JP2000170076A - Hydrophilic nonwoven fabric and absorbing article using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hydrophilic nonwoven fabric having good liquid permeating property and durability of hydrophilicity and suitable for liquid permeating surface sheets for absorbing articles by preparing a hydrophilizing agent containing an alkylphosphate salt and a specific alkylglycine derivative and applying the hydrophilizing agent to a nonwoven fabric. SOLUTION: An alkylphosphate salt in an amount of 50-80 wt.% is compounded with 10-30 wt.% trialkylglycine derivative and 5-20 wt.% (poly) alkylpolyalkyleneamide dialkylglycine to provide a hydrophilizing agent having 50-70 deg. contact angle with a thermoplastic resin film measured in 1% aqueous solution. This hydrophilic nonwoven fabric is obtained by applying 0.1-2.0% of the hydrophilizing agent to a nonwoven fabric. The hydrophilic nonwoven fabric is used as a liquid-permeating surface sheet and a liquid-impermeable rear sheet is laminated through an absorber to the surface sheet to provide the objective absorbing article.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrophilic nonwoven fabric suitable for a topsheet of absorbent articles such as disposable diapers and sanitary articles, and an absorbent article using the hydrophilic nonwoven fabric as a topsheet. The present invention relates to an absorbent article using a surface sheet having improved properties and improved skin irritation to a wearer.

[0002]

2. Description of the Related Art In general, absorbent articles such as disposable diapers and sanitary articles are made of an absorbent material such as cotton-like pulp or a highly absorbent polymer material between a liquid-permeable top sheet and a liquid-impermeable back sheet. The body is arranged. Urine and body fluids are absorbed by the absorber through the topsheet. At this time, in order to avoid discomfort, the speed at which urine or bodily fluid is completely absorbed (hereinafter, referred to as absorption speed) is high, and urine or bodily fluid returns from the absorber to the surface (hereinafter, referred to as "return amount"). ) Must be small. In addition, the nonwoven fabric which is a surface sheet is a portion that directly touches the skin, and it is necessary that the nonwoven fabric has a good touch for practical use and hygiene, and that there is no skin irritation as required performance. Has become.

As a surface sheet for absorbent articles such as disposable diapers and sanitary articles, a nonwoven fabric made of hydrophobic fibers such as polyolefin resin or polyester resin is widely used. Various attempts have been made to improve. As a method for improving the hydrophilicity of a fiber product containing a hydrophobic polymer, there are (a) a method of applying a hydrophilic agent to the surface of the fiber product,
(B) a method in which a hydrophilic agent is graft-polymerized on the surface of a textile, (c) a method in which the textile is treated with a chemical solution or low-temperature plasma to form a hydrophilic group on the surface of the textile, or (d) a hydrophilic agent. A method of adding it to a polymer is known.

[0004] For example, as a method (a), (a) a porous film-like material made of polypropylene with an anionic surfactant containing at least one base such as a sulfate base, a phosphate base, and a sulfonate base; (B) a method of treating a microporous hydrophobic membrane made of polypropylene or the like with an organic solvent solution of a fatty acid monoester of sorbitan (Japanese Patent Application Laid-Open No. Sho.
No. 9-501049), and (c) a method of coating a polyolefin-based fiber with a polyether-modified aminopolysiloxane (JP-A-61-15192). However, in any of the methods, when the hydrophilizing agent is repeatedly contacted with water such as urine or body fluid, the properties (hereinafter, referred to as durability) that do not flow out of the fiber surface and remain are poor, and furthermore, heat treatment is performed due to heat fusion. There is a problem that the later hydrophilicity is reduced.

Further, (d) a method of coating a fiber with a polyoxyalkylene-modified silicone and a nonionic surfactant (JP-A-63-303184, JP-A-2-806)
No. 72), there is a problem that the entanglement and thermal bonding between the fibers are hindered and the cost is high. U.S. Pat. No. 4,943,612 states that a nitrogen compound such as alkylamino acrylate or betaine ester and a copolymer latex such as glycidyl acrylate have good water resistance and film forming properties. Also, US Pat.
No. 0 describes a method of reacting a polyurethaneurea polyamine with epichlorohydrin by using an amphoteric agent during the reaction generation and applying the same to a nonwoven fabric to obtain an effect of improving texture and surface coating performance. But,
Both of the inventions have a problem that the film of the polymer latex is easily peeled off when the nonwoven fabric for napkins and diapers is rubbed, and the skin is irritated.

