JPH09310259A - Ultrafine fiber nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ultrafine fiber nonwoven fabric, comprising a hydrophilic compound in one component of a conjugated component and ultrafine fibers oriented in the flow direction of the nonwoven fabric and suitable for a disposable diaper, etc., capable of reducing the transverse leakage and excellent in liquid diffusivity, softness, absorbency and comfortableness. SOLUTION: This ultrafine nonwoven fabric comprises ultrafine fibers, having <=1 denier size and obtained by splitting a splittable type conjugated fiber composed of a thermoplastic resin such as a polyolefin-based resin and is prepared by incorporating and adding preferably 0.3-7wt.% one or more hydrophilic components such as surfactants selected from the group consisting of fatty acid glycerides, alkoxylated alkylphenols and polyoxyalkylene esters of fatty acids to at least one conjugated component. The ultrafine fibers are oriented in the flow direction of the nonwoven fabric and the liquid diffusion ratio is 1.1-5. An absorbent article is preferably produced by using the ultrafine fiber nonwoven fabric.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrafine fibrous nonwoven fabric having excellent liquid diffusibility, an absorbent article and a fibrous molded article made of the nonwoven fabric. More specifically, disposable diapers,
Sanitary napkins, absorbent articles such as pads for incontinence, medical hygiene materials, civil engineering materials, etc. can be suitably used, especially ultrafine fiber nonwoven fabric excellent in liquid diffusion required for absorbent articles, and the nonwoven fabric The present invention relates to an absorbent article and a fiber molded product which have excellent absorbency and an effect of preventing leakage when used.

[0002]

BACKGROUND ART A number of proposals aimed at improving the absorbency of body fluids in absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads have been made and improved so far. Most of these improvements were the improvement of absorption amount and absorption rate, prevention of liquid return from the absorber to the surface, prevention of leakage and reduction of stickiness to the body. For example, instead of hydrophilic absorbent paper or pulp that absorbs and retains liquid in a physical fine space, it has been proposed to improve absorption capacity and prevent liquid return by using a superabsorbent polymer as the material of the absorber. ing. According to this proposal, at present, an absorbent body in which pulp and a superabsorbent polymer are used in combination is used in most of the absorbent articles.

However, even these absorbent articles are still insufficient in terms of improvement of absorption amount, prevention of liquid return, and prevention of leakage. That is, a superabsorbent polymer is a type that absorbs and retains a liquid by ionic osmotic pressure, and cannot absorb quickly unless the body fluid gets wet.Therefore, there is a limit to the absorption rate of the body fluid, and it is used in combination with pulp, which has a high absorption rate. I had to use it. However, the combined use of the superabsorbent polymer and pulp locally absorbs and retains body fluids, and therefore many absorbent articles currently in use have not been efficiently utilized as a whole.

In view of such a point, various attempts have been reported to diffuse and absorb body fluid throughout the absorbent body. For example, in JP-A-56-60555, the diffusivity is improved by laminating a diffusive sheet of rayon by a spun bond method on the upper surface or both surfaces of an absorbent sheet made of pulp and a super absorbent polymer. The effect is described. Further, JP-A-6-70953 discloses that a sheet having both liquid permeability and liquid diffusibility can be obtained by mixing bulky hydrophilic fibers and hydrophilic fine fibers in a specific ratio. There is a description. Further, in JP-A-6-38998, there is described a liquid transportation zone having a concave portion having a relatively high fiber density and a heating / pressurizing portion for suppressing liquid permeation, which is obtained by processing a melt blown nonwoven fabric or a spunbonded nonwoven fabric with an embossing roll. There is. However, in these non-woven fabrics, the fiber orientation is random, and when this is used as the surface material of an absorbent article, it cannot be said that the liquid diffusibility in the major axis direction of the absorbent article is sufficient.

Further, Japanese Patent Laid-Open No. 3-234255 discloses that
Although a sheet in which a hydrophilic web and a hydrophobic web are integrated in a layered form is described, when this is used for an absorbent article, the absorption rate and the liquid diffusibility cannot be said to be sufficient. As described above, liquid-diffusing nonwoven fabrics have been proposed by various methods in order to improve the absorption amount of the absorbent article, prevent leakage, and improve the liquid return property, but none of them has been satisfactory.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ultrafine fiber non-woven fabric having excellent liquid diffusibility which can be used for improving absorption and preventing leakage required for absorbent articles and the like. The present invention is to provide absorptive articles and fiber moldings.

[0007]

As a result of intensive studies to solve the above problems, at least one of the composite components of the present invention has been solved.
It was found that the intended purpose can be achieved by using an ultrafine fiber nonwoven fabric obtained by dividing a splittable conjugate fiber containing a hydrophilic compound as a component, and the fibers are mainly oriented in the flow direction of the nonwoven fabric. The present invention has been completed.

