JP2015108213A - Nonwoven cloth, and absorbent article comprising the same nonwoven cloth, and formation method of the sane nonwoven cloth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonwoven cloth being easily deformed but hard to collapse and having excellent air permeability in the planar direction.SOLUTION: A nonwoven cloth comprises a continuous fiber and a bonded part formed by bonding a plurality of fibers including the continuous fiber. The nonwoven cloth comprises a first surface and a second surface which is the opposite side of the first surface; the first surface comprises a plurality of projecting parts (V) including the bonded part, a plurality of projecting parts (V) not including the bonded part, and a recessed part (C); the second surface comprises a plurality of recessed parts (C) which is overlapped with at least some of the projecting parts (V) including the bonded part on the first surface; and the diameter variation coefficient of the continuous fiber is 10% or more.

Description

  The present invention relates to a nonwoven fabric, an absorbent article including the nonwoven fabric, and a method for forming the nonwoven fabric.

  Nonwoven fabrics are used in absorbent articles such as sanitary and disposable diapers, cleaning articles such as wipers, and medical articles such as masks. However, these products often employ non-woven fabrics that have performance specific to the use of the product, the site used, and the like.

For example, an absorbent article requires a non-woven fabric that expands and contracts in accordance with the movement of the body when worn or used without causing the user to feel uncomfortable. In addition, disposable diapers and sanitary napkins are required to be nonwoven fabrics that have high stretchability and strength that does not break when stretched, and that also have good touch, breathability, and liquid permeability.
In these products, nonwoven fabrics having desired performance are often designed and manufactured for each product. Therefore, if a non-woven fabric having a desired performance can be easily formed by processing a certain non-woven fabric, for example, a commercially available non-woven fabric, in particular, a spunbond non-woven fabric, a melt-blown non-woven fabric, etc., which are relatively inexpensive, the manufacturing cost, This is desirable from the viewpoint of environmental protection.

  As a method of forming a non-woven fabric suitable for use in absorbent articles made from non-woven fabric, Patent Document 1 discloses a non-woven fabric having alternating ridges and groove portions extending in one direction and having openings in the groove portions. In addition, a nonwoven fabric is disclosed in which the amount of fibers is substantially greater in the collar than in the groove, and the fiber density is different between the top of the collar and the end of the aperture. Further, in [0049] of Patent Document 1, an air-through nonwoven fabric or the like can be used as a raw material for the nonwoven fabric, and when a fiber assembly having a bond at a fiber intersection is used, such as an air-through nonwoven fabric, Alternatively, it is described that it is preferable to use a steam flow.

  However, in the invention described in Patent Document 1, if an air-through nonwoven fabric is used as a raw material, for example, the nonwoven fabric has each fiber fixed and is difficult to move. Therefore, in order to form the collar portion, the groove portion, and the opening portion, It is necessary to increase the energy and temperature of fluid processing. However, when the energy, temperature, etc. of the fluid treatment are increased, the fibers in the nonwoven fabric are fused, and the formed ridges and grooves are hardened. As a result, according to the description in Patent Document 1, the nonwoven fabric formed from the air-through nonwoven fabric is less likely to be deformed by an external force, and is used in a portion that is in direct contact with the skin and damages the skin when body pressure is applied There is a possibility.

In addition, according to the description in Patent Document 1, when an attempt is made to process a spunbond nonwoven fabric, a melt blown nonwoven fabric, or the like, which is a nonwoven fabric that is thin like paper and has a low cushion feeling, each fiber is firmly bonded by embossing. Since it is difficult to form, for example, the entire sheet is crushed during compression, and the air permeability in the planar direction is particularly poor. Also,
When trying to process the above spunbond nonwoven fabric, melt blown nonwoven fabric, etc. so as to have a clear irregular shape according to the description of Patent Document 1, it is necessary to increase fluid energy, in particular, flow rate and temperature. The fibers are melted, the fibers are fused to each other, a hard and rough nonwoven fabric is formed, and the manufacturing cost is also increased.

JP 2009-62650 A

  Accordingly, an object of the present invention is to provide a non-woven fabric that is easily deformed but is not easily crushed and has excellent air permeability in a planar direction.

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention are non-woven fabrics that include continuous fibers and joint portions formed by joining a plurality of fibers including the continuous fibers. Includes a first surface and a second surface opposite to the first surface, and the first surface includes a plurality of convex portions (V ₁₁ ) including joint portions, and a plurality of joint portions. A plurality of convex portions (V ₁₂ ) that do not include a concave portion (C ₁₁ ), and the second surface overlaps at least a part of the convex portion (V ₁₁ ) that includes the joint portion of the first surface. It was found that the above-mentioned problems can be solved by a non-woven fabric characterized in that the above-mentioned concave portion (C ₂₁ ) is included and the variation coefficient of the diameter of the continuous fiber is 10% or more, and the present invention has been completed.

Specifically, the present invention relates to the following aspects.
[Aspect 1]
A nonwoven fabric comprising continuous fibers and a joint formed by joining a plurality of fibers including the continuous fibers,
The nonwoven fabric includes a first surface and a second surface opposite to the first surface;
The first surface includes a plurality of convex portions (V ₁₁ ) including a joint portion, a plurality of convex portions (V ₁₂ ) not including the joint portion, and a concave portion (C ₁₁ ),
The second surface includes a plurality of concave portions (C ₂₁ ) overlapping at least part of the convex portions (V ₁₁ ) including the joint portion of the first surface, and the coefficient of variation of the diameter of the continuous fiber is: 10% or more, characterized in that
The nonwoven fabric.

[Aspect 2]
The nonwoven fabric according to aspect 1, wherein the second surface does not include a concave portion that overlaps the convex portion (V ₁₂ ) of the first surface that does not include the bonding portion.
[Aspect 3]
The second surface further includes a plurality of convex portions (V ₂₁ ) and a plurality of concave portions (C ₂₂ ) that do not overlap the convex portions (V ₁₁ ) of the first surface. Non-woven fabric.

[Aspect 4]
The nonwoven fabric as described in any one of aspects 1 to 3, which has one or a plurality of apertures connecting the recess (C ₁₁ ) on the first surface and the recess (C ₂₂ ) on the second surface. .
[Aspect 5]
The nonwoven fabric according to any one of aspects 1 to 4, wherein the continuous fiber has a plurality of constricted portions having a partially narrowed diameter.

[Aspect 6]
A spunbond nonwoven fabric or meltblown nonwoven fabric comprising continuous fibers and a joint formed by joining a plurality of fibers including the continuous fibers so that a nonwoven fabric having a high stretch region and a low stretch region is formed. A non-woven fabric that is stretched non-uniformly and has a high stretch region and a low stretch region is disposed on a support, and the ejected fluid is sprayed onto the non-woven fabric having the high stretch region and the low stretch region. The nonwoven fabric as described in any one of the aspects 1-5 formed by these.
[Aspect 7]
An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body between the liquid-permeable top sheet and the liquid-impermeable back sheet,
The liquid-permeable top sheet is the nonwoven fabric according to any one of aspects 1 to 6,
The above absorbent article.

