JP6468803B2 - Laminated nonwoven fabric - Google Patents

Description

  The present invention relates to a laminated nonwoven fabric.

In absorbent articles such as sanitary napkins, panty liners, disposable diapers, etc., a nonwoven fabric with a concavo-convex structure or a nonwoven fabric with a two-layer structure is used depending on its function.
For example, the nonwoven fabric having a concavo-convex structure of Patent Document 1 has a single-layer structure, and has a concavo-convex structure on the first surface side and the second surface side which is the opposite surface. This nonwoven fabric has fiber orientation along the direction connecting the first projecting portion that is convex on the first surface side and the second projecting portion that is convex on the second surface side.

  Moreover, the nonwoven fabric of the two-layer structure of patent document 2 has an unevenness | corrugation in the 1st surface side and the 2nd surface side of the opposite surface. As for this nonwoven fabric, the 1st layer and the 2nd layer are joined over the whole surface. Moreover, it has the 1st protrusion part which becomes convex seeing from the 1st surface side, and the hollow part which becomes concave, and the 2nd protrusion seen from the bottom part of the hollow part from the top part of the 1st protrusion part, ie, the 2nd surface side. It has fiber orientation in the direction connecting the top of the part.

  Further, the laminated nonwoven fabric of Patent Document 3 is formed into a concavo-convex shape including thermoplastic fibers, and an unfused fiber web is laminated as a second fiber layer on the thermally fused first fiber layer. The laminated nonwoven fabric forms a second fiber layer in which the first fiber layer and the second fiber layer are heated with hot air to thermally bond the fibers of the fiber web. And the fiber of the 1st fiber layer and the fiber of the 2nd fiber layer are joined by heat fusion. The uneven shape has a lower density in the order of the convex portion of the first fiber layer, the lower portion of the convex portion of the second fiber layer, and the upper portion of the second fiber layer. Moreover, the fiber which comprises the wall part of a 1st fiber layer has fiber orientation in the direction which connects the top part of a convex part, and the bottom part of a recessed part. However, the second fiber layer does not have orientation. Furthermore, there is a space between the convex portion of the first fiber layer and the convex portion of the second fiber layer.

  Furthermore, the two-layer nonwoven fabric of Patent Document 4 is a top sheet having a first layer and a second layer. The surface sheet has a large number of skin contact convex portions formed by protruding part of the first layer toward the skin contact surface side, and part of each of the first layer and the second layer is on the non-skin contact surface side. And a liquid introduction recess formed by a large number of emboss joints. The first layer and the second layer are joined to each other at the lower end of the liquid introduction recess to form a joint, and the first layer is longer than the second layer between adjacent joints. The layers and the second layer are wavy in cross section. Moreover, it has an opening part in the bottom part of a liquid introduction recessed part.

JP 2012-136790 A JP 2014-012913 A JP 2013-124428 A JP 2009-089965 A

Since the nonwoven fabric of Patent Document 1 is a single layer, there is no gap in the nonwoven fabric, and the nonwoven fabric of Patent Document 2 has no gap between the layers because the first layer and the second layer are bonded over the entire surface. Therefore, there is room for improving the touch when the load is low.
In the nonwoven fabric of patent document 3, since only the upper layer has orientation in a wall part, there was room for improving the liquid return property under high load. Moreover, since the fiber density of the lower layer is lower than the fiber density of the upper layer in the convex portion, there is room for improving the liquid drawability and the liquid return property.
In the surface sheet (nonwoven fabric) of Patent Document 4, since the wall portion does not have orientation, there is room for improving the liquid return property under a high load. Moreover, since the clearance for the purpose of improving the texture is not designed, there is room for improving the texture. Furthermore, since the liquid introduction recess is formed by emboss bonding, the upper layer is not easily crushed, so there is room for improving the texture from this point. Furthermore, since the bottom of the recess has an opening, there is room for improving the liquid return property.

  An object of the present invention is to provide a laminated nonwoven fabric that enables an absorbent article having a good touch and a small amount of liquid return, and a method for producing the same.

The laminated nonwoven fabric of the present invention has a convex portion projecting to the first surface side on the side of the planar view of the sheet-like laminated nonwoven fabric, and a concave portion recessed on the second surface side opposite to the first surface side. The convex portions and the concave portions are alternately and continuously arranged in different directions intersecting in plan view of the laminated nonwoven fabric,
The laminated nonwoven fabric has a first fiber layer and a second fiber layer,
Having a gap between the first convex part of the first fiber layer and the second convex part of the second fiber layer;
The first wall layer disposed between the top of the first convex portion and the bottom of the concave portion in the first fiber layer, and the top of the second convex portion and the bottom of the concave portion in the second fiber layer. The second wall portion provides a laminated nonwoven fabric having fiber orientation in the thickness direction at any position.

  The laminated nonwoven fabric of the present invention gives the absorbent article a function with excellent touch under a low load. In addition, the liquid return amount is reduced under a high load, and the liquid return property is improved.

1 is a partial cross-sectional perspective view schematically showing a preferred embodiment of a laminated nonwoven fabric according to the present invention. It is sectional drawing which showed typically the principal part cross section of the laminated nonwoven fabric under a low load. It is sectional drawing which showed the principal part cross section of the laminated nonwoven fabric under a high load typically. It is the schematic block diagram which showed preferable embodiment (1st Embodiment) of the manufacturing method of the laminated nonwoven fabric which concerns on this invention. It is the schematic block diagram which showed another preferable embodiment (2nd Embodiment) of the manufacturing method of the laminated nonwoven fabric which concerns on this invention. It is the partially cutaway perspective view which showed typically the disposable diaper as one preferable embodiment of the absorbent article using the surface sheet which concerns on this invention.

A preferred embodiment (first embodiment) of the laminated nonwoven fabric according to the present invention will be described below with reference to FIG.
The laminated nonwoven fabric 10 of the present invention is preferably applied to a top sheet of an absorbent article such as a sanitary napkin or a disposable diaper. At that time, it is preferable to use the first surface side Z1 facing the wearer's skin surface and the second surface side Z2 arranged on the absorber (not shown) side inside the article. Hereinafter, it demonstrates considering the embodiment which uses 1st surface side Z1 of the laminated nonwoven fabric 10 shown in drawing toward a wearer's skin surface. The present invention is not construed as being limited thereby.

  As shown in FIG. 1, the sheet-like laminated nonwoven fabric 10 has a first convex portion 11 </ b> A and a second convex portion 11 </ b> B that are convex portions 11 projecting to the first surface side Z <b> 1 on the side in plan view. The laminated nonwoven fabric 10 has a first recess 12A and a second recess 12B, which are recesses 12 recessed in the second surface side Z2 opposite to the first surface side Z1. The first recess 12A and the second recess 12B are joined. Moreover, the convex part 11 and the recessed part 12 are alternately distribute | arranged to each of the different direction which crosses planar view of this laminated nonwoven fabric 10 alternately. Specifically, they are alternately and continuously arranged in the X direction and the Y direction that intersect in plan view. The Z direction is the thickness direction of the nonwoven fabric.

  The laminated nonwoven fabric 10 has a first fiber layer 10A and a second fiber layer 10B. There is a gap 13 between the first convex portion 11A of the first fiber layer 10A and the second convex portion 11B of the second fiber layer 10B. Accordingly, the first fiber layer 10A and the second fiber layer 10B are separated from each other by the gap 13 in the other region where the first recess 12A and the second recess 12B are joined. In other words, the second convex portion 11B is arranged corresponding to the position where the first convex portion 11A is arranged, and the second concave portion 12B is arranged corresponding to the position where the first concave portion 12A is arranged. ing.

  The first wall portion 14A is distributed between the top portion 11AT of the first convex portion 11A and the bottom portion 12AB of the first concave portion 12A in the first fiber layer 10A. The second wall portion 14B is disposed between the top portion 11BT of the second convex portion 11B and the bottom portion 12BB of the second concave portion 12B in the second fiber layer 10B. At any position of the first wall portion 14A and the second wall portion 14B, it has fiber orientation in the thickness direction.

Each top part, wall part, and bottom part in the laminated nonwoven fabric 10 are defined as follows. In the first fiber layer 10A, the nonwoven fabric thickness T1 is divided into three equal parts. The upper part PA1 is the top part 11AT of the first convex part 11A, the intermediate part PA3 is the first wall part 14A, and the lower part PA2 is the bottom part 12AB of the first concave part 12A. Further, the nonwoven fabric thickness T2 of the second fiber layer 10B is divided into three equal parts, the upper PB1 being the top 11BT of the second convex part 11B, the intermediate part PB3 being the second wall part 14B, and the lower PB2 being the bottom part 12BB of the second concave part 12B. .
The thickness of the nonwoven fabric is measured with a digital microscope VHX-1000 manufactured by Keyence Co., Ltd., with the nonwoven fabric specimen cut into a cross section in the CD direction and the cut surface thereof being unloaded. At that time, the measurement site is enlarged to a size (10 to 100 times) that can be sufficiently measured by entering the visual field.

The laminated nonwoven fabric 10 has room for the first fiber layer 10A to sink into the gap 13 when a load is applied due to the presence of the gap 13 between the layers. Therefore, at the time of a low load (1.00 gf / cm ² ), the first convex portion 11A is easily crushed so as to fill the gap 13.
On the other hand, when the load is high (3.5 kPa), the first fiber layer 10A and the second fiber layer 10B are less likely to be crushed in a state where the gap 13 is eliminated. This balances, for example, a gentle touch when a person touches the surface lightly and a sense of security when the person keeps touching with a strong force. When this laminated nonwoven fabric 10 is incorporated into an absorbent article, a gentle touch can be felt from the preparation stage before wearing, and a comfortable wearing feeling can be obtained.
In addition, under high load, due to the gap 13, the two convex portions (the first convex portion 11A and the second convex portion 11B) are not suddenly crushed and gradually collapsed from the first convex portion 11A. become. For this reason, the impact to skin is relieved and it has a gentle cushioning property. In this way, the first convex portion 11A is crushed so that the gap 13 is not lost. When a load is further applied, the first fiber layer 10A and the second fiber layer 10B are integrated. For this reason, under a high load, the load is received by the two layers of the first fiber layer 10A and the second fiber layer 10B. Thus, since the load is received by the two layers, the first convex portion 11A is not easily crushed. And since it has fiber orientation in the thickness direction in any position of 14A of 1st wall parts and 14B of 2nd wall parts, the crushing difficulty of 11 A of 1st convex parts is raised further.
As a result, when the laminated nonwoven fabric 10 is incorporated into the absorbent article as a top sheet as described above, the thickness of the top sheet is maintained. For this reason, a liquid becomes difficult to return toward the skin surface (not shown) distribute | arranged to the 1st fiber layer 10A side from the absorber (not shown) normally distribute | arranged to the 2nd fiber layer 10B side. Therefore, the liquid return amount is reduced and the liquid return property is improved.