The present invention has the following constitution in order to solve the above problems. (1) An ultrafine fiber nonwoven fabric having a fineness of 1 denier or less obtained by dividing a splittable conjugate fiber made of a thermoplastic resin, wherein a hydrophilic compound is contained in at least one component of the composite component, and the ultrafine fiber is a nonwoven fabric. An ultrafine fiber non-woven fabric characterized by being oriented in the flow direction. (2) The ultrafine fiber nonwoven fabric according to item (1), wherein the thermoplastic resin is a polyolefin resin. (3) The ultrafine fiber nonwoven fabric according to the item (1), wherein the ultrafine fibers are long fibers. (4) The ultrafine fiber nonwoven fabric according to the item (1), wherein the ultrafine fibers are short fibers. (5) The liquid diffusion ratio is 1.1 to 5 (1) to
The ultrafine fiber nonwoven fabric according to any one of (4). (6) The hydrophilic compound is at least one surfactant selected from the group of compounds consisting of fatty acid glyceride, alkoxylated alkylphenol, and polyoxyalkylene fatty acid ester, and at least one of the composite components
The ultrafine fiber nonwoven fabric according to any one of (1) to (5) above, which uses splittable conjugate fibers in which 0.3 to 7% by weight is added as a component. (7) The hydrophilic compound is at least one hydrophilic compound selected from the group of compounds consisting of polyethylene glycol, a homopolymer of vinyl alcohol, a copolymer of vinyl alcohol and ethylene, and a polyether block amide copolymer. The extra fine fiber nonwoven fabric according to any one of the above items (1) to (5), which is a resin and uses a splittable conjugate fiber which is kneaded and added to at least one component of the composite component in an amount of 20 to 95% by weight. (8) An absorbent article using the ultrafine fiber nonwoven fabric according to any one of (1) to (7) above. (9) A fiber molded product using the ultrafine fiber nonwoven fabric according to any one of (1) to (7). Hereinafter, the present invention will be described in detail.

As a combination of the composite components constituting the splittable conjugate fiber used in the ultrafine fiber nonwoven fabric of the present invention, a combination of a polyolefin resin and a polyolefin resin, a combination of a polyolefin resin and a polyester resin, or a polyamide resin. And a polyolefin resin. The polyolefin resin is an ethylene homopolymer, a propylene homopolymer,
It is a copolymer of ethylene or propylene with another α-olefin, and a mixture of these polymers. As the α-olefin copolymer, other α mainly composed of propylene
There are binary or terpolymers with olefins. Specific examples of these copolymers include propylene as a main component and a copolymer with ethylene or butene-1 or 4-methylpentene-1. Two of these polyolefin resins have low compatibility with each other
Used in the present invention by selecting one or more kinds of resins or by combining them with a polyester-based resin or a polyamide-based resin and arranging them in a radial shape, a parallel shape or a parallel shape as illustrated in FIGS. A splittable conjugate fiber is obtained.

In the splittable conjugate fiber used in the present invention, a hydrophilic compound is kneaded into at least one component of the composite component. A hydrophilic compound may be kneaded and added to multiple components, but if one component of the composite component remains water-repellent, when a nonwoven fabric is used, the liquid retention amount of the nonwoven fabric can be reduced and liquid diffusion can be achieved. It is preferable because the property is improved. Examples of the hydrophilic compound added to the splittable conjugate fiber include nonionic surfactants such as fatty acid glyceride, alkoxylated alkylphenol, polyoxyalkylene fatty acid ester and fatty acid amide, or ethers such as ethylene glycol and vinyl alcohol. A hydrophilic resin such as a homopolymer, a copolymer of vinyl alcohol and ethylene or propylene, and a polyether block amide copolymer is used. The above surfactants can be used alone or as a mixture. Among them, examples of desirable surfactants evaluated based on the thermal stability during spinning and the ability to impart hydrophilicity include general formula (I) CH ₂ (OR ₁ ) CH (OR ₂ ) CH ₂ (OR ₃ ) (formula In the formula, OR ₁ , OR ₂ and OR _{3 each} independently represent a hydroxy group or a fatty acid ester group, provided that at least one is a fatty acid ester.) General formula (II) R-Ph-O- (CH ₂ CH ₂ O) _n -CH ₂ CH ₂ OH (In the formula, R represents an alkyl group having 1 to 20 carbon atoms, Ph represents a ferl group, and n is an integer of 10 to 55.) General formula (III) R '- (CH 2 CH 2 O) n -CH 2 CH 2 OH ( wherein, R'. represents a fatty acid ester group of saturated or unsaturated, n is an integer of 10 to 55) is Can be mentioned.
The kneading addition amount of the surfactant necessary for achieving the object of the present invention is 0.3 to 7% by weight based on the added components.
Is preferred. Particularly, 3 to 6% by weight is more preferable.
When the amount of the surfactant added is less than 0.3% by weight, it is difficult to obtain sufficient hydrophilicity, and when it exceeds 7% by weight, the spinnability in the melt spinning step may be poor.

The above-mentioned hydrophilic resins used as the hydrophilic compound in the present invention can be used alone or as a mixture. Among them, examples of desirable hydrophilic resins evaluated based on the thermal stability during spinning and the ability to impart hydrophilicity include thermoplastic polyethylene glycol resin (trade name: Aquacork; manufactured by Sumitomo Seika Co., Ltd.) and ethylene vinyl alcohol Polymer (trade name Eval; Kuraray Co., Ltd.)
Manufactured), polyether block amide copolymer (trade name P
EBAX; manufactured by ATOCHEM) and the like. The kneading addition amount of the hydrophilic resin necessary for achieving the object of the present invention is preferably 20 to 95% by weight with respect to the added components. When the addition amount of the hydrophilic resin is less than 20% by weight,
It does not show sufficient liquid diffusivity. On the other hand, if it exceeds 95% by weight, the affinity between the composite component to which the hydrophilic resin is added and the composite component to which the hydrophilic resin is not added is lowered, and the splitting in the spinning process progresses, resulting in poor spinnability. Cause.

