main body is formed of the composite stretchable sheet.

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