  In the present embodiment, the first convex portion 11A and the second convex portion 11B have a truncated cone shape or a hemispherical shape with rounded tops. In addition, 11 A of 1st convex parts and the 2nd convex part 11B are not limited to the said shape, What kind of protrusion form may be sufficient, for example, it is practical that they are various cone shapes. In the present specification, the term “conical shape” means that a cone, a truncated cone, a pyramid, a truncated pyramid, an oblique cone, and the like are included. The inner space of the first convex portion 11A is a gap 13 between the second convex portion 11B, and this gap 13 is a truncated cone-shaped or hemispherical inner space with a rounded top.

The first fiber layer 10A shaped in a concavo-convex shape has a wall portion 14A (15) on the lower side of the top portion (hereinafter also referred to as a convex portion top portion) in the first convex portion 11A. The wall portion 15 forms an annular structure at the first convex portion 11A. The first recess 12A has a wall portion 14A (16) continuous with the wall portion 15 on the upper side of the bottom portion 12AB (hereinafter also referred to as a recess bottom portion). The wall portion 16 has an annular structure in the first recess 12A. The “annular” here is not particularly limited as long as it has an endless series of shapes in plan view. Therefore, it may have any shape such as a circle, an ellipse, a rectangle, or a polygon in plan view. In order to maintain the continuous state of the sheet suitably, a circle or an ellipse is preferable. Furthermore, if the "annular" is considered as a three-dimensional shape, a cylindrical shape, a slanted columnar shape, an elliptical columnar shape, a truncated cone shape, a truncated oblique cone shape, a truncated elliptical cone shape, a truncated quadrangular pyramid shape, a truncated oblique pyramid shape Arbitrary ring structures, such as a shape, are mentioned, In order to implement | achieve a continuous sheet | seat state, cylindrical shape, elliptic cylinder shape, truncated cone shape, and truncated elliptical cone shape are preferable.
Regarding the structure of the wall portion 14, the second fiber layer 10B has the same structure as the first fiber layer 10A.

Each of the first fiber layer 10A and the second fiber layer 10B of the laminated nonwoven fabric 10 does not have a bent portion, and is composed of a curved surface that is continuous as a whole. Thereby, it becomes a sheet | seat shape without a level | step difference in the surface, and the touch of the laminated nonwoven fabric 10 surface becomes good.
Thus, the laminated nonwoven fabric 10 preferably has a continuous structure in the surface direction. This “continuous” means that there are no intermittent portions or small holes. However, fine holes such as gaps between fibers are not included in the small holes. The small hole can be defined, for example, as a hole having a diameter equivalent to a circle of 1.0 mm or more.

  The fiber material that can be used for the laminated nonwoven fabric 10 of the present invention is not particularly limited. Specific examples include the following fiber materials. Examples thereof include fibers made by using a thermoplastic resin such as a polyolefin resin such as polyethylene (PE) or polypropylene (PP), a polyester resin such as polyethylene terephthalate (PET), or a polyamide resin. Moreover, the composite fiber of structures, such as a core sheath type and a side-by-side type, is mentioned. Representative examples of the core-sheath fiber include core-sheath fibers such as PET (core) and PE (sheath), PP (core) and PE (sheath), and PP (core) and low melting point PP (sheath). It is done. Moreover, these fibers may be used alone to form a nonwoven fabric, or may be used as a mixed fiber in which two or more kinds are combined.

  The fibers constituting the first and second wall portions 14A and 14B have fiber orientation in the Z direction, which is the thickness direction, at any position of the first and second wall portions 14A and 14B. In other words, the fibers of the first wall portion 14A have fiber orientation in the direction connecting the convex top portion 11AT of the first convex portion 11A and the first concave bottom portion 12AB of the first concave portion 12A. Further, the fibers of the second wall portion 14B have fiber orientation in the direction connecting the convex top portion 11BT of the second convex portion 11B and the first concave bottom portion 12BB of the second concave portion 12B. Therefore, when viewed in a plan view, it has a radial fiber orientation toward the convex top 11AT and the concave bottom 12BB. The second fiber layer 10B is also oriented in the same manner as the fiber orientation of the first fiber layer 10A. In the present invention, having fiber orientation in the thickness direction means having fibers in a line in the thickness direction. Specifically, in the measurement method described later, it means that the orientation angle is 50 ° or more and 130 ° or less and the orientation strength is 1.05 or more. When the fiber is oriented in the thickness direction, the gap 13 is crushed at high loads, so that it has a great effect of receiving the compressive deformation of the first convex portion 11A and the second convex portion 11B, preventing crushing, and maintaining the thickness. . When the fiber orientation is in the horizontal direction, the effect of preventing crushing at high loads is reduced and the thickness is reduced. Preventing crushing under high load, reducing the amount of liquid return, and having a gap between the first fiber layer 10A and the second fiber layer 10B at low load makes it easy to crush under low load and has a good touch To. From such a viewpoint, the fiber orientation angle in the CD direction of the first wall portion 14A is 50 ° or more, preferably 70 ° or more, and more preferably 75 ° or more. And it is 130 degrees or less, Preferably it is 110 degrees or less, More preferably, it is 105 degrees or less. Moreover, they are 50 degree or more and 130 degrees or less, Preferably they are 70 degrees or more and 110 degrees or less, More preferably, they are 75 degrees or more and 105 degrees or less. The fiber orientation strength in the CD direction of the first wall portion 14A is 1.05 or more, preferably 1.2 or more, and more preferably 1.3 or more. The fiber orientation angle in the CD direction of the second wall portion 14B is 50 ° or more, preferably 55 ° or more, and more preferably 60 ° or more. And it is 130 degrees or less, Preferably it is 125 degrees or less, More preferably, it is 120 degrees or less. Moreover, they are 50 degree or more and 130 degrees or less, Preferably they are 55 degrees or more and 125 degrees or less, More preferably, they are 60 degrees or more and 120 degrees or less. The fiber orientation strength in the CD direction of the second wall portion 14B is 1.05 or more, preferably 1.07 or more, and more preferably 1.1 or more. By setting the fiber orientation angle and fiber orientation strength as described above, the load in the thickness direction is firmly received, and the first and second convex portions 11A and 11B can be crushed even under high loads. Disappear. As a result, the liquid return amount can be reduced.

In the laminated nonwoven fabric 10, the overall thickness of the laminated nonwoven fabric 10 is TS, and the overall thickness of the second fiber layer 10B is T2. More specifically, TS is the total thickness in the Z direction when the laminated nonwoven fabric 10 is viewed from the side. T2 is the overall thickness in the Z direction when the second fiber layer 10B is viewed from the side.
Then, from the viewpoint of reducing the liquid return amount, T2 / TS is 50% or more, preferably 52% or more, and more preferably 55% or more. From the viewpoint of securing a gap, facilitating crushing under a low load, and improving the touch, T2 / TS is 90% or less, preferably 87% or less, and more preferably 85% or less. Further, T2 / TS is 50% or more and 90% or less, preferably 52% or more and 87% or less, and more preferably 55% or more and 85% or less.

In the laminated nonwoven fabric 10, the gap 13 is preferably crushed under a load of 3.5 kPa, and the inside of the first convex portion 11A and the outside of the second convex portion 11B are preferably in contact with each other. Accordingly, the load is received by the two layers of the first fiber layer and the second fiber layer under a high load of 3.5 kPa assuming the pressure when the wearer is seated. As a result, it becomes difficult for the liquid to return from the absorbent body normally disposed on the second fiber layer side toward the skin surface disposed on the first fiber layer side.
The collapsed state of the laminated nonwoven fabric 10 under a load of 3.5 kPa is observed as follows. For example, a non-woven fabric test body is cut into a cross section in the CD direction, and the cut surface is observed using a digital microscope VHX-1000 manufactured by Keyence Corporation. At that time, the observation site is sufficiently entered into the field of view of the microscope and enlarged to a size that allows observation (10 to 100 times). And in the state which applied the load of 3.5 kPa to the nonwoven fabric, the cross section of the laminated nonwoven fabric 10 is observed, it confirms that there is no gap | interval 13, and measures the whole thickness.

In the first embodiment, the fiber density decreases in the order of the concave portion 12, the top portion 11BT of the second convex portion 11B of the second fiber layer 10B, and the top portion 11AT of the first convex portion 11A of the first fiber layer 10A.
The fiber density was evaluated by measuring the number of fibers per 1 mm ² . That is, as the number of fibers per 1 mm ² is larger, the fiber density is higher.
The fiber density of the recesses 12 is preferably 250 / mm ² or more, more preferably 300 / mm ² or more, from the viewpoint of making it difficult to crush under a high load and reducing the liquid return amount. And it is preferably 500 / mm ² or less, more preferably 450 / mm ² or less. Further, it is preferably 250 / mm ² or more and 500 / mm ² or less, more preferably 300 / mm ² or more and 450 / mm ² or less.
The fiber density of the first convex portion 11A of the first fiber layer 10A is preferably 50 / mm ² or more, more preferably 70 / mm, from the viewpoint of easily crushing under a low load and improving the touch. ² or more. And it is preferably 180 / mm ² or less, more preferably 150 / mm ² or less. Further, it is preferably 50 / mm ² or more and 180 / mm ² or less, more preferably 70 / mm ² or more and 150 / mm ² or less.
Since the order of the fiber density is as described above, the laminated nonwoven fabric 10 of the first embodiment is preferably used when the excreta is a highly viscous liquid and excreted in a small amount (menstrual blood, loose stool). This is because a density gradient occurs between the first convex portion 11A of the first fiber layer 10A and the second convex portion 11B of the second fiber layer 10B, so that the drawability of the liquid into the second fiber layer 10B is increased, and the skin This is because the remaining liquid amount of the first fiber layer that comes into contact with can be reduced. The fiber density in the 2nd convex part 11B of the 2nd fiber layer 10B at that time becomes like this. Preferably it is 120 piece / mm < ² > or more, More preferably, it is 150 piece / mm < ² > or more. And it is preferably 330 / mm ² or less, more preferably 300 / mm ² or less. Further, it is preferably 120 / mm ² or more and 330 / mm ² or less, more preferably 150 / mm ² or more and 300 / mm ² or less.