Further, the methods (b) and (c) have problems that mass production is difficult, a special device is required, and hydrophilicity is not sufficient. Further, in the method (d), if a hydrophilic agent is added to the polymer until the hydrophilic performance is exhibited, there are problems such as a decrease in productivity and a lack of stability against heat or light. It has not been.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the surface sheet of the conventional absorbent article, and to provide not only a high absorption rate and a small amount of reversion, but also hydrophilicity and durability. It is an object of the present invention to provide a hydrophilic nonwoven fabric for an absorbent article which is excellent in skin irritation and has no skin irritation, and an absorbent article using the same.

[0008]

A first aspect of the present invention is a nonwoven fabric comprising a thermoplastic resin and a hydrophilic agent having a contact angle with a thermoplastic resin film of 50 to 70 degrees when measured with a 1% by weight aqueous solution. In a hydrophilic nonwoven fabric coated with 0.1 to 2.0% by weight of the above, the hydrophilicizing agent contains 50 to 80% by weight of an alkyl phosphate salt, 10 to 30% by weight of a trialkylglycine derivative and (poly) ) Alkylpolyalkyleneamide dialkylglycine derivative
It relates to a hydrophilic nonwoven fabric characterized by containing 20% by weight.

A second aspect of the present invention is an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber disposed between the two sheets. An absorbent article formed of the hydrophilic nonwoven fabric according to the first aspect.

In the present invention, the ratio of the application amount of the hydrophilic agent on the skin contact surface side of the topsheet to the application amount on the opposite surface side is 100 when the skin contact surface side is 100. The present invention relates to the absorbent article according to the second aspect, which is 10 to 90.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The hydrophilic nonwoven fabric of the present invention comprises a hydrophilic agent made of a specific compound having a contact angle of 50 to 70 degrees with a film made of a thermoplastic resin as measured with a 1% by weight solution. And 0.1 to 2.0% by weight of a non-woven fabric made of a thermoplastic resin. The hydrophilic nonwoven fabric obtained by using such a hydrophilic agent has good liquid permeability because the hydrophilic agent is uniformly applied to the nonwoven fabric, and also has good durability of the hydrophilic agent. is there. In addition, as described above, the absorbent article of the present invention has a topsheet formed of the hydrophilic nonwoven fabric. in this case,
The application of the hydrophilizing agent to the topsheet is performed such that the ratio of the amount of application on the skin contact surface side of the topsheet to the amount of application on the opposite surface is 10 to 90 when the skin contact surface side is 100.
It is preferred that By using the topsheet having such a configuration, the absorbent article of the present invention has good durability of the hydrophilizing agent, and thus has a high absorption rate of urine and body fluid, a small amount of reversion, and a wearer. It does not irritate the skin.

The alkyl phosphate salt which is a component of the hydrophilizing agent used in the present invention preferably has 8 to 22 carbon atoms as an alkyl group.
Examples thereof include octyl, lauryl, myristyl, palmityl, and stearyl, and particularly those having 12 to 18 carbon atoms are preferable.

Examples of the alkyl phosphate salt include lauryl phosphate potassium salt and lauryl phosphate sodium salt. When used, they can be used alone or as a mixture. As the alkyl phosphate salt, a mixture of two or more compounds having different alkyl groups can be used. In this case, 70% by weight or more of the compound in the mixture contains an alkyl group having 8 to 18 carbon atoms. It is preferable to have.

The alkyl phosphate salt is incorporated in the hydrophilizing agent in an amount of 50 to 80% by weight. 80% by weight
If it exceeds, other components cannot be blended, and the durability is deteriorated. On the other hand, if the amount is less than 50% by weight, sufficient hydrophilicity cannot be obtained, and the absorption rate of urine and body fluid is undesirably reduced.

The trialkylglycine derivative used in the present invention is a compound having a betaine structure. As the alkyl group, those having 1 to 22 carbon atoms are preferable,
A mixture of trialkylglycine derivatives having different numbers of carbon atoms may be used. The trialkylglycine derivative is incorporated in the hydrophilizing agent in an amount of 10 to 30% by weight. 30% by weight
If it exceeds, the rate of urine and body fluid absorption slows down,
Since the amount of reversal is increased, the feeling of dryness when touching the topsheet (hereinafter referred to as "sarat feeling") is lacking. If the compounding amount is less than 10% by weight, durability cannot be obtained, and the absorption rate at the beginning is high, but the absorption rate at the second and subsequent times is undesirably low.

The (poly) alkyl polyalkyleneamide dialkyl glycine derivative used in the present invention has the following structure. In the following structural formula, R1 represents a fatty acid having 12 or more carbon atoms, for example, monovalent fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid and unsaturated fatty acids. Or a saturated or unsaturated divalent fatty acid such as maleic acid or adipic acid, or a monovalent or divalent aromatic carboxylic acid such as benzoic acid or phthalic acid. R2 represents an alkylene group having 1 to 4 carbon atoms, and R3 represents a lower alkyl group such as a methyl group or an ethyl group.

[0017]

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The (poly) alkyl polyalkyleneamide dialkyl glycine derivative is contained in the hydrophilizing agent in an amount of 5 to 2%.
0% by weight is blended. If the amount exceeds 20% by weight, the durability is deteriorated and the skin irritation is also deteriorated.
If the amount is less than 5% by weight, hydrophilicity cannot be obtained, which is not preferable.

In the hydrophilic nonwoven fabric of the present invention, the hydrophilizing agent applied to the nonwoven fabric made of a thermoplastic resin has a contact angle with the thermoplastic resin film of 50 to 70 degrees as measured by a 1% by weight aqueous solution thereof. is there. As a matter of course,
The contact angle is a value measured using a film that has not been subjected to any surface treatment such as corona discharge treatment. When the contact angle is less than 50 degrees, the coatability of the hydrophilic agent to the nonwoven fabric is good, and the hydrophilicity of the nonwoven fabric is good, but the durability of the hydrophilic agent is poor, and the hydrophilic agent flows out. It is not preferable because it may cause rough skin. Also, when the contact angle is 7
If it exceeds 0 degrees, the coatability of the hydrophilic agent to the nonwoven fabric will be poor, and a nonwoven fabric having good hydrophilicity cannot be obtained.

In the absorbent article of the present invention, the hydrophilizing agent is used in an amount of 0.1 to 2.0% by weight, preferably 0.5 to 2.0% by weight based on the thermoplastic resin nonwoven fabric used as the surface sheet.
1.0% by weight is applied. If the amount of application is less than 0.1% by weight, the permeability of urine and body fluids becomes insufficient, making it unsuitable for sanitary materials. On the other hand, if the applied amount exceeds 2.0% by weight, the amount of urine or body fluid that returns to the skin increases, and the salat feeling is deteriorated, which is not preferable for hygiene. Furthermore, since the amount of application is large, irritation to the skin is strong, and the skin becomes rough, which makes it unsuitable as an absorbent article.

Further, the ratio of the coating amount on the skin contacting surface side of the topsheet to the coating amount on the opposite surface side is 100% for the skin contacting surface side.
When the ratio of the coating amount on the opposite surface side is 10 to 90
It is preferred that If the ratio of the amount of application on the side opposite to the skin contact side is less than 10, it is difficult to transmit urine and body fluid to the absorber, which is not preferable. On the other hand, if the ratio of the application amount on the opposite side exceeds 90, hydrophilicity is increased on both sides of the topsheet, the amount of urine and bodily fluids reversing increases, and the feeling of salat deteriorates.

In the present invention, the hydrophilic agent can be applied to the nonwoven fabric by a gravure method, a flexographic method, a roll coating method such as a gate roll method, or a spray coating method. Is not particularly limited as long as can be adjusted one by one. As a drying method, a method of drying with hot air or infrared rays, a method of drying by contacting with a heat source, or the like may be used.

In the present invention, the non-woven fabric made of a thermoplastic resin used as the surface sheet is, in particular, a polyolefin fiber, a fibrillated polyolefin fiber, a polyester fiber, a nylon fiber, a PVC fiber, and a polyester / polyethylene-based or polyester / core-sheath structure. It is formed of polypropylene-based, polyethylene-polypropylene-based, copolypropylene-polypropylene-based, copolyester-polyester-based composite fibers, and the like.

A web made of such fibers and their combined fibers, and a nonwoven fabric formed by using one or more of these webs have excellent hydrophilicity to repeated water permeation. As the nonwoven fabric, nonwoven fabrics such as spunbond, spunlace and meltblown can be used.

In particular, even if the nonwoven fabric is formed by heat-sealing and thermocompression bonding a web, the treatment effect of the hydrophilizing agent of the present invention is not impaired, and the obtained nonwoven fabric is hydrophilic and resistant to repeated water infiltration. There is.

The basis weight of the nonwoven fabric used in the present invention is 10 to 5
The range is 0 g / m ² . If the basis weight exceeds 50 g / m ² , the nonwoven fabric becomes too thick, the bending rigidity and the like become large, and the feel becomes poor.
When a stretchable elastic body is arranged, it is difficult to form gathers. Conversely, if the basis weight is less than 10 g / m ² , the strength of the nonwoven fabric becomes too weak, and it becomes difficult to manufacture.

The fineness of the fibers of the nonwoven fabric used in the present invention is in the range of 1 to 10 denier. If the fiber fineness exceeds 10 denier, the flexural rigidity of the nonwoven fabric itself increases, and the feel becomes poor, which is not preferable as a surface sheet. Conversely, if the fineness is less than 1 denier, it becomes difficult to manufacture.

The absorbent used in the present invention is made from a known absorbent material commonly used in conventional absorbent articles. That is, it may be formed of a single-layer or multi-layer mat made of absorbent fibers such as cotton-like pulp and rayon, and may be wrapped with a hydrophilic sheet. Further, the superabsorbent polymer may be uniformly mixed in each mat or may be arranged in a layer between each mat. Alternatively, 3 to 60% by weight of a heat-fusible substance may be mixed with the cotton-like pulp and thermocompression-bonded. Further, the absorber may be an absorbent sheet in which a mixture of an absorbent material such as a superabsorbent polymer and fine fibers is dispersed and applied to a substrate.

As the cotton-like pulp, a chemical pulp sheet,
A fiber having a fiber length of 5 mm or less obtained by defibrating a mechanical pulp sheet or a waste paper pulp sheet with a crusher can be advantageously used. The pulp raw material is not limited to conifers, and hardwoods, straws, bamboos, kenafs and the like are also applicable. The amount of the pulp used varies depending on the intended absorber, for example, depending on whether the pulp is used alone, laminated, or used in combination with other absorbents.
４００400 g / m ² . In addition, synthetic fibers, a heat-sealing component, an adhesive, and the like may be contained together with the cotton-like pulp.

As the superabsorbent polymer, starch-based polymers,
Cellulose type and synthetic polymer type are mentioned. That is, a saponified starch-acrylic acid (salt) graft copolymer, a saponified starch-ethyl acrylate graft copolymer, a saponified starch-methyl methacrylate graft copolymer, and a saponified starch-acrylonitrile graft copolymer Product, saponified product of starch-acrylamide graft copolymer, saponified product of starch-acrylonitrile 2-acrylamide-2-methylpropanesulfonic acid graft copolymer, acrylic acid (salt) polymer, poly (acrylic acid) Examples include crosslinked products of ethylene oxide, sodium carboxymethylcellulose, and crosslinked products of polyvinyl alcohol-maleic anhydride reactant. Of these, those which absorb urine, body fluid and water at least 20 times their own weight, and polyacrylic Sodium acid-based ones from the point of absorption performance It is also suitable.

The amount of the superabsorbent polymer used is from 10 to 500 parts by weight based on 100 parts by weight of the dry cotton-like pulp.
It is preferably 15 to 300 parts by weight, and when such amount of superabsorbent polymer is substantially uniformly distributed in the cotton-like pulp, when the superabsorbent polymer absorbs moisture and swells, its particles Have minimal interference with each other, rarely form a permeation barrier due to continuous contact, and transmit and absorb urine and bodily fluids in three-dimensional directions.

In the present invention, the topsheet and the absorber are adhered by an adhesive. Adhesion in the absorber is performed entirely or partially, and a water-soluble glue such as starch or CMC (carboxymethylcellulose) or a highly fluid adhesive can be used as the adhesive. Is advantageously used.

The back sheet used in the present invention is a liquid-impermeable polyethylene sheet, preferably a polyethylene sheet having fine pores formed thereon, a moisture-permeable liquid-impermeable sheet obtained by adding a filler to a thermoplastic resin and stretching. Is used.

[0034]

EXAMPLES The present invention will be described more specifically with reference to examples below, but the present invention is of course not limited to these. The evaluation items and evaluation methods in the respective examples and comparative examples are as follows. Further,% and parts in each of Examples and Comparative Examples represent% by weight and parts by weight, respectively.

(1) Contact Angle One drop (5 μl) of a 1% by weight solution of a hydrophilizing agent was dropped on a polypropylene film not subjected to surface treatment.
The contact angle one second after contact with the polypropylene film was measured using a dynamic absorption tester (FIB).
RO Co., Ltd.) and the average of five measurements was calculated.

(2) Hydrophilicity A nonwoven fabric coated with a hydrophilizing agent, cut into a size of 15 cm × 15 cm, is placed on a filter paper, and when 30 drops of artificial urine are dropped 30 drops at 30 places, 3 seconds are required. Determine the number of drops absorbed within, and determine the water permeability ((number of absorbed drops / 30)
× 100) to evaluate the hydrophilicity. The composition of the artificial urine used is as follows. Urea 1.9% NaCl 0.8% CaCl ₂ 0.1% MgSO ₄ 0.1%

(3) Durability hydrophilicity Thirty minutes after the measurement of the water permeability, artificial urine was dropped again at the place where artificial urine was dropped.
The number of droplets absorbed within a second was determined, and the water permeability was calculated. Further, 30 minutes after the second measurement of the water permeability, the water permeability was measured in the same manner to evaluate the durability and hydrophilicity.

(4) Coatability The state of application when 0.5% of a hydrophilizing agent having a concentration of 1.5% was applied to one surface of the nonwoven fabric by a gravure coater was evaluated in the following three grades. ：: Uniformly applied. Δ: Repelling was slightly observed on the coated surface. ×: Many repelling is observed on the coated surface.

(5) Absorption speed A stainless steel plate having a hole with a diameter of 2.5 cm is placed on the surface sheet of the absorbent article, and 50 ml of artificial urine is injected into the hole, and 50 ml of artificial urine is absorbed by the absorbent article. The time (sec) until the measurement was performed was measured. Next, 30 minutes later, the time until 50 ml of artificial urine is absorbed by the absorbent article is measured again, and 50 ml of artificial urine is absorbed in the same manner 30 minutes after the second measurement. The time until was measured, and the absorption rate was evaluated.

(6) Return amount The sample whose absorption rate was measured was weighed in advance by 10
Ten pieces of filter paper (cm × 10 cm, No. 63, manufactured by Advantech Toyo Co., Ltd.) were stacked, a load of 5 kg was applied to the filter paper, and the filter was allowed to stand for 10 minutes. Then, the weight increase of the filter paper was measured to determine the amount of reversion (g).

(7) Skin irritation Cut the surface sheet into a circle having a diameter of 1.5 cm, and affix it to the inside of the upper arm of an adult with a patch test patch so that the skin contact surface is in contact with the upper arm. Of the skin was observed. The evaluation was performed in the following three stages. ：: Skin roughness is not observed in 90% or more of the monitor. Δ: No rough skin was observed in 50% or more of the monitor. ×: Rough skin was observed in 90% or more of the monitor.

Example 1 Alkyl phosphate sodium salt (manufactured by Matsumoto Yushi Co., Ltd., trade name: Fcol 301, concentration: 100%) 70
Parts, 20 parts of a trialkylglycine derivative (manufactured by Matsumoto Yushi Co., Ltd., trade name: VISTER MS, concentration 100%)
(Poly) alkyl polyalkylene amide dialkyl glycine derivative (Matsumoto Yushi Co., Ltd., trade name: VISTER C
(AP, concentration: 100%) A hydrophilizing agent having a concentration of 1.5% containing 10 parts was prepared, and a gravure coater was used to prepare a non-woven fabric having a basis weight of 25 g / m ^{2 made} of polypropylene fibers using the gravure coater. 0.25%) to produce a hydrophilic nonwoven fabric. The contact angle between the hydrophilic agent and the polypropylene film was 66 degrees.

Example 2 A 1.5% concentration hydrophilizing agent containing 80 parts of an alkyl phosphate sodium salt, 15 parts of a trialkylglycine derivative, and 5 parts of a (poly) alkylpolyalkyleneamidedialkylglycine derivative was prepared. In the same manner as in Example 1, a hydrophilic nonwoven fabric was produced. The contact angle between the hydrophilic agent and the polypropylene film was 60 degrees.

Example 3 A 1.5% concentration hydrophilizing agent containing 50 parts of an alkyl phosphate sodium salt, 30 parts of a trialkylglycine derivative, and 20 parts of a (poly) alkylpolyalkyleneamidedialkylglycine derivative was prepared. In the same manner as in Example 1, a hydrophilic nonwoven fabric was produced. The contact angle between the hydrophilic agent and the polypropylene film was 54 degrees.

Comparative Example 1 A hydrophilic nonwoven fabric was prepared in the same manner as in Example 1 except that a hydrophilizing agent containing 70 parts of an alkyl phosphate sodium salt and 30 parts of a trialkylglycine derivative was prepared at a concentration of 1.5%. The contact angle between the hydrophilic agent and the polypropylene film was 75 degrees.

Comparative Example 2 A hydrophilic nonwoven fabric was prepared in the same manner as in Example 1 except that a hydrophilizing agent having a concentration of 1.5% containing 60 parts of an alkyl phosphate sodium salt and 40 parts of a trialkylglycine derivative was prepared. The contact angle between the hydrophilic agent and the polypropylene film was 79 degrees.

Comparative Example 3 A hydrophilizing agent having a concentration of 1.5% containing 70 parts of an alkyl phosphate sodium salt and 30 parts of a (poly) alkyl polyalkyleneamide dialkyl glycine derivative was prepared. A non-woven fabric was produced. The contact angle between the hydrophilic agent and the polypropylene film was 46 degrees. Using the hydrophilic nonwoven fabrics obtained in Examples 1 to 3 and Comparative Examples 1 to 3, hydrophilicity, durable hydrophilicity and coating properties were evaluated. Table 1 shows the results.

[0048]

[Table 1]

[0049] Example 4 wrapped cotton-like pulp 200 g / m ^2, and consists of sodium polyacrylate those allowed superabsorbent polymer 200 g / m ² is uniformly distributed to the tissue, followed by treatment with a press roll bulk density Produced an absorbent having a concentration of 0.10 g / cm ³ . Further, the same hydrophilizing agent as used in Example 1 was used, and this was applied with a gravure coater to a non-woven fabric made of polypropylene fiber having a basis weight of 25 g / m ² , 0.5% on the skin contact side and 0.5% on the opposite side. 0.3% was applied to prepare a topsheet. Then, a thickness of 24 μ made of polyester
m, the above-mentioned absorber was arranged on the back sheet, and the above-mentioned top sheet was further arranged on the absorber to produce an absorbent article, which was used as a test sample.

Example 5 An absorbent article was produced in the same manner as in Example 4. However,
The same one as used in Example 2 was used as the hydrophilizing agent, and 0.6% was placed on the skin-contacting surface side of the nonwoven fabric and 0.1% was placed on the opposite surface side.
4% was applied to prepare a topsheet.

Example 6 An absorbent article was produced in the same manner as in Example 4. However,
As the hydrophilizing agent, the same one as used in Example 3 was used, with 1.0% on the skin contact surface side of the nonwoven fabric and 0.1% on the opposite surface side.
3% was applied to prepare a topsheet.

Comparative Example 4 An absorbent article was produced in the same manner as in Example 4. However,
The same hydrophilizing agent as that used in Comparative Example 1 was used, with 1.3% on the skin contact surface side of the nonwoven fabric and 0.1% on the opposite surface side.
5% was applied to prepare a topsheet.

Comparative Example 5 An absorbent article was produced in the same manner as in Example 4. However,
The same hydrophilizing agent as that used in Comparative Example 3 was used, with 1.0% on the skin-contacting surface side of the nonwoven fabric and 0.1% on the opposite surface side.
5% was applied to prepare a topsheet.

Comparative Example 6 An absorbent article was produced in the same manner as in Example 4. However,
Alkyl phosphate sodium salt 60 as a hydrophilizing agent
Part, trialkyl glycine derivative 10 parts, (poly) alkyl polyalkylene amide dialkyl glycine derivative 3
Using a material containing 0 parts, a surface sheet was prepared by applying 1.0% on the skin contact surface side and 0.8% on the opposite surface side of the nonwoven fabric.

Comparative Example 7 An absorbent article was produced in the same manner as in Example 4. However,
As the hydrophilizing agent, the same one as used in Example 1 was used. 1.5% was placed on the skin-contacting surface side of the nonwoven fabric and 1.
5% was applied to prepare a topsheet.

Comparative Example 8 An absorbent article was produced in the same manner as in Example 4. However,
Alkyl phosphate sodium salt 40 as hydrophilizing agent
Part, trialkyl glycine derivative 30 parts, (poly) alkyl polyalkylene amide dialkyl glycine derivative 3
Using a material containing 0 part, 0.7% was applied on the skin contact surface side and 1.0% on the opposite surface side of the nonwoven fabric to prepare a topsheet. Using the absorbent articles obtained in Examples 4 to 6 and Comparative Examples 4 to 8, the absorption rate, the amount of reversion and the skin irritation were evaluated. Table 2 shows the results.

[0057]

[Table 2]

As is evident from Table 1, the hydrophilic nonwoven fabrics of Examples 1 to 3 of the present invention have a hydrophilicity agent uniformly applied to the surface of the nonwoven fabric and have good hydrophilicity and durable hydrophilicity. On the other hand, the hydrophilic nonwoven fabrics of Comparative Examples 1 to 3 were inferior in hydrophilicity, durable hydrophilicity or coatability, and the effect of the present invention was confirmed.

As is clear from Table 2, Examples 4 to
The absorbent article of the present invention No. 6 has a high absorption rate, a small amount of reversion, and is extremely excellent without skin irritation, whereas the absorbent articles of Comparative Examples 4 to 8 are all excellent. The amount of reversion was large, and the absorption rate or skin irritation was inferior, confirming the effect of the present invention.

[0060]

The water-absorbent nonwoven fabric of the present invention comprises a nonwoven fabric made of a thermoplastic resin and a hydrophilic agent having a contact angle of 50 to 70 degrees with a film made of a thermoplastic resin as measured by a 1% by weight solution. By applying 0.1 to 2.0% by weight to the non-woven fabric, the hydrophilic agent is uniformly applied to the nonwoven fabric, so that the liquid permeability is good and the durability of the hydrophilic agent is high. Is also good. In addition, the absorbent article of the present invention has a high absorption rate, a small amount of reversion, and a skin irritation by using, as the topsheet, those having different amounts of the hydrophilic agent applied on the side in contact with the skin and on the opposite side. It is also excellent in safety without harm.

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Claims (2)

[Claims] 1. A hydrophilizing agent having a contact angle with a thermoplastic resin film of 50 to 70 degrees as measured with a 1% by weight aqueous solution is added to a nonwoven fabric made of a thermoplastic resin in an amount of 0.1 to 10%.
In a hydrophilic nonwoven fabric coated by 2.0% by weight, the hydrophilicizing agent may be an alkyl phosphate salt in an amount of 50 to 80.
A hydrophilic non-woven fabric, comprising 10% to 30% by weight of a trialkylglycine derivative and 5 to 20% by weight of a (poly) alkylpolyalkