JPH0791765B2 - Nonwoven fabric, method for producing the same, and absorbent article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a nonwoven fabric, a method for producing the same, and an absorbent article,
More specifically, the present invention relates to a nonwoven fabric having irregularities suitable as a surface material for absorbent articles such as disposable diapers and sanitary napkins, a method for producing the same, and an absorbent article using the nonwoven material as a surface material.

[Conventional technology]

One of the problems of absorbent articles such as paper diapers and sanitary napkins is to suppress or prevent leakage of body fluids such as urine, loose stools, and menstrual blood from the absorbent articles. For that purpose, the members constituting the absorbent article, that is, the surface material, the absorber, the back surface material, and the like, are each creatively devised to suppress or prevent liquid leakage.

In general, a non-woven fabric is often used for the surface material, and the non-woven fabric is often formed of a hydrophilic thermoplastic fiber in order to improve the absorbability of body fluid. Also,
In order to prevent exudation and leakage of body fluids, attempts have been made to make the side parts or the peripheral parts of the nonwoven fabric, which is the surface material of sanitary goods, hydrophobic.

On the other hand, highly viscous body fluids such as loose stools and highly viscous menstrual blood have poor permeability in ordinary non-woven fabrics, and flow through the non-woven fabric surface until they are absorbed by the internal absorbent body to stain clothes and sometimes skin irritation. It may cause discomfort.

Conventionally, as measures against these, for example, a method of perforating a non-woven fabric with a pin, a needle or the like, a method of interlacing a web with a high-speed water flow to form a perforated shape or a mesh shape (Japanese Patent Publication No. 62-62175).
Japanese Patent Laid-Open No. 62-28219), and a method of reducing the basis weight of a non-woven fabric or increasing the distance between fibers with thick denier fibers has been proposed.

[Problems to be Solved by the Invention]

However, the conventional nonwoven fabrics and the manufacturing methods thereof have the following problems, respectively.

That is, the non-woven fabric perforated with a pin, a needle, etc., has a poor feel on the surface because of the formation of protrusions around the perforations on the surface, and also lacks the morphological stability of the perforation. , Fluff is liable to occur, and bulkiness cannot be obtained unless the basis weight is increased. In addition, the fiber treatment agent may fall off due to a high-speed water flow, and a fiber composed of thermoplastic fibers may become hydrophobic. There was Also enough confounding,
In order to provide the perforations, there is a problem that the processing speed cannot be increased, the water flow is scattered around the manufacturing apparatus, which is not preferable in the working environment, and rust is generated in the manufacturing apparatus. Furthermore, in the case of a mesh non-woven fabric, the return of body fluid absorbed by the absorber is large, and when used as a surface material,
There was also a problem that a dry feeling could not be obtained.

In short, conventional non-woven fabric, when used as a surface material,
Although permeability to excrements such as body fluids with high viscosity is recognized to some extent, they are not always sufficient as liquid permeability, and in addition, the ability to suppress body fluid return, which is required as a surface material for absorbent articles. However, properties such as bulkiness and texture such as touch were not always satisfactory.

Therefore, the object of the present invention, when used as a surface material of an absorbent article, is to ensure that permeates such as body fluids having high viscosity are permeated and that their leakage is suppressed or prevented, and that they are required as a surface material. It is an object of the present invention to provide a comprehensively excellent non-woven fabric having various properties as well as a method for producing the same and an absorbent article utilizing the various properties by using the non-woven fabric as a surface material.

[Means for Solving the Problems]

The present inventors have conducted various studies on a nonwoven fabric having a form capable of preventing the flow of a highly viscous liquid and having excellent permeability and a method for producing the same, and as a result, after forming irregularities on the fiber web by a specific means, the fiber web was formed. It was found that the above object can be achieved by heating and fusing the thermoplastic fiber contained in the.

The present invention was made based on the above findings, in a nonwoven fabric obtained by melting and integrating thermoplastic fibers of a fibrous web containing thermoplastic fibers, wherein the nonwoven fabric has a hydrophilic central portion and a central portion. Having adjacent hydrophobic ends, the central portion is formed of a convex portion and a concave portion dispersed throughout, and the fiber aggregation density of the concave portion is lower than the fiber aggregation density of the convex portion, and Both ends provide a non-woven fabric characterized in that the fiber aggregate density is substantially uniform.