The ratio of the composite components can be 3/7 to 7/3, but is more preferably 1/1. In the splittable conjugate fiber, an additive that imparts other functionality to the application, such as a colorant, a flame retardant, or a stabilizer, is selected, and appropriately mixed within a range that does not impair the object of the present invention. can do.

In order to obtain the splittable conjugate fiber used in the present invention, a known splittable conjugate fiber is prepared from a thermoplastic resin in which a predetermined amount of a surfactant is kneaded in advance, or a mixture of a thermoplastic resin and a hydrophilic resin. Spinning is carried out by the above spinning method, and after stretching, mechanical crimping is applied if desired. It is also a common method to attach an oil agent by a roller method or the like in the spinning and drawing steps. The single-filament fineness of the splittable conjugate fiber used for producing the ultrafine fiber nonwoven fabric of the present invention is not particularly limited, but in order to obtain fibers with good spinnability and fineness after splitting, the single-filament fineness is 30 denier or less, preferably 0.5 to 10 denier. The splittable conjugate fiber preferably has 10 to 17 crimps / inch. When the number of crimps is less than 10 pieces / inch, the entanglement between fibers is weak, and when the number of crimps is more than 17 pieces / inch, the entanglement between fibers becomes too strong, which makes it difficult to produce a uniform web. It is not preferable. The obtained splittable conjugate fiber is made into a web in the form of a long fiber or a short fiber, and by subjecting this to high-pressure water flow treatment, entanglement occurs between the fibers and the fibers are split. The fineness of the ultrafine fibers obtained after the division is preferably 1 denier or less, preferably 0.01 to 1 denier, and particularly 0.01 to 0.2 denier because the liquid diffusion property of the nonwoven fabric is excellent. The division rate for displaying the degree of division is 10 to 100%,
More preferably, it is preferably divided into 50 to 100%.

When the splittable conjugate fiber is a long fiber, a long fiber web obtained by a spunbond method, a melt blow method or the like can be used, but in order to obtain a non-woven fabric in which the fibers are better oriented in the flow direction of the non-woven fabric, Most preferably it is used in the form of a tow web. In the case of a crimped long fiber tow, the tow web is separated by a separating guide or the like. When the splittable conjugate fiber is a short fiber, it can be passed through a card or a random webber and used as a fibrous web such as a random web, a parallel web or a crosslap web, but the parallel web in which the fibers are more oriented is preferable. The fiber length of the splittable conjugate fiber is required to be 20 mm or more, preferably 30 to 150 mm in order to orient the fibers in the flow direction of the nonwoven fabric, and more preferably 50 to 130 mm in consideration of the card passing property. is there.

In both cases of long fibers and short fibers, the basis weight of the web is preferably about 10 to ²⁰⁰ g / m ² . When the basis weight of the web is less than 10 g / m ² , the degree of contact between the fibers is small, the formation unevenness is caused by the high-pressure water stream treatment, and the obtained nonwoven fabric is difficult to exhibit sufficient liquid diffusibility.
Further, when the basis weight is more than 200 g / m ² , it becomes difficult for a high-pressure water stream to pass through the web, and the fibers are likely to be insufficiently divided. In the web, to the extent that the effects of the present invention are not impaired,
If necessary, other fibers can be mixed and used.
Other fibers include synthetic fibers such as polyamide, polyester, polyolefin and acrylic, natural fibers such as cotton, wool and hemp, regenerated fibers such as rayon, cupra and acetate, and semi-synthetic fibers. Also, the fibers to be mixed are
Either short fibers or long fibers may be used.

This web is placed on a support such as a wire mesh of about 50 to 200 mesh, and a high-pressure water stream is jetted from above to cause fiber division (fine fiberization) and entanglement. The nozzle diameter for injecting a high-pressure water stream is 0. 0 in order to efficiently split and entangle the fibers and keep the formation of the nonwoven fabric good.
The range of 01 to 0.5 mm, the nozzle interval is 0.1 to 1.
5 mm is preferable. Water pressure is 10 ~ 250kg / cm ²
It is preferable to use in the range of. Processing speed is 5-20
It can be used in the range of m / min. If the water pressure is low, sufficient ultrafine fibers and entanglement cannot be obtained. On the other hand, if the water pressure is higher than necessary, the formation of the nonwoven fabric is disturbed or damaged, which is not preferable. By injecting the high-pressure water stream onto the web in multiple stages while sequentially increasing the water pressure, the formation can be sufficiently entangled without disturbing the formation. In addition, by decreasing the nozzle diameter and / or the nozzle interval in sequence, or by inserting a wire mesh of 40 to 100 mesh between the nozzle and the web in the latter stage to scatter the high-pressure water stream, or by lowering the water pressure in the last stage, It is possible to improve the combination.

