JPS61125343A - Surface material of absorbable article and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a surface material for absorbent articles used for treating body fluids, such as disposable diapers, incontinence pads, and sanitary napkins.

(Prior Art) The following types of surface materials for absorbent articles of this type are mainly known and have been or are currently in practical use.

(1) Nonwoven fabric whose main component is hydrophilic fibers This is a nonwoven fabric whose main component is hydrophilic fibers such as rayon, which improves the permeability of body fluids. A large amount of body fluid remains on the surface of the nonwoven fabric, and the surface that comes into contact with the wearer's skin is always wet.

(2) A nonwoven fabric with a two-layer structure, in which the surface component is hydrophobic fibers and the bottom layer component is hydrophilic fibers.Since the first surface layer is hydrophobic fibers, this is a nonwoven fabric that can overcome the drawbacks of (1) above. However, the improvement effect has been recognized.

In order to avoid impairing the permeability of body fluids, it is necessary to make the table N as thin as possible, and as a result, the above-mentioned effects are not improved much and are still unsatisfactory. (3) From only hydrophobic fibers This is a non-woven fabric to which a drug that imparts hydrophilic properties is attached.Although this is seen to be effective in improving the drawbacks of (1) and (2) above, this only applies to the first time it comes into contact with body fluids. Then, the hydrophilic drug is washed away by the second body fluid permeation, and from the second time onward, the body fluid permeates the body and becomes smoother.

(4) A flexible plastic film with a large number of holes formed by thermoforming, and a fiber layer bonded to the bottom surface of the film with an adhesive.
, (2), and (3) are notable improvements, but since there is no air permeability in the non-perforated area and the moisture generated on the skin surface does not pass through, the surface becomes stuffy and has a cloth-like feel. In addition to lacking in moisture, it also gives the skin an unpleasant cool and dry feeling, especially during the cold season.

(Problems to be Solved by the Invention) Characteristics required for the surface material of this type of absorbent article include: 1) rapid permeability of body fluids; In other words, giving the skin a dry feel (dry touch), 0
Examples include having the ability to prevent body fluids from returning (rewetting) due to pressure applied to the surface material after the body fluids have permeated therein, and having a good texture when wearing the 7D.

The above-mentioned characteristics, especially ■, ■, and ■, are contradictory, but as is clear from the above-mentioned drawbacks, the above-mentioned conventional technology has the ability to simultaneously satisfy each of the above-mentioned characteristics by adjusting or controlling them well. is not.

(Means for Solving the Problems) The present invention aims to provide a surface material for an absorbent article that can satisfy each of the above-mentioned characteristics at the same time, and the gist of the structure for achieving the purpose is as follows.

In the surface material of an absorbent article, which is a composite nonwoven fabric having different fiber compositions and comprising a first layer forming a surface in contact with the user's skin and a second layer forming the back surface thereof; The fiber composition of the layer is 70-100% by weight of hydrophobic 11 fibers.
and 4 0 to 30% by weight of hydrophilic fibers, has a basis weight of at least 15 g/m2, has a large number of pores with a shortest diameter of 0.5 to 5 dm, and has a porosity that is equal to or smaller than that of the first layer. The second layer has a fiber composition of 50 to 100% by weight of hydrophilic fibers and 0 to 60% by weight of hydrophobic fibers.

The surface material has a basis weight of 5 to 50 g/rrr and is non-porous.

The following is a further explanation based on five illustrated examples of the present invention.

As shown in FIGS. 1 to 3, a surface material 1 is provided.

It is made of a nonwoven fabric in which a first layer 3 having a large number of pores 2 and forming a surface in contact with the skin, and a second layer 4 forming a back surface thereof are integrally composited.

In order to achieve the intended purpose of the present invention, the first layer 3:
The fiber composition consists of 100% by weight of hydrophobic fibers, and has a basis weight of 15
g/resistant or higher, density 0.03 to 0.3 g/rffl,
Preferably 0.1 to 0.2 g/ly1. m degrees 0.2~
2d, preferably 0.5 to 1d. However, even if it contains some R aqueous IM fibers, it does not particularly impede the intended purpose.

Its permissible content is a maximum of 30% by weight. The second layer 4 is
Similarly, in order to achieve the intended purpose, the fiber composition should be 100% by weight of hydrophilic fibers, with a basis weight of 5 to 50 g/resistant,
Density 0.01-0.2 g/rd, preferably 0.02
-0.07g/cj, fineness 0.7-15d, preferably 3-8d. However, depending on the size of the -N3 opening 2, the porosity therebetween, the density of the second layer 4, etc.
Even if it contains up to 50% by weight of hydrophobic fibers, it will not impede the intended purpose, and on the contrary, it may be preferable to contain some of it in terms of elasticity retention under wet conditions. Moreover, the -N3th opening 2 is.