Further, the present invention is an absorbent article comprising a surface material that comes into contact with skin and an absorbent body covered with the surface material, wherein the surface material is formed of the non-woven fabric in an absorbent article that absorbs excrements such as body fluids. And an absorbent article characterized by the above.

Further, the present invention, as a suitable production method for producing the above-mentioned nonwoven fabric, comprises a first fibrous web which contains thermoplastic fibers and is hydrophobic as a whole, and a hydrophilic fiber which contains thermoplastic fibers and is entirely hydrophilic. After each of the second fibrous webs is formed, the second fibrous web is placed on an air-permeable conveyor having irregularities, and a gas is jetted onto the surface of the fibrous web while the fibrous web is conveyed while being placed. Then, the fibrous web is made to follow the concave portion of the breathable conveyor to form the concavo-convex portion of the fibrous web, and then the second fibrous web is provided between the first fibrous webs conveyed with a gap. After placing
The present invention also provides a method for producing the above-mentioned nonwoven fabric, which comprises heating both of them to fuse the respective thermoplastic fibers to integrate them.

[Action]

According to the absorbent article using the non-woven fabric of the present invention, it comes into good contact with the skin when worn, and after being worn, the highly viscous body fluid is surely permeated and absorbed by the absorbent body in the central portion, and the liquid returns from the absorbent body. It is possible to suppress or prevent the leakage of bodily fluid at both ends.

Further, according to the method for producing a nonwoven fabric of the present invention, a first fibrous web containing thermoplastic fibers and being hydrophobic as a whole,
And a hydrophilic second containing thermoplastic fibers
After forming each of the fibrous webs, the second fibrous web is placed on a breathable conveyor having irregularities, and while the fibrous web is conveyed while being placed, a gas is jetted onto the fibrous web surface, The concave-convex portion of the breathable conveyor is followed by the fibrous web to form an uneven portion on the fibrous web,
Then, after arranging the second fibrous web between the first fibrous webs which are conveyed with a gap therebetween, when these vehicles are heated to fuse the respective thermoplastic fibers, they are integrated with each other to form a nonwoven fabric. It can be manufactured.

〔Example〕

The present invention will be described below based on the embodiments shown in FIGS. In each figure, FIG. 1 is a partial perspective view conceptually showing one embodiment of the nonwoven fabric of the present invention, and FIG.
A sectional view taken along line II, FIG. 3 is a perspective view showing a non-woven fabric manufacturing apparatus that can be suitably used when carrying out the non-woven fabric manufacturing method of the present invention, and FIG. 4 is formed by the non-woven fabric manufacturing apparatus shown in FIG. Schematic diagram showing a cross section of the first strip-shaped web,
The figure is equivalent to FIG. 4 showing the second strip-shaped web, FIG. 6 is the equivalent diagram to FIG. 4 showing a state in which uneven portions are formed on the second strip-shaped web, and FIG. 7 is shown in FIG. 6th to 1st web
FIG. 8 is a view corresponding to FIG. 4 showing a state in which the second strip-shaped web shown in the figure is arranged, and FIG. 8 is a view corresponding to FIG. 4 showing a state where the semi-finished product shown in FIG. 7 is trimmed.

The nonwoven fabric 10 of this embodiment is formed by melting and integrating thermoplastic fibers of a fibrous web containing thermoplastic fibers, and as shown conceptually in FIG. It has hydrophobic end portions 12, 12 adjacent to the central portion 11.