The high-pressure water stream can be sprayed not only on one side of the web but also on both sides. Alternatively, a web in which fibers are entangled by jetting a high-pressure water stream is laminated, and a high-pressure water stream may be jetted onto the webs to generate entanglement between the webs. Thus, after removing water from the web subjected to the high-pressure water stream treatment by a method such as suction or pressing, it is dried using an air dryer, an air-through dryer, a suction drum dryer, etc., whereby the ultrafine fiber nonwoven fabric of the present invention is obtained. can get.

The diffusion of the liquid in the ultrafine fiber non-woven fabric is such that the liquid moves along the fibers of the non-woven fabric mainly due to the capillary phenomenon, and the distance that the liquid vertically moves in the non-woven fabric changes according to the capillary pressure. . The capillary pressure of a cylindrical capillary tube is expressed by the following equation. Pc = 2γ cos θ / r where Pc is the capillary pressure, γ is the surface tension of the liquid, θ is the contact angle between the liquid and the fiber, and r is the capillary radius. For the same type of liquid, the capillary pressure increases with the contact angle between the liquid and the fiber, and increases with decreasing capillary radius. Therefore, in order to improve the liquid diffusibility, it is preferable that the fiber surface is hydrophilic, the interfiber distance is small, and the fibers are oriented in a fixed direction. For example, the distance between the fibers can be further reduced by subjecting the nonwoven fabric obtained by the entanglement processing with a high-pressure water stream to thermal calendering with an embossing roll, a flat roll, or the like.
Further, by narrowing the distance between fibers, it is possible to suppress the passage of body fluid locally and diffuse the liquid in a wide range. However, if the distance between the fibers is made too small, the liquid diffusibility is improved, but when used in an absorbent article, the liquid permeability is deteriorated, and therefore it is necessary to balance the liquid diffusibility.

Here, the liquid diffusion ratio of the ultrafine fiber nonwoven fabric will be described. The liquid diffusion ratio is expressed as the ratio of the maximum length in the length / width in which the liquid is diffused, when the orientation direction of the fibers in the nonwoven fabric is the lengthwise direction. For example, when 0.9 wt% physiological saline is used, the liquid diffusion ratio is preferably 1.1 or more, more preferably 1.5 or more. If the liquid diffusion ratio is less than 1.1, it may cause side leakage when used in an absorbent article. In order to increase the liquid diffusion ratio, it is effective to orient the fibers in the non-woven fabric in the longitudinal direction of the absorbent article, and in particular, by making the non-woven fabric from the shape of a tow web, it is possible to obtain the most effective longitudinal diffusivity. Can be raised.

Next, an absorbent article using the ultrafine fiber nonwoven fabric of the present invention as a material will be described. The ultrafine fiber nonwoven fabric of the present invention may be used alone, or may be used in the state of being laminated or integrated with other nonwoven fabric, knitted fabric or mesh-like material, film, molded article and the like. The absorbent article of the present invention comprises a top sheet, a back sheet, and at least one or more absorbers, and the ultrafine fiber nonwoven fabric of the present invention is placed in intimate contact with the absorber. Specifically, the ultrafine fiber nonwoven fabric is between the topsheet and the absorber,
Alternatively, the liquid is diffused by aligning the orientation direction of the fibers of the ultrafine fiber nonwoven fabric with the long axis direction of the absorbent article both between the top sheet and the absorbent body and between the absorbent body and the back sheet so as to surround the absorbent body. It is arranged as an absorption layer.

The topsheet may be a topsheet known in the art, such as polypropylene, polyethylene,
Although a thin nonwoven fabric made of polyester, cellulose, or rayon can be used, a nonwoven fabric made of a short fiber or long fiber web such as polypropylene or polyethylene is particularly preferable.

The backsheet may be any backsheet known in the art, such as polyethylene, polypropylene,
Alternatively, a liquid-impermeable film made of polyester, a non-woven fabric, a knitted fabric, or a composite thereof can be used.

As the absorbent body, an absorbent body which is a combination of pulp and a superabsorbent polymer known in the art can be used.
As the high-absorbent polymer, those having a saturated absorption amount of 25 g / g or more are preferable, and fibrous or particulate ones can be used. When the polymer absorber is in the form of particles, it is desirable that the particle diameter is 0.1 to 0.8 mm. Specifically, a starch-acrylic acid (salt) graft polymer, a saponified product of a starch-acrylonitrile copolymer, a crosslinked product of sodium carboxymethyl cellulose, an acrylic acid (salt) polymer and the like can be preferably exemplified. These polymer absorbers may be a single kind or a mixture of plural kinds. The compounding ratio of the superabsorbent polymer in the absorber is usually in the range of 20 to 85% by weight based on the total weight of the absorber. Further, it is also preferable to mix the heat-fusible composite fiber with pulp in the absorbent body. The mixing ratio of the heat-fusible composite fiber is preferably 0 to 60% by weight with respect to the absorber. The reason for mixing the heat-fusible conjugate fiber is that the heat-fusible conjugate fiber is bonded to the entire absorber by heat-treating the heat-fusible conjugate fiber, and the deformation of the absorbent article due to the movement of the user is caused. Morphological stability increases,
This is because it is possible to prevent a decrease in the body fluid absorption performance of the absorber.

Further, by interposing a highly permeable hydrophilic bulky fiber nonwoven fabric between the topsheet and the ultrafine fiber nonwoven fabric constituting the absorbent article described above, the body fluid that has passed through the topsheet can be quickly passed through the ultrafine fiber nonwoven fabric. Can be widely diffused to be absorbed in the absorbent body, and the liquid return of the absorbed body fluid can be significantly suppressed, and an absorbent article which can be comfortably used by the user can be obtained. The fiber nonwoven fabric can be used more effectively.

As the hydrophilic bulky fiber nonwoven fabric, a hydrophilic property is imparted by coating or kneading a surfactant or a hydrophilic resin, and the single yarn fineness is 0.5 to 10 denier, preferably 1.5 to 4 Denier with 10 crimps /
It is composed of olefin-based composite fibers or polyester-based composite fibers having spiral crimps of at least 20 inches / inch, more preferably at least 20 pieces / inch, and has a basis weight of 15 to 80.
g / m ^2, preferably nonwoven 20 to 50 g / m ² can be used. The composite fiber having a spiral crimp is a fiber obtained by composite spinning of two or more kinds of polymers having different thermal properties into a sheath core type, an eccentric sheath core type, a side-by-side type, etc., and is obtained by a conventionally known spinning drawing method. After being made into a web by the card or air ray method, it is heat-treated to give a nonwoven fabric. When the composite fiber itself does not have the heat-sealing performance, the binder fiber may be mixed and heat treated.

By using the ultrafine fiber nonwoven fabric of the present invention as a liquid diffusion / absorption layer in absorbent articles such as diapers and sanitary napkins, it is possible to widely diffuse body fluid in the fiber orientation direction of the ultrafine fiber nonwoven fabric. Therefore, the body fluid can be distributed and absorbed in a wide range of the absorber. Therefore, it is possible to reduce the amount of the absorbent body used in the absorbent article, reduce the thickness of the absorbent article, and prevent lateral leakage by diffusing body fluid in the long axis direction of the absorbent article. You can

As fiber moldings using the ultrafine fiber nonwoven fabric of the present invention other than the above-mentioned absorbent articles, sweat absorbing pads, wristbands, surgical sponges, bandages, footwear insoles, wiping cloths, cleaning cloths, plant cultivation An example is a water conduit.
Also, in the field of geotextiles, the liquid-diffusible fiber molding is useful, and the nonwoven fabric of the present invention can be used.

[0028]

EXAMPLES The effects of the present invention will be described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The definitions of terms and methods for measuring physical properties in Examples and Comparative Examples are as follows. (Unit weight): A value obtained by dividing the sample weight by the area and expressing it by the weight (g) per 1 m ^{2 of} the nonwoven fabric. (Division rate): A fiber bundle is embedded in wax and sliced at right angles to the fiber axis with a microtome to obtain a sample piece.
Observing this with a microscope, image processing of the cross-sectional image of the fiber,
The total cross-sectional area (A) of the divided ultrafine fibers and the total cross-sectional area (B) of the undivided splittable conjugate fibers were measured and calculated by the following formula. Split rate% = {A / (A + B)} × 100 (permeation rate): A cylinder having an inner diameter of 30 mm and a weight of 700 g is placed on the top sheet of the sample absorptive article, and the concentration is 0.9% by weight therein. 200 ml of the physiological saline solution was charged all at once, and the time from the charging to the absorption by the sample was measured and used as the permeation rate. (Liquid return :) After measuring the permeation rate, leave the cylinder in place 3
Let stand for a minute and filter paper (ADVANTE
C, No. 2) was placed, and when a load of 35 g / cm ² was applied for 3 minutes, the weight of physiological saline absorbed by the filter paper was expressed as the liquid reverting property.

(Liquid diffusion area): A cylinder having an inner diameter of 30 mm and a weight of 50 g was placed on the top sheet of the sample absorbent article, and 50 ml of a physiological saline solution having a concentration of 0.9% by weight was placed therein for 30 seconds. inject. After the physiological saline solution is completely absorbed, the sample is disassembled and the wetted area on the surface of the absorbent body is measured. Five samples were measured, and the average value was used as the liquid diffusion area. (Liquid diffusion ratio): Using a sample whose liquid diffusion area was measured, the maximum in the long axis direction (vertical direction) of the absorbent article and in the direction (horizontal direction) perpendicular to the wetted portion on the absorber The spread width is measured and the liquid diffusion ratio is calculated using the following formula. Five samples were measured, and the average value was used as a representative value. Liquid diffusion ratio = maximum spread width in vertical direction (mm) / maximum spread width in horizontal direction (mm)

(Top sheet): polyethylene / polypropylene composite fiber having mechanical crimp (manufactured by Chisso Corporation:
Dry heat bonded non-woven fabric using product name ES fiber
Density under load of 3g / m ² , 20gf / cm ² is 0.04g
/ Cm ³ ) was used as the top sheet. (Absorbent body and back sheet): The absorbent body and back sheet were used by disassembling a commercially available diaper for children. (Sample absorbent article): a lower layer of the absorbent body, in which the ultrafine fiber nonwoven fabric of the present invention is interposed between the top sheet and the absorbent body such that the orientation direction of the fibers coincides with the long axis direction of the absorbent article. A backsheet was placed on the sample to make a sample absorbent article.

Example 1 A polypropylene homopolymer having an MFR of 30 g / 10 min (230 ° C.) was used as a first component, and MI of 25 g / 10 min (19
A high-density polyethylene (0 ° C.) in which a nonionic surfactant (ICI, trade name: Atomer 685) consisting of an ethoxylated alkylphenol and a mixed glyceride was kneaded and added to the high-density polyethylene at 1% by weight
As the component, the split type composite fiber spinning die having the split structure shown in FIG. 4 was used, and the volume ratio of the first component to the second component was 5
A split type conjugate fiber of 0/50 and 12 denier single yarn was spun. This unstretched yarn is stretched 6.0 times at 100 ° C. and crimped with a crimper to 17 crimps / inch, and a split type with a single denier of 2.1 denier and a total denier of 100,000 denier The composite fiber tow was collected in a tow can. This tow is made into a tow web with a fiber separation guide, and 8
Placed on a 0 mesh plain weave net, nozzle diameter 0.1m
m, pitch 1mm nozzle plate, water pressure 20kg
/ Cm ² and then treated 3 times with high water pressure of 80 kg / cm ² , then the entangled tow web was inverted and treated 3 times with high water pressure of 80 kg / cm ² from the same nozzle plate. After drying, an ultrafine fiber nonwoven fabric having a basis weight of 45 g / m ² , a division rate of 90%, and a fineness of 0.1 denier after division was obtained. An absorbent article was produced using this.

Example 2 A polypropylene homopolymer having an MFR of 30 g / 10 min (230 ° C.) was used as a first component and MI 25 g / 10 min (19
(0 ° C.) high-density polyethylene with a surfactant (I containing ethoxylated alkylphenol and mixed glyceride)
A unit weight of 48 g / m ² was obtained in the same manner as in Example 1 except that 6 wt% of Attomer 685 (trade name, manufactured by CI), which was kneaded with high-density polyethylene, was used as the second component.
An ultrafine fiber nonwoven fabric having a division ratio of 91% and a fineness of 0.1 denier after division was obtained. An absorbent article was produced using this.

Example 3 A polypropylene homopolymer having an MFR of 30 g / 10 min (230 ° C.) was used as a first component, and MI of 25 g / 10 min (19
High-density polyethylene (0 ° C) with a surfactant (IC) containing ethoxylated alkylphenol and mixed chryslide
Atm 685) (trade name, manufactured by I. Co., Ltd.) was added to a high-density polyethylene by 6% by weight as a second component, and a split-type composite fiber spinning spinneret having a structure shown in FIG. 4 was used. A splittable conjugate fiber having a volume ratio of the first component and the second component of 50/50 and a single denier of 5 denier was spun. This unstretched yarn was drawn 5.5 times at 100 ° C. and crimped with a crimper to 17 crimps / inch, and a split type composite with a single yarn denier of 1.0 denier and a total denier of 100,000 denier. It was collected in a tow can as fiber tow. This tow was made into a tow web with a fiber-splitting guide, and in the same manner as in Example 1, an ultrafine fiber nonwoven fabric having a basis weight of 44 g / m ² , a division ratio of 96%, and a fineness after division of 0.06 denier was obtained. An absorbent article was produced using this.

Example 4 A polypropylene homopolymer having an MFR of 30 g / 10 min (230 ° C.) was used as a first component and MI of 25 g / 10 min (19).
High-density polyethylene (0 ° C) with a surfactant (IC) containing ethoxylated alkylphenol and mixed chryslide
I, manufactured by I, trade name Atomer 685) was added to high-density polyethylene by 6% by weight as a second component, and the split type composite fiber spinning die of FIG.
The volume ratio of the first component to the second component is 50/50, single yarn denier 3
Denier splittable conjugate fibers were spun. This unstretched yarn was stretched 5.0 times at 100 ° C. and crimped with a crimper to 17
The piles / inch were subjected to a crimping process, and collected in a tow can as a split type composite fiber tow having a single yarn denier of 0.6 denier and a total denier of 100,000 denier. This tow is made into a tow web by a fiber-splitting guide, and in the same manner as in Example 1, a basis weight 4
An ultrafine fiber nonwoven fabric having ² g / m ² , a division rate of 94%, and a fineness after division of 0.03 denier was obtained. An absorbent article was produced using this.

Example 5 A polypropylene homopolymer having an MFR of 30 g / 10 minutes (230 ° C.) was used as a first component, and MI 25 g / 10 minutes (19
Thermoplastic polyethylene glycol resin (trade name: Aquacork: Sumitomo Seika Co., Ltd.)
Made by mixing 40% by weight with high density polyethylene as the second component and using the splitting type composite fiber spinning die having the structure shown in FIG. 4, the volume of the first component and the second component Splittable conjugate fibers having a 50/50 ratio and a single denier of 6 denier were spun. This unstretched yarn was stretched 3.0 times at 100 ° C. and crimped with a crimper to 17 crimps / inch, and a split type composite with a single yarn denier of 1.9 denier and a total denier of 100,000 denier. It was collected in a tow can as fiber tow. This tow was made into a tow web by a fiber-splitting guide, and in the same manner as in Example 1, an ultrafine fiber nonwoven fabric having a basis weight of 40 g / m ² , a division ratio of 85%, and a fineness after division of 0.1 denier was obtained. An absorbent article was produced using this.

Example 6 A polypropylene homopolymer having an MFR of 30 g / 10 minutes (230 ° C.) was used as a first component and MI of 25 g / 10 minutes (19).
0 ° C) high density polyethylene, ethylene copolymerization ratio 4
A resin obtained by mixing 80 mol% of ethylene vinyl alcohol copolymer (trade name: Eval: manufactured by Kuraray Co., Ltd.) of 4 mol% and MFR 5.5 g / 10 min (190 ° C.) with high density polyethylene was used as a second component. Except for the above, in the same manner as in Example 1, an ultrafine fiber nonwoven fabric having a basis weight of 52 g / m ² , a division ratio of 88%, and a fineness after division of 0.1 denier was obtained. An absorbent article was produced using this.

Example 7 A polypropylene homopolymer having an MFR of 30 g / 10 min (230 ° C.) was used as a first component and MI of 25 g / 10 min (19).
(0 ° C.) high density polyethylene and a polyether block amide copolymer (trade name PEBAX: manufactured by ATOCHEM) in an amount of 80 wt% were mixed in the same manner as in Example 1 except that a resin was used as the second component. An ultrafine fibrous nonwoven fabric having 55 g / m ² , division rate of 85%, and fineness of 0.1 denier after division was obtained. An absorbent article was produced using this.

Example 8 MFR 30 g / 10 min (230 ° C.) polypropylene homopolymer as the first component, MI 25 g / 10 min (19
(0 ° C.) high density polyethylene, polyvinyl alcohol having a degree of polymerization of 500 and a saponification degree of 88% was mixed with the high density polyethylene in an amount of 20% by weight. Thus, an ultrafine fiber nonwoven fabric having a basis weight of 49 g / m ² , a division rate of 81% and a fineness of 0.1 denier after division was obtained. An absorbent article was produced using this.

Example 9 The ultrafine long fiber nonwoven fabric having a basis weight of 48 g / m ² prepared in Example 2 was calendered at 125 ° C. and a flat roll speed of 6 m / min, and an absorbent article was produced using this calendered nonwoven fabric. did.

Example 10 A polypropylene homopolymer having an MFR of 30 g / 10 min (230 ° C.) was used as a first component and MI of 25 g / 10 min (19).
High-density polyethylene (0 ° C) with a surfactant (IC
I, product name Atomer 685) kneaded and added at 6% by weight as a second component, and using the splitting type composite fiber spinning die having the structure shown in FIG. 4, the first component and the second component A splittable conjugate fiber having a volume ratio of 50/50 and a single yarn denier of 12 denier was spun. This unstretched yarn was stretched 6.0 times at 100 ° C. and crimped with a crimper to a crimp number of 17 ridges / inch. Single yarn denier was 2 denier, fiber length was 76 mm and strength was 3.0 g / d. A staple fiber having an elongation of 38% was obtained. The obtained staple fiber,
A card was used as a parallel web, which was subjected to a high-pressure water stream treatment under the same conditions as in Example 1 to have a basis weight of 49 g / m ² and a division rate of 89
%, A fine fiber nonwoven fabric having a fineness after division of 0.1 denier was obtained. An absorbent article was produced using this.

Example 11 A bulky dry heat-bonded non-woven fabric using a polyethylene / polypropylene composite fiber having spiral-shaped crimp (manufactured by Chisso Corporation: trade name ES fiber) (unit weight: 30 g / m ² ,
Density under load of 20 gf / cm ² is 0.02 g / cm ³ )
Was inserted between the top sheet of the absorbent article prepared in Example 1 and the ultrafine fiber nonwoven fabric to prepare an absorbent article.

Comparative Example 1 An absorbent article was produced in which an ultrafine long-fiber nonwoven fabric was not inserted between the topsheet and the absorber.

Comparative Example 2 MFR 30 g / 10 min (230 ° C.) polypropylene homopolymer as the first component, MI 25 g / 10 min (19
High-density polyethylene (0 ° C) with a surfactant (IC
An ultrafine long-fiber nonwoven fabric was obtained in the same manner as in Example 1 except that 0.1% by weight of Atomer 685) manufactured by I Co., Ltd. was used as the second component. However, even if physiological saline was dropped onto this non-woven fabric, it did not absorb and diffuse the liquid,
No absorbent article was made.

Comparative Example 3 A polypropylene homopolymer having an MFR of 30 g / 10 min (230 ° C.) was used as a first component and MI of 25 g / 10 min (19).
High-density polyethylene (0 ° C) with a surfactant (IC
9% by weight of Atomer 685) manufactured by I Co., Ltd. was used as the second component, and spinning was performed using the splitting type composite fiber spinning die having the structure shown in FIG. 1, but the spinnability was stable. No
No sample was obtained.

Comparative Example 4 MFR 30 g / 10 min (230 ° C.) polypropylene homopolymer as the first component, MI 25 g / 10 min (19
Thermoplastic polyethylene glycol resin (trade name: Aquacork: Sumitomo Seika Co., Ltd.)
An ultrafine long fiber non-woven fabric was obtained in the same manner as in Example 1 except that a resin prepared by mixing 10% by weight of the product) was used as the second component. However, even if physiological saline was dropped onto this non-woven fabric, the liquid did not absorb and diffuse, so no absorbent article was produced.

Comparative Example 5 The tow web of Example 2 had a basis weight of 50 g / m ² and 50
An absorbent article was produced in the same manner as in Example 2 except that the nonwoven fabric was processed at a high water pressure of kg / cm ² . Example 1
10 and Comparative Examples 1 to 5 are shown in Table 1.

[0047]

[Table 1]

As is clear from Table 1, the product of the present invention has the same or superior permeation rate and liquid return property as compared with Comparative Example 1, and the liquid diffusion area and liquid diffusion ratio both show very good results. There is. That is, the absorbent article using the ultrafine fiber nonwoven fabric of the present invention is excellent in liquid diffusion area and liquid diffusion ratio while maintaining the permeation rate and the liquid return property of the conventional performance, and therefore is thin and extremely absorbable. Many, it is possible to provide a comfortable absorbent article for the user.

Example 12 A polypropylene homopolymer having an MFR of 30 g / 10 min (230 ° C.) was used as a first component and MI of 25 g / 10 min (19).
(0 ° C.) high-density polyethylene with 6% by weight of ethoxylated alkylphenol and mixed glyceride (ICI, trade name Atomer 685) added as the second component, a split-type composite having the structure shown in FIG. Using the fiber spinning die, the volume ratio of the first component and the second component is 50/5.
A split type conjugate fiber having 0 and 12 denier per yarn was spun. The undrawn yarn was drawn 6.0 times at 100 ° C.,
Crimper is used to crimp the 17 crimps / inch,
It was collected in a tow can as a split type composite fiber tow having a single yarn denier of 2 denier and a total denier of 50,000 denier.
This splittable composite fiber tow was made into a tow web with a fiber-splitting guide, and in the same manner as in Example 1, an ultrafine fiber nonwoven fabric having a basis weight of 50 g / m ² , a splitting rate of 91%, and a fineness after splitting of 0.1 denier was obtained. This non-woven fabric was wound into a rod shape having a diameter of 1 cm using a general-purpose plug machine, and heat-treated with a hot air dryer at 130 ° C. to prepare a water guiding rod. A water tank containing an aqueous solution in which the fertilizer component was dissolved was placed next to the flowerpot, one end of this water guiding rod was inserted into the soil in the flowerpot, and the other end was immersed in the water tank. By doing so, water is supplied from the aquarium to the flowerpot by the capillary phenomenon of the fibers forming the water guiding rod,
The plant did not wither or die even if left alone for 1 month.

[0050]

INDUSTRIAL APPLICABILITY The ultrafine fiber nonwoven fabric of the present invention is excellent in liquid diffusibility in the fiber orientation direction because the fibers are oriented in one direction. The ultrafine fiber nonwoven fabric of the present invention is flexible,
In the absorbent article of the present invention using the nonwoven fabric, the body fluid is quickly diffused and distributed in the longitudinal direction by the ultrafine fiber nonwoven fabric, and the absorption efficiency of the superabsorbent polymer can be maximized. Therefore, it is possible to make the absorbent article relatively thin, reduce the risk of sideways leakage, and provide the absorbent article that can be comfortably used by the user.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a splittable conjugate fiber that can be used in the present invention.

FIG. 2 is a cross-sectional view of a splittable conjugate fiber that can be used in the present invention.

FIG. 3 is a cross-sectional view of a splittable conjugate fiber that can be used in the present invention.

FIG. 4 is a cross-sectional view of a splittable conjugate fiber that can be used in the present invention.

FIG. 5 is a cross-sectional view of a splittable conjugate fiber that can be used in the present invention.

[Explanation of symbols]

 1 First component 2 Second component

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Claims (9)

[Claims] 1. A non-woven fabric made of ultrafine fibers having a fineness of 1 denier or less obtained by dividing a splittable conjugate fiber made of a thermoplastic resin, wherein at least one component of the composite component contains a hydrophilic compound. Fibers are oriented in the flow direction of the non-woven fabric, which is a very fine fibrous non-woven fabric. 2. The ultrafine fiber nonwoven fabric according to claim 1, wherein the thermoplastic resin is a polyolefin resin. 3. The ultrafine fiber nonwoven fabric according to claim 1, wherein the ultrafine fibers are long fibers. 4. The ultrafine fiber nonwoven fabric according to claim 1, wherein the ultrafine fibers are short fibers. 5. The ultrafine fiber nonwoven fabric having excellent liquid diffusibility according to claim 1, wherein the liquid diffusion ratio is 1.1 to 5. 6. The hydrophilic compound is at least one surfactant selected from the group consisting of fatty acid glyceride, alkoxylated alkylphenol, and polyoxyalkylene fatty acid ester, and 0 is contained in at least one component of the splittable conjugate fiber. The ultrafine fiber nonwoven fabric according to any one of claims 1 to 5, which is kneaded and added in an amount of 3 to 7% by weight. 7. The hydrophilic compound is at least one hydrophilic selected from the group consisting of polyethylene glycol, a homopolymer of vinyl alcohol, a copolymer of vinyl alcohol and ethylene, and a polyether block amide copolymer. The ultrafine fiber nonwoven fabric according to any one of claims 1 to 5, which is a resin and is mixed in at least one component of the splittable conjugate fiber in an amount of 20 to 95% by weight. 8. An absorbent article using the ultrafine fiber nonwoven fabric according to claim 1. 9. A fiber molded product using the ultrafine fiber nonwoven fabric according to any one of claims 1 to 7.