Further, in the laminated nonwoven fabric 10, the fiber density of the second convex portion 11B and the first convex portion 11A is lower than that of the concave portion 12. For this reason, even if a low load of 0.30 gf / cm ² to 1.00 gf / cm ² is applied, the first convex portion 11A of the first fiber layer 10A is easily crushed and the touch is improved. Usually, the load when a human touches an absorbent article feels the touch with a very light load of around 1 g / cm ² . In order to express the original touch, characteristic values in a range smaller than the conventional load are useful. The low load of 0.30 gf / cm ² to 1.00 gf / cm ^{2 is} a load that a wearer, an infant's mother, or the like feels comfortable when touching the absorbent article directly with the skin.
Further, under a high load of 3.5 kPa, the gap 13 is crushed, and the first convex portion 11A of the first fiber layer 10A and the second convex portion 11B of the second fiber 10B come into contact with each other and are integrated. . For this reason, even under a heavy load, the first convex portion 11A and the second convex portion 11B are not easily crushed. Therefore, when an absorbent body (not shown) is disposed below the laminated nonwoven fabric 10, it is difficult for the liquid absorbed by the absorbent body to return to the upper skin surface side of the laminated nonwoven fabric 10. Thereby, it becomes the laminated nonwoven fabric 10 excellent in the liquid return property. Therefore, the laminated nonwoven fabric 10 can achieve both improvement in touch and reduction in the liquid return amount.

Next, the dimension specification in the laminated nonwoven fabric 10 of this embodiment is demonstrated below.
What is necessary is just to adjust the whole thickness TS of the laminated nonwoven fabric 10 suitably according to a use. For example, when used as a surface sheet of diapers, sanitary products, etc., the total thickness TS of the laminated nonwoven fabric 10 is preferably 1 mm or more, more preferably 1.5 mm or more. And preferably it is 7 mm or less, More preferably, it is 5 mm or less. Moreover, Preferably they are 1 mm or more and 7 mm or less, More preferably, they are 1.5 mm or more and 5 mm or less. By setting it as this range, the liquid return from the absorber at the time of use can be suppressed, and furthermore, an excellent touch can be realized. The overall thickness T2 of the second fiber layer 10B may be appropriately adjusted depending on the application.
What is necessary is just to adjust the space | interval of the said convex parts 11 suitably according to a use. Moreover, the basic weight of the said laminated nonwoven fabric 10 is not specifically limited. For example, the average value of the entire sheet is 15 g / m ² or more, preferably 20 g / m ² or more. And it is 70 g / m < ² > or less, Preferably it is 40 g / m < ² > or less. Further, 15 g / ^{m 2} or more 70 g / ^{m 2} or less, preferably 20 g / ^{m 2} or more 40 g / ^{m 2} or less.

The laminated nonwoven fabric 10 described in the above embodiment has the following effects.
The laminated nonwoven fabric 10 has an excellent feel at a low load.
As shown in FIG. 2, the laminated nonwoven fabric 10 of the present embodiment has a gap 13 between the first convex portion 11A of the first fiber layer 10A and the second convex portion 11B of the second fiber layer 10B. 12 is joined. Therefore, when a low load WL is applied to the laminated nonwoven fabric 10, the first convex portion 11 </ b> A of the first fiber layer 10 </ b> A is easily moved and easily crushed. From this, even if it is a case where the skin touches and the 1st fiber layer 10A surface is stroked, the 1st convex part 11A will move sensitively with a skin surface. The ease of movement of the first convex portion 11A gives a feeling that the touch is excellent on the skin surface. Thus, the load that the wearer or the mother of an infant touches the absorbent article directly and feels good touch is the low load. Therefore, a particularly excellent touch is exhibited.
In addition, there is a correlation between the compression characteristic value (easiness of crushing) at the time of low load and the touch (see Japanese Patent Application No. 2012-092475). That is, the lower the compression characteristic value at the time of low load, the easier it is to be crushed, and it is possible to express the good feeling of feeling human touch.
On the other hand, even if it is a laminated nonwoven fabric, as in the invention described in Patent Document 2 described above, in the laminated nonwoven fabric without the gap 13, the first fiber layer on the skin surface side is sensitive to the movement of the skin surface. Because it does not follow, the touch is not exceptional.

The laminated nonwoven fabric 10 is excellent in a small liquid return amount under a high load.
As shown in FIG. 3, under a high load WH, the gap 13 (see FIG. 2) is crushed and the first fiber layer 10A and the second fiber layer 10B are integrated. For this reason, as the whole laminated nonwoven fabric 10, it becomes difficult to be crushed in the thickness direction. And the wall part 14 has fiber orientation in the thickness direction. Due to these synergistic effects, the convex portion 11 is not easily crushed even under a high load WH, so that the liquid return amount is reduced as described above.

  Moreover, since the said laminated nonwoven fabric 10 will be in a state like a point contact with respect to the 1st convex part 11A, the said laminated nonwoven fabric 10 follows well also to the three-dimensional movement of a skin surface. Furthermore, since the wall part 14 has fiber orientation in the thickness direction, it exhibits cushioning properties. Moreover, even if it is crushed, the shape restoring force becomes large, and the initial cushioning force is easily maintained even if the packaging state and wearing are continued. That is, under the high load WH, the convex portion 11 and the concave portion 12 are not easily crushed and are likely to recover even if deformation occurs.

Next, a preferred embodiment (first embodiment) of the method for producing a laminated nonwoven fabric according to the present invention will be described below with reference to the drawings.
As shown in FIG. 5, a support body 100 having a concavo-convex shape and having air permeability is prepared by providing a protruding portion 110. A first fiber web 31 having a predetermined thickness is supplied by a card machine (not shown) to the upper surface side of the support body 100 where the protruding portions 110 are arranged. The support body 100 is arranged so that the protrusion 110 corresponds to the position where the concave portion of the first fiber layer is disposed, and the ventilation portion (not shown) corresponds to the position where the first convex portion of the first fiber layer is disposed. It is arranged to do.
Examples of the fiber material that can be used for the fibers of the first fiber web 31 include the above-described fibers.

  Then, a first air-through process is performed in which the first hot air W <b> 1 indicated by an arrow is blown onto the first fiber web 31 to follow the uneven shape of the breathable support body 100. In the first air-through process, the first hot air W1 is blown from the first nozzle (not shown) to the first fiber web 31 fed to the surface of the support 100. At this time, the first hot air W <b> 1 is blown from the vertical direction against the surface of the first fiber web 31 placed on the support body 100. The number of blowouts of the first nozzle may be a plurality of locations along the conveying direction of the first fiber web 31.

By the first hot air W1, the first fiber web 31 follows the shape of the protruding portion 110 of the support body 100 and is shaped into an uneven shape. At this time, the temperature of the first hot air W1 is not uniquely determined because it varies depending on the type of fiber, the processing speed, the speed of the hot air, and the like. The temperature of the first hot air W1 is preferably a temperature equal to or lower than the melting point of the thermoplastic fibers constituting the first fiber web 31, and more preferably a temperature lower than this melting point by 5 ° C. or more. And it is preferably a temperature lower than this melting point in the range of 70 ° C. or lower, more preferably a temperature lower than this melting point in the range of 50 ° C. or lower. Further, the temperature is preferably 0 to 70 ° C. lower than the melting point, and more preferably 5 to 50 ° C. lower than the melting point.
In addition, when the temperature of the 1st hot air W1 is too low, the return of a fiber will arise and a shaping property will fall. On the other hand, when the temperature of the 1st hot air W1 is too high, fibers will melt | fuse at a stretch and shaping will be impaired by the fall of a freedom degree.

  Moreover, the wind speed of the 1st hot air W1 becomes like this. Preferably it is 20 m / sec or more, More preferably, it is 30 m / sec or more. And preferably it is 150 m / sec or less, More preferably, it is 100 m / sec or less. Moreover, it is preferably 20 m / sec or more and 150 m / sec or less, more preferably 30 m / sec or more and 100 m / sec or less. When the wind speed of the 1st hot air W1 is too slow, sufficient shaping cannot be performed and shaping property may be impaired. On the other hand, when the wind speed of the 1st hot air W1 is too high, the fiber of the 1st fiber web 31 will be sorted by the projection-shaped part 110, and will be in the state which was shaped too much.

Furthermore, the spray time of the first hot air W1 is preferably 0.01 seconds or more, and more preferably 0.04 seconds or more. And preferably it is 0.5 second or less, More preferably, it is 0.08 second or less. Moreover, it is preferably 0.01 seconds or more and 0.5 seconds or less, and more preferably 0.04 seconds or more and 0.08 seconds or less. If the spraying time is too short, shaping of the fibers of the first fiber web 31 becomes insufficient, and shaping that sufficiently follows the uneven shape cannot be performed. On the other hand, if the spraying time of the first hot air W1 is too long, the fibers of the first fiber web 31 are sorted by the protruding portions 110 and become too shaped.
And the 1st hot air W1 which passed the 1st fiber web 31 is discharged | emitted through the ventilation part of the support body 100 outside.

Next, the second fiber web 33 is transported onto the first fiber web 31 while the first fiber web 31 is transported along the uneven shape of the surface of the support 100. Examples of the fiber material that can be used for the fibers of the second fiber web 33 include the above-described fibers.
The second hot air W2 indicated by an arrow is blown onto the second fiber web 33, the gap 13 is disposed between the first fiber web 31 and the second fiber web 33, and the second fiber web 33 is supported on the support 100. A second air-through process is performed in which the shape is made to follow the uneven shape. At this time, the second hot air W <b> 2 is blown from the direction perpendicular to the surface of the second fiber web 33. Moreover, it is preferable that the number of blowouts of a second nozzle (not shown) that blows the second hot air W <b> 2 is a plurality of places along the conveyance direction of the second fiber web 33.