Thus, the central portion 11 is formed of the convex portion 11A and the concave portion 11B dispersed throughout. The concave portion 11B has a first
Although it is expressed as a state where the holes are completely opened in FIGS. 2 and 3, originally, the fibrous web is diffused into the convex portions 11A around the fibrous web to form a low fiber aggregate density. In other words, the convex portion 11A surrounding the concave portion 11B has a higher fiber aggregate density, and as a result, the fiber aggregate density of the concave portion 11B is lower than that of the convex portion 11A. In addition, it is preferable that the fiber assembly density in the concave portion 11B becomes low as described above, and that the concave portion 11B is substantially open. The convex portions 11A and the concave portions 11B are preferably arranged alternately and regularly as shown in FIG. 1, and the nonwoven fabric 10 is formed by regularly dispersing the irregularities in this manner. The appearance quality can be improved. Further, the preferable pitch of the unevenness is 3 to 20 mm. If the pitch is less than 3 mm, the unevenness is too small and the bulkiness is deteriorated. On the contrary, if the pitch exceeds 20 mm, the unevenness is too large and only the appearance is good. However, the pitch of the concave portions 11B that function as absorption holes for the highly viscous liquid becomes large, and the permeability of the highly viscous liquid decreases. Further, the hole diameter of the open hole portion in terms of a perfect circle is preferably φ2 to φ6 mm, and the bottom surface of the concave portion 11B and the convex portion 1
The height difference h from the bottom surface of 1A is characterized by h> 0, and h> 0.5 mm is more preferable.

On the other hand, the hydrophobic end portions 12 and 12 are respectively formed into the convex portion 11
A and the concave portion 11B are not formed, are formed to be substantially flat, the fiber aggregate density is formed to be substantially uniform, the touch is improved, and leakage of leakage in the corresponding portion is prevented.

Thus, the non-woven fabric 10 of this embodiment preferably has a basis weight of 9 to 40 g / m ² , and more preferably 15 to 30 g / m ² . When the basis weight is low, the bulkiness is low, the feeling of unevenness is inferior, and the liquid returning property is deteriorated. On the contrary, even if the basis weight is increased more than necessary, there is a cost disadvantage.

Further, the fiber aggregate density of the convex portion 11A and the concave portion 11B,
With the middle of the top of the convex portion 11A and the bottom of the concave portion 11B of the nonwoven fabric 10 as a boundary, the fibrous web in the upper portion from the middle is attributed to the convex portion 11A, and the fibrous web in the lower portion from the middle is concave. Assuming that the fiber web belongs to the portion 11B, the fiber assembly density of the convex portion 11A is 1 × 10 ⁻⁵ to 8
× 10 ^-5 g / mm ² , and the fiber assembly density of the concave portion 11B is
It is preferably 0 to 2 × 10 ⁻⁵ g / mm ² . Here, the fiber aggregate density is defined by the following formula, and means the average basis weight in a minute area.

As the thermoplastic fiber forming the central portion 11, for example,
Polyester type such as polyethylene terephthalate (melting point 255 ° C) and polybutylene terephthalate (melting point 215 ° C), polyolefin type such as polyethylene (melting point 130 ° C), polypropylene (melting point 165 ° C), nylon-6 (melting point 2)
Examples of the fibers include polyamides such as 20 ° C.) and nylon-66 (melting point 260 ° C.), and modified polymers thereof. The thermoplastic fiber is surface-treated with a hydrophilic surfactant to impart hydrophilicity. Examples of the hydrophilic surfactant include any one of a metal salt of polyoxyethylene alkyl sulfate or a metal salt of alkyl sulfate, a metal salt of mono- or dialkylsulfosuccinic acid and a sorbitan fatty acid ester, or a mixture thereof.

Further, the thermoplastic fibers forming the both ends 12 are completely hydrophobic, and are further surface-treated with a hydrophobic surfactant to impart hydrophobicity. Examples of the hydrophobic surfactant include fluorine, paraffin waxes, silicon, and metal salts of alkyl phosphates.

Thus, the fibrous web preferably contains 50% by weight or more of thermoplastic fiber, and the thermoplastic fiber is preferably a composite fiber composed of a low melting point component and a high melting point component. The composite fiber is composed of two or more kinds of thermoplastic fibers in which ones having different melting points among the thermoplastic fibers are appropriately selected. Examples of the composite fiber include a core-sheath type in which the sheath side has a lower melting point than the core side. Examples thereof include thermoplastic composite fibers and / or laminating type thermoplastic composite fibers having different melting points. It is preferable that both the core-sheath type and the laminated type composite fibers have a melting point difference of 30 ° C. or more between the high melting point component and the low melting point component.