[Aspect 8]
A method of forming the nonwoven fabric according to any one of aspects 1 to 6,
Preparing a nonwoven fabric comprising continuous fibers and a joint formed by joining a plurality of fibers including the continuous fibers;
A non-woven fabric including the continuous fiber and a joint formed by joining a plurality of fibers including the continuous fiber is stretched non-uniformly so that a non-woven fabric having a high stretch region and a low stretch region is formed. And a non-woven fabric having a high stretch region and a low stretch region is disposed on a support, and the non-woven fabric having the high stretch region and the low stretch region is any one of embodiments 1 to 6. Spraying the ejected fluid to form the described nonwoven;
Including the above method.
[Aspect 9]
The method according to aspect 8, wherein, in the step of spraying the ejected fluid, the support has protrusions and depressions having a predetermined shape and arrangement on a surface in contact with the nonwoven fabric.

[Aspect 10]
The method according to aspect 8 or 9, wherein the fluid is heated air, saturated steam or superheated steam.
[Aspect 11]
The nonwoven fabric containing the said continuous fiber and the junction part formed by joining the some fiber containing the said continuous fiber is a spun bond nonwoven fabric or a melt blown nonwoven fabric as described in any one of aspects 8-10. Method.

Since the nonwoven fabric of the present invention has a variation coefficient of the diameter of continuous fibers of 10% or more, the ease of deformation when force is applied varies depending on each continuous fiber, and the entire nonwoven fabric is easily deformed, It has the characteristic that it is not easily crushed.
Further, the nonwoven fabric of the present invention, the first surface comprises a plurality of protrusions including joints and (V _11), a plurality of protrusions containing no joints and (V _12), and a second surface However, since it includes a plurality of concave portions (C ₂₁ ) overlapping at least a part of the convex portion (V ₁₁ ) including the joint portion on the first surface, it has a characteristic that it is easily deformed but is not easily crushed.
Furthermore, since the nonwoven fabric of this invention contains an unevenness | corrugation in the 1st surface, it is excellent in the air permeability of a plane direction.

FIG. 1 is a scanning electron micrograph of one embodiment of the nonwoven fabric of the present invention. FIG. 2 is a scanning electron micrograph of the cross section of the convex portion (V ₁₁ ) 3 including the joint portion. FIG. 3 is a scanning electron micrograph of the cross section of the convex portion (V ₁₂ ) 4 not including the joint portion. FIG. 4 is a scanning electron micrograph of continuous fibers in the nonwoven fabric shown in FIG. FIG. 5 is a schematic diagram for explaining a gear stretching device in which a plurality of teeth are arranged on the outer peripheral surface of the gear roll in parallel to the rotation axis of the gear roll. FIG. 6 is a schematic diagram for explaining a gear stretching device in which a plurality of teeth are arranged on the outer peripheral surface of the gear roll perpendicular to the rotation axis of the gear roll. FIG. 7 is a schematic diagram for explaining a gear stretching device in which a plurality of teeth are arranged on the outer peripheral surface of the gear roll so as to be inclined with respect to the rotation axis of the gear roll. FIG. 8 is a diagram illustrating an example of a fluid processing step. FIG. 9 is a view for explaining an example of a nonwoven fabric formed using the support 19 shown in FIG. FIG. 10 is a view for explaining embossing of the spunbonded nonwoven fabric used in Example 5 and Comparative Example 3.

Hereinafter, the nonwoven fabric of the present invention, the absorbent article containing the nonwoven fabric, and the method for forming the nonwoven fabric will be described in detail.
[Nonwoven fabric of the present invention]
The nonwoven fabric of this invention is a nonwoven fabric containing continuous fiber and the junction part formed by joining the some fiber containing the said continuous fiber. In the nonwoven fabric of the present invention, the nonwoven fabric includes a first surface and a second surface opposite to the first surface, and the first surface includes a plurality of convex portions (V ₁₁ including a joint portion). ), A plurality of convex portions (V ₁₂ ) not including a joint portion, and a concave portion (C ₁₁ ), and the second surface is a convex portion (V ₁₁ ) including the joint portion of the first surface. of it overlaps at least a portion comprises a plurality of recesses (C _21), and coefficient of variation of the diameter of the continuous fibers is 10% or more (hereinafter, also referred to as "a specific shape and a specific variation coefficient" is there).

FIG. 1 is a scanning electron micrograph of one embodiment of the nonwoven fabric of the present invention. The nonwoven fabric shown in FIG. 1 is obtained by photographing the first surface 1 from obliquely above. The opposite side of the first surface 1 is the second surface 2. The nonwoven fabric shown in FIG. 1 includes a plurality of convex portions (V ₁₁ ) 3 including a joint portion, a plurality of convex portions (V ₁₂ ) 4 not including the joint portion, and a concave portion (C ₁₁ ) 5. . Although not shown, the second surface 2 includes a plurality of concave portions (C ₂₁ ) 8 that overlap at least a part of the convex portion (V ₁₁ ) 3 including the joint portion of the first surface 1. Further, in the nonwoven fabric shown in FIG. 1, the convex portion (V ₁₁ ) 3 including the joint portion includes the joint portion 7.

The nonwoven fabric shown in FIG. 1 also includes a plurality of apertures 6. Opening 6, the second face 2 further includes a plurality of recesses (C ₂₂₎ (not shown), and a recess (C ₁₁₎ of the first surface, the recess of the second surface (C ₂₂ ) Are connected to each other. By forming the opening portion, the air permeability and liquid permeability in the thickness direction of the nonwoven fabric of the present invention are greatly improved. Therefore, when the nonwoven fabric of this invention is used for the top sheet | seat of an absorbent article, the absorbed liquid can be rapidly transferred to an absorber through the said opening part.
In addition, although the nonwoven fabric shown by FIG. 1 contains the aperture part, in this invention, an aperture part is a requirement by necessity and does not need to be.

FIG. 2 is a scanning electron micrograph of the cross section of the convex portion (V ₁₁ ) 3 including the joint portion. In FIG. 2, the upper side is the first surface 1 and the lower side is the second surface 2. The convex portion (V ₁₁ ) 3 including the joint shown in FIG. 2 includes two joints 7. In FIG. 2, the second surface 2 includes a concave portion (C ₂₁ ) 8 that overlaps the convex portion (V ₁₁ ) 3 including the joint portion of the first surface 1.

In the present specification, the term “overlap” used for the recesses and the protrusions means that the protrusions and the recesses have substantially the same three-dimensional shape, and the tops of the protrusions and the bottoms of the recesses are the thickness of the nonwoven fabric. Although it is separated in the direction, it means having substantially the same position in the plane direction. Therefore, the concave portion and the convex portion having substantially the same three-dimensional shape but having the positions where the top portion of the convex portion and the bottom portion of the concave portion are not substantially the same in the planar direction are not included in the concept of “overlap” in this specification. .
In addition, the top part of a convex part means the highest place in a thickness direction in a convex part, and the bottom part of a recessed part means the lowest place in the thickness direction in a recessed part.

FIG. 3 is a scanning electron micrograph of the cross section of the convex portion (V ₁₂ ) 4 not including the joint portion. In FIG. 3, the upper side is the first surface 1 and the lower side is the second surface 2. In FIG. 3, the second surface 2 does not include a concave portion that overlaps the convex portion (V ₁₂ ) 4 of the first surface 1 that does not include a joint portion.
In the embodiment shown in FIG. 1, the second surface does not include a concave portion that overlaps the convex portion (V ₁₂ ) of the first surface that does not include the joint portion. In the present invention, the second surface The surface may include a concave portion that overlaps the convex portion (V ₁₂ ) of the first surface that does not include the joint portion.