To achieve the intended purpose, the shortest diameter should be 0.5 to 5 m.
, preferably 1 to 3 mm, the porosity is 10 to 60%,
It is preferably 20 to 50%, and one strength is that the fibers of the first layer 3 are formed by being distributed without being cut, that is, by being pushed or scraped apart. , preferable in terms of feel, appearance, etc.

The first layer 3 is preferably made into a non-woven fabric by intertwining fibers. Such a nonwoven fabric can be obtained by intertwining the fibers of a predetermined fibrous web, which is the material of the nonwoven fabric, on a support by spraying a high-speed water jet. A preferred method is JP-A No. 55-1999, filed by the present applicant.
No. 71853, JP-A-57-3!11268, JP-A-5! The technique disclosed in J-125-ri No. 54 is mentioned. The second layer 4 is also preferably made into a non-porous nonwoven fabric by interlacing the fibers in the above method, but this is formed by fusing the fibers by heat and pressure treatment. It doesn't hinder things. When formed by such fusing, it is preferable that some or all of the hydrophobic fibers contained in the second H4 are heat-fusible fibers at a temperature of 90 to +40'(': The most preferable method is to make the layer 1-N3 and the second layer 4 into non-woven fabrics, and to integrally composite them.

After the fiber web to be the N3th fiber web is entangled with the fibers by the above method, the second layer 4 and the separated fiber web are superimposed on this, and the web is again entangled with the fibers by the above method from above, and at the same time A method of interlacing fibers in the first layer 3;
First layer 3 formed by interlacing fibers in the above method
A fibrous web containing the heat-fusible fibers to form the second layer 4 is stacked on top of the fibrous web, and the web is subjected to pressure treatment in the presence of the above-mentioned temperature to fuse the fibers and simultaneously form the first layer 3. For example, a method of fusing fibers to a fiber is mentioned.

In the case of the former method, as illustrated in Figure 2,
Although some of the fibers in the first layer 3 and the second layer 4 are mixed and the boundaries between these layers are not clearly defined, in the case of the latter method, as illustrated in FIG. 3.

Since the fibers of the first layer 3 and the second layer 4 are fused mainly in the overlapping region of the two layers, the boundary is relatively clear.

Adopting the method of fiber entanglement to form the first layer 3 is very convenient for forming the apertures 2 by distributing the fibers. That is, as illustrated in FIG. 5, the fibrous web to be the first layer 3 is sprayed with a high-speed water jet on a support 6 having aperture-forming elements 5 consisting of a large number of protrusions, through holes, or concave surfaces. It can be formed by intertwining the fibers and simultaneously distributing the fibers using the aperture forming element 5. As a method for forming the openings 2 in this way, there are known techniques, for example, Japanese Patent Publication No. 719-280.
No. 23, JP-A-51-1'12072, JP-A No. 51-10
No. 5480.

Techniques disclosed in Japanese Patent No. 53-414874, Japanese Patent No. 511-132155, etc. can be used. The support body 6 is.

It may be a roll or a curved plate like the illustrated example, or a mesh belt.

The hydrophobic fiber of the first layer 3 is polyester.

Examples of the second layer 4 include polypropylene, polyethylene, acrylic, polyurethane, etc., synthetic fibers such as polyester whose fiber surface has been treated with parent wood, rayon, cotton, etc., and these can be used alone or in combination. However, preferably, the first layer 3 is mainly made of polyester fibers, and the second layer 4 is mainly made of polyester fibers whose surface has been treated with wood grains. This processed polyester fiber is used, for example, in Japanese Patent Publication No. 44-2580,
It is preferable to use a treatment agent made hydrophilic by the method for producing a treatment agent for polyester molded articles disclosed in No. 4-2581 and No. 44-3967.

To refer to a particularly important point among the numerical values specified in the present invention, if the basis weight of the -N3 is 15 g/d or less and the density is 0.03 g/d or less, the prevention of body fluid backflow is insufficient, and the second Layer 4 has a basis weight of 50g/endurance or more, density 0.2
g/cj or more, the permeability of body fluids is low, and the first layer 3
If the aperture 2 has a shortest diameter of 0.5 m+ or less and an aperture ratio of 10% or less, the permeability of bodily fluids is poor, and the aperture has a shortest diameter of 5 m or less.
- If the porosity is 60% or more, the second layer 4 in the pores will come into direct contact with the skin, or body fluid will flow back through the pores, giving a moist feeling to the skin. Note that even if the basis weight of the first layer 3 is 40 to 50 g/rrr or more, there is no particular difference in the function of the first layer 3, but anything more than that is economically disadvantageous.