After forming a fibrous web having a predetermined shape with the constituent fibers obtained by mixing a predetermined amount of non-composite fibers into the above-mentioned conjugate fibers, the constituent fibers are formed by heating and melting the low-melting point component of the conjugate fibers. It is formed by integrating them.

As a method of heating and melting the fibrous web, there is a method of passing the fibrous web through a pair of heating rolls, but the bulkiness,
In consideration of giving a texture and the like, a method of passing the material through a heated air chamber as described later is preferable.

Further, the content of the thermoplastic fiber constituting the conjugate fiber is preferably 50% by weight or more as described above, and therefore, the content of the non-composite fiber used in combination is preferably less than 50%. If the content of the composite fiber is less than 50% by weight, the strength of the nonwoven fabric as the surface material of the absorbent article described below may not be obtained.

Examples of the non-composite fibers include non-composite fibers made of polyethylene terephthalate, polybutylene terephthalate, polypropylene, nylon-6, nylon-66 and the like.

Further, each of the thermoplastic fibers used to form the nonwoven fabric 10,
Considering the process of manufacturing a nonwoven fabric and the texture when used as a surface material of an absorbent article, the fineness is preferably 1 to 6 denier. Incidentally, the composite fiber and the non-composite fiber,
The fibers are not limited to those described above, and various other fibers can be selected as necessary. However, non-thermoplastic fibers such as rayon, cupra, and cotton are not preferable as a material for a non-woven fabric used as a surface material of an absorbent article in consideration of fluff drop, decrease in bulkiness, strength and the like.

Nonwoven fabric 10 of the present embodiment, as described above, the central portion 11 is formed with convex portions 11A and concave portions 11B that are regularly dispersed,
Since the convex portion 11A has a high fiber aggregate density, it has bulkiness (cushioning property), and when used as a surface material of an absorbent article, it is difficult for liquid to return, and the concave portion 11B has a fiber aggregate density. Since it has a low temperature and is in a substantially open state, it has excellent permeability for highly viscous liquids.
Since 2 and 12 are hydrophobic, they can suppress or prevent leakage due to bleeding and have an excellent texture, and have a good texture as a surface material as a whole.

Next, one example of the absorbent article of the present invention using the above-mentioned nonwoven fabric 10 will be described.

The absorbent article of this example includes a liquid-permeable surface material (surface sheet) that comes into contact with the skin, an absorber covered with the surface sheet, and a back sheet that covers the back surface of the absorbent body. It has a basic structure and absorbs or stores excrement such as urine, feces and menstrual blood. Such an absorbent article is, for example, a conventionally known disposable diaper. Incontinence pad,
There are adult diapers and sanitary napkins.

Thus, the present absorbent article, the surface sheet is formed by the nonwoven fabric 10 described in detail above, the central portion 11 having a convex portion 11A and a concave portion 11B in the nonwoven fabric 10 in the central portion in the longitudinal direction of the surface sheet. , And both end portions 12, 12 having a uniform fiber aggregate density in the non-woven fabric 10 are located at both end portions in the width direction. Further, the absorber is a conventionally known one,
For example, there are a combination of a high-molecular absorbing polymer mainly composed of crushed pulp, and a mixture obtained by heat-treating a mixture of a thermoplastic resin, a cellulose fiber and a high-molecular absorbing polymer. Note that the present absorbent article may be appropriately provided with an elastic member for gather formation, etc., depending on its application.

Since the absorbent article is provided with the non-woven fabric 10 as a topsheet, the central portion 11 has a substantially open convex portion 11B having a low fiber aggregate density without flowing high viscosity liquid such as loose feces and menstrual blood. From the absorbent body to the absorbent body, soft contact with the skin in the bulky convex portion, and effective prevention of the return of highly viscous body fluid, and a flat surface with uniform fiber aggregate density at both ends Thus, it is possible to make a good contact with the relevant portion and prevent leakage of the highly viscous body fluid.

Next, one embodiment of the method of the present invention for producing the non-woven fabric 10 will be described with reference to FIGS. 3 and 4.

A nonwoven fabric manufacturing apparatus that is preferably used when carrying out the nonwoven fabric manufacturing method of the present invention is configured as shown in FIG.