In this specification, the convex portion (V ₁₁ ) including the joint portion, the convex portion (V ₁₂ ) not including the joint portion, and the concave portion (C ₁₁ ) that can be formed on the first surface are referred to as “first”. The first surface having these may be referred to as the “first surface having unevenness”.
Further, in the present specification, the concave portion (C ₂₁ ) and the desired convex portion (V ₂₁ ) and the concave portion (C ₂₂ ) that can be formed on the second surface are the cases where the convex portion (V ₂₁ ) does not exist. even, sometimes referred to as a "second surface of the concavo-convex", and the second surface having such, even when the convex portions (V ₂₁₎ is not present, the second having a "bumpy Sometimes referred to as “surface”.

  FIG. 4 is a scanning electron micrograph of continuous fibers in the nonwoven fabric shown in FIG. As FIG. 4 shows, the continuous fiber in the nonwoven fabric shown in FIG. 1 has distribution in the diameter, and the variation coefficient of the diameter of the said continuous fiber is 10% or more. Further, as shown in FIG. 4, the continuous fiber in the nonwoven fabric shown in FIG. 1 has a plurality of constricted portions 9 having a partially narrowed diameter.

In this specification, the “variation coefficient” is obtained by photographing continuous fibers with an electron microscope or the like, measuring 50 fiber diameters arbitrarily from the photographed images, and calculating the following equation (1) from the standard deviation and arithmetic mean. ).
Coefficient of variation (%) = 100 × standard deviation / arithmetic mean equation (1)

  As is clear from the fact that the nonwoven fabric of the present invention has a coefficient of variation of the diameter of continuous fibers of 10% or more, the continuous fibers in the nonwoven fabric of the present invention have a partially thick fiber part, Are mixed with a portion having a small fiber diameter. Therefore, the non-woven fabric of the present invention is soft and easily deformed in a portion with a small fiber diameter, but has a characteristic that it is difficult to be deformed and crushed in a portion with a large fiber diameter, that is, cushioning properties.

Further, in the nonwoven fabric of the present invention, the first surface comprises a convex portion (V ₁₁₎ including a joining portion, further the second surface, the convex portion (V ₁₁₎ including a first surface, the junction A plurality of recesses (C ₂₁ ) overlapping at least a part of. Accordingly, in the nonwoven fabric of the present invention, the first surface is used as a top sheet of an absorbent article, and when pressure is applied, a convex portion that is soft and easily deformed, and a convex portion that is not easily deformed and is not easily crushed. Both will exist. As a result, the non-woven fabric of the present invention has the property of being easily deformed but not easily crushed in addition to the above-described variation coefficient of 10% or more.
Therefore, since the nonwoven fabric of this invention has the above-mentioned cushioning property, it is suitable for uses, such as a top sheet of an absorbent article.

  Although it does not restrict | limit especially as a raw material of the said continuous fiber, For example, a thermoplastic resin, for example, polyolefin, for example, polyethylene, a polypropylene, polybutene, polyester, nylon, a polystyrene etc. can be mentioned. The continuous fiber may be a composite fiber such as a core-sheath composite fiber, a sea-island composite fiber, a split composite fiber, or a side-by-side composite fiber.

The fineness of the continuous fiber is not particularly limited, but is preferably in the range of about 1 to about 6 dtex when used for a top sheet of an absorbent article. When the fineness of the continuous fiber is less than about 1 dtex, the strength of the continuous fiber is lowered, and thus the thickness of the nonwoven fabric is reduced, and the air permeability and liquid permeability of the nonwoven fabric tend to be reduced. If the fineness of the continuous fiber exceeds about 6 dtex, the strength of the continuous fiber itself tends to increase and the tactile sensation tends to decrease.
The nonwoven fabric of this invention can contain 2 or more types of continuous fibers.
As said junction part, a thermocompression bonding part is mentioned, for example.

In the nonwoven fabric of the present invention, the amount of the plurality of convex portions (V ₁₁ ) including the joint portion, the plurality of convex portions (V ₁₂ ) not including the joint portion, and the concave portion (C ₁₁ ) on the first surface, In addition, the amount of the plurality of concave portions (C ₂₁ ) overlapping the at least part of the convex portions (V ₁₁ ) including the joint portion of the first surface in the second surface depends on the desired performance of the nonwoven fabric of the present invention. However, for example, a non-woven fabric including continuous fibers and a joint formed by joining a plurality of fibers including the continuous fibers, such as a spunbond non-woven fabric or a melt-blown non-woven fabric, a high stretch region and a low stretch region A non-woven fabric having a high-stretch region and a low-stretch region is disposed on a support, and the non-woven fabric has a high-stretch region and a low-stretch region. Spray the ejected fluid on An amount such as formed by Rukoto and by adjusting the uneven stretching step and the fluid treatment step, it is possible to adjust the stated amount.

When the nonwoven fabric of the present invention is used for a liquid-permeable top sheet or the like of an absorbent article, the nonwoven fabric of the present invention may have hydrophilicity. This is because, when coming into contact with hydrophilic excrement (such as urine, sweat, stool, etc.), the excrement is easily permeated into the absorbent article without remaining on the surface of the nonwoven fabric.
In order for the nonwoven fabric of the present invention to have hydrophilicity, for example, the nonwoven fabric is treated with a hydrophilic agent, the nonwoven fabric is produced from a composite fiber kneaded with a hydrophilic agent, a surfactant is applied to the nonwoven fabric, etc. Is mentioned.

  The nonwoven fabric of the present invention may further contain short fibers that are usually used in the technical field, in addition to the continuous fibers, within the range where the effects of the present invention are exhibited. Examples of the short fibers include natural fibers, semi-natural fibers, and synthetic fibers. As the short fiber, a synthetic fiber is preferable. It is because the flexibility of the nonwoven fabric of the present invention is increased. When the nonwoven fabric of the present invention contains short fibers, the proportion of short fibers is preferably about 30% by mass or less, more preferably about 20% by mass or less, and about 10% by mass of the total amount of fibers. More preferably, it is as follows.

When the short fiber is a short fiber made of a synthetic fiber, the short fiber is less likely to be crushed even when a user's body pressure is applied, and air permeability tends to be good.
Examples of the short fiber material made of the synthetic fiber include polyethylene, polypropylene, and polyester. The short fiber preferably has a fineness of about 1 to about 6 dtex in consideration of moldability.

Although the 1st surface of the nonwoven fabric of this invention is easy to deform | transform, since it is hard to be crushed and is excellent in cushioning properties, it can be used suitably for the skin contact surface of the top sheet of an absorbent article.
The second surface of the nonwoven fabric of the present invention includes a plurality of concave portions (C ₂₁ ) that overlaps at least a part of the convex portions (V ₁₁ ) including the joint portions, so that liquid such as sweat, urine, menstrual blood, etc. is temporarily contained Therefore, it can be suitably used for the skin contact surface of the top sheet of the absorbent article.
When the second surface of the nonwoven fabric of the present invention, the first surface does not include a recess overlapping the convex portion that does not include the joint (V ₁₂₎ is of the second surface, and the contacted object Can increase the contact area. Therefore, in this case, when the nonwoven fabric of the present invention is used as a top sheet so that the second surface is on the non-skin contact surface side, the absorbed liquid can be quickly transferred to the lower absorber. Can do.
The nonwoven fabric of the present invention will be described in more detail below together with the description of the method for forming the nonwoven fabric of the present invention.

