JP3397668B2 - Moisture permeable film and absorbent article using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a disposable diaper,
The present invention relates to a moisture-permeable film suitable for absorbent articles such as sanitary napkins, and an absorbent article using the moisture-permeable film.

[0002]

2. Description of the Related Art Sheets and films having breathability and liquid impermeability (hereinafter collectively referred to as "breathable liquid impermeable sheets") are disposable diapers and sanitary napkins. In recent years, it has come to be widely used as a leak-proof sheet for absorbent articles such as. Such an air-permeable liquid impermeable sheet is generally produced by kneading a filler resin fine particle with a polyolefin-based resin to form a film by melt-molding it and making it porous by a uniaxial or biaxial stretching process. There is. In such a breathable film, stretching causes microvoids (fine pores) starting from the interface between the polyolefin resin and the filler particles, thereby forming pores with a diameter of about 0.04 to 4 μm. However, such a film has a problem that it has a crisp, paper-like feel due to the rigidity peculiar to the stretched film and is not suitable for applications requiring a soft feel. Further, a method for producing a flexible porous sheet by adding the same kind of low melting point polymer, rubber-like polymer, olefin-based thermoplastic elastomer, etc. to the polyolefin resin together with the inorganic filler has also been proposed, but the air permeability is sufficient. Not only that, but there was a problem that the film strength was poor.

Therefore, various proposals have been made to impart flexibility to a stretched breathable film composed of a polyolefin resin and an inorganic filler. For example,
1) JP-A-60-257221 discloses 100 parts by weight of a polyolefin resin, 25 to 400 parts by weight of a filler, a liquid or waxy hydrocarbon polymer, or the hydrocarbon polymer and an epoxy group-containing organic compound. Mixtures 1 to 1
There is disclosed a method for producing a porous film having excellent flexibility by melt-extruding a composition comprising 100 parts by weight and biaxially stretching the obtained film.

2) Japanese Patent Laid-Open No. 62-10141 discloses that
Disclosed is a method for producing a porous film or sheet, which comprises subjecting a film or sheet obtained by melt-molding a composition containing a polyolefin resin, a filler and triglyceride to a stretching process. 3) In JP-A-62-27438, a breathable film is produced by stretching a film made of a composition of 42 to 87% by volume of a polyolefin resin and 58 to 13% by volume of an inorganic filler in at least one axial direction. In the method described above, the polyolefin resin is linear low density polyethylene 50.
To 95% by weight and branched low density polyethylene 50 to 5% by weight, and 100 parts by weight of the mixture has 10 carbon atoms.
Of aliphatic alcohol fatty acid ester, which is a compound of a fatty acid of 22 to 22 and an aliphatic alcohol of 1 to 12 carbon atoms,
Disclosed is a method for producing a breathable film, characterized in that the content is ˜35 parts by weight.

4) Japanese Patent Publication No. 63-57721 discloses that
A liquid-impermeable, leak-proof sheet integrally formed by stacking absorbers for a disposable diaper, which was produced by hydrogenating 100 parts by weight of a polyolefin resin, 28 to 200 parts by weight of a filler, and hydroxyl-terminated liquid polybutadiene. Liquid or waxy polyhydroxy saturated hydrocarbon 10
There is disclosed a film in which 70 parts by weight of a composition is kneaded to form a film, which is then stretched 1.2 times or more in at least one direction to form fine pores.

5) JP-A-9-25372 discloses that 55 to 80 parts by weight of linear low density polyethylene, ethylene-α
Molding a composition containing 80 to 200 parts by weight of calcium carbonate based on 100 parts by weight of a resin component consisting of 5 to 30 parts by weight of an olefin copolymer and 5 to 20 parts by weight of branched low density polyethylene. The linear low-density polyethylene is a moisture-permeable film made of ethylene and 4 carbon atoms.
To 12 of α-olefin, the density thereof is 0.905 to 0.940 g / cm ³ , and the melt flow rate is 0.5 to 10 g / 10 min. The ethylene-α-olefin copolymer is obtained by copolymerizing ethylene with an α-olefin having 3 to 10 carbon atoms, and has a density of 0.850 to 0.900 g / cm ³ and a melt flow rate. Is 0.5 to 15 g / 10 min. , DSC peak temperature is below 100 ℃, stress at 200% elongation is 1
0 to 80 kg / cm ² , the branched low-density polyethylene is obtained by polymerizing ethylene by a high pressure method,
Melt flow rate is 0.5 to 10 g / 10 min. And a melt tension of the composition is 1.5 to 4.0 g.

6) Japanese Patent No. 2597895 discloses that
(A) Ethylene-propylene-diene copolymer 50-6
8% by weight, and (B) ethylene-vinyl acetate copolymer 30
~ 48 wt% and (C) linear low density polyethylene 2 to 2
A film is formed from a composition containing 0% by weight, and the obtained film, woven fabric and nonwoven fabric are heat-sensitively pressure-bonded at 70 to 150 ° C. to fix the film to the woven fabric or nonwoven fabric and to cause heat shrinkage. There is disclosed a method for producing a composite sheet having waterproofness and breathability, which is characterized by making the film microporous.

7) Japanese Patent Laid-Open No. 3-133625 discloses that
A non-woven fabric made of only the heat-adhesive conjugate fibers or a non-woven fabric made of a mixed web with other fibers containing 30% or more of the heat-adhesive conjugate fibers, and a film having a large number of micropores having a pore diameter of 100 μm or less are crimped. Of 5% to 40% and bonded at pressure-bonding points, wherein the thermoadhesive conjugate fiber comprises 15% by weight of ethylene / acrylic acid ester / maleic anhydride terpolymer. The first component containing the above and the second component made of a thermoplastic resin having a melting point of 30 ° C. or more higher than the melting point of the first component are formed in the length direction on at least a part of the fiber surface. As described above, there is disclosed a moisture permeable laminate, which is a heat-adhesive conjugate fiber that is composite-spun into a parallel type or a sheath-core type.