By the second hot air W2, the second fiber web 33 follows the shape of the protruding portion 110 of the support 100, and the gap 13 is arranged between the first fiber web 31 and shaped into an uneven shape. Is done. A portion where the gap 13 is disposed corresponds to a ventilation portion of the support body 100 through which the second hot air W2 blows. The temperature of the second hot air W2 at this time is preferably a temperature not higher than the melting point of the thermoplastic fibers constituting the web 33, and more preferably 5 ° C. or more lower than this melting point. And it is preferably a temperature lower than this melting point in the range of 70 ° C. or lower, more preferably a temperature lower than this melting point in the range of 50 ° C. or lower. Further, the temperature is preferably 0 to 70 ° C. lower than the melting point, and more preferably 5 to 50 ° C. lower than the melting point.
In addition, when the temperature of the 2nd hot air W2 is too low, a return of a fiber will occur and a shaping property will fall. On the other hand, when the temperature of the second hot air W2 is too high, the fibers are fused at a stretch, and the formability is impaired due to a decrease in the degree of freedom.

  Moreover, the wind speed of the 2nd hot air W2 is set slower than the wind speed of the 1st hot air W1, Preferably it is 10 m / sec or more, More preferably, it is 20 m / sec or more. And it is preferably 140 m / sec or less, more preferably 110 m / sec or less. Moreover, it is preferably 10 m / sec or more and 140 m / sec or less, and more preferably 20 m / sec or more and 110 m / sec or less. If the wind speed of the second hot air W2 is too slow, sufficient shaping cannot be performed, and the shaping may be impaired. On the other hand, if the wind speed of the second hot air W2 is too fast, the fibers of the second fiber web 33 come into contact with the first fiber web 31, and if the wind speed is too fast, the fibers are selected by the protruding portions 110 and are too shaped. It becomes a state.

Furthermore, the spraying time of the second hot air W2 is preferably 0.01 seconds or more, and more preferably 0.04 seconds or more. And preferably it is 0.5 second or less, More preferably, it is 0.08 second or less. Moreover, it is preferably 0.01 seconds or more and 0.5 seconds or less, and more preferably 0.04 seconds or more and 0.08 seconds or less. If the spraying time is too short, the shaping of the second fiber web 33 becomes insufficient, and shaping that sufficiently follows the uneven shape cannot be performed. On the other hand, if the blowing time of the second hot air W2 is too long, the second fiber web 33 comes into contact with the first fiber web 31, and the gap 13 cannot be obtained. If the length is too long, the fibers of the second fiber web 33 are sorted out by the protruding portions 110 and become too shaped.
And the 2nd hot air W2 which passed the 2nd fiber web 33 is discharged | emitted through the ventilation part of the support body 100 outside.

Next, in a state where the first fiber web 31 and the second fiber web 33 are shaped and the gap 13 is maintained, the first fiber web 31 and the second fiber web 33 are moved, and the third fiber indicated by the arrow is moved. Hot air W3 is blown. And simultaneously with the heat fusion fiber What happened fibers What happened and the second fiber web 33 of the first fibrous web 31, joined by heat fusion fibers of the first fibrous web 31 and the second fiber web 33 . At this time, the gap 13 is maintained. In this way, a first fiber layer 10A composed of the first fiber web 31 and a second fiber layer 10B composed of the second fiber web 33 are obtained.

The temperature of the third hot air W3 is not uniquely determined because it varies depending on the type of fiber, the processing speed, the wind speed of the hot air, and the like. Considering the fiber material used for the nonwoven fabric 10, the temperature of the third hot air W3 is a temperature equal to or higher than the melting point of the melting point of the thermoplastic fibers constituting the first fiber web 31 and the second fiber web 33. The temperature is preferably 5 ° C. or more higher than this melting point. Preferably, the temperature is higher in the range of 70 ° C. or lower than the melting point, and more preferably higher in the range of 50 ° C. or lower than the melting point.
Moreover, when the temperature of the 3rd hot air W3 is too low, the retainability of uneven | corrugated shape falls, and when temperature is too high, fibers will be melt | fused too much and a feeling will worsen and it will become difficult to bulk.

The wind speed of the third hot air W3 is set slower than the first hot air W1 and the second hot air W2, and is preferably 1 m / sec or more, more preferably 3 m / sec or more. And preferably it is 10 m / sec or less, More preferably, it is 8 m / sec or less. Moreover, it is preferably 1 m / sec or more and 10 m / sec or less, more preferably 3 m / sec or more and 8 m / sec or less. For the third hot air W3 is the purpose of fusion of fibers the same workers, no fast wind speed is necessary. On the other hand, if the wind speed of the third hot air W3 is too slow, the fibers are excessively fused with each other, resulting in poor texture and less bulk. On the other hand, since the amount of heat is insufficient when the wind speed of the third hot air W3 is too high, the nonwoven fabric strength of the first fiber layer 10A and the second fiber layer 10B becomes insufficient. If the wind speed is too high, the fibers of the second fiber web 33 come into contact with the first fiber web 31 and the gap 13 is crushed. Moreover, since the thickness of the 2nd fiber web 14 becomes small with a wind pressure and it heats in that state, since the fusion | bonding of fibers will increase, the touch of the nonwoven fabric 10 will become hard and liquid permeability will become inadequate.

Furthermore, the blowing time of the third hot air W3 is preferably 0.01 seconds or more, more preferably 0.04 seconds or more. And preferably it is 0.5 second or less, More preferably, it is 0.08 second or less. Moreover, it is preferably 0.01 seconds or more and 0.5 seconds or less, and more preferably 0.04 seconds or more and 0.08 seconds or less. If the spraying time is too short, the fibers of the first fiber web 31 and the fibers of the second fiber web 33 are not sufficiently fused, and the nonwoven fabric strength of the first fiber layer 10A and the second fiber layer 10B is insufficient. Become. On the other hand, if the blowing time of the third hot air W3 is too long, the fibers are too fused together, and the texture becomes worse and the bulk becomes difficult.
And the 3rd hot air W3 which passed the 2nd fiber web 33 and the 1st fiber web 31 passes through the ventilation part of the support body 100, and is discharged | emitted outside.
Incidentally, drawn circular portion layered nonwoven fabric 10 in the drawings denotes a fused portion of the fibers the mechanic schematically emphatically.

  In the manufacturing method of the laminated nonwoven fabric of the first embodiment described above, the shaping of the first fiber web 31 and the shaping of the second fiber web 33 can be performed with separate hot air. Therefore, it can be shaped into an optimum shape by changing the hot air blowing conditions without selecting the fiber type. In addition, the optimum shape of the shaped shape of the first fiber web 31 and the shaped shape of the second fiber web 31 can be easily controlled by the blowing conditions of the first hot air W1 and the second hot air W2. For this reason, the value of T2 / TS can be easily controlled by controlling the gap interval.

Next, another preferred embodiment (second embodiment) of the method for producing a laminated nonwoven fabric according to the present invention will be described below with reference to FIG. The same components as those described in the first embodiment are given the same reference numerals for description.
As shown in FIG. 5, a support body 100 having a concavo-convex shape and having air permeability is prepared by providing a protruding portion 110. A first fiber web 31 and a second fiber web 33 made to a predetermined thickness by a card machine (not shown) are overlapped with the second fiber web 33 facing upward, and the protruding portions 110 of the support 100 are arranged. To the upper surface side. The first fiber web 31 has higher formability than the second fiber web 33. The support body 100 is arranged so that the protruding portions 110 correspond to the positions where the concave portions of the laminated nonwoven fabric are arranged, and the ventilation portion (not shown) is arranged so as to correspond to the positions where the convex portions of the laminated nonwoven fabric are arranged. Yes.
As the fiber material that can be used for the fibers of the first fiber web 31, the fibers mentioned in the first embodiment can be used as long as the formability is higher than that of the second fiber web 33. Further, as the fiber material that can be used for the fibers of the second fiber web 33, the fibers mentioned in the first embodiment can be used as long as the formability is lower than that of the first fiber web 31.
High formability means that the fiber web is easily deformed by the first hot air W1, and it is difficult to return to the original flat state before the third hot air W3 (fusion) is blown. On the contrary, the low formability means that the fiber web is not easily deformed by the first hot air W1 and is likely to return to the original flat state before the third hot air W3 (fusion) is blown.
The index indicating the strength of formability is as follows.
A web having a basis weight of 30 g / m ² is prepared, and the compression data is measured with a KES compression tester. The ease of deformation is determined from the difference in thickness at the time of load from 0 kPa to 1 kPa. The ease of return is determined by the RC (compression resilience) value. In addition to the conditions of the first hot air W1 and the third hot air W3, T2 / TS can be set to the preferred range by changing the shaping property of the web itself. Therefore, it is different from the prior art to vary the structure of the nonwoven fabric produced by adjusting the parameters indicating these formability.

The fibers of the first fiber web 31 are selected so as to be more easily deformed and less likely to return than the fibers of the second fiber web 33. The larger the difference between the values, the larger the gap 13 becomes.
The ease of deformation of the fibers of the first fiber web 31 is 2.7 mm or more, preferably 2.8 mm or more. The ease of return is 38% or less, and more preferably 39% or less.
The ease of deformation of the fibers of the second fiber web 33 is 2.6 mm or less, preferably 2.5 mm or more. And the ease of return is 39% or more, more preferably 40% or more.
Since the ease of deformation and the difficulty of returning depend on the following fiber properties, they are adjusted as appropriate.
First, when the fineness increases, the rigidity of the fiber increases, and the fiber becomes difficult to deform and easily returns. For this reason, the formability deteriorates.
Moreover, when the addition amount of the titanium oxide which raises the whiteness of a nonwoven fabric is increased, the rigidity of a fiber will fall, it will deform | transform easily and it will be hard to return. Therefore, the formability is improved.
Furthermore, with regard to crimped physical properties (number of crimps, crimp rate, residual crimp rate), when the crimp becomes strong, the entanglement between the fibers becomes strong, easily deformed, and difficult to return. Therefore, the shapeability is improved.
When the fiber length becomes long, the entanglement between the fibers becomes strong, and it is easy to deform and hard to return. Therefore, the shapeability is improved.

  Then, an air-through process is performed in which the first hot air W1 is blown onto the laminated web 30 of the first fiber web 31 and the second fiber web 33 to follow the uneven shape of the air-permeable support 100. In this air-through process, first hot air W1 indicated by an arrow is blown from a first nozzle (not shown) from the second fiber web 33 side of the laminated web 30 fed to the surface of the support 100. At this time, the first hot air W <b> 1 is blown from the direction perpendicular to the surface of the laminated web 30 placed on the support body 100. Further, the number of blowouts of the first nozzle may be a plurality of locations along the transport direction of the laminated web 30.