[Formation method of nonwoven fabric of the present invention]
The nonwoven fabric formation method of the present invention includes a step of preparing a nonwoven fabric including continuous fibers and a joint formed by joining a plurality of fibers including the continuous fibers. The nonwoven fabric used in the step is not particularly limited as long as it is a nonwoven fabric containing the above-described continuous fibers and joints. For example, a spunbond nonwoven fabric, a meltblown nonwoven fabric, or the like containing the above-described continuous fibers and joints. Can be.

Continuous fibers represented by spunbond, melt-blown, etc. have higher fiber elongation than short fibers used in the card method. Therefore, in the non-uniform stretching step described later, the joint portion is relatively difficult to break and a high stretch region is easily formed. Therefore, there is an advantage that the first surface having the unevenness and / or the second surface having the unevenness can be easily formed by the fluid treatment step described later.
In this specification, the nonwoven fabric prepared in this step may be referred to as “nonwoven fabric before non-uniform stretching”.

Examples of the nonwoven fabric before non-uniform stretching include commercially available nonwoven fabrics such as commercially available spunbond nonwoven fabrics and meltblown nonwoven fabrics.
The nonwoven fabric before the non-uniform stretching may have hydrophilicity when the nonwoven fabric formed in the nonwoven fabric forming method of the present invention is used for a liquid-permeable top sheet of an absorbent article. This is because the nonwoven fabric formed by the nonwoven fabric forming method of the present invention leads to hydrophilicity. The method for imparting hydrophilicity to the nonwoven fabric is as described above.

  The non-uniform stretched nonwoven fabric may further include short fibers in addition to the continuous fibers within the range where the effects of the present invention are exhibited. The non-woven fabric before non-uniform stretching can contain the above-described fibers in the above-mentioned proportion as the short fibers.

  The nonwoven fabric forming method of the present invention is a nonwoven fabric having a high stretch region and a low stretch region, the nonwoven fabric including the continuous fiber and a joint formed by joining a plurality of fibers including the continuous fiber. A step of non-uniform stretching so as to be formed (hereinafter, sometimes referred to as “non-uniform stretching step”).

In the non-uniform stretching step, (i) continuous fibers are stretched and plastically deformed, particularly in a high stretch region. Each continuous fiber in the nonwoven fabric is randomly oriented without being oriented in a certain direction. Therefore, for example, when a nonwoven fabric containing fibers having a diameter a is stretched “uniformly” by a factor of b in a certain direction, the fibers contained in the nonwoven fabric after stretching have been stretched by a factor of 1 (unstretched) to b times. The fibers will be mixed, and their diameter will have a distribution of a / b to a. In the non-uniform stretching step in the present invention, the nonwoven fabric containing continuous fibers is stretched not “uniformly” but “non-uniformly”, so that the diameter of any part of the continuous fibers after stretching has a wider distribution. It seems to become.
As a result, in the nonwoven fabric of the present invention, the variation coefficient of the diameter of the continuous fiber is about 10% or more.

In the non-uniform stretching step, in particular, in the high stretching region, in addition to the above (i), (ii) a part of the joint portion may be broken and a part of the nonwoven fabric may be made into a web.
Furthermore, in the non-uniform stretching step, particularly when gear stretching described later is used, particularly in the high stretching region, (iii) in the portion where the number of continuous fibers is large and the fibers are intertwined, The resistance of the fiber surface is increased, and the fiber is locally stretched in the length direction, which may cause a constricted portion.
The constricted portion can be a starting point of bending of the fiber when pressure is applied, etc., so that the nonwoven fabric of the present invention can be easily deformed, but the constricted portion can exist randomly, It is considered that a certain degree of crushed difficulty can be maintained. Therefore, the nonwoven fabric of this invention is used suitably for the top sheet etc. of an absorbent article also from a viewpoint of a constriction part.

In the present specification, the “high stretch region” means a region in the nonwoven fabric that has been stretched to have a higher degree of elongation than the low stretch region, and the “low stretch region” is stretched more than the high stretch region. It means a region in the nonwoven fabric that has been stretched to a low degree, and includes a region that has not been stretched, that is, an unstretched region.
In the present specification, “extending unevenly” means stretching a nonwoven fabric so that a nonwoven fabric having a high stretch region and a low stretch region is formed, that is, a nonwoven fabric having a different degree of stretch depending on the position. This means that the nonwoven fabric is stretched so that is formed.

  The non-uniform stretching step is not particularly limited as long as it is a means capable of forming a nonwoven fabric having a high stretch region and a low stretch region, and can be carried out by any means. A pair of gear rolls having a rotation axis perpendicular to each other, and passing the nonwoven fabric through a gap between the gear rolls rotating while meshing a plurality of teeth arranged on the respective outer peripheral surfaces (hereinafter referred to as “gear stretching”) May be performed).

  FIG. 5 is a schematic diagram for explaining a gear stretching device in which a plurality of teeth are arranged on the outer peripheral surface of the gear roll in parallel to the rotation axis of the gear roll. The gear stretcher 11 shown in FIG. 5 has a pair of gear rolls 12 and 12 '. A plurality of teeth 14 and 14 'are arranged on the outer peripheral surfaces 13 and 13' of the gear rolls 12 and 12 ', respectively. In the gear stretching device 11 shown in FIG. 4, the rotation axes of the gear rolls 12 and 12 ′ are each perpendicular to the transport direction A. Further, a plurality of teeth 14 and 14 'are disposed on the outer peripheral surfaces 13 and 13' in parallel with the rotation axis, respectively.

  In the gear stretching apparatus 11 shown in FIG. 5, a nonwoven fabric 15 including continuous fibers and a joint formed by joining a plurality of fibers including the continuous fibers in the roll gap between the pair of gear rolls 12 and 12 ′. When passing through the gear rolls 12 and 12 ′, the continuous fibers and the plurality of fibers including the continuous fibers are joined by the plurality of teeth 14 and 14 ′ of the gear rolls 12 and 12 ′ meshing with each other. The nonwoven fabric 15 including the bonded portion is stretched by the principle of three-point bending to form a nonwoven fabric 16 having a high stretch region and a low stretch region. The nonwoven fabric 16 having a high stretch region and a low stretch region has a high stretch region and a low stretch parallel to the orthogonal direction orthogonal to the transport direction A (hereinafter, the orthogonal direction orthogonal to the transport direction is simply referred to as “orthogonal direction”). Stretching regions are alternately arranged in the transport direction A.

In the nonwoven fabric 15 including continuous fibers and a joint portion formed by joining a plurality of fibers including the continuous fibers, the fabric of the nonwoven fabric is fixed in a region in contact with the tips of the plurality of teeth 14 and 14 '. Therefore, it is not stretched at all or substantially, and a low stretch region is formed. On the other hand, in the area | region which does not contact | abut the front-end | tip part of several teeth 14 and 14 ', it extends | stretches greatly and a high extending | stretching area | region is formed.
In addition, as described above, in particular, in the high stretch region, (i) the continuous fiber is stretched and plastically deformed, and the variation coefficient of the diameter of the continuous fiber is about 10% or more, and (ii) bonding In some cases, a part of the part is broken, and a part of the nonwoven fabric may be made into a web. Thus, the fiber may be locally stretched in the length direction to generate a constricted portion.