That is, the above manufacturing apparatus uses the first fiber supplied from the first fiber supply unit 20 to the first fiber web (not shown).
Forming a first card machine 30 and the first fibrous web formed by the first card machine 30 at predetermined intervals in the width direction and cutting at three points in the flow direction, A first suction device for suction-removing the excessive first fibrous web located to form three first strip-shaped webs 12 '.
40 and the three firsts formed by the first suction device 40
Horizontal conveyors 50, 60, 60 for transporting the strip-shaped web 12 'to the downstream side and joining with a second strip-shaped web 11' which will be described later are sequentially provided on the downstream side. Further, a separation interval is formed between the first strip-shaped webs 12 'and 12' by the width obtained by removing the fibrous web by the first suction device 40, and the one schematically showing this relationship is shown in FIG. It is FIG. As can be seen from the figure, the three first strip-shaped webs 12 'are formed to have the same width l ₁ , respectively, and the separation distance between the two is made.
l ₂ is formed.

Further, as shown in FIG. 3, the above-described manufacturing apparatus includes a second fiber supply unit 70 located downstream of the first card machine 30 and above the horizontal conveyor 60, and a second fiber supply unit 70. A second card machine 80 for forming a second fibrous web (not shown) from the second fibers supplied by
The second fibrous web formed by the above is cut at two positions in the flow direction with a predetermined interval in the width direction, and the excess second fibrous web located at both ends and the center of the second fibrous web is removed by suction to remove the second fibrous web. Second for forming two strip webs 11 ", 11"
And the suction devices 90 are sequentially provided on the downstream side. And, a separation interval is formed between the two second strip-shaped webs 11 ″ and 11 ″ by the width obtained by removing the fibrous web.
FIG. 5 schematically shows this relationship. As can be seen from the figure, the two second strip-shaped webs 11 ″, 11 ″ are formed to have the same width l ₃ , and the separation distance l ₄ is provided between the respective second strip-shaped webs 11 ″, 11 ″. Are formed. Then, there is a relationship of l ₃ > l ₂ and l ₁ > l ₄ between the above-mentioned dimensions.

Further, as shown in FIG. 3, the manufacturing apparatus receives the second strip-shaped web 11 ″ on the downstream side of the second suction device 90 and forms the irregularities on the strip-shaped web 11 ″.
Is equipped with. The concavo-convex forming portion 100 includes the second strip-shaped web 1
A pair of ventilation conveyors 10 that conveys while sandwiching 1 ″ and 11 ″
It is equipped with 1, 102 at the top and bottom. The breathable conveyor 101 arranged on the lower side is a mesh-shaped endless conveyor, and it is preferable that unevenness is formed on the surface and the height difference h ′ thereof is set to 3 to 10 mm. If the height difference h'is less than 3 mm, as described later,
It is difficult to form unevenness or perforations on the strip-shaped web 11 ″ together. On the contrary, if it exceeds 10 mm, the strip-shaped web 11 ″ after the formation of irregularities is difficult to peel off from the air-permeable conveyor 101, which is not preferable. Further, the number of convex portions is preferably set to 10 to 35 / in ² . When the number of protrusions is less than 10 / in ² , the structural fibers are easily scattered by the jetted air flow, and when it exceeds 35 / in ² , it is difficult to form irregularities, which is not preferable. On the other hand, the breathable conveyor 102 disposed on the upper side is formed in a mesh shape of 3 to 15 mesh, and the second strip-shaped web 11 ″ is pressed against the lower breathable conveyor 101 to sandwich the strip-shaped web 11 ″. It is an endless conveyor formed substantially flat so as to obtain, and is rotatably supported by four rolls.

