JPS61176346A - 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] (Industrial application field) The present invention relates to sanitary napkins and disposable diapers.

It relates to surface materials for absorbent articles such as incontinence pads.

(Prior Art) Fibrous nonwoven fabrics have conventionally been generally used as surface materials for absorbent articles. Various methods are known to improve the permeability of this surface material to body fluids, one of which involves providing a large number of pores.

The following methods are known as means or methods for providing this opening.

(1) A surface material is formed using a known paper or nonwoven fabric manufacturing method, and then punched with a punching cutter to provide holes.

This is an extremely simple method for providing holes, but since the fibers are pressed out, there are many cut ends at the edges of the hole area, which feel bad when they come into contact with the skin, and the surface This reduces the tensile and tear strength of the material, and also causes fibers to become frayed or fluffed from the edges of the perforated area.

(2) Pores are provided during or after forming the surface material using a known paper or nonwoven fabric manufacturing method, by applying a jet of water to push or scrape the fibers and distribute them.

This does not have the drawbacks mentioned in (1) above because the fibers are distributed, but there is some 1w inside the aperture area or at the edge.
T-fibers remain and complete pores are not formed. Especially as a component of this type of surface material.

Hydrophobic fibers are preferred, but if such m-fibers remain within the aperture area or at the edges, the desired body fluid permeability cannot be achieved.

(3) After forming the surface material using a known nonwoven fabric manufacturing method.

Open holes are created by melting the fibers by pressing them with a heated embossing roll.

This is because the edge of the aperture area is pressed and melted, so a film is formed by welding the fibers on the edge, and the film is partially torn, and as a result, a complete hole is not formed as in (2) above. .

(9!Problems to be solved by Ming) The above-mentioned known technology not only has the above-mentioned drawbacks, but also does not leave a moist feeling on the surface of the surface material after body fluids have passed through it, that is, it does not leave a feeling of dryness on the skin. feel (dry touch)
No particular consideration or creation has been made to provide a property that prevents body fluids from returning (rewetting) by applying pressure to the surface material after body fluids have permeated therethrough.

In addition, the performance required for this type of surface material is as follows:
In addition to having the above-mentioned two properties, that is, dry touch properties and anti-rewetting properties, it also has quick permeability of body fluids and good texture; however, these properties are contradictory to each other. However, the above-mentioned known techniques are not able to simultaneously satisfy these performances by adjusting or controlling them well.

(Means for Solving the Problems) An object of the present invention is to provide a surface material for an absorbent article that can simultaneously satisfy each of the above-mentioned performances.

One aspect of the present invention for achieving this object will be described below based on illustrated examples.

As shown in FIGS. 1 to 3, the surface material 1 has a large number of openings 2.6 In order to achieve the intended purpose of the present invention, the surface material 1 has a heat-melted hydrophobic material. It is made of fibers, has a fiber diameter of 10μ or less, has a basis weight of 10g/m or more, and has a surface material of 1
The total area ratio of each opening 2 in
The measured value according to the water resistance method A (low water pressure method) in JIS-L1092 is 10 cm or more.

If the diameter of the pores 2 is 0.3 nWO or less and the porosity is 10% or less, the permeability of body fluids, especially the rate, will be significantly reduced, and if the diameter is 2 mm or more and the porosity is 50% or more. ,
More body fluid flows out from the opening 2. If the fiber diameter is 10μ or more and the basis weight is 10g/m or less, even if all the constituent fibers are hydrophobic, a relatively large amount of space will be created between the fibers, so the amount of body fluid remaining in the non-pore area 3 will be reduced. If the water pressure resistance is less than 101, the non-porous area 3 will be impregnated with body fluids or body fluids will flow back through the area due to pressurization during use. , same as above, the dry touch property cannot be changed. Note that the date only needs to be 10g/m2 or more.

In particular, from the standpoint of performance, there is no upper limit, but from the standpoint of cost, it is likely to be 50 to 60 g/rtf or less.

As the heat-melting hydrophobic fiber, polyester, polypropylene, polyethylene, etc. may be used alone or in a mixture of appropriate amounts thereof.

The surface material 1 is made of such fibers, the fiber diameter is 10μ or less, and the basis weight is Log/n? If it is above, the water pressure resistance will be 10 cm or more, but in order to further improve the water pressure resistance.

The entire surface material 1 may be treated to be water repellent. The water repellent is not particularly limited, but in view of non-irritation to the skin, water repellent effect, etc., known silicone-based agents are preferred.

Furthermore, in order to achieve the intended object of the present invention, the facing material 1 is free of fibers in the area of the apertures 2.

and that the fibers at the edges of the region are fused, that is, the pores are substantially complete, regardless of the shape of the pores, such as circular, elliptical, square, or any irregular shape thereof. It is preferable that it is formed.

If the apertures 2 are not formed in this manner, the fibers present within the aperture region or at the edges are hydrophobic, which would impede the permeability of body fluids in that region. A typical example of fibers existing at the edge of the aperture 2 is that the fibers exist as fluff at the edge, but even if the fluff is extremely small, the fluff lifts body fluid droplets. 9 prevents the body fluid droplets from coming into contact with the absorbent body disposed on the lower surface of the surface material 1, resulting in poor transfer of body fluids to the absorbent body.

The surface material 1 can be manufactured by the following method.

...First method... The fibrous web formed by the card is shown in FIG. 4A.

As illustrated in B, on a support 5 having aperture-forming elements 4 consisting of a large number of protrusions, through holes, or recesses, the fibers are entangled to form a nonwoven fabric by a jet treatment of high-speed water, and at the same time, the aperture-forming elements are 4, the fibers are distributed to form apertures 2. As a method for forming the openings 2 at the same time as forming a non-woven fabric in this way, for example, Japanese Patent Publication No. 49-28023,
JP-A-51-82072, JP-A No. 51-105480,
Techniques disclosed in Japanese Patent No. 53-114874, Japanese Patent No. 5g-132155, etc. can be used. Support 5
The hole 2 may be a roll or a curved plate as shown in the illustrated example, or a belt. 6 Generally, when the hole 2 thus formed is examined with the naked eye, the presence of fiber fluff within the area or at the edge is clearly visible. However, according to a magnifying lens or a microscope aim, it is not necessarily completely formed, and there are fine fiber fuzz within the area of the aperture 2, especially at the edge of the area. (See Figure 5).

Accordingly, in the present invention, complete apertures 2 are formed by burning the surface material 1 with flame to melt or burn off the fiber fuzz within the area of the apertures 2.

This searing treatment is preferably carried out in a state where the fiber web or the surface material 1 contains sprayed water. In this case, since the fiber web or surface material 1 contains water, only the fiber fuzz can be easily and completely melted or burned off without any adverse effects of heat on the entire web. However, in the present invention.

It is not excluded or prohibited that this roasting treatment be carried out while the fiber web or surface material 1 is in a dry state.

The order of fiber entanglement, opening, and roasting in the above manufacturing method is as follows:
You can browse for products that accomplish your desired purpose, regardless of which of the following:

A. Entanglement of the fiber web by jetting high-speed water onto a support having aperture-forming elements, formation of apertures→drying of the web→
Broiled processing of the fish.

B. Entanglement of a fibrous web by jetting a high-speed water jet onto a support having aperture-forming elements, formation of apertures→broiling treatment of the web→drying of the web.

Entanglement of the fibrous web by spraying a high-speed water jet on a support having C0 aperture-forming elements, formation of apertures → broiling treatment of the web on the support → entanglement of the web by spraying on the support again →Drying the web.

D. Entanglement of the fibrous web by jetting high-speed water jets on a support having aperture-forming elements, formation of apertures → roasting treatment of the web on the support → on a support without internuclear pore-forming elements Entanglement of the web by the jetting again→broiling treatment of the web→drying of the web.

E. Entanglement of the fiber web by jetting a high-speed water jet on a support having an aperture-forming element, formation of apertures → Entanglement of the web by the jet again on a support without an internuclear pore-forming element →
Roasting the twig → drying the twig.

F. Formation of pores in the fiber web by jetting high-speed water jets on a support having pore-forming elements → broiling the web on the support → forming pores on a support without internuclear pore-forming elements Entanglement of the web by jetting → drying of the web.

In addition, in the cases of C, D, and E, the reason why the high-speed water jet is jetted again is to further improve the strength of fiber entanglement.

Second method: After obtaining a non-porous non-woven fabric by a known method, the non-woven fabric is pierced with a number of heated needles to melt the fibers and form pores. Preferably, the fibers are bonded using heat weldability or the fibers are entangled by the jetting of the high-speed water jet.If the fibers are bonded using other emulsion binders or the like, the melt openings will not be uniform.

In addition, the above-mentioned No. 1. The surface material 1, which is a perforated nonwoven fabric obtained by the second method, may have a fiber layer made of woody fibers on the back surface of the surface material 1, preferably a nonwoven fabric whose fibers are entangled by jetting the high-speed water jet, or a fused fabric, depending on the purpose of use. A nonwoven fabric bonded with fibers may be integrally composited. This joining can be accomplished by either fiber entanglement by jetting the high-speed water jet or fiber bonding by fusion.

The surface material 1 having the above-mentioned configuration is used for absorbent articles such as sanitary napkins, disposable diapers, and incontinence pads, as illustrated in FIG. It is constructed by placing an absorbent material 6 such as pulp or water-absorbing paper on at least the upper surface and a water-impermeable sheet 7 such as a plastic film on the lower surface, and the other specific construction is a known article of this kind. This is done by the means disclosed in . Incidentally, in the case of a composite in which a hydrophilic fiber layer is integrally formed on the back surface of the surface material 1, it goes without saying that the fiber layer is located between the surface material 1 and the upper surface of the absorbent body 6. do not have.

(Function) As shown in Fig. 3, when body fluid is excreted into the area formed by the surface material 1 while the surface material 1 is used in an absorbent article,
Absorption is absorbed into the absorbent body 6 through each of the apertures 2 in the surface area, but each aperture 2 has fibers at the edges of those areas melted and is substantially intact, so body fluids are absorbed into the absorbent body. Absorption occurs quickly. In addition, the absorbed body fluid 1 is such that the fibers in the non-porous region 3 forming the surface material 1 are hydrophobic, the fiber diameter is 10 μ or less, the basis weight is 1 Og/bo or more, and the shortest diameter of the pores 2 is 0. 3
Since the porosity is 10 to 50% at a length of ~2 m, there is no possibility that the surface material will grow back.

In addition, although the non-porous region 3 is made of very thin fibers and has a relatively high density, it is made up of a collection of fibers and therefore has air permeability.

(Example) As shown in Table 1. However, in Examples 1 to 7 in Table 1, the surface material (see Figure 6) was manufactured by the first method, and in Example 8, the surface material (see Figure 7) was manufactured by the second method. was manufactured.

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 30g/m2 consisting of 50% by weight of rayon fibers of 1.5d x 5mm and 50% by weight of polyester fibers of 1.4d x 44+nm. 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/rrl' polyethylene film and has a large number of holes of 0.5 nnφ and 1 mm intervals, with a low porosity. is 20%.

The performance shown in Table 2 was based on the 7th order test method.

(1) Sample (surface material) on the top surface of the absorbent body made of permeable cotton-like wood pulp.
5 mQ of artificial urine 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) Rewetting property Place a sample on the top of an absorbent made of 100cnT cotton-like wood pulp, pour 5 times the weight of Biulet artificial urine on top of the sample, and then place the sample on top of the rubber trade artificial urine. Layer the skin sheets and make 100 cuts on the top surface, 7
A plate weight of 1 kg was applied, and after 3 minutes, the weight was removed, and the amount of artificial urine adhering to the artificial skin sheet 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 1 (Note) PET indicates polyester fiber.

PP indicates polypropylene fiber.

Table 2 (Note) ◎ indicates the best.

○ 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-described structure and function, it simultaneously achieves conflicting performances such as quick permeability of body fluids, dry touch properties, anti-rewetting properties, and texture, as well as breathability. be satisfied and achieve the desired goal. Moreover, since the edges of the apertures, which serve as guides for body fluid permeation, are formed by melting, fibers do not fray from the edges of the apertures, become fluffy, or break. Strength is always maintained.

Furthermore, according to the manufacturing method of the present invention, a surface material having the above-mentioned performance can be manufactured relatively easily and industrially stably.

[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 sectional view of Figure 1, Figure 3 is a partial sectional view of the surface material applied as an absorbent article, and Figures 4A and B. Figure 5 is a partial perspective view of a support used when the surface material is formed by spraying a high-speed water jet, and Figure 5 shows a case in which the pores are formed only by the jetting treatment of a high-speed water jet, and the pores are completely removed by roasting. Fig. 6 is a photograph showing a partially enlarged plane of the surface material in a state where the openings in Fig. 5 have been roasted, and Fig. 7 is a photograph showing a partially enlarged plane of the surface material in a state where the openings in Fig. 5 have been roasted. It is a photograph showing a partially enlarged plane of a surface material in which openings have been formed with a heated needle. DESCRIPTION OF SYMBOLS 1...Surface material 2...Open hole 3...Non-hole area 4...Open hole forming element 5...Support No. 1 Fig. 2 Fig. 3 Fig. 4 (A) B) Figure 5 Figure 6 - (~~ Procedural amendment (method) (Retsutsutsumi 1985 Patent Application No. 15121 2 Name of invention Surface material of absorbent article and manufacturing method thereof 3, Amendment) Patent applicant Unicharm Corporation 4, agent May 8, 1985 (shipped May 28, 1985) 6 ``Brief explanation of drawings'' section of the specification subject to amendment The section on the brief description of the drawings is amended as follows: In the 3rd, 4th, and 6th lines of page 20 of the description, after "Surface material", "[Texture of fibrous nonwoven fabric"] is added respectively. Join. That's all.

Claims (11)

[Claims] (1) A surface material made of a nonwoven fabric having a large number of holes for use in absorbent articles, wherein the surface material is made of heat-melted hydrophobic fibers, has a fiber diameter of 10 μm or less, and has a basis weight of 10 g/m.
^2 or more, the porosity is 10-50%, the shortest diameter of the pores is 0.3-2mm, and the water pressure resistance of the non-porous area is 10c.
m or more, there are no fibers in the aperture region, and the fibers at the edges of the aperture region are melted. (2) The surface material of an absorbent article according to claim 1, wherein the surface material is formed by fiber entanglement. (3) The surface material of an absorbent article according to claim 1, wherein the surface material is formed by fiber fusion. (4) In a method for producing a surface material made of a nonwoven fabric having a large number of holes for use in absorbent articles, the surface material is a heat-melted hydrophobic material having a fiber diameter of 10 μ or less and a basis weight of 10 g/m^2 or more. Using a fibrous web, the fibrous web is sprayed with a high-speed water jet to entangle the fibers and distribute the fibers to form a pore area with a porosity of 10 to 50% and a shortest diameter of the pores of 0.
The surface is characterized in that it comprises a step of providing apertures of 3 to 2 mm, and a step of melting or burning out fibers remaining in the aperture areas by burning the fibrous web with a flame. The manufacturing method of the material. (5) The method for producing a surface material for an absorbent article according to claim 4, wherein the roasting treatment is performed while the fibrous web is in a wet state. (6) The method for producing a surface material for an absorbent article according to claim 4, wherein the fiber entanglement and the provision of apertures are performed on a support having aperture forming elements arranged at predetermined intervals. (7) The method for producing a surface material for an absorbent article according to claim 6, wherein the roasting treatment is performed on the support during the steps of fiber entanglement and aperture provision. (8) The method for producing a surface material for an absorbent article according to claim 7, wherein after the roasting treatment, the spraying treatment is performed again on the support. (9) In a method for producing a surface material made of a nonwoven fabric having a large number of holes for use in absorbent articles, the surface material is a heat-melted hydrophobic fiber having a fiber diameter of 10 μ or less and a basis weight of 10 g/m^2 or more. A process of bonding the fibers by heat-treating the web using a web, and melting the fibers with heating needles having a predetermined diameter arranged at a predetermined interval to achieve a porosity of 10 to 50%. The shortest diameter of the opening is 0.
1. A method for producing a surface material for an absorbent article, the method comprising the step of providing apertures with a diameter of 3 to 2 mm. (10) The method for producing a surface material for an absorbent article according to claim 4, wherein the surface material is formed by fiber entanglement. (11) The method for producing a surface material for an absorbent article according to claim 4, wherein the surface material is formed by fiber fusion.