However, the aeration liquid impermeable sheet according to the above-mentioned proposals 1) to 7) is obtained by mixing fine particles of filler to obtain fine pores, melt-molding the mixture, and stretching the mixture. Is smooth and has a light reflection peculiar to a plastic film, and this light reflection generally gives a feeling of lightness and is not preferred, and it is uncomfortable that it becomes sticky when it comes into contact with the skin, and it is easy to wear and detach when sliding. There was a flaw. In addition, the above-described 6) aeration liquid impermeable film proposed in Japanese Patent No. 2597895 is easily sticky because the resin composition is sticky, and is thinned at the interface with the fiber because it is thermally softened during thermocompression bonding. There is a drawback that it easily leaks water. Further, the complicated process of forming the fiber web and the sheet in advance and thermocompressing the webs together is required, resulting in poor productivity. Further, the resin composition EPDM has a strong odor peculiar to a diene, and EVA has a strong acetic acid odor and is not suitable as a material that comes into contact with the human body. Further, the above 7) JP-A-3-133625.
The same applies to the breathable liquid impermeable sheet proposed in Japanese Patent Publication No.
The adhesiveness of pressing with the fiber web becomes sticky and the terpolymers acrylic acid and maleic acid give off a unique odor. Furthermore, in the conventionally proposed venting liquid impermeable sheet as described above, it is not possible to satisfy the required physical properties with a single material, and it is necessary to bond other materials to the resulting breathable film for use. Therefore, there is a drawback that the number of necessary materials increases and secondary processing is required, resulting in an increase in price.

Therefore, an object of the present invention is to have breathability, moisture permeability and water resistance (liquid impermeability), and further, it has a good appearance and texture and is easy to install and remove even when wet, without slipping. Excellent,
Another object of the present invention is to provide a moisture-permeable film that can be produced industrially, inexpensively, safely, and at high speed in a conventional manufacturing process, and an absorbent article using the same.

[0011]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have made certain fine particles adhere to the surface of a breathable liquid-impermeable microporous film made of a polyolefin resin composition. It was found that the moisture-permeable film made of the above can achieve the above object.

[0012] The present invention has been made based on the above findings, the surface of the breathable liquid-impervious microporous film made of polyolefin-based resin composition comprising a polyolefin resin, Yes is adhered organic fine particles, the Organic fine particles are
Disperse it in a solution of adhesive resin to
It is applied on the surface of the perforated film and the solvent is volatilized and adhered.
The above organic fine particles are cellulose-based fine powder, leather
The present invention provides a moisture permeable film characterized by being powder, synthetic resin foam or porous fine particles .

Further, in the present invention, the polyolefin resin composition contains 30 to 80% by weight of filler fine particles in the polyolefin resin composition, and the breathable liquid-impervious microporous film comprises: It is intended to provide the above-mentioned moisture-permeable film obtained by subjecting a polyolefin-based resin composition to a film and then performing an aperture forming step including at least a stretching treatment. The present invention also provides the moisture-permeable film, wherein the polyolefin resin is linear low-density polyethylene . Also, the present invention, the adhesive resin, nitrocellulose dissolved in a solvent, a polyamide resin, alkyd resin, acrylic resin, polyurethane resin,
It is intended to provide the above-mentioned moisture-permeable film, which is a resin composition containing, as a main component, one or a combination of two or more cyclized rubbers and chlorinated rubbers.

[0014]

In the present invention, the ratio of the area of the part to which the organic fine particles are adhered to the area of the part to which the organic fine particles are not adhered in the air-permeable liquid-permeable microporous film (area of the adhered part: Area of non-bonded part) is 1:99
The present invention provides the moisture permeable film having a volume ratio of about 60:40, and a plurality of island portions formed by adhering the organic fine particles to the breathable liquid-impervious microporous film via the adhesive resin. , A breathable liquid-impervious microporous film is formed into a sea-island shape including the exposed sea part, and the area of the island part is 0.1 to 100 mm ² , and the width of the sea part located between the island parts. Is 0.1 to 10 mm, and the sea part formed by adhering the organic fine particles to the moisture-permeable film or the gas-permeable, liquid-permeable, microporous film through the adhesive resin, and the gas-permeable, liquid-permeable, microporous film. The film is formed in a sea-island shape consisting of a number of exposed islands, and the area of the islands is 0.1 to 100.
mm ² and the width of the sea between the islands is 0.1-1
The moisture permeable film having a thickness of 0 mm is provided.

The present invention also provides the moisture permeable film as described above, wherein the organic fine particle layer formed by adhering the organic fine particles to the surface of the breathable liquid-impervious microporous film has a thickness of 5 to 1000 μm. It is a thing. Further, in the present invention, the thickness of the portion where the organic fine particles are not adhered is 10 to 100.
μm, and the moisture permeability of the moisture permeable film is 0.4 to 4.0.
g / 100 cm ² · h and water pressure resistance is 1000 mm · H
_The above-mentioned moisture-permeable film having ₂ O or more is provided.

Further, the present invention provides an absorbent article comprising a liquid-permeable surface material, a liquid-impermeable back material, and an absorber interposed between the surface material and the back material, wherein the back surface is An absorbent article characterized by using the moisture-permeable film as a material.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The moisture-permeable film of the present invention will be described in detail below. The moisture-permeable film of the present invention is characterized in that organic fine particles are adhered to the surface of a breathable liquid-impermeable microporous film made of a polyolefin-based resin composition containing a polyolefin-based resin.