Further, the unevenness forming unit 100, a pair of breathable conveyor 10
Air is jetted from above onto the second strip-shaped web 11 ″ sandwiched between the first and second 102, so that the strip-shaped web 11 ″ is placed on the lower side of the air permeable conveyor 10
An air injection device 103 is provided that penetrates into and follows the concave portion of the surface 1 and perforates the irregularities or the irregularities. The air injection device 103 is an injection duct 103A inserted laterally inside the rotation of the upper air-permeable conveyor 102, and a recovery duct installed sideways inside the rotation of the lower air-permeable conveyor 101. The duct 103B is provided, and the blower 103C blows air onto the entire surface of the second belt-shaped web 11 ″ pressed by the air-permeable conveyor 102 by passing the air-permeable conveyor 102 from the injection duct 103A. The uneven surface is used to form the unevenness on the second web 11 ″.
The air flow passing through the second belt-shaped web 11 ″ and the lower breathable conveyor 101 passes through the recovery duct 103B and blower 10
It is designed to reflux to 3C. Blower 10
The injection speed of air by 3C is preferably set to 20 to 200 m / sec. For the second web 11 ″. 20 m / se
If it is less than c., it is difficult to form irregularities or perforations on the irregularities, and conversely, if it exceeds 200 m / sec., the second web 1
1 ″ is disturbed and the energy load on the blower 103C tends to be excessive and uneconomical. Also, in order to minimize the energy loss of the blast air flow, a substantially flat mesh ventilation From the side of the property conveyor 102, it is preferable to inject from a rotation internal position as close as possible to the air permeable conveyor 102. Further, the shape of the injection port is possible even when a large number of orifice-shaped pores are provided, The slit shape is preferable because it can reduce energy loss.
The conveying speed of the second belt-shaped web 11 ″ by the breathable conveyors 41, 42 is set in relation to the jet speed of air,
It is preferably set to 10 to 100 m / min.

Further, the second strip-shaped web 11 'formed with concavities and convexities or with perforations formed on the concavities and convexities is conveyed to the downstream side through the descending inclined conveyor 110 and the ascending inclined conveyor 120 that is connected to the descending inclined conveyor 110. first strip web 12 described above which are conveyed by the conveyor 60 'and complementing the separation distance l ₂ to each other to polymerize the outer edge and wide semifinished product 10' to form a passing heat-treated portion 130 Is configured.

The semi-finished product 10 ′ has a first band-shaped web 12 ′ which is heat-treated by the heat treatment section 130 and a second band-shaped web 11 ′ having concavities and convexities having perforations formed on the entire surface, which are overlapping sections. The edges are heat-sealed and integrated as shown in FIG. As the heat treatment section 130, a heated air chamber or a pair of heating rolls is used.

On the downstream side of the heat treatment section 130, a cutter 140 is located at the center of the width direction of each of the first belt-shaped webs 12 'and 12'.
As shown in FIG. 8, the semi-finished product 10 'is arranged in parallel and cut in the flow direction at both side edges and the center of the semi-finished product 10' and wound up as two nonwoven fabrics 10 by a winder 140.

Next, one embodiment of the method for producing a nonwoven fabric of the present invention will be described.

First, a fiber containing a thermoplastic fiber is added to the first fiber supply unit.
Supplying from 20 to the first card machine 30, the first card machine
A fibrous web is formed at 30 and the fibrous web is first
To produce the first web 12 '. On the other hand, when a fiber containing a thermoplastic fiber is supplied from the second fiber supply unit 70 to the second card machine 80, a fiber web is formed in the second card machine 80, and this fiber web is sucked by a second suction device. 90 forms a second belt-shaped web 11 ″, and the second belt-shaped web 11 ″ is a pair of upper and lower air-permeable conveyors.
While the second strip-shaped web 11 ″ is conveyed by the 101 and 102 and passes through the unevenness forming portion 100, the air supplied by the blower 103C is blown into the entire width by the injection duct 103A to form the unevenness in the longitudinal direction. 11A, 11B or uneven portion 11A, 1
Second strip web 1 in which 1B and concave portion 11B are opened and dispersed
Form 1 '. Then, the first web 12 'and the second web 12'
The side edge portions of the belt-shaped web 11 'are superposed and conveyed to the heat treatment section 50, where they are fused and integrated to form a semi-finished product 10'. Thereafter, while being conveyed, the slitter 140 cuts in the longitudinal direction at the widthwise central portion of the first strip-shaped web 12 ′ to disperse the uneven portion 11.
A and 11B are provided in the central part 11, and both end parts 12 and 12 adjacent to this are provided.
The non-woven fabric 10 formed as a flat surface is wound into two rolls by the winding unit 150.