The gear stretching can also be performed using a gear stretching apparatus as shown in FIG.
FIG. 6 is a schematic diagram for explaining a gear stretching device in which a plurality of teeth are arranged on the outer peripheral surface of the gear roll perpendicular to the rotation axis of the gear roll. FIG. 6 is a perspective view of the gear stretching apparatus 11, and a state immediately before the nonwoven fabric 15 including continuous fibers and a joint portion formed by joining a plurality of fibers including the continuous fibers is stretched in gear. Is shown. The nonwoven fabric 15 including continuous fibers and a joint formed by joining a plurality of fibers including the continuous fibers is gear-stretched by proceeding from the front to the back.

  The gear stretcher 11 shown in FIG. 6 has a pair of gear rolls 12 and 12 '. A plurality of teeth 14 and 14 'are arranged on the outer peripheral surfaces 13 and 13' of the gear rolls 12 and 12 ', respectively. Moreover, in the gear extending | stretching apparatus 11 shown by FIG. 6, several teeth 14 and 14 'are each arrange | positioned on the outer peripheral surfaces 13 and 13' perpendicularly to the rotating shaft line of the gear rolls 12 and 12 ', respectively. . By disposing the plurality of teeth 14 and 14 ′ in this way, it is possible to form a non-woven fabric having high stretch regions and low stretch regions that are parallel to the conveying direction alternately in the orthogonal direction.

Moreover, the gear extending | stretching apparatus may be arrange | positioned so that several teeth may incline with respect to the rotating shaft line of a gear roll in the outer peripheral surface of a gear roll.
FIG. 7 is a schematic diagram for explaining a gear stretching device in which a plurality of teeth are arranged on the outer peripheral surface of the gear roll so as to be inclined with respect to the rotation axis of the gear roll. The gear stretcher 11 shown in FIG. 7 has a pair of gear rolls 12 and 12 ′. A plurality of teeth 14 and 14 'are arranged on the outer peripheral surfaces 13 and 13' of the gear rolls 12 and 12 ', respectively. In the gear stretching device 11 shown in FIG. 7, the rotation axes of the gear rolls 12 and 12 ′ are each perpendicular to the transport direction A. Further, the plurality of teeth 14 and 14 ′ are arranged on the outer peripheral surfaces 13 and 13 ′ so as to have a constant angle θ with respect to the rotation axis, respectively.

The said gear extending | stretching apparatus can be suitably selected according to the desired performance of the nonwoven fabric formed with the formation method of the nonwoven fabric of this invention.
For example, when high extensibility is required in both the transport direction and the orthogonal direction, the nonwoven fabric before non-uniform stretching is stretched using the gear stretching apparatus shown in FIG. 5, and then the gear shown in FIG. Further stretching can be performed using a stretching apparatus.
Moreover, after extending | stretching the nonwoven fabric before non-uniform extending | stretching using the gear extending | stretching apparatus shown by FIG. 6, it can also be extended | stretched further using the gear extending | stretching apparatus shown by FIG.

In the gear stretching apparatus as shown in FIGS. 5-7, the gear pitch is preferably about 1 to about 10 mm, and more preferably about 2 to about 6 mm. When the gear pitch is less than about 1 mm, it is necessary to make the gear blade thinner, and the nonwoven fabric may be partially cut. When the gear pitch is more than about 10 mm, the draw ratio is low, and the plastic deformation of the continuous fiber In some cases, web formation of a part of the nonwoven fabric, formation of a constricted portion, etc. may be insufficient.
The gear pitch means an interval between adjacent teeth represented by reference numeral 17 in FIG.

In the gear stretching apparatus, the gear biting depth is preferably about 0.5 mm or more. When the gear biting depth is less than about 0.5 mm, the draw ratio is low, and plastic deformation of the continuous fiber, partial web formation of the nonwoven fabric, formation of a constricted portion, and the like may be insufficient.
The gear biting depth means a depth of a portion represented by reference numeral 18 in FIG. 6 where the teeth of the upper gear roll and the teeth of the lower gear roll overlap.

  In a nonwoven fabric having a high stretch region and a low stretch region, the stretch ratio is preferably from about 30 to about 400%, and more preferably from about 50 to about 200%. If the draw ratio is less than about 30%, the draw ratio is low, plastic deformation of continuous fibers, partial web formation of a nonwoven fabric, formation of a constricted portion, etc. may be insufficient, and the draw ratio is about 400%. If it exceeds 1, the strength of the nonwoven fabric having the high stretch region and the low stretch region is weak, and the stretched fibers are likely to fall off, which may make conveyance difficult.

In the present specification, the “stretch ratio” is the following formula when the gear pitch is P and the gear biting depth is D:
Means the value calculated by.

  The unwinding speed of the nonwoven fabric before non-uniform stretching varies depending on the desired stretching ratio and the like, but can be, for example, about 10 m / min or more.

  In the nonwoven fabric forming method of the present invention, the nonwoven fabric having the high stretch region and the low stretch region is disposed on a support, and the nonwoven fabric having the high stretch region and the low stretch region has a specific shape and a specific shape. A step of spraying the ejected fluid so as to form a nonwoven fabric having a coefficient of variation of (hereinafter, may be referred to as a “fluid treatment step”).

FIG. 8 is a diagram illustrating an example of a fluid processing step. The support body 19 shown in FIG. 8 has protrusions 20 and depressions 21 that are parallel to the orthogonal direction B, and the protrusions 20 and depressions 21 are alternately arranged in the transport direction A. Has been. In FIG. 8, the projecting portion 20 and the recessed portion 21 have a cubic shape.
FIG. 8 also shows the fluid nozzle 22, and a suction portion (not shown) for receiving the fluid is provided below the fluid nozzle 22 with the support 19 interposed therebetween.

  The non-woven fabric 23 having a specific shape and a specific coefficient of variation is sprayed by the fluid ejected from the fluid nozzle 22 onto the non-woven fabric 16 having a high-stretch region and a low-stretch region, which has been placed and carried on the support 19. Form. The sprayed fluid is discharged from a suction part (not shown).

An example of a nonwoven fabric formed using the support 19 shown in FIG. 8 is shown in FIG. In the nonwoven fabric 23 having a specific shape and a specific coefficient of variation shown in FIG. 9, the upper side is the second surface 2 and the lower side is the first surface 1. Further, in FIG. 9, the support body 19 is indicated by a dotted line in order to help understanding.
In the fluid processing step, a surface on which the fluid collides (hereinafter sometimes referred to as “fluid collision surface”) corresponds to the second surface, and a surface opposite to the fluid collision surface (hereinafter referred to as “non-fluid collision surface”). May be referred to as “surface”) corresponds to the first surface.