The breathable liquid-impervious microporous film used in the moisture-permeable film of the present invention contains the above-mentioned polyolefin-based resin, and more preferably, a polyolefin-based resin composition containing 30 to 80% by weight of filler fine particles. A breathable liquid-impervious microporous film obtained by undergoing an aperture forming step including at least a stretching treatment is preferably used. That is, the polyolefin resin composition preferably contains filler fine particles in an amount of 30 to 80% by weight in the polyolefin resin composition, and the breathable liquid-impervious microporous film is the polyolefin resin composition. It is preferable that the film is obtained by subjecting the product to a film and then subjecting it to an aperture forming step including at least a stretching treatment.

In the moisture-permeable film of the present invention, the above-mentioned polyolefin resin contained in the above-mentioned polyolefin-based resin composition is not particularly limited as long as it is used in a usual moisture-permeable film, but it has a low density in view of flexibility. Polyethylene is preferable, and linear low-density polyethylene is more preferable from the viewpoint of mechanical strength. And among these, the density is 0.900 to 0.934 g
/ Cm ³ , melt index 0.5 to 5.0 g / 1
Those within the range of 0 minutes (190 ° C., 2.16 kg load) are preferable in terms of film moldability, film strength and flexibility.

As the filler fine particles preferably used in the polyolefin resin composition, fine particles which do not melt or soften at the kneading temperature or the film forming temperature of the polyolefin resin composition or do not flow even when softened are used. Specifically, inorganic filler fine particles and organic filler fine particles can be used, and preferably inorganic filler fine particles are used. As the inorganic filler fine particles,
What is used for the microporous film formed by the conventional stretching treatment disclosed in JP-A-5-230252 can be used without particular limitation, and specific examples thereof include calcium carbonate and barium sulfate. To be Also,
Examples of the organic filler fine particles include polyamide such as 6-nylon, fluororesin, polyimide, silicone resin, phenol resin, cross-linked resin obtained by copolymerizing acrylic acid and the like with a cross-linking agent such as divinylbenzene, acrylic acid, methacrylic acid. Examples thereof include fine particles of a polymer obtained by polymerizing a salt of an acid or the like with an alkali metal.

The average particle size of the filler fine particles is preferably 0.5 to 4.0 μm, more preferably 0.7 to 2.
It is 0 μm. If the average particle size is less than 0.5 μm, it is difficult to uniformly disperse the particles during kneading, and the film tends to have aggregates of the inorganic filler, and uniform stretching becomes difficult, causing breakage during stretching. If the average particle size exceeds 4.0 μm, the voids become large, and the water resistance and strength of the film decrease, so it is preferable to set it within the above range. Further, in order to improve the dispersibility in the resin composition, it is preferable to use the filler fine particles whose surface is subjected to a known surface treatment with a fatty acid or the like. When using the inorganic filler fine particles which are not surface-treated, fatty acid or the like may be added when kneading with the polyolefin resin.

The amount of the fine filler particles blended is preferably 30 to 80% by weight, more preferably 40 to 70% by weight. If it is less than 30% by weight, air permeability and moisture permeability will be insufficient, and if it exceeds 80% by weight, the water resistance, strength and moldability of the film will be deteriorated, which is not preferable.

Further, a plasticizer (softening agent) may be used in the above polyolefin resin composition. As the plasticizer, those generally used for films of this type disclosed in JP-A-5-230252 and the like can be used without particular limitation. Specifically, esters of fatty acids and alcohols can be used. , Fatty acid amide, ketone resin, silicone oil and the like are used. The amount of the plasticizer blended in the polyolefin resin composition is preferably 0.
It is 1 to 20% by weight, and more preferably 1.0 to 10% by weight. If the amount is less than 0.1% by weight, there is substantially no plasticizing effect, and if the amount is more than 20% by weight, the film surface bleeds out and becomes sticky, the texture is deteriorated, and the adhesiveness becomes poor. Also, of these plasticizers,
Esters and the like synthesized from fatty acids and alcohols also have a dispersing function for the filler fine particles, and are therefore particularly preferably used.

In addition, the breathable liquid-impervious microporous film contains additives that are generally used, such as a dispersant, a lubricant,
Antioxidants, antistatic agents, colorants and the like can also be used as necessary.

The breathable liquid-impervious microporous film is manufactured as follows. That is, it is obtained by melt-kneading the above-mentioned polyolefin-based resin composition comprising the above-mentioned polyolefin-based resin, the above-mentioned filler fine particles, the above-mentioned plasticizer and the like to form a film, and then uniaxially or biaxially stretching it. In detail, first, the above polyolefin resin composition, after mixing with a mixer such as a cone blender, a ribbon blender, a Henschel mixer, a single screw extruder shaft, a twin screw extruder, a Banbury mixer, a mixing roll, etc. Knead and pelletize using a kneader. Next, this pellet is used to form a film. Specifically, both the inflation method and the T-die forming method are possible, but the T-die method is superior in order to obtain a film having a uniform thickness, and the inflation method is superior in terms of mass productivity. . Then, the obtained film is stretched. In this stretching, a usual roll stretching machine, a tenter stretching machine, a mandrel stretching machine or the like is used, but uniaxial stretching with a roll stretching machine is preferable from the viewpoint of productivity. The roll stretching will be described in detail. The film is preheated by a preheating roll, uniaxially stretched in the machine direction (MD direction) by the stretching roll, and then relaxed and heat set. By stretching the film-shaped molded product, physical microvoids are generated between the filler particles and the resin, so that the film is provided with air permeability and moisture permeability. In order to generate such microvoids in the film, it is appropriate to perform stretching at about 120 to 500% (1.2 to 5 times the length before stretching), depending on the intended use.