Therefore, according to this embodiment, the nonwoven fabric 10 having the hydrophilic uneven portions 11A and 11B in the central portion 11 and the hydrophobic flat surfaces at 12 and 12 at both ends can be easily and rapidly manufactured. You can

Hereinafter, the nonwoven fabric of the present invention will be specifically described based on the following examples.

Example 1 In this example, an invention product 1 was manufactured as follows by using the nonwoven fabric manufacturing apparatus shown in FIG.

Hydrophobic surfactant containing alkyl phosphate potassium salt as the main component 0.3% by weight of polypropylene / polyethylene core-sheathed thermoplastic short fibers (3 denier x 51 mm) with hydrophobicity added to the surface 1st band web 12 ″ consisting of a hydrophobic thermoplastic fibrous web with a width of 170 mm and a separation of 300 mm at 25 g / m ^{2 with} a card machine 30 and a first suction device 40
3 are formed.

On the other hand, heat-fusible short fibers of polyester / polyethylene core-sheath structure (3 denier x 51 mm) whose surface is made hydrophilic by 0.3% by weight of a hydrophilic surfactant containing polyethylene glycol-added sodium lauryl ether sulfate as a main component. )
With the second card machine 80 and the second suction device 90
Two second strip-shaped webs 11 ″, 11 ″ made of a hydrophilic thermoplastic fibrous web having a thickness of 0 mm and a separation distance of 300 mm and a weight of 25 g / m ² are formed. Next, the strip-shaped web 11 ″, 11 ″ is sandwiched between the uneven support net 101 having air permeability and the plain weave net 102,
From the side of the plain weave net 102, two 150-mm width jets are made in the width direction to fill the concave portion of the uneven support net 101 with the strip-shaped web 1.
By pushing in 1 ″ and 11 ″, the second band-shaped webs 11 ′ and 11 ′ in which the dense and dense portions of the fibers are formed at a predetermined pitch are formed. Then, said hydrophobic first web 1
2'and the hydrophilic second strip-shaped web 11 'are alternately arranged, and the side edges of the webs 11' and 12 'are polymerized by 10 mm and passed through the heat treatment section (heated air chamber) 130. During the heating, heat treatment with hot air at 140 ° C was applied to each web 11 ', 1
Sheet-shaped semi-finished product by fusing 2'thermoplastic fibers 10 '
After that, the widthwise central portion of the hydrophobic first strip-shaped web 12 'is cut in the flow direction at the widthwise center by the cutter 140, and the convex portion 11A and the concave portion 11B are formed in the hydrophilic central portion 11. A non-woven fabric having a predetermined pitch formed, the concave portions 11B opened, and the hydrophobic ends 12 and 12 being substantially uniform was produced.

Comparative Example 1 In this comparative example, Comparative product 1 was prepared as follows.

The web 12 'formed by the first card machine 40 is
Of the second substantially flat hydrophilic hydrophilic web 11 ″ formed by the card machine 80 of FIG. 1 are arranged alternately, and the central part 11 is substantially hydrophilic and the both ends 12, 12 are substantially hydrophobic. A uniform nonwoven fabric was prepared as Comparative Product 1.

Comparative Example 2 In this comparative example, Comparative product 2 was prepared as follows.

The hydrophilic second strip web 11 ″ formed by the first card machine 40 and the hydrophilic second strip web 11 ″ formed by the second card machine 80 are formed alternately. As a comparative product 2, a non-woven fabric in which the central portions 11 were arranged and the convex portions 11A and the concave portions 110 were formed at a predetermined pitch, and the concave portions were perforated and the entire surface was hydrophilic.

Next, the invention item 1, the comparative item 1 and the comparative item 2 were tested for the evaluation items shown in Table 1 below, and the results are shown in the corresponding columns of the same table.

According to the results shown in Table 1 above, the product 1 of the present invention is not only permeated by artificial loose stool, which is a highly viscous liquid, as compared with the comparative products 1 and 2, and has no bleeding leakage to the side part and is absorbed. It can be seen that the properties required for the surface material of the elastic article are satisfied.