The surface material 1 having the above-mentioned configuration is used for absorbent articles such as disposable diapers, incontinence pads, and sanitary napkins, as illustrated in FIG.

Basically, the article is placed on the upper surface of the absorbent body 7 mainly made of cotton-like wood pulp so that No. -N3 is the surface,
It is constructed by placing a water-impermeable sheet 8 such as a plastic film on the lower surface, and other specific constructions are made by means disclosed in known articles of this type.

(Function) As shown in FIG. 4, when body fluid is excreted into the surface area of the first layer 3 while the surface material 1 is used in the absorbent article,
The second N4 passes through each opening 2 in the area and is absorbed by the absorber 7. At least 50% by weight of the fibers forming the first layer 3 are hydrophobic, and the pores 2 have a shortest diameter of 5 at the maximum and a porosity of 60% at the maximum. It rarely goes back from Material 1. Depending on the method of compositing the first layer 3 and the second layer 4, the second M4 may appear raised in the opening 2, but even in that case, it remains retracted from the surface of the first layer 3. Even if the second layer 4 is wet with body fluids, the second layer 4 rarely comes into direct contact with the skin. Furthermore, since the materials forming the surface material 1 are all fibers that are intertwined or partially fused, the surface material 1 has air permeability not only in the apertures 2 but also in the entire surface material 1.

(Example) As shown in Table 1.

Table 2 shows the performance of the examples shown in Table 1 and the performance of the comparative example.

Comparative Example 1 is a surface material used by the present applicant for disposable diapers, which is made of 5 d of rayon fibers of 1.5 d x 5 m.
0% by weight and 1.4dX44cm polyester fiber 5
30g/r+ consisting of 0% by weight? It is a nonwoven fabric made by intertwining the fibers with a high-speed water jet treatment.

Comparative Example 2 is a surface material used by Company A for disposable diapers, which is made of a 25 g/rrr polyethylene film and has a large number of holes of 0.5 mφ and 1 m intervals, and its porosity is is 20%.

The performance shown in Table 2 was based on the following test method.

(1) Sample (surface material) on the top surface of the absorbent body made of permeable cotton-like wood pulp.
and artificial urine 5++1 in a beaker was poured over it all at once, and the number of seconds required for it to completely penetrate the sample was measured.

(2) Place a sample on the top surface of an absorbent body made of cotton-like wood pulp with rewetting property of 100 aJ, pour 5 times the weight of Biuret artificial urine on top of the sample, and then The skin sheets were stacked, and a flat weight of 100 cm and 1.7 kg was placed on top of the sheets. After 3 minutes, the weight was removed and the amount of artificial urine adhering to the 9 artificial skin sheets was measured.

(3) Dry touch property After the above rewet measurement, the sample was touched with the palm of the hand to test its wetness.

Table 2 (Note) ◎ indicates the best.

O mark indicates good.

A Δ mark indicates a defect.

The X mark indicates the worst quality.

(Effects of the Invention) Since the surface material according to the present invention has the above-mentioned structure and function, it simultaneously satisfies contradictory properties such as quick permeability of body fluids, dry touch properties, anti-rewetting properties, texture, and breathability. It is possible to achieve the intended purpose. In addition, the openings that serve as the guide portions for body fluid permeation are formed by distributing the fibers, that is, without partially cutting the fibers. The fibers do not become frayed, fluffed, or damaged, and the strength of the entire first layer that comes into contact with the skin is always maintained.

Furthermore, in the manufacturing method according to the present invention, particularly when forming the surface material by entangling fibers by jetting high-speed water jet treatment, the first layer and the openings can be formed simultaneously, and the second layer Since the formation of the second layer and the bonding of the second layer to the first layer can be performed at the same time, the manufacturing method is relatively simple and suitable for low-cost mass production of the surface material. Since it is a so-called binder-free nonwoven fabric in which no binder is used, it is extremely suitable for practical use, particularly as a diaper for infants.

[Brief explanation of drawings]

The drawings show embodiments of the surface material according to the present invention,
Figure 1 is a partial perspective view of the surface material, Figure 2 is a partial cross-sectional view schematically showing the state in which the first and second layers of the surface material are joined by high-speed water jet treatment, and Figure 3 is a partial perspective view of the surface material. FIG. 4 is a partial cross-sectional view schematically showing the state in which the bond is formed by pressure treatment, and FIG. 5 is a partial cross-sectional view showing a state in which the surface material is applied as that of an absorbent article. B is a partial perspective view showing a support used when a surface material is formed by spraying a high-speed water jet. l... Surface material 2... Opening 3... First layer 4... Second layer 5... Opening forming element 6... Support 'ii Figure 4 Figure 5 ( A) (B) Procedural Amendment March 8, 1985 Patent Application No. 245563 of 1988 2, Name of invention Surface material for absorbent articles and its manufacturing method 3, Person making the amendment Relationship with the case Patent applicant Unicharm Co., Ltd. 4, Agent 6, amend section 7 of "Detailed Description of the Invention" of the specification to be amended and "Table 1" on page 17 of the specification of the contents of the amendment as shown in the attached document.

Claims (13)

[Claims] (1) In a surface material for an absorbent article that is a composite nonwoven fabric that has different fiber compositions and includes a first layer forming the surface that contacts the user's skin and a second layer forming the back surface thereof; The first layer has a fiber composition of 70 to 100% by weight of hydrophobic fibers and 0 to 30% by weight of hydrophilic fibers, has a basis weight of at least 15 g/m^2, and has a shortest diameter of 0.5 to 5.
The second layer has a large number of pores with a porosity of 10 to 50% of the surface area of the first layer; the second layer has a fiber composition of 50 to 100% by weight of hydrophilic fibers and hydrophobic fibers. Sexual fiber 0~
60% by weight, has a basis weight of 5 to 50 g/m^2, and is non-porous. (2) The surface material of an absorbent article according to claim 1, wherein the openings are formed by distributing fibers. (3) The first layer and the second layer are each formed by intertwining fibers, and are integrally composited by intertwining the fibers of both layers. Surface material of the absorbent article described in Section 1. (4) The surface material for an absorbent article according to claim 1, wherein some or all of the hydrophobic fibers included in the second layer are heat-fusible fibers that melt at a temperature of 90 to 140°C. (5) The first layer is made into a non-woven fabric by intertwining the fibers, and the second layer is made into a non-woven fabric by fusing the fibers, and is integrally composited with the first layer. A surface material for an absorbent article according to claim 4. (6) The fibers of the first layer have a fineness of 0.2 to 2d and a density of 0.
03~0.3g/cm^3, and the fiber of the second layer has a fineness of 0.7~15d and a density of 0.01~0.2g/cm^3.
The surface material of the absorbent article according to claim 1, which has a diameter of cm^3. (7) The fiber composition of the first layer is hydrophobic fiber 70-10
0% by weight and 0 to 30% by weight of hydrophilic fibers and has a basis weight of at least 15 g/m^2, the shortest diameter is 0.5 to 5 mm, and the porosity is 10 to 50
% of the pores to form a non-woven fabric, and then the second layer has a fiber composition consisting of 50 to 100% by weight of hydrophilic fibers and 0 to 50% by weight of hydrophobic fibers, and a fabric weight of 5 to 50% by weight. 5
A method for producing a surface material for an absorbent article, which comprises forming a non-porous non-woven fabric in a state in which a second fiber web having a weight of 0 g/m^2 is stacked, and at the same time integrally compounding this and the first layer. . (8) The first layer is formed by jetting the first fiber web with a high-speed water jet on a support having aperture-forming elements arranged at predetermined intervals to entangle the fibers and at the same time form the apertures. 8. The method for producing a surface material for an absorbent article according to claim 7, wherein the apertures are formed by distributing fibers through a forming element. (9) The second layer is formed by intertwining the fibers of the second fibrous web by spraying a high-speed water jet onto the second fibrous web overlaid on the first layer; Claim 7 in which fibers are entangled in a single layer
A method for producing a surface material for an absorbent article according to item 8 or item 8. (10) The second layer is formed at a temperature of 90 to 140°C as part or all of the hydrophobic fiber web in the second fiber web.
Using heat-fusible fibers that melt at a temperature, the second fiber web is stacked on the first layer and processed under the temperature above to fuse the fibers, and at the same time to form the second fiber web on the first layer. A method for producing a surface material for an absorbent article according to claim 1 or 8, wherein fibers are fused. (11) The fibers of the first fiber web have a fineness of 0.2 to 2 d.
and the fibers of the second fiber web have a fineness of 0.7
15d. The method for producing a surface material for an absorbent article according to claim 7. (12) The first layer and the second layer each have a density of 0.
03~0.3g/cm^3 Density 0.01~0.2g/c
A method for producing a surface material for an absorbent article according to claim 7, 8, 9, or 10, wherein the surface material is treated to have a surface material of m^3. (13) The method for manufacturing a surface material for an absorbent article according to claim 8, wherein the pore-forming element is at least one of a protrusion, a through hole, and a concave surface provided on the support surface.