When the fluid ejected from the fluid nozzle 22 collides with the protruding portion 20 of the support 19 through the nonwoven fabric 16 having the high stretch region and the low stretch region, the fluid flows around the recess portion 21. As a result, the stretched continuous fiber having a high degree of freedom moves toward the hollow portion 21 along the flow of the fluid, so that the continuous fiber per unit area at the location where the fluid and the protruding portion 20 intersect. The amount of continuous fibers per unit area is large at the place where the fluid and the depression 21 intersect, while the amount is reduced and the recess (C ₁₁ ) 5 is formed in the nonwoven fabric 16 having the high stretch region and the low stretch region. Thus, the nonwoven fabric 16 having a high stretch region and a low stretch region is provided with two types of convex portions, that is, a convex portion (V ₁₁ ) 3 including a joint portion and a convex portion (V ₁₂ ) 4 including no joint portion. Form.

In the convex part (V ₁₁ ) 3 including the joint part, when the fluid moves the elongated continuous fiber toward the hollow part 21 along the flow of the fluid, the joint part 7 is moved to the periphery of the joint part 7. Together with the continuous fibers in the vicinity of the joint 7 on the second surface, in the direction of the recess 21. As a result, the second surface 2 includes a plurality of concave portions (C ₂₁ ) 8 that overlaps at least a part of the convex portion (V ₁₁ ) 3 including the joint portion of the first surface. The reason for being “at least partly” is that when the joint portion is at the peripheral edge of the convex portion, the concave portion is not formed on the second surface, or the concave portion is formed on the second surface. This is because the convex portion (V ₁₁ ) 3 including the joint portion may not overlap.
In addition, although it is common that the junction part in a spun bond nonwoven fabric, a melt blown nonwoven fabric, etc. becomes thinner than parts other than a junction part, in FIG. 9, the thinness of a junction part is not reflected. This is because it is considered that the understanding of the unevenness formed by the fluid processing step is hindered.

In the convex portion that does not include a convex portion (V ₁₁₎ and a joint portion including a joint (V _12), since there is a tendency for the thickness direction of the nonwoven fabric, elongated continuous fibers rises, the nonwoven fabric of the present invention Compression resistance and liquid permeability are improved. Moreover, since the 1st surface has an unevenness | corrugation, the nonwoven fabric of this invention is excellent in air permeability, especially the air permeability of a planar direction, and also is excellent in the touch because a contact area decreases.

In the fluid treatment step, depending on the basis weight of the nonwoven fabric having the high stretch region and the low stretch region, the stretch ratio of the non-uniform stretch step, the type and amount of the fluid to be ejected, the ejected fluid may be The second surface further includes a plurality of convex portions (V ₂₁ ) and a plurality of concave portions (C ₂₂ ), which are selected in the planar direction, for example, the orthogonal direction, in accordance with the collision and then rebounding. It may become. The concave portion (C ₂₂ ) in the second surface is different from the concave portion (C ₂₁ ) in the formation process, and the concave portion (C ₂₂ ) is a convex portion including the joint portion on the first surface. (V ₁₁ ) and in principle do not overlap.

Also, the second surface, in addition to the recess (C _21), a plurality of convex portions and (V _21), when further comprising a plurality of recesses (C _22), the second surface, they together May have complex surface shapes.

Furthermore, the recess (C ₁₁ ) on the first surface and the recess (C ₂₂ ) on the second surface may be connected to form an opening. The concave portion (C ₂₂ ) of the second surface is formed as the ejected fluid collides and then rebounds, but when the energy of the ejected fluid is large, more fibers are sorted, A larger second surface recess (C ₂₂ ) may be formed immediately below the ejected fluid. Therefore, the concave portion (C ₁₁ ) of the first surface is present on the opposite side of the larger concave portion (C ₂₂ ) of the second surface. A local stretching degree or the like may be added to form a hole portion in which the concave portion (C ₁₁ ) on the first surface and the concave portion (C ₂₂ ) on the second surface are connected.

  When the non-woven fabric has the first surface having irregularities and / or the second surface having irregularities, the contact area with the skin is reduced, and the sticky feeling due to stuffiness due to the large contact area is rubbed. Since the resulting irritation can be reduced, it is suitable for applications such as absorbent articles.

  In FIG. 8, the support body 19 is shown in which the protruding portions 20 and the recessed portions 21 are parallel to the orthogonal direction and are alternately arranged in the transport direction. However, in the nonwoven fabric forming method of the present invention, The shape of the support is not particularly limited, and as an example of the support, (i) a support having protrusions and depressions parallel to the transport direction and alternately arranged in the orthogonal direction Or (ii) a support having protrusions and depressions that are inclined with respect to the transport direction and are alternately arranged in a direction perpendicular to the direction of the inclination. Or (iii) projections and / or depressions having a predetermined shape (eg, cubic, cylindrical, hemispherical, etc.) are arranged in a predetermined arrangement (eg, heart-shaped, star Support arranged in an array of molds, etc.) It can be mentioned.

The protrusions preferably have a fluid permeability that is lower than the fluid permeability of the recesses. Because the projecting portion has low fluid permeability, the fluid colliding with the projecting portion flows toward the recessed portion, and a larger convex portion can be formed on the nonwoven fabric formed by the above method. is there.
Examples of the material for the protrusions include metals and plastics.

  The shape and material of the projecting portion and the recessed portion are not particularly limited, and the support is, for example, a metal or plastic conveyor net normally used as a fluid-permeable support, a papermaking network, On the punching plate or the like, a metal having a cube shape or a cylindrical shape can be formed by arranging them in a predetermined arrangement such as maintaining a certain interval.

Projections and / or depressions having a predetermined shape (for example, a cubic shape, a cylindrical shape, a hemispherical shape, etc.) are arranged in a predetermined shape (for example, a heart shape, a star shape, etc.) Examples of the supporting member include a support in which a hemispherical metal is arranged in a predetermined arrangement (for example, a heart shape) on a punching plate. If the said support body is used, the nonwoven fabric which has a recessed part of a predetermined pattern (for example, heart shape) can be formed.
Further, for example, when a support having a projecting portion and a dent portion, in which a hemispherical dent shape is arranged in a predetermined pattern (for example, a heart shape) on the punching plate, the predetermined shape is determined. A non-woven fabric having convex portions of a pattern (for example, a heart shape) can be formed.

Furthermore, the punching plate itself can be used as a support. Examples of the punching plate that can be used as the support include, for example, a round hole type, for example, a round hole 60 ° zigzag type, a round hole square zigzag and a round hole series type, a square hole type, a round ten type, a cloud type, and a cloud zigzag. Examples thereof include punching plates such as molds. When the punching plate is used as a support, the plate portion becomes a projecting portion and the opening portion becomes a hollow portion.
The method for forming a nonwoven fabric of the present invention can give a desired pattern, desired air permeability, desired flexibility, etc. to the nonwoven fabric before non-uniform stretching by selecting the shape of the support, and is commercially available. The non-woven fabric can be processed easily and at low cost according to the application.

  Further, when the fluid treatment step is performed on a roll, it is a roll-shaped support, the outer periphery of which is made of a fluid-permeable material such as a mesh, and the outer peripheral surface has a predetermined shape and The thing by which the protrusion part and hollow part of an arrangement | sequence are arrange | positioned can be used. Examples of the predetermined shape and arrangement include the shapes and arrangements described above.

  In the support body having the protrusions and the depressions, the widths thereof vary depending on the characteristics required for the nonwoven fabric having a specific shape and a specific coefficient of variation. For example, in the support body shown in FIG. The width of the ridge is preferably in the range of about 0.5 to about 10 mm, and the width of the recess is preferably in the range of about 1 to about 10 mm.