Although the nonwoven fabric of the present invention has been specifically described based on the above examples, the nonwoven fabric of the present invention is not limited to the above examples and can be variously modified without departing from the scope of the present invention. Can be changed. For example, the opening of the concave portion does not have to be a clear hole and may be substantially open. Further, the above-mentioned openings are not always necessary, and the recessed portions may be recessed to the extent that body fluid can permeate, and the fiber aggregate density is low, and the irregular shape of the nonwoven fabric is regularly arranged. It does not have to be provided.

Further, the method for producing a nonwoven fabric of the present invention is not limited to the above-mentioned embodiment in which the second fibrous web is sandwiched by the pair of air-permeable conveyors 41, 42 having the concavities and convexities to sandwich the second fibrous web. Instead, it suffices that the irregularities are formed on the second fibrous web while the second fibrous web is carried on the air-permeable conveyor having the irregularities while being conveyed.

〔The invention's effect〕

The non-woven fabric of the present invention can surely allow the high-viscosity liquid to permeate in the hydrophilic center part, can suppress the reversion of the liquid, and can prevent the leakage of the high-viscosity liquid at both ends, and the touch and the like. The texture is excellent.

Further, the absorbent article of the present invention is excellent in permeability of highly viscous body fluid such as loose stool and menstrual blood, suppresses reversion of the highly viscous body fluid, absorbs and holds the absorbent in the absorbent body, and prevents bleeding leakage on both side portions. can do.

Further, according to the method for producing a nonwoven fabric of the present invention, the above-mentioned nonwoven fabric suitable as a surface material for absorbent articles can be easily produced at high speed.

[Brief description of drawings]

FIG. 1 is a partial perspective view conceptually showing one embodiment of the nonwoven fabric of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a method of manufacturing the nonwoven fabric of the present invention. FIG. 4 is a schematic view showing a cross section of the first belt-shaped web formed by the manufacturing apparatus shown in FIG. 3, and FIG. Corresponding to FIG. 4 showing the strip-shaped web of FIG. 6, FIG. 6 corresponding to FIG. 4 showing a state in which uneven portions are formed on the second strip-shaped web, and FIG. 7 showing the first strip-shaped web shown in FIG. FIG. 4 is a view corresponding to FIG. 4 showing a state in which the second strip-shaped web shown in FIG. 6 is arranged, and FIG. 8 is a view corresponding to FIG. 4 showing a state in which the semi-finished product shown in FIG. 7 is trimmed. 10; Non-woven fabric, 11; Central part 11A; Convex part, 11B; Concave part 12; Both end parts 11 ', 11 "; First band web 12'; First band web

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location D04H 1/54 P (56) Reference JP-A-3-146755 (JP, A) JP-A-3 -185168 (JP, A) JP 4-24261 (JP, A) JP 4-24263 (JP, A) JP 3-137258 (JP, A) JP 61-655 (JP, A) ) JP-A-2-229255 (JP, A)

Claims (3)

[Claims] 1. A non-woven fabric obtained by melting and integrating thermoplastic fibers of a fibrous web containing thermoplastic fibers, wherein the non-woven fabric has a hydrophilic central portion and hydrophobic end portions adjacent to the central portion. The central portion is formed of a convex portion and a concave portion dispersed throughout, and the fiber assembly density of the concave portion is lower than the fiber assembly density of the convex portion, and the both end portions have a fiber aggregate density substantially. Non-woven fabric characterized by being uniformly uniform. 2. An absorbent article comprising a surface material that comes into contact with skin and an absorbent body covered with the surface material, which absorbs excrements such as body fluids, wherein the surface material is the surface material of claim 1. An absorbent article formed of a non-woven fabric. 3. A second fibrous web containing thermoplastic fibers and generally hydrophobic, and a second fibrous web containing thermoplastic fibers and generally hydrophilic, are each formed into a second fibrous web. The fibrous web is placed on an air-permeable conveyor having irregularities, and a gas is jetted onto the surface of the fibrous web while the fibrous web is conveyed in a state where the fibrous web is placed, so that the fibrous web is recessed in the air-permeable conveyor. Following the formation of the irregularities of the fibrous web, the second fibrous web is placed between the first fibrous webs that are conveyed with a gap therebetween, and then both are heated to produce the respective thermoplastic fibers. The method for producing a non-woven fabric according to claim 1, wherein the two are integrated by fusing the two.