By the first hot air W1, the first fiber web 31 and the second fiber web 33 of the laminated web 30 follow the shape of the protruding portion 110 of the support body 100, and are formed into an uneven shape. The temperature of the 1st hot air W1 at this time is the temperature below the melting | fusing point of the thermoplastic fiber which comprises the 1st fiber web 31 and the 2nd fiber web 33, More preferably, it is 5 degreeC or more lower than this melting | fusing point. is there. And it is preferably a temperature lower than this melting point in the range of 70 ° C. or lower, more preferably a temperature lower than this melting point in the range of 50 ° C. or lower.
In addition, when the temperature of the 1st hot air W1 is too low, the return of a fiber will arise and a shaping property will fall. On the other hand, when the temperature of the 1st hot air W1 is too high, fibers will melt | fuse at a stretch and shaping will be impaired by the fall of a freedom degree.

  The wind speed of the first hot air W1 is set similarly to the wind speed described in the first embodiment. Therefore, when the wind speed is too fast or when the wind speed is too slow, it is the same as in the first embodiment.

Further, the blowing time of the first hot air W1 is set similarly to the blowing time described in the first embodiment. Therefore, when the spraying time is too short or when the spraying time is too long, it is the same as in the first embodiment.
And the 1st hot air W1 which passed the 1st fiber web 31 and the 2nd fiber web 33 is discharged | emitted outside through the ventilation part of the support body 100. FIG.

Next, in a state where the first fiber web 31 and the second fiber web 33 are shaped and the gap 13 is maintained, the first fiber web 31 and the second fiber web 33 are moved, and the third fiber indicated by the arrow is moved. Hot air W3 is blown. And simultaneously with the heat fusion fiber What happened fibers What happened and the second fiber web 33 of the first fibrous web 31, joined by heat fusion fibers of the first fibrous web 31 and the second fiber web 33 . In this way, a first fiber layer 10A composed of the first fiber web 31 and a second fiber layer 10B composed of the second fiber web 33 are obtained.
The conditions for blowing the third hot air W3 are the same as those in the first embodiment.
Incidentally, drawn circular portion layered nonwoven fabric 10 in the drawings denotes a fused portion of the fibers the mechanic schematically emphatically.

In the second embodiment, the fiber density decreases in the order of the concave portion 12, the top portion 11AT of the first convex portion 11A of the first fiber layer 10A, and the top portion 11BT of the second convex portion 11B of the second fiber layer 10B. In this case, it is good to use when the excrement is a low-viscosity liquid and excreted in large quantities (urine). This is because the first convex portion 11A of the first fiber layer 10A and the second convex portion 11B of the second fiber layer 10B have a sparse structure, so that even a large amount of liquid quickly moves to the absorber and comes into contact with the skin. This is because the remaining liquid amount of the first fiber layer 10A can be reduced.
The fiber density in the recess 12 at that time is the same as the range of the recess 12 described in the first embodiment from the viewpoint of making it difficult to be crushed under a high load and reducing the amount of liquid return.
The fiber density in the first convex portion 11A of the first fiber layer 10A is the same as the range of the first convex portion 11A described in the first embodiment from the viewpoint of facilitating crushing under a low load and improving the touch. is there.
The fiber density in the 2nd convex part 11B of the 2nd fiber layer 10B becomes like this. Preferably it is 30 piece / mm < ² > or more, More preferably, it is 50 piece / mm < ² > or more. And it is preferably 130 / mm ² or less, more preferably 100 / mm ² or less. Further, it is preferably 30 pieces / mm ² or more and 130 pieces / mm ² or less, more preferably 50 pieces / mm ² or more and 100 pieces / mm ² or less.

  In the method for manufacturing a laminated nonwoven fabric of the second embodiment described above, the first fiber web 31 and the second fiber web 33 can be shaped simultaneously with the first hot air W1. As a result, energy used in manufacturing can be saved. That is, the manufacturing method of the second embodiment can reduce the hot air blowing process by one step compared to the manufacturing method of the first embodiment. This makes it possible to reduce the number of processes and manufacturing time.

  By using the laminated nonwoven fabric 10 produced by the above production method, it is possible to obtain a surface material having a good touch and a small liquid return amount, and an absorbent article having a good touch and a low liquid return amount can be obtained.

  The laminated nonwoven fabric 10 described above can be used for various applications. For example, it can be suitably used as a surface sheet for absorbent articles such as disposable diapers, sanitary napkins, panty liners, urine absorption pads and the like. Furthermore, since the both sides of the laminated nonwoven fabric 10 are excellent in air permeability and liquid diffusibility due to the concavo-convex structure, deformation characteristics at the time of pressing force, etc., the surface sheet such as diapers and sanitary products and the absorbent body It can also be used as a sublayer interposed therebetween. In addition, the form utilized as a gather of an absorbent article, an exterior sheet, and a wing is also mentioned. Furthermore, the form utilized as a wiping wipe sheet | seat, a cleaning sheet | seat, and a filter is also mentioned.

  Next, an application example of the disposable diaper 200 to the main body 4 as a preferred embodiment of an absorbent article using the laminated nonwoven fabric according to the present invention as a surface material (hereinafter also referred to as a surface sheet) with reference to FIG. This will be described below. The disposable diaper shown in the figure is a tape-type disposable diaper for infants, and is shown in a state where the diaper developed in a plane is bent slightly and viewed from the inside (skin contact surface side). Further, the X direction corresponding to FIG. 1 indicates the width direction of the diaper, the Y direction indicates the longitudinal direction of the diaper, and the Z direction indicates the thickness direction of the diaper.

As shown in FIG. 6, the disposable diaper 200 includes a liquid permeable top sheet 1 disposed on the skin contact surface side, a liquid poorly permeable back sheet 2 disposed on the non-skin contact surface side, and the above-mentioned A liquid-retaining absorbent 3 is disposed between both sheets.
The laminated nonwoven fabric 10 of the said embodiment is applied to the surface sheet 1, and the 1st convex part 11 side is made into the skin contact surface.

The back sheet 2 is in an unfolded state, and both side edges thereof have a shape confined to the inside in the longitudinal central portion C. Even if the back sheet 2 is composed of a single sheet, it is composed of a plurality of sheets. Also good.
The back sheet 2 is not particularly limited as long as it has waterproofness and moisture permeability. For example, a film is formed by melt-kneading a hydrophobic thermoplastic resin and a fine inorganic filler made of calcium carbonate or the like or an incompatible organic polymer, and the film is obtained by uniaxial or biaxial stretching. And a porous film. Examples of the thermoplastic resin include polyolefin. Examples of the polyolefin include high-density to low-density polyethylene, linear low-density polyethylene, polypropylene, and polybutene, and these can be used alone or in combination.

As the absorbent body 3, various forms used for this type of article can be widely adopted as long as they have liquid retention. For example, there are various types such as those in which pulp fibers are coated with a core wrap sheet, sheets in which an airlaid nonwoven is used, and sheets in which a superabsorbent polymer is sandwiched between fiber sheets. Examples of the pulp fiber include wood pulp such as softwood kraft pulp and hardwood kraft pulp, and natural cellulose fiber such as non-wood pulp such as cotton pulp and straw pulp. In addition, polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, single fibers made of synthetic resins such as polyvinyl alcohol resins, composite fibers containing two or more of these resins, semi-synthetic materials such as acetate and rayon Fibers may be included in part. In addition, as the highly water-absorbing polymer, various polymer materials usually used for this type of article can be used. The water-absorbing polymer is preferably a superabsorbent polymer compound capable of absorbing and retaining water or saline more than 20 times its own weight.
The covering sheet is a hydrophilic member. Examples thereof include thin paper (thin paper) such as hydrophilic tissue paper, crepe paper, and non-woven fabric. Non-woven fabrics made of hydrophilic fibers such as cotton and rayon, non-woven fabrics made by subjecting synthetic resin fibers to hydrophilic treatment, such as air-through non-woven fabrics, point-bonded non-woven fabrics, spunlaced non-woven fabrics, spunbonded non-woven fabrics, spunbonded fabrics Mention may be made of meltblown-spunbond (SMS) nonwoven fabrics and the like.

  As the side sheet 5, a water-repellent nonwoven fabric is preferable. For example, water-repellent materials or various non-woven fabrics treated with water repellency can be mentioned among nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, heat roll nonwoven fabrics, needle punched nonwoven fabrics and the like manufactured by the card method. . Particularly preferably, for example, a spunbond nonwoven fabric, a spunbond-meltblown (SM) nonwoven fabric, a spunbond-meltblown-spunbond (SMS) nonwoven fabric, or the like is used.

  In this example, a side leakage prevention gather 7 formed by the side seats 5 is provided, whereby side leakage of liquid or the like in the hip joint portion due to movement of the infant can be effectively prevented. In the diaper of this embodiment, a functional structure part, a sheet material, etc. may be provided. In addition, in FIG. 6, the arrangement | positioning relationship and boundary of each member are not illustrated strictly, and if it is set as the general form of this kind of diaper, the structure will not be specifically limited.

  The diaper is shown as a tape type, and a fastening tape 6 is provided on the flap portion on the back side R. Fastening tape 6 can be affixed to a tape affixing part (not shown) provided in the flap part of ventral side F, and a diaper can be mounted and fixed. At this time, the center part C of the diaper is gently bent inward so that the absorbent body 3 is worn along the baby's buttocks and lower abdomen. As a result, excreta is absorbed and held in the absorber 3 accurately. By using in such a form, in particular, by applying the laminated nonwoven fabric 10 as the top sheet 1, it is possible to achieve both prevention of liquid return on the skin contact surface and good touch. Further, higher air permeability is obtained by the uneven shape of the laminated nonwoven fabric 10.

  The absorbent article of the present invention is not limited to the disposable diaper of the above embodiment, and can be applied to, for example, sanitary napkins, panty liners, incontinence pads, urine collection pads, and the like. In addition to the top sheet 1, the back sheet 2, and the absorbent body 3, members may be incorporated as appropriate according to the purpose and function as constituent members of the absorbent article.

This invention discloses the following laminated nonwoven fabrics, the manufacturing method, surface material, and an absorbent article further regarding embodiment mentioned above.
<1>
A convex portion protruding to the first surface side of the sheet-like laminated nonwoven fabric in plan view, and a concave portion recessed to the second surface side opposite to the first surface side, the convex portion and the concave portion Are arranged alternately and continuously in different directions intersecting in plan view of the laminated nonwoven fabric, the laminated nonwoven fabric has a first fiber layer and a second fiber layer,
Having a gap between the first convex part of the first fiber layer and the second convex part of the second fiber layer;
The first wall portion disposed between the top portion of the first convex portion and the bottom portion of the first concave portion in the first fiber layer, and the top portion of the second convex portion and the bottom portion of the second concave portion in the second fiber layer. The second wall portion disposed therebetween is a laminated nonwoven fabric having fiber orientation in the thickness direction at any position.
<2>
<1> The laminated nonwoven fabric according to <1>, wherein the fibers of the first wall portion have fiber orientation in a direction connecting the convex top portion of the first convex portion and the concave bottom portion of the first concave portion.
<3>
The fiber orientation angle in the CD direction of the first wall portion is 50 ° or more, preferably 70 ° or more, and more preferably 75 ° or more. And it is 130 degrees or less, Preferably it is 110 degrees or less, More preferably, it is 105 degrees or less. The laminated nonwoven fabric according to <1> or <2>, which is 50 ° to 130 °, preferably 70 ° to 110 °, more preferably 75 ° to 105 °.
<4>
The fiber orientation strength in the CD direction of the first wall portion is 1.05 or more, preferably 1.2 or more, more preferably 1.3 or more, any one of <1> to <3> The laminated nonwoven fabric described in 1.
<5>
The fiber orientation angle in the CD direction of the second wall portion is 50 ° or more, preferably 55 ° or more, more preferably 60 ° or more, and 130 ° or less, preferably 125 ° or less. More preferably 120 ° or less, 50 ° or more and 130 ° or less, preferably 55 ° or more and 125 ° or less, and more preferably 60 ° or more and 120 ° or less <1> to <4> The laminated nonwoven fabric according to any one of the above.
<6>
The fiber orientation strength in the CD direction of the second wall portion is 1.05 or more, preferably 1.07 or more, more preferably 1.1 or more, and any one of <1> to <5> The laminated nonwoven fabric described in 1.
<7>
The laminated nonwoven fabric according to any one of <1> to <6>, wherein T2 / TS is 50% or more and 90% or less, where TS is the entire thickness of the laminated nonwoven fabric, and T2 is the overall thickness of the second fiber layer.
<8>
The laminated nonwoven fabric according to any one of <1> to <7>, wherein the gap is crushed under a load of 3.5 kPa, and the inside of the first protrusion and the outside of the second protrusion are in contact.
<9>
The fiber density in the recesses is preferably 250 / mm ² or more, more preferably 300 / mm ² or more, and 500 / mm ² or less from the viewpoint of preventing crushing under high load and reducing the liquid return amount. 450 / mm ² or less is more preferable, 250 / mm ² or more and 500 / mm ² or less is preferable, and 300 / mm ² or more and 450 / mm ² or less is more preferable <1> to <8 > The laminated nonwoven fabric according to any one of
<10>
The fiber density in the first convex portion of the first fiber layer is preferably 50 / mm ² or more, more preferably 70 / mm ² or more from the viewpoint of facilitating crushing under a low load and improving the touch. 180 / mm ² or less is preferable, 150 / mm ² or less is more preferable, 50 / mm ² or more and 180 / mm ² or less is preferable, and 70 / mm ² or more and 150 / mm ² or less is more. The laminated nonwoven fabric according to any one of <1> to <9> is preferred.
<11>
The laminated nonwoven fabric according to any one of claims <1> to <10>, wherein the fiber density decreases in the order of the concave portion of the laminated nonwoven fabric, the top portion of the second convex portion, and the top portion of the first convex portion.
<12>
Fiber density in the second protrusion of the second fibrous layer is preferably 120 present / mm ² or more, more preferably 150 present / mm ² or more, and preferably 330 present / mm ² or less, 300 lines / mm ² or less The laminated nonwoven fabric according to <11>, more preferably 120 pieces / mm ² or more and 330 pieces / mm ² or less, and more preferably 150 pieces / mm ² or more and 300 pieces / mm ² or less.
<13>
The laminated nonwoven fabric according to any one of <1> to <10>, wherein the fiber density decreases in the order of the concave portion of the laminated nonwoven fabric, the top portion of the first convex portion, and the top portion of the second convex portion.
<14>
Fiber density in the second protrusion of the second fibrous layer is preferably 30 present / mm ² or more, more preferably 50 lines / mm ² or more, and preferably 130 present / mm ² or less, 100 / mm ² or less The laminated nonwoven fabric according to <13>, more preferably from 30 pieces / mm ^{2 to} 130 pieces / mm ^{2, and} more preferably from 50 pieces / mm ^{2 to} 100 pieces / mm ² .
<15>
A first fiber web containing thermoplastic fibers is transported onto a support having an uneven shape and air permeability, and hot air is blown onto the first fiber web to follow the uneven shape. The process of shaping and
While the first fiber web is transported along the surface of the support, the second fiber web is transported onto the first fiber web, hot air is blown onto the second fiber web, and the first fiber A step of forming a gap between the web and the second fiber web so that the second fiber web follows the uneven shape;
By blowing hot air to the first fiber web and the second fiber web, to maintain a and the gap state and the vehicle, said first fibrous web of fibers the workers and the second fiber web of fibers What happened And a heat fusion step of thermally fusing the fibers of the first fiber web and the second fiber web together to obtain a first fiber layer and a second fiber layer. Nonwoven fabric manufacturing method.
<16>
The temperature of the first hot air is preferably a temperature not higher than the melting point of the thermoplastic fiber constituting the web, and more preferably 5 ° C. or lower. And it is preferably a temperature lower than this melting point in the range of 70 ° C. or less, more preferably a temperature lower than this melting point in the range of 50 ° C. or less, and it is preferably 0 with respect to the melting point of the thermoplastic fiber constituting the web. <15> The method for producing a laminated nonwoven fabric according to <15>, which is a temperature that is lower by 70 ° C to 70 ° C, and more preferably lower than this melting point in the range of 5 ° C to 50 ° C.
<17>
The wind speed of the first hot air is preferably 20 m / sec or more, more preferably 30 m / sec or more, and preferably 150 m / sec or less, more preferably 100 m / sec or less, and preferably Is 20 m / sec or more and 150 m / sec or less, more preferably 30 m / sec or more and 100 m / sec or less, <15> or <16>.
<18>
The time for blowing the first hot air is preferably 0.01 seconds or more, more preferably 0.04 seconds or more, and preferably 0.5 seconds or less, more preferably 0.08 seconds or less. The laminated nonwoven fabric according to any one of <15> to <17>, which is preferably 0.01 seconds to 0.5 seconds and more preferably 0.04 seconds to 0.08 seconds. Manufacturing method.
<19>
The temperature of the second hot air is preferably a temperature not higher than the melting point of the thermoplastic fibers constituting the web, more preferably 5 ° C. or lower. And it is preferably a temperature lower than this melting point in the range of 70 ° C. or less, more preferably a temperature lower than this melting point in the range of 50 ° C. or less, and it is preferably 0 with respect to the melting point of the thermoplastic fiber constituting the web. The laminated nonwoven fabric according to any one of <15> to <18>, which is a low temperature in the range of from 70 ° C to 70 ° C, more preferably a temperature lower than this melting point in the range of from 5 ° C to 50 ° C. Production method.
<20>
The wind speed of the second hot air is set slower than that of the first hot air, preferably 10 m / sec or more, more preferably 20 m / sec or more, and preferably 140 m / sec or less, more preferably 110 m / sec or less, preferably 10 m / sec or more and 140 m / sec or less, and more preferably 20 m / sec or more and 110 m / sec or less. The laminated nonwoven fabric according to any one of <15> to <19> Production method.
<21>
The blowing time of the second hot air is preferably 0.01 seconds or more, more preferably 0.04 seconds or more, and preferably 0.5 seconds or less, more preferably 0.08 seconds or less, Moreover, Preferably it is 0.01 second or more and 0.5 second or less, More preferably, it is 0.04 second or more and 0.08 second or less, The manufacturing method of the laminated nonwoven fabric as described in any one of <15> to <20> .
<22>
The method for producing a laminated nonwoven fabric according to any one of <15> to <21>, wherein the third hot air is set to a wind speed slower than that of the first hot air and the second hot air.
<23>
A first fiber web containing thermoplastic fibers and a second fiber web containing thermoplastic fibers and having lower formability than the first fiber web on a support having an uneven shape and air permeability. A step of conveying the layers, blowing hot air to the first fiber web and the second fiber web, forming a gap between the first fiber web and the second fiber web, and following the uneven shape; ,
Said first fiber web and said blowing hot air to the second fiber web, fused fiber What happened of the fibers while shaping the uneven shape of the support the first fibrous web the worker and the second fiber web At the same time, a method for producing a laminated nonwoven fabric, comprising: a heat fusion step of thermally bonding the first fiber web and the second fiber web to obtain a first fiber layer and a second fiber layer.
<24>
The method for producing a laminated nonwoven fabric according to <23>, wherein the number of crimps of the first fiber web is greater than that of the second fiber web.
<25>
The method for producing a laminated nonwoven fabric according to <23> or <24>, wherein the fineness of the fibers of the first fiber web is lower than that of the second fiber web.
<26>
The temperature of the first hot air is preferably a temperature not higher than the melting point of the thermoplastic fibers constituting the web 31 and the web 33, more preferably 5 ° C. or lower. And it is preferably a temperature lower than this melting point in the range of 70 ° C. or less, more preferably a temperature lower than this melting point in the range of 50 ° C. or less, and it is preferably 0 with respect to the melting point of the thermoplastic fiber constituting the web. The laminated nonwoven fabric according to any one of <23> to <25>, which is a low temperature in the range of from 70 ° C to 70 ° C, more preferably a temperature lower than this melting point in the range of from 5 ° C to 50 ° C. Production method.
<27>
The wind speed of the first hot air is preferably 20 m / sec or more, more preferably 30 m / sec or more, and preferably 150 m / sec or less, more preferably 100 m / sec or less, and preferably Is 20 m / sec or more and 150 m / sec or less, More preferably, it is 30 m / sec or more and 100 m / sec or less, The manufacturing method of the laminated nonwoven fabric as described in any one of <23> to <26>.
<28>
The time for blowing the first hot air is preferably 0.01 seconds or more and 0.5 seconds or less, more preferably 0.04 seconds or more and 0.08 seconds or less, and preferably 0.5 seconds or less. More preferably, it is 0.08 seconds or less, preferably 0.01 seconds or more and 0.5 seconds or less, and more preferably 0.04 seconds or more and 0.08 seconds or less. <23> to <27> The manufacturing method of the laminated nonwoven fabric of any one of 27.
<29>
The method for producing a laminated nonwoven fabric according to any one of <23> to <28>, wherein the third hot air is set to a wind speed slower than that of the first hot air and the second hot air.
<30>
A surface material using the laminated nonwoven fabric according to any one of <1> to <14> or the laminated nonwoven fabric produced by the production method according to any one of <15> to <29>.
<31>
An absorbent article using the laminated nonwoven fabric according to any one of <1> to <14> or the laminated nonwoven fabric produced by the production method according to any one of <15> to <29>.

  Hereinafter, the present invention will be described in more detail with reference to examples in which a shaped nonwoven fabric was produced by the method for producing a shaped nonwoven fabric according to the first and second embodiments described above and comparative examples. The present invention is not limited to these examples.

[Example 1-7]
The laminated nonwoven fabric 10 of Example 1 uses a card web for the first fiber web 31 for producing the first fiber layer 10A, and also uses a card web for the second fiber web 33 for producing the second fiber layer 10B. It manufactured on condition of the following by the 1st manufacturing method. That is, for the fibers of the first fiber web 31, a core-sheath composite fiber having a core part of polyethylene terephthalate (melting point: 258 ° C.) and a sheath part of polyethylene (melting point: 130 ° C.) was used. The mixing ratio was 100%, the fineness was 2.4 dtex, the fiber length was 45 mm, the number of crimps was 15 peaks / 25 mm, the crimp ratio was 13%, the residual crimp ratio was 12%, and the basis weight was 12 g / m ² . The first fiber web 31 was conveyed by the support 100, and the first hot air W1 was blown on the surface of the support 100 so as to be formed into an uneven shape. The first hot air W1 was sprayed using air as the blowing gas, the temperature of the air was set to 130 ° C., the wind speed was set to 50 m / s, and the blowing time was set to 0.01 seconds.

Next, the first fiber web 31 is conveyed in a state of being shaped on the support 100, the second fiber web 33 is conveyed on the first fiber web 31, and the gap 13 is arranged on the first fiber web 31. Overlapped in state. As the fiber of the second fiber web 33, the same fiber as the first fiber web 31 was used.
After the second fiber web 14 is superimposed on the upper surface side of the first fiber web 31 that has maintained the shaped state, the second hot air W2 is blown, and the gap 13 is disposed in the recessed portion of the first fiber web 31. The second fiber web 33 was shaped. The second hot air W2 was blown using air as the blowing gas, the temperature of the air was set to 130 ° C., the wind speed was set to 30 m / s, and the blowing time was set to 0.01 seconds.

Then, while maintaining the shaped state, the laminated web 30 of the first fibrous web 31 and the second fiber web 33, the second fiber web 33 side blown third hot air, the fibers the Judges of the fibrous web Fused. At the same time, the first fiber web 31 and the second fiber web 33 were fused. In this way, the laminated nonwoven fabric of the first embodiment in which the first fiber layer 10A and the second fiber layer 10b are joined at the concave portion 12 and the gap 13 is provided between the convex portions of the first fiber layer 10A and the second fiber layer 10B. was gotten.

The laminated nonwoven fabric 10 of 2nd Example was produced with the manufacturing method similar to the said 1st Example except the wind speed of 2nd hot air W2 having been 20 m / s.
The laminated nonwoven fabric 10 of the third example was produced by the same manufacturing method as in the first example except that the wind speed of the second hot air W2 was 10 m / s.

In the laminated nonwoven fabric 10 of the fourth embodiment, the fineness of the first fiber web 31 is 1.8 dtex, the crimp rate is 12%, the residual crimp rate is 10%, and the fineness of the second fiber web 33 is 4.4 dtex, The manufacturing method was the same as that of the first example except that the crimp rate was 16%, the residual crimp rate was 15%, and only the first hot air W1 was blown without blowing the second hot air W2.
The laminated nonwoven fabric 10 of the fifth example was produced by the same manufacturing method as in the fourth example except that the fiber length of the second fiber web 33 was 38 mm.
The laminated nonwoven fabric 10 of the sixth example is the same as the fourth example except that the number of crimps of the second fiber web 33 is 11 crests / 25 mm, the crimp rate is 13%, and the residual crimp rate is 12%. It was produced by a simple manufacturing method.
In the laminated nonwoven fabric 10 of the seventh example, the fineness of the second fiber web 33 is 6.6 dtex, the fiber length is 38 mm, the number of crimps is 11 peaks / 25 mm, the crimp rate is 13%, and the residual crimp rate is 9%. Except for the above, the same manufacturing method as in the fourth embodiment was used.

[Comparative Example 1-2]
Comparative Example 1 was produced by the same manufacturing method as in the first example except that the wind speed of the second hot air W2 was 50 m / s.
Comparative Example 2 was produced by the same manufacturing method as in the first example except that the wind speed of the second hot air W2 was 2 m / s.

When analyzing from a commercially available diaper or the like, a cold spray is sprayed on the target diaper or the like to solidify the hot melt adhesive. Then, each material is carefully peeled off to obtain a target nonwoven fabric, which is cut and measured as described above.
Next, the measurement method will be described.
[Measurement method of fineness]
The fineness was determined according to JIS L1015.
[Measurement method of fiber length]
The fiber length was determined according to JIS L1015.
[Measurement method of crimp number]
The number of crimps was determined according to JIS L1015.
[How to find the crimp rate]
The crimp rate was determined according to JIS L1015.
[How to determine the residual crimp rate]
The residual crimp rate was determined according to JIS L1015.

[Measurement method of hot air temperature and wind speed]
The temperature of the 1st hot air W1 and the 2nd hot air W2 was measured by the Nippon Canomax Co., Ltd. Anemo Master Model 6162 (brand name) just under the blower outlet of the 1st and 2nd nozzle. At this time, Model 0203 manufactured by Nippon Kanomax Co., Ltd. was used as the probe. The wind speed is measured by drawing the static pressure from the total pressure just below the outlets of the first and second nozzles using a test pressure sensor tester 521-2 (trade name) manufactured by testo. Asked. The temperature and wind speed of the third hot air W3 were measured directly under the third nozzle outlet by the anemo master.

[Measurement method of thickness]
The nonwoven fabric test body is cut into a cross section in the CD direction, and the cut surface is measured with a digital microscope VHX-1000 manufactured by Keyence Corporation. At that time, the measurement site is enlarged to a size (10 to 100 times) that can be sufficiently measured by entering the visual field. Then, the total thickness Ts (mm) of the laminated nonwoven fabric and the total thickness T2 (mm) of the second fiber layer were measured under no load. The measurement was performed five times for each, and the average value was calculated as Ts and T2. Thereafter, the total thickness Ts (mm) of the laminated nonwoven fabric was measured in a state where a load of 3.5 kPa was applied to the nonwoven fabric test body. The measurement was performed five times for each, and the average value was calculated as the thickness (mm) at a load of 3.5 kPa.

[Measurement method of fiber layer deformability]
For the measurement of the ease of deformation, a fiber web having a basis weight of 30 g / m ² was used as a test material, and a KES compression tester (KES FB-3 manufactured by Kato Tech Co., Ltd.) was used. The KES compression tester evaluated the compression characteristics up to 5.0 kPa in the normal mode, and examined the thickness deformation amount (mm) under load from 0 kPa to 1.0 kPa. The measurement was performed three times, and the average value was calculated as a value.
[Evaluation method of difficulty of return (compression recovery)]
For compression recovery, a fiber web having a basis weight of 30 g / m ² was used as a test material, and a KES compression tester (KES FB-3 manufactured by Kato Tech Co., Ltd.) was used. The KES compression tester evaluated the compression characteristics up to 5.0 kPa in the normal mode, and read the RC value. As measurement values, three points were measured and the average value was defined as compression recovery. This KES compression tester is a plate having a circular plane with a compression area of 2 cm ² , a compression speed of 0.02 mm / s, a maximum compression pressure of 5.0 kPa, and a compression direction when the compression maximum pressure is reached. Is reversed and the process proceeds to the recovery process. The RC value indicates the percentage of energy recovered relative to the energy during compression, and the greater the RC value, the better the resilience to compression and the greater the elasticity. The RC value in the compression characteristic evaluation is the time integral value of the pressure from the time T ₀ when the initial pressure applied to the nonwoven fabric specimen is 0.05 kPa to the time T _m when the maximum pressure is 5.0 kPa, up to the maximum pressure of 5.0 kPa. Divided by the amount of work and expressed in%.

[Measurement of fiber orientation (orientation angle, orientation strength)]
A scanning electron microscope JCM-5100 (trade name) manufactured by JEOL Ltd. was used. The sample was allowed to stand so that the direction connecting the top portion of the first convex portion 11A or the second convex portion 11B and the concave portion 12 in FIG. 1 would be up and down, and photographed from a direction perpendicular to the measurement surface of the sample. . The photographed image (adjusted to a magnification capable of measuring 10 or more fibers to be measured; 100 to 300 times) was printed, and the fiber image was traced on a transparent PET sheet. The said image was taken in in the personal computer and the said image was binarized using the NexusNewQube [tradename] (stand-alone version) image processing software. Next, the binarized image was subjected to Fourier transform using Fiber Orientation Analysis 8.13 Single software (trade name), which is a fiber orientation analysis program, to obtain a power spectrum, and from an elliptical distribution map, an orientation angle was obtained. And the orientation strength was obtained.
The orientation angle indicates the angle at which the fibers are most oriented, and the orientation strength indicates the strength at the orientation angle. In the measurement of the middle part of the wall, the orientation angle close to 90 ° indicates that the fiber is oriented in the central direction of the top, and if it is 50 ° or more and 130 ° or less, the fiber is oriented in the central direction of the top. Are oriented.
Moreover, it represents that the direction of a fiber has gathered, so that the value of orientation strength is large. The case where the orientation strength is 1.05 or more is assumed to be oriented.
Measurement was performed at three locations, and the average was taken as the orientation angle and orientation strength of the sample.

The fiber orientation described above is a concept consisting of the orientation angle and orientation strength of the fiber.
The fiber orientation angle is a concept that indicates in which direction a plurality of fibers having various directions are oriented as a whole, and the shape of the fiber aggregate is quantified. The orientation strength of the fiber is a concept indicating the amount of fibers exhibiting an orientation angle. The orientation strength is less than 1.05 and is hardly oriented, and it can be said that the orientation strength is 1.05 or more. However, in this embodiment, the fiber orientation changes depending on the part. That is, the orientation strength is changed during the transition from a part having a certain orientation angle to a part having a different orientation angle (while the fiber is changing from a state in which the orientation strength is strong in one direction to a part having a strong strength in a different orientation). It has various states such as a weak state and a high state due to reorientation. Therefore, it is preferable that the orientation angle of the fiber is changed between the part showing a strong orientation angle and the part showing a strong orientation angle in another direction even if the orientation strength of the fiber is weak, and the orientation strength is high. Is more preferable. An example of the orientation angle and orientation strength is shown in this embodiment. The orientation angle is preferably 50 ° or more and 130 ° or less, more preferably 60 ° or more and 120 with respect to the curved surface structure of the wall portion 13 of the first protrusion 11. The orientation strength is preferably 1.05 or more, and more preferably 1.10 or more.
When the laminated nonwoven fabric 10 is used as the top sheet of the absorbent article, the laminated nonwoven fabric 10 has sufficient compression resistance even under high pressure due to the fiber orientation of each wall portion 14, and the convex portion 11 of the laminated nonwoven fabric 10. Prevent crushing. This sufficiently exhibits the effect of preventing liquid return.

[Measurement of fiber density]
The nonwoven fabric was cut into cross sections in the CD direction, and the cut surfaces were magnified and observed using a scanning electron microscope, and the cross-sectional areas of the fibers cut at the cut surfaces per certain area were counted. The magnification observation was adjusted to a magnification (150 to 500 times) at which about 30 to 60 fiber cross sections could be measured. In this embodiment, the magnification is 100 times. The observation site was set near the center of the thickness of each of the top 11AT of the first protrusion 11A of the first fiber layer, the top 11BT of the second protrusion 11B of the second fiber layer, and the recess 12. Next, it was converted into the number of cross sections of the fiber per 1 mm ² , and this was defined as the fiber density (lines / mm ² ). The measurement was performed at three locations, and the fiber density of the sample was averaged. JCM-5100 (trade name) manufactured by JEOL Ltd. was used for the scanning electron microscope.

Next, the evaluation method will be described. Evaluation examined the performance of the nonwoven fabric as sheet performance.
As for sheet performance, the “texture”, “compression characteristic value at low load” and “liquid return amount” of the laminated nonwoven fabric were evaluated.
Low load means when a load of 0.30 gf / cm ² to 1.00 gf / cm ² is applied.

[Evaluation method of touch]
Twenty monitors (a mother who has a child who is currently using a diaper) will be able to touch the non-woven fabric in an invisible state, and the touches such as flexibility, softness, and cushioning will be comprehensively as follows. Evaluation was made according to the following four criteria. The results are shown as an average value of 20 people.
<Evaluation criteria>
4: Excellent 3: Good 2: Slightly inferior 1: Inferior

[Evaluation method of compression characteristics at low load]
In the present invention, under a 22 ° C. and 65% RH environment, the compression characteristic value at the time of low load is defined as a new characteristic value representing the touch. 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 the basis for calculating the compression characteristic value at low load. Three pieces of nonwoven fabric 1 are cut into 20 cm × 20 cm to prepare measurement samples. Next, one of the measurement samples is placed on the test bench. Next, it compresses between the steel plates which have a circular plane with an area of 2 cm < ² >. The compression speed is 20 μm / s, the maximum compression load is 1.0 gf / cm ² , and the recovery process is also measured at the same speed. At this time, the displacement amount between the steel plates is set to x (mm), the load is set to y (gf / cm ² ), and the position of the point where the load is detected is set to x = 0 and measured in the compression direction. The value of x increases as it is compressed.
The compression characteristic value at the time of low load is calculated by extracting the deformation amount of the thickness at the time of low load from the measured data (x, y). Specifically, the first load that is not a recovery process, a 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 x and y is approximated A straight line is obtained by the method of least squares, and the slope at that time is taken as the above characteristic value (unit (gf / cm ² )). 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 thereof is set as the compression characteristic value at the time of low load of the nonwoven fabric.

[Measurement method of liquid return amount]
As an example of the absorbent article 100, the liquid return amount is measured by removing the surface sheet from a diaper for infants (made by Kao Corporation: Merry's Sarah Air Through (registered trademark) M size, made in 2012), and instead of the laminated nonwoven fabric 10 An infant diaper for evaluation obtained by using a test body (hereinafter referred to as a nonwoven fabric test body) and fixing its periphery was used.
A pressure of 3.5 kPa was applied uniformly on the non-woven fabric test piece, a cylinder having a cross-sectional area of 1000 mm ² placed at the approximate center of the test piece was applied, and artificial urine was injected therefrom. As the artificial urine, physiological saline was used, and a total of 160 g of artificial urine was infused 4 times by 40 g every 10 minutes.
After standing for 10 minutes from the completion of the injection, the above cylinder and pressure were removed. And filter paper No. made by Advantech Co., Ltd. A weight adjusted so that a pressure of 3.5 kPa was applied to an absorbent sheet (mass = M1) in which 20 sheets of 5C (100 mm × 100 mm) were stacked was placed on the nonwoven fabric specimen around the injection point.
After standing for 5 minutes, the weight was removed, the mass (M2) of the filter paper was measured, and the amount of liquid return was calculated according to the following equation.
Liquid return amount (g) = mass of filter paper after pressurization (M2) −mass of filter paper before pressurization (M1)

  About the laminated nonwoven fabric 10, physical properties (fineness, fiber length, number of crimps, crimp rate, residual crimp rate, basis weight, ease of deformation, difficulty of returning, low load thickness, high load thickness, fiber orientation angle, fiber The results are shown in Table 1 for the degree of orientation, fiber density, etc.) and performance (texture, liquid return amount).

As is clear from the results shown in Table 1, each of Examples 1 to 7 obtained good results in any evaluation item. The touch was evaluated as “good” or “excellent”. Moreover, the compression characteristic value at the time of low load was as low as 4.0 (gf / cm < ² >) / mm to 5.2 (gf / cm < ² >) / mm. Furthermore, the liquid return amount was as small as 1.0 to 1.5 g. Thus, in each Example 1-7, coexistence with obtaining the touch more than favorable and reducing a liquid return amount was achieved.

Comparative Example 1 was evaluated as “slightly inferior” because there was no gap. The compression characteristic value at low load was as high as 15.0 (gf / cm ² ) / mm. However, the liquid return amount was as small as 1.0 g. Further, Comparative Example 2 was evaluated as “excellent” because the gap was too wide. Moreover, the compression characteristic value at the time of low load was as low as 4.0 (gf / cm < ² >) / mm. However, the liquid return amount was as large as 2.5 g. Thus, in Comparative Examples 1 and 2, it was not possible to achieve both good touch and reduced liquid return amount.

  In addition, Examples 4 to 7 are examples in which fibers having low formability of the fibers of the second fiber layer of Examples 1 to 3 were used for the second fiber layer. As described above, when fibers having low formability with respect to the fibers of the first fiber layer are used, there is a gap even if the wind speed of the first hot air W1 and the wind speed of the second hot air W2 are the same. The second fiber web can be shaped. This means that the laminated nonwoven fabric of the present invention is also produced by the second production method. Therefore, it is proved that the laminated nonwoven fabric 10 of this embodiment can be manufactured regardless of the first manufacturing method and the second manufacturing method.

DESCRIPTION OF SYMBOLS 10 Laminated nonwoven fabric 10A 1st fiber layer 10B 2nd fiber layer 11 Convex part 11A 1st convex part 11B 2nd convex part 11AT Top part 12 Concave part 12A 1st recessed part 12B 2nd recessed part 12BB Bottom part 13 Crevice 14 Wall part 14A 1st wall part 14B 2nd wall part 31 1st fiber web 33 2nd fiber web 100 Support body 110 Protruding part 200 Disposable diaper

Claims (6)

A convex portion protruding to the first surface side of the sheet-like laminated nonwoven fabric in plan view, and a concave portion recessed to the second surface side opposite to the first surface side, the convex portion and the concave portion Are arranged alternately and continuously in different directions intersecting in plan view of the laminated nonwoven fabric, the laminated nonwoven fabric has a first fiber layer and a second fiber layer,
Having a gap between the first convex part of the first fiber layer and the second convex part of the second fiber layer;
The first wall portion disposed between the top portion of the first convex portion and the bottom portion of the first concave portion in the first fiber layer, and the top portion of the second convex portion and the bottom portion of the second concave portion in the second fiber layer. second wall portion disposed between even have a fiber orientation in the thickness direction at any position,
The recess of the laminated nonwoven fabric, the top of the second convex portion, the first convex portion of the top order in the fiber density is low such that the laminated nonwoven fabric.   The laminated nonwoven fabric according to claim 1, wherein T2 / TS is 50% or more and 90% or less, where TS is the entire thickness of the laminated nonwoven fabric and T2 is the overall thickness of the second fiber layer.   The laminated nonwoven fabric according to claim 1 or 2, wherein the gap is crushed under a load of 3.5 kPa, and the inside of the first protrusion and the outside of the second protrusion are in contact with each other. A first fiber web containing thermoplastic fibers and a second fiber web containing thermoplastic fibers and having lower formability than the first fiber web on a support having an uneven shape and air permeability. A step of conveying the layers, blowing hot air to the first fiber web and the second fiber web, forming a gap between the first fiber web and the second fiber web, and following the uneven shape; ,
Said first fiber web and said blowing hot air to the second fiber web, fused fiber What happened of the fibers while shaping the uneven shape of the support the first fibrous web the worker and the second fiber web At the same time, a method for producing a laminated nonwoven fabric, comprising: a heat fusion step of thermally bonding the first fiber web and the second fiber web to obtain a first fiber layer and a second fiber layer. The surface sheet using the laminated nonwoven fabric of any one of Claims 1-3 , or the laminated nonwoven fabric manufactured by the manufacturing method of Claim 4 . An absorbent article using the laminated nonwoven fabric according to any one of claims 1 to 3 , or the laminated nonwoven fabric produced by the production method according to claim 4 .

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