The size of the fine pores in the resulting breathable liquid-impervious film is preferably 0.1 to 5 μm, more preferably 0.3 to 2 μm. If the size of the fine pores is smaller than 0.1 μm, the air permeability and moisture permeability are poor, and if it is larger than 5 μm, the water resistance is adversely affected, which is not preferable. Furthermore, moisture permeability of the breathable liquid-impervious film is preferably from ^{0.4~4.0g / 100cm 2 · h, 1.0~3.0g} / 100cm 2 · h
Is more preferable. Also, the water pressure of the breathable liquid-impervious film is preferably at 1000 mm · H ₂ O or more, and even more preferably from 2000~4000mm · H ₂ O.

The organic fine particles used in the moisture-permeable film of the present invention include those obtained by mechanically treating natural polymers or synthetic polymers, for example, those obtained by cutting, crushing, melt spray cooling, etc .; Chemically treated, for example, by dissolution and reprecipitation, partial decomposition, partial dissolution, and the like; synthetic polymers include those synthesized under the condition that fine particles are formed at the time of synthesis. Specifically, cellulose-based fine powder, leather powder, synthetic resin foam or porous fine particles are preferable. Moreover, the maximum diameter (or the length in the case of a needle shape) of the organic fine particles is 5 to 1000 μm.
The diameter is preferably m, and the minimum diameter (or the width in the case of needles) is preferably 0.1 to 50 μm. Further, the shape of the organic fine particles is a shape having no voids in one particle, a shape having voids, a shape in which voids extend to the surface of the particle, a hollow shape, or a combination of two or more of these shapes. Shape etc. are mentioned.

The above organic fine particles will be described in more detail.
The above-mentioned cellulose-based fine powder is, for example, one obtained by finely pulverizing wood cellulose by acid hydrolysis treatment and mechanical treatment, and having a particle diameter of 5 to 200 μm or a long diameter of 20 to
Examples include a short fiber having a short diameter of 5 to 50 μm and a diameter of 500 μm. Examples of the above-mentioned leather powder include those obtained by crushing the leather of animals such as cows and horses and having a particle size of 5 to 300 μm. As the synthetic resin foam, for example,
Examples thereof include those obtained by foaming synthetic resin particles made of a homopolymer or copolymer having a diameter of 10 to 700 μm, such as ethylene, butadiene, styrene, methacrylic acid esters such as methyl methacrylate, and dimethylsiloxane, by a known method. Examples of the porous fine particles include those obtained by making the synthetic resin fine particles porous by a known method, and the organic fine particles include the synthetic resin particles themselves or those obtained by crosslinking the same. In addition, short fibers may be used as the organic fine particles. For example, short fibers made of rayon, polyester, polyamide, polypropylene or the like having a diameter of 3 to 100 μm or two or more composite fibers cut into a length of 50 to 1000 μm can also be used.

In the present invention, the most preferable organic fine particles are cellulosic fine powders, and the second preferable ones are synthetic resin foams, porous fine particles and leather powders. In addition, commercially available products can also be used as the organic fine particles. As an example of the above-mentioned cellulose-based fine powder, trade names "KC Frog W-200" and "KC" manufactured by Nippon Paper Industries Co.
Frog W-250 "," KC Frog W-300 ",
"KC Frog W-400"; product name "Avicel PH-101", "Avicel PH-M2" manufactured by Asahi Kasei Corporation.
5 "," Avicel PH-M15 "," Avicel PH-M "
06 ”and the like. As an example of the porous fine particles, Sekisui Plastics Co., Ltd. trade name "Techpolymer MB"
P "," Techpolymer SBP "and the like.

The amount of the organic fine particles used is preferably 1 to 500 g / m ² as the average basis weight of the adhesive portion.

Further, the organic fine particles as a method to adhere to the breathable liquid-impervious microporous films, are dispersed in the adhesive resin solution the organic fine particles, a gravure printing method, a method of coating by a relief printing method preferably At this time, it is preferable to disperse the adhesive resin solution and apply it as a dispersion liquid. That is, the organic fine particles, dispersed in a solution of the adhesive resin, that is bonded to volatilize applied solvent to the surface of the breathable liquid-impervious microporous films. Examples of the adhesive resin include nitrocellulose dissolved in a solvent, polyamide-based resin such as polyamide synthesized from polymerized fatty acid and polyamine, aromatic carboxylic acid and polyamine, polyester synthesized from polybasic acid and polyhydric alcohol. Alkyd resin such as, acrylic resin such as polyethyl acrylate and polybutyl acrylate, polyurethane resin such as polyurethane synthesized from ester-based or ether-based polyol and isocyanate, cyclized rubber, chlorinated rubber, etc. 1 or 2
Examples thereof include a resin composition containing, as a main component, a combination system of one or more kinds. That is, as the adhesive resin, a resin composition containing these as main components is preferably used. Incidentally, only one of these may be used, or a resin composition composed of two or more of these may be used. When other components of the resin listed above are used in this resin composition, the other components include:
Known antioxidants, dispersants, lubricants, colorants and the like are used in inks and paints, and the amount of the other components used is the same as that of the main component 1 described above.
It is preferably 0.001 to 10 parts by weight with respect to 00 parts by weight. When nitrocellulose is used, if necessary, a plasticizer such as dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, dioctyl adipate, rosin ester may be used. The plasticizer may be used alone or in combination of two or more, and the amount thereof is 70 to 0 parts by weight based on 100 parts by weight of nitrocellulose.

The preferred solvent for dissolving the adhesive resin is ethyl acetate, butyl acetate, etc. esters, acetone, methyl ethyl ketone, etc. ketones, ethanol, isopropanol, etc. alcohols, toluene,
Aromatic compounds such as xylene can be used, and when used, they can be used alone or as a mixture of two or more.

When the organic fine particles are adhered to the surface of the breathable liquid-impervious microporous film via an adhesive, the fine pores of the breathable liquid-impervious microporous film are blocked with an adhesive resin, and the air permeability is improved. Therefore, the area where the organic fine particles are adhered is limited by the moisture permeability required for the moisture permeable film. Therefore, the ratio of the area of the part to which the organic fine particles are adhered to the area of the part to which the organic fine particles are not adhered in the air-permeable liquid-permeable microporous film (area of the adhered part: Area) is preferably 1:99 to 60: 4
0, and a more preferable area ratio is 5:95 to 50: 5.
0, and the most preferable area ratio is 10:90 to 40:60. If the area ratio of the adhered portions is less than 1, the desired effect of the present invention cannot be obtained, and if it exceeds 60, the moisture permeability decreases, which is not preferable.

The moisture-permeable film has a) a large number of island portions formed by adhering the organic fine particles to the air-permeable liquid-impervious microporous film via the adhesive resin, and the air-permeable liquid-impervious property. The microporous film is formed in the shape of a sea-island consisting of the exposed sea part, or b) the sea part is formed by adhering the organic fine particles to the breathable liquid-impermeable microporous film via the adhesive resin. It is preferable that the breathable liquid-impermeable microporous film is formed in a sea-island shape including a large number of exposed islands. In the case of the above a) or b), the area of the island is preferably 0.1 to 100 mm ^2.
The width of the sea area located between the islands is preferably 0.
1 to 10 mm, more preferable area of each island is 0.3
A ~60mm ^2, the width of the sea portion located between more preferred that each island portion is 0.3 to 5 mm. If the area is less than 0.1 mm ² when configured as in a) above,
If the texture is not recognized and the width exceeds 100 mm ² , the texture is deteriorated due to the reduced flexibility of the film, and the width is 0.
If it is less than 1 mm, the flexibility of the film is reduced, and it is 10 mm.
If it exceeds, it is not preferable because the texture is hard to be recognized and light is reflected to deteriorate the appearance. In the case of the above b), if the area is less than 0.1 mm ² , the flexibility of the sheet is poor, and if it exceeds 100 mm ² , the texture is hard to be recognized and the width is less than 1 mm. If it is, the flexibility of the film is inferior, and if it exceeds 10 mm, it is not preferable because the texture is hard to be recognized and the appearance is poor due to light reflection. And
It is preferable that the island portions are evenly distributed over the entire surface of the moisture-permeable film.

The organic fine particle layer formed by adhering the organic fine particles to the surface of the breathable liquid-impervious microporous film preferably has a thickness of 5 to 1000 μm. When the thickness is less than 5 μm, the texture is hard to be recognized,
If it exceeds 1000 μm, the unevenness is too large and the texture becomes poor, and the film strength decreases.

Further, the part to which the organic fine particles are not adhered
It is preferable that the thickness of the film is 10 to 100 μm.
The moisture permeability of the film is 0.4-4.0g / 100cm²・ H
Is preferable, and the water pressure resistance is 1000 mm · H.₂O
The above is preferable. The thickness is less than 10 μm
Then, the film strength is weak.
It becomes difficult to achieve both humidity and water pressure resistance. In addition, the above-mentioned moisture permeability
But 0.4g / 100cm²・ If it is less than h, stuffiness and
Less blurring prevention effect 4.0g / 100cm ²・ Over h
If so, it becomes difficult to increase the water pressure resistance to 1000 mm or more. Furthermore,
The water pressure resistance is 1000 mm ・ H₂Liquid protection is less than O
Poor leakability. In the present specification, the water vapor transmission rate is J
It is measured according to IS Z 0208,
The water pressure resistance is measured according to JIS L 1092B method.
Is determined.

Next, the moisture-permeable film of the present invention will be described with reference to the drawings. Here, FIG. 1 is a perspective view showing one form of the moisture-permeable film of the present invention, and FIG. 2 is an enlarged plan view showing a main part of the moisture-permeable film of the form shown in FIG. As shown in FIGS. 1 and 2, the moisture permeable film 100 of this embodiment is formed by adhering organic fine particles 102 to the surface of a gas-permeable, liquid-impermeable microporous film 101. Then, as shown in FIG. 2, the organic fine particles 102 are adhered to each other via an adhesive resin 103, whereby the moisture permeable film 100 is formed on the breathable liquid impermeable microporous film 101. 102 is formed in a sea-island shape including a large number of islands 110 formed by adhering the resin 102 through the adhesive resin 103 and a continuous sea 120 formed by exposing the air-permeable liquid-impermeable microporous film 102. Has been done. In addition, the island portion 110 is a minute convex portion having the size described above, and is evenly distributed over the entire surface of the moisture-permeable film. That is, it is configured as described in a) above. Further, the organic fine particles 102 are located at the center, and the adhesive resin 103 is located so as to cover the periphery thereof. In the present invention, it is sufficient that the microscopic projections are present in a macroscopically uniform manner, and it is not necessary that they are evenly present in the entire film. In this specification, the term "micro" refers to about 1 to 1000 µm, and the term "macro" refers to about 1 to 20 mm. In addition, as shown in FIG. 2, the organic fine particle layer 130 is formed by adhering the organic fine particles 102 to the surface of the breathable liquid-impervious microporous film 101. The thickness of the organic fine particle layer 130 described above is
It is apparent thickness.

The moisture-permeable film of the present invention can be manufactured inexpensively and safely by using the same manufacturing process as the conventional one, and due to the elasticity of the organic fine particles, the convex top contacting with the skin. It is possible to obtain a soft, dry and moisture-permeable moisture-permeable film having good elasticity and soft texture. Furthermore, since the organic fine particles themselves are more elastic than the inorganic fine particles, they give a soft feeling when they come into contact with the human body, and the fine surface irregularities eliminate the sticky feeling and give a dry feeling, and are excellent in texture. . Also,
There is no light reflection peculiar to a plastic film, and it is preferable from the appearance. Furthermore, when using the above-mentioned adhesive resin,
Since it adheres well to both the organic fine particles and the microporous film composed of the polyolefin-based resin composition, the amount of the adhesive resin used can be small, which also improves the texture. Further, in the step of adhering the organic fine particles, some printing is performed to increase the commercial value even when the conventional moisture-permeable film is used as the backing material of the absorbent article. It can be implemented without adding additional manufacturing steps. INDUSTRIAL APPLICABILITY The moisture-permeable film of the present invention can be used not only as a leak-proof material (back surface material) for absorbent articles such as disposable diapers and sanitary napkins, but also as dust-proof, germ-proof, medical clothing, cold clothing, and the like.

As shown in FIG. 3, the moisture-permeable film of the present invention is formed by adhering organic fine particles 102 in a lattice pattern to the air-permeable, liquid-impervious microporous film 101 via an adhesive resin 103, thereby forming an organic compound. A structure in which a continuous sea part 120 formed by adhering fine particles 102 and a large number of island parts 110 formed by exposing the breathable liquid-impervious microporous film 101 are formed, that is, b) above. It is also possible to have a configuration of.

The moisture permeable film of the present invention can be produced by first adhering the organic fine particles to the above-mentioned gas-impermeable, microporous film by the above-mentioned adhesion method. Further, the moisture-permeable film may be subjected to post-processing such as stretching, embossing, and printing. As the embossing, for example, a method in which any one of a rubber roll, a steel roll, a paper roll, a cotton roll, etc. and a steel roll on which a pattern is engraved is used, or the convex portion of one roll is the other. It can be performed by a method of penetrating between the rolls in which patterns are engraved so as to correspond to the concave portions of the rolls. The embossing can also be performed by heating.

Next, a preferred embodiment of the absorbent article of the present invention using the moisture-permeable film of the present invention will be described with reference to FIG. Here, FIG. 4 is a perspective view showing a disposable diaper as a preferred embodiment of the absorbent article of the present invention.

The disposable diaper 1 of the embodiment shown in FIG.
Is a liquid permeable front material 2, a liquid impermeable back material 3,
An absorbent body (not shown) interposed therebetween is provided, and the front surface material 2 and the back surface material 3 and the first elastic material interposed therebetween are provided in the abdominal waist portion 5 and the back waist portion 5 ′. Waist gathers 7 and 7 ', which are composed of the member 6, are provided. The abdominal waist portion 5 and the back waist portion 5 ′ are arranged so as to be located around the front and rear end portions of the absorbent body.

Leg gathers 9 and 9'consisting of the surface material 2, the back surface material 3 and the second elastic member 8 interposed therebetween are formed at the leg portions on both sides in the longitudinal direction of the diaper 1. Has been done.

Fastening tapes 10 for fastening the abdominal waist portion 5 and the back waist portion 5'when the diaper 1 is worn on both sides in the width direction of the back waist portion 5'of the diaper 1. 10 'are provided. Further, a landing tape 11 as an adhered portion of the fastening tapes 10 and 10 'is arranged on the surface of the back surface material 3 in the ventral waist portion 5 of the diaper 1.
The fastening tapes 10 and 10 ′ are configured to be fixed to the landing tape 11.

The absorbent body has a portion corresponding to the crotch portion of the diaper, which is twisted, and is curved in an hourglass shape. Then, in the abdominal waist portion 5 and the dorsal waist portion 5 ′ and the left and right leg portions located around the absorber, the first elastic member 6 and the second elastic member 8 are the surface material 2 and the back surface, respectively. It is stretched between the material 3 and
The first elastic member 6 and the second elastic member 8 are contracted in a free state to form waist gathers 7 and 7 ′ and leg gathers 9 and 9 ′ so that they can be fitted to the waist and crotch of the wearer. Is configured.

The surface material 2, the absorbent body, the first elastic member 6 and the second elastic member 8 constituting the diaper 1 are arranged.
As such, those normally used in this type of disposable disposable diaper can be used without particular limitation.

Thus, in the disposable diaper 1 of the embodiment shown in FIG. 4, the moisture permeable film of the present invention described above is used as the back material. Above disposable diaper 1
Since the moisture-permeable film of the present invention described above is used as the backing material as described above, it does not slip even when wet, and thus has excellent attachment / detachability. The method for manufacturing the disposable diaper of the present embodiment is not particularly limited, and a conventional method for manufacturing a disposable diaper is appropriately applied.

The moisture-permeable film and the absorbent article of the present invention are not limited to the above-mentioned forms, and can be variously modified without departing from the spirit of the present invention. For example, the embodiment shown in FIG. 4 is a deployable disposable diaper,
The absorbent article of the present invention can be similarly applied to a pants-type disposable diaper. Further, the absorbent article of the present invention is not limited to disposable diapers, but can be similarly applied to sanitary napkins, incontinence pads and the like.

EXAMPLES The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following examples.

[Example 1] Preparation of resin composition; linear low-density polyethylene (manufactured by Mitsui Petrochemical Industry Co., Ltd., trade name "Ultox 2520")
F ", MFR 2.3 g / 10 min, density 0.925 g / c
m ³ ) 35.9% by weight, surface-treated calcium carbonate (manufactured by Bihoku Powder Co., Ltd., Ryton 22S, average particle size 1.0 μ)
m) 56.3% by weight, and polyester (trimethylolpropane / adipic acid / stearic acid = 3.5 mol /
2.5 mol / 5.5 mol SV = 265, AV =
1.2, OHV = 8.6) 3.8% by weight was mixed with a Henschel mixer, and then a twin screw extruder having a diameter of 45 mm (PCM-45-33.5 manufactured by Ikegai Tekko KK) at a set temperature of 1
The resin composition was obtained by kneading and pelletizing at 60 ° C. and a screw rotation speed of 150 rpm.

Film molding: Using the resin composition obtained, a single-screw extruder having a diameter of 50 mm (L / D = 28) and a diameter of 10 were used.
A tubular film having a film thickness of 60 μm and a folding width of 380 mm was molded using an inflation molding facility including a 0 mm circular die (die lip clearance 1.0 mm) to obtain a film having a basis weight (unit weight) of 80 g / m ² . The molding conditions are set temperature 160 ° C., discharge amount 2
The blow rate was 5 kg / h and the blow ratio was 2.5.

Stretching treatment: preheating roll, stretching roll, annealing roll (roll diameters of 600 mm and 100 m, respectively)
m, 600 mm, and a width of 1000 mm), using a roll stretching equipment having a roll setting temperature of 80 ° C.
The drawing roll is set to 50 ° C., the annealing roll is set to 80 ° C., the draw ratio is set to 2.3 times, and 2.1 is obtained by the aryl ring.
The film was returned to the original size and uniaxially stretched to obtain a breathable liquid-impervious microporous film having a basis weight of 40 g / m ² .

Preparation of organic fine particle suspension: 35 parts by weight of a 40% solution (solvent composition: toluene / isopropyl alcohol = 2/1) of a polyamide resin (trade name “Reomide SP-40N”; Kao Corporation), nitrification Cotton [Product name "RS-1
/ 4 "; 20% solution of Daicel Chemical Industries, Ltd. (solvent composition; toluene / isopropyl alcohol / ethyl acetate =
2/1/1)] 15 parts by weight and 2 parts by weight of rosin ester (trade name "Hariester KT2" Harima Kasei Co., Ltd.) and organic fine particles (1) {trade name "Avicel" PH-M25 ", average particle diameter 25 μm; cellulose powder manufactured by Asahi Kasei Kogyo Co., Ltd.} 30 parts by weight was mixed with 18 parts by weight of ethyl alcohol, and the resulting mixture was mixed with 3 parts.
The mixture was shaken and stirred for 0 minutes to obtain a cellulose powder suspension in which organic fine particles were dispersed in an adhesive resin solution.

The above cellulose suspension was prepared by using a letterpress roll {letterpress (1)} in which the number of ellipses having a coating area of 1.5 mm ^{2 at} one point was approximately uniformly distributed in a rhombus at a ratio of 900 within 100 cm ² . Applying to the breathable liquid-impervious microporous film so that the maximum coating thickness (total coating thickness-film thickness before coating) becomes 35 μm at one point after drying,
It was dried with warm air at 40 ° C. for 10 minutes to obtain the moisture-permeable film of the present invention. When the cellulose powder suspension is applied by letterpress, the suspension becomes viscous, and the thickest point is at approximately the center. The moisture permeable film obtained was evaluated according to the following criteria. The results are shown in [Table 1].

Evaluation Criteria: (1) Water vapor transmission rate; measured according to JIS Z 0208.
(G / 100 cm ² · h) (2) Water pressure resistance; measured according to JIS L 1092B method. (MmH ₂ O) (3) Tensile hardness; measured according to JIS P 8113. MD direction (film forming direction), CD direction (MD
Strength per 1 cm width (cN / c)
m) (4) Tear strength; JIS in the stretching direction (MD direction)
Measured in accordance with P 8116. (CN) (5) Texture; The film obtained in the stretching treatment step was evaluated according to the following criteria by touch feeling with fingers. ◎: Soft and non-greasy and very good texture ○: Flexible and non-greasy and good texture △: Slightly sticky and slightly bad texture ×: Greatly sticky and poor texture (6) Appearance: Film obtained in the stretching process It was evaluated according to the following criteria by visual observation. ⊚: No light reflection, very good appearance ○: No light reflection, good appearance Δ: Slight light reflection, slightly bad appearance ×: Large light reflection, bad appearance The results evaluated according to the above evaluation criteria [Table 1] Shown in.

Example 2 Organic Fine Particles (1) of Example 1
Instead of organic fine particles (2) {"Techpolymer MB
P ”, (synthesized resin fine particles manufactured by Sekisui Plastics Co., Ltd., having a particle size of 10 to 30 μm selected)} were used in the same manner as in Example 1 except that the gas-permeable microporous film was produced. ,
The suspension of the adhesive resin solution was adjusted and the suspension was applied to obtain a moisture-permeable film having a maximum application thickness of 38 μm. The obtained moisture permeable film was evaluated in the same manner as in Example 1. The results are shown in [Table 1].

[Embodiment 3] Instead of the relief plate (1) of Embodiment 1, a willow-leaf-shaped projection having a coating area of about 43 mm ^{2 at} one spot was distributed uniformly in 50 cm within 100 cm ² . Using the above relief roll {relief plate (2)} so that the maximum coating thickness (thickness of the entire coating portion-film thickness before coating) at one point after drying the above cellulose suspension is 40 μm. A moisture permeable film was obtained in the same manner as in Example 1, except that the coating was applied to the above and dried at 40 ° C. for 10 minutes. The obtained film was evaluated in the same manner as in Example 1. The results are shown in [Table 1].

Comparative Example 1 A breathable liquid-impermeable microporous film made of the linear low-density polyethylene resin composition obtained in Example 1 was used as a moisture-permeable film without adhering organic fine particles, It evaluated similarly to 1. The results are shown in [Table 1].

Comparative Example 2 In the same manner as in Example 3 except that the inorganic fine particles (1) {titanium oxide (trade name "Taipaque R-630" manufactured by Ishihara Sangyo Co., Ltd.) was used in place of the organic fine particles (1). A breathable liquid-impermeable microporous film was prepared, a suspension of an adhesive resin solution was prepared, and the suspension was applied to obtain a moisture-permeable film having a maximum coating thickness of 12 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in [Table 1].

[0060]

[Table 1]

Example 4 and Comparative Example 3 (Examples for Body Fluid Treatment Products, Comparative Example) The moisture permeable films obtained in Example 3 and Comparative Example 2 were used as the backing material, and the surface material, the absorber, Disposable diapers each having the form shown in FIG. 4 composed of a backing material and a fastening tape were manufactured (referred to as Example 4 and Comparative Example 3 in that order). As a result, the disposable diaper of Example 4 is softer than the conventional diaper using the backing material (Comparative Example 3) but has a non-greasy dry feel, and has a moisture-permeable and excellent feel to the wearer. It gave a comfortable fit. In addition, the diaper of Comparative Example 3 has light reflection peculiar to the plastic film which the user does not like, and slips when wet, whereas the disposable diaper of Example 4 has no light reflection and does not get wet. It did not slip and exhibited excellent wearability and detachability.

[0062]

EFFECT OF THE INVENTION The moisture-permeable film of the present invention has breathability, moisture permeability, and water resistance, and further has the characteristics of good texture and the fact that it does not slip when wet. It is an industrially, safely, and highly productive product that can be continuously produced at high speed. Moreover, since the absorbent article of the present invention does not slip even when wet, it is excellent in loading / unloading properties and is economically advantageous.

[Brief description of drawings]

FIG. 1 is a perspective view showing one form of a moisture-permeable film of the present invention.

FIG. 2 is an enlarged plan view showing a main part of the moisture-permeable film having the form shown in FIG.

FIG. 3 is an enlarged plan view showing a main part of the moisture-permeable film having the form shown in FIG.

FIG. 4 is a perspective view showing a disposable diaper as a preferred embodiment of the absorbent article of the present invention.

[Explanation of symbols]

100 moisture permeable film 101 Breathable liquid impermeable microporous film 102 Organic fine particles 103 Adhesive resin 110 island 120 Kaifu 130 Organic fine particle layer

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-7-279335 (JP, A) JP-A-8-336885 (JP, A) JP-A-9-3224 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 A41B 13/02 A61F 13/15-13/84

Claims (10)

(57) [Claims] To 1. A surface of the breathable liquid-impervious microporous film made of polyolefin-based resin composition comprising a polyolefin resin, Yes is adhered organic fine particles, the organic fine particles are dispersed in a solution of the adhesive resin On top
Apply it to the surface of the breathable liquid-impervious microporous film to volatilize the solvent
The particles are dispersed and adhered, and the above-mentioned organic fine particles are made of cellulose fine powder, leather powder, synthetic
A moisture-permeable film, which is a resin foam or porous fine particles . 2. The polyolefin-based resin composition comprises filler particles in an amount of 30 to 8 in the polyolefin-based resin composition.
The breathable liquid-impervious microporous film contains 0% by weight, and is obtained by subjecting the polyolefin-based resin composition to a film form and then performing an aperture forming step including at least a stretching treatment. The moisture permeable film according to claim 1. 3. The polyolefin resin is linear low density polyethylene, wherein the polyolefin resin is linear low density polyethylene.
The moisture-permeable film described. 4. The adhesive resin is mainly one or a combination of two or more of nitrocellulose, polyamide resin, alkyd resin, acrylic resin, polyurethane resin, cyclized rubber and chlorinated rubber which are soluble in a solvent. It is a resin composition as a component, The moisture permeable film in any one of Claims 1-3 characterized by the above-mentioned. 5. The ratio of the area of the part to which the organic fine particles are adhered to the area of the part to which the organic fine particles are not adhered in the air-permeable liquid-permeable, microporous film (area of adhered part: not adhered). the area of the portion) is 1: 99 to 60: moisture-permeable film according to any one of claims 1-4, characterized in that the 40. 6. A large number of island portions formed by adhering the organic fine particles to the gas-permeable, impermeable microporous film through the adhesive resin, and a sea portion in which the gas-permeable, impermeable microporous film is exposed. Is formed in the shape of a sea-island, and the area of the island is 0.1 to 100 mm ² , and the width of the sea located between the islands is 0.1 to 10 mm. Term
5. The moisture-permeable film as described in 5 . 7. A sea part formed by adhering the organic fine particles to a gas-permeable, liquid-permeable, microporous film through the adhesive resin, and a large number of islands, on which the gas-permeable, liquid-permeable, microporous film is exposed. Is formed in the shape of a sea-island, and the area of the island is 0.1 to 100 mm ² , and the width of the sea located between the islands is 0.1 to 10 mm. Term
5. The moisture-permeable film as described in 5 . 8. according to claim 1-7 in which the thickness of the breathable liquid-impervious microporous film organic fine particle layer formed by adhering the organic fine particles on the surface of which being a 5~1000μm The moisture-permeable film as described in any one. 9. The thickness of the portion where the organic fine particles are not adhered is 10 to 100 μm, the moisture permeability of the moisture permeable film is 0.4 to 4.0 g / 100 cm ² · h, and the water pressure resistance is 1000 mm. breathable film according to any one of claims 1-8, characterized in that H is ₂ O or more. 10. An absorbent article comprising a liquid-permeable front material, a liquid-impermeable back material, and an absorber interposed between the front material and the back material, wherein the back material is the back material. 1
An absorbent article comprising the moisture-permeable film according to any one of claims 1 to 9 .