  Examples of the fluid used in the fluid treatment step include air, for example, heated air, water vapor, for example, saturated water vapor and superheated water vapor, or water, for example, hot water. Considering that the subsequent drying step is unnecessary or less, heated fluid, saturated steam, and superheated steam are preferable as the fluid.

  The fluid can be sprayed from a fixed fluid nozzle to a nonwoven fabric having a high stretch region and a low stretch region or from a fluid nozzle that reciprocates in an orthogonal direction. Moreover, the fluid can be sprayed from a fluid nozzle continuously or intermittently to a nonwoven fabric having a high stretch region and a low stretch region. Moreover, these can also be combined.

The said fluid can be suitably selected with the form of the nonwoven fabric which has a high extending | stretching area | region and a low extending | stretching area | region. For example, when processing a non-woven fabric with a small gear pitch and a high draw ratio, a non-woven fabric having a specific shape and a specific coefficient of variation can be formed with relatively low energy, so air or water vapor is selected as the fluid. It is preferable to do. Also, when using a nonwoven fabric with a large gear pitch and many low stretch regions, there are many joints between continuous fibers, so a relatively high energy is required to form a nonwoven fabric with a specific shape and a specific coefficient of variation. Therefore, it is preferable to select water or steam as the fluid, and steam is more preferable. This is because moisture hardly remains in a portion where the amount of continuous fibers is large, the joint portion where the amount of continuous fibers is large is less likely to break, and the stretched continuous fibers of the portion to be moved are easily moved. Because it can.
The fluid treatment step can be performed using a known device in the art and by a known method.

  The nonwoven fabric of the present invention and the nonwoven fabric formed by the method of the present invention are useful for absorbent articles such as sanitary and disposable diapers, cleaning products such as wipers, and medical products such as masks.

The nonwoven fabric formed by the above method can be used, for example, as a liquid-permeable top sheet for absorbent articles. By using a nonwoven fabric that is easily deformed but is not easily crushed and has excellent air permeability in the planar direction, an absorbent article excellent in these can be produced.
The absorbent article includes a nonwoven fabric of the present invention as a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body between the liquid-permeable top sheet and the liquid-impermeable back sheet. Can be included.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated, this invention is not limited to these Examples.
The measurement conditions of the items evaluated in the examples and comparative examples are as follows.
[Basis weight]
The basis weight is measured according to 5.2 of JIS L 1906.
[Bulk]
The bulk is measured using THICKNESS GAUGE UF-60 manufactured by Daiei Kagaku Seiki Seisakusho.

[Compression characteristics]
The compression characteristics are evaluated using an automated compression tester, KES-FB3, manufactured by Kato Tech Co., Ltd.
The measurement conditions are as follows.
SENS: 2
Speed: 0.02mm / sec Stroke: 5mm / 10V
Pressurized area: 2 cm ²
Uptake interval: 0.1 seconds Upper limit load: 50 g / cm ²
Repeat count: 1 time

Compression properties, and WC, which means compression energy per nonwoven 1 cm ^2, and T _0, which means the thickness of the sample at a pressure 0.5 gf / cm ^2, and T _m, which means the thickness of the sample at a pressure 50 gf / cm ² Evaluate by WC means that the larger the value, the easier it is to compress.

[Air permeability]
The air permeability is measured using a KES-F8-AP1 air permeability tester manufactured by Kato Tech Co., Ltd., and the unit is converted to “m ³ / m ² / min”.
The air permeability in the thickness direction of the nonwoven fabric is measured by setting a nonwoven fabric cut to a size of 100 mm × 100 mm in a breathability tester.
For the air permeability in the plane direction of the nonwoven fabric, a nonwoven fabric cut to a size of 100 mm × 100 mm is set in a breathability tester, and an acrylic plate having a size of 100 mm × 100 mm is further set on the nonwoven fabric. Measure under a weight of cm ² .

[Liquid permeability]
The liquid permeability is evaluated using a LISTER strike-through tester manufactured by LENZING. The evaluation procedure is as follows.
(1) A sample cut to a size of 100 × 100 mm is placed on five pieces of filter paper (ADVANTEC FILTER PAPER GRADE 2) cut to a size of 100 × 100 mm, and an electrically permeable liquid plate is placed thereon. .
(2) Set a filter paper, a sample and a current-permeable plate on the strike-through tester body.
(3) Put 5 mL of physiological saline into the strike-through tester body.
(4) The physiological saline (room temperature) is dropped from the strike-through tester main body into the opening of the conductive liquid-permeable plate.
(5) Record the energization time of the energized permeable plate.
(6) The measurement is repeated twice, and the average of three times in total is defined as the liquid permeation time.
In the case where the sample was not set, that is, the liquid permeation time in 5 sheets of filter paper was 69 seconds.

[Example 1]
-Preparation of non-woven fabric-
Spunbond nonwoven fabric 1 was prepared. The spunbond nonwoven fabric 1 contained continuous fibers made of polypropylene and was a commercial product. In addition, the spunbond nonwoven fabric 1 has a round hole square staggered emboss, the emboss diameter is about 0.5 mm, and the MD pitch and CD pitch are about 2 mm and about 2 mm, respectively. It was.
The characteristic values of the spunbond nonwoven fabric 1 are shown in Table 1.

-Gear extension-
The spunbonded nonwoven fabric 1 is gear-stretched using a gear stretching device (gear pitch: 2.5 mm, gear tip width: 0.2 mm, gear biting depth: 2.0 mm) as shown in FIG. A nonwoven fabric having a high stretch region and a low stretch region was formed. The processing speed was 30 m / min. The stretch ratio of the nonwoven fabric having the high stretch region and the low stretch region was 89%.
Table 1 shows the characteristic values of the nonwoven fabric having the high stretch region and the low stretch region.

-Steam treatment-
A non-woven fabric having the above-described high-stretch region and low-stretch region is formed from a round hole 60 ° staggered punching plate (φ: 3.0 mm, MD pitch: 6.93 mm, CD pitch: 4.0 mm, thickness: 1.0 mm). ). Next, the nonwoven fabric having the high stretch region and the low stretch region is subjected to a steam treatment system having a plurality of nozzles (φ: 0.5 mm) at an interval of 1.0 mm (jet pressure: 0.5 Mpa, steam temperature: about 149 ° C.), the nonwoven fabric 1 was obtained at a speed of 30 m / min while maintaining the distance between the nozzle and the support at 2.0 mm.
The characteristic values of the nonwoven fabric 1 are shown in Table 1.

[Example 2]
A nonwoven fabric 2 was obtained in the same manner as in Example 1 except that the gear biting depth was 3.0 mm and the draw ratio was changed to 160%. The characteristic values of the nonwoven fabric 2 are shown in Table 1.

[Comparative Example 1]
A nonwoven fabric 3 was obtained in the same manner as in Example 1 except that the spunbond nonwoven fabric 1 was directly steam-treated without going through the gear stretching step. The characteristic values of the nonwoven fabric 3 are shown in Table 1.

[Example 3]
Spunbond nonwoven fabric 2 was prepared. The spunbond nonwoven fabric 2 contained a core-sheath type composite fiber whose core was made of polypropylene and whose sheath was a copolymer of ethylene and propylene. In addition, the spunbond nonwoven fabric 2 has square staggered embossing, and the embossing has a rhombus shape of about 0.6 mm × about 0.6 mm, and the MD pitch and CD pitch are about 2 mm and It was about 2 mm. The characteristic values of the spunbond nonwoven fabric 2 are shown in Table 2.
The spunbond nonwoven fabric 1 was changed to the spunbond nonwoven fabric 2, and the nonwoven fabric 4 was obtained in the same manner as in Example 1 except that the water vapor ejection pressure was changed to 0.4 Mpa and the water vapor temperature was changed to about 141 ° C. . The characteristic values of the nonwoven fabric 4 are shown in Table 2.

[Example 4]
A nonwoven fabric 5 was obtained in the same manner as in Example 3 except that the gear biting depth was 3.0 mm and the draw ratio was changed to 160%. The characteristic values of the nonwoven fabric 5 are shown in Table 2.

[Comparative Example 2]
A nonwoven fabric 6 was obtained in the same manner as in Example 3 except that the spunbond nonwoven fabric 2 was directly subjected to steam treatment without performing gear stretching. The characteristic values of the nonwoven fabric 6 are shown in Table 2.

[Example 5]
A spunbond nonwoven fabric 3 was prepared. The spunbond nonwoven fabric 3 includes a core-sheath type composite fiber whose core is made of polypropylene and whose sheath is a copolymer of ethylene and propylene. Also, the spunbond nonwoven fabric 3 was provided with a joint 7 as an emboss as shown in FIG. Table 3 shows the characteristic values of the spunbond nonwoven fabric 3.
The non-woven fabric 7 was changed in the same manner as in Example 3 except that the spunbond non-woven fabric 2 was changed to the spunbond non-woven fabric 3 and the gear biting depth was 2.5 mm and the draw ratio was changed to 124%. Obtained. The characteristic values of the nonwoven fabric 7 are shown in Table 3.

[Comparative Example 3]
A nonwoven fabric 8 was obtained in the same manner as in Example 5 except that the spunbond nonwoven fabric 3 was directly steam-treated without going through the gear stretching step. The characteristic values of the nonwoven fabric 8 are shown in Table 3.

[Example 6]
A spunbond nonwoven fabric 4 was prepared. The spunbond nonwoven fabric 4 includes a core-sheath type composite fiber whose core is made of polypropylene and whose sheath is a copolymer of ethylene and propylene. In addition, the spunbonded nonwoven fabric 4 was provided with a joint 7 as an emboss as shown in FIG. Table 4 shows the characteristic values of the spunbond nonwoven fabric 4.
A nonwoven fabric 9 was obtained in the same manner as in Example 5 except that the spunbond nonwoven fabric 3 was changed to the spunbond nonwoven fabric 4. The characteristic values of the nonwoven fabric 9 are shown in Table 4.

[Comparative Example 4]
A nonwoven fabric 10 was obtained in the same manner as in Example 6 except that the spunbond nonwoven fabric 4 was directly steam-treated without going through the gear stretching step. The characteristic values of the nonwoven fabric 10 are shown in Table 4.

Since the nonwoven fabric formed in Examples 1-6 has a large WC value compared to the nonwoven fabric formed in the corresponding comparative example, it is easily deformed with a small force, and because the _Tm value is large, the nonwoven fabric is crushed. I find it difficult.
It can be seen that the nonwoven fabrics formed in Examples 1 to 6 also have higher air permeability in the planar direction than the nonwoven fabrics formed in the corresponding comparative examples.

1 the convex portion including a first surface 2 the second surface 3 junction (V ₁₁₎
4 Convex part not including joint (V ₁₂ )
5 Recess (C ₁₁ )
6 Opening 7 Bonding 8 Recess (C ₂₁ )
9 Constriction part 11 Gear stretcher 12, 12 'Gear roll 13, 13' Outer peripheral surface 14, 14 'A plurality of teeth 15 A continuous fiber and a joint part formed by joining a plurality of fibers including the continuous fiber Nonwoven fabric 16 Nonwoven fabric having high stretch region and low stretch region 17 Gear pitch 18 Gear biting depth 19 Support 20 Protruding portion 21 Depressed portion 22 Fluid nozzle 23 Nonwoven fabric having specific shape and specific variation coefficient A Conveying direction B Orthogonal direction perpendicular to transport direction

Claims (11)

A nonwoven fabric comprising continuous fibers and a joint formed by joining a plurality of fibers including the continuous fibers,
The nonwoven fabric includes a first surface and a second surface opposite to the first surface;
The first surface includes a plurality of convex portions (V ₁₁ ) including a joint portion, a plurality of convex portions (V ₁₂ ) not including the joint portion, and a concave portion (C ₁₁ ),
The second surface includes a plurality of concave portions (C ₂₁ ) overlapping at least a part of the convex portion (V ₁₁ ) including the joint portion of the first surface, and the coefficient of variation of the diameter of the continuous fiber is: 10% or more, characterized in that
The nonwoven fabric. The nonwoven fabric according to claim 1, wherein the second surface does not include a concave portion that overlaps the convex portion (V ₁₂ ) of the first surface that does not include a joint portion. The second surface further includes a plurality of convex portions (V ₂₁ ) and a plurality of concave portions (C ₂₂ ) that do not overlap with the convex portions (V ₁₁ ) of the first surface. Non-woven fabric. A recess in the first surface (C _11), connecting the recess (C ₂₂₎ of the second surface, having one or more openings, as claimed in any one of claims 1 to 3 Non-woven fabric.   The nonwoven fabric according to any one of claims 1 to 4, wherein the continuous fiber has a plurality of constricted portions having a partially narrowed diameter.   A spunbond nonwoven fabric or meltblown nonwoven fabric comprising continuous fibers and a joint formed by joining a plurality of fibers including the continuous fibers so that a nonwoven fabric having a high stretch region and a low stretch region is formed. A non-woven fabric that is stretched non-uniformly and has the high stretch region and the low stretch region is disposed on a support, and the ejected fluid is sprayed onto the non-woven fabric having the high stretch region and the low stretch region. The nonwoven fabric as described in any one of Claims 1-5 formed by these. An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body between the liquid-permeable top sheet and the liquid-impermeable back sheet,
The liquid-permeable top sheet is the nonwoven fabric according to any one of claims 1 to 6,
The absorbent article. A method for forming the nonwoven fabric according to any one of claims 1 to 6,
Preparing a nonwoven fabric comprising continuous fibers and a joint formed by joining a plurality of fibers including the continuous fibers;
A non-woven fabric including the continuous fiber and a joint formed by joining a plurality of fibers including the continuous fiber is stretched non-uniformly so that a non-woven fabric having a high stretch region and a low stretch region is formed. And a non-woven fabric having the high-stretch region and the low-stretch region disposed on a support, and the non-woven fabric having the high-stretch region and the low-stretch region. Spraying the ejected fluid to form a nonwoven fabric as described in
Including said method.   The method according to claim 8, wherein the support has protrusions and depressions having a predetermined shape and arrangement on a surface in contact with the nonwoven fabric.   The method according to claim 8 or 9, wherein the fluid is heated air, saturated steam, or superheated steam.   The nonwoven fabric containing the said continuous fiber and the junction part formed by joining the some fiber containing the said continuous fiber is a spun bond nonwoven fabric or a melt blown nonwoven fabric, It is any one of Claims 8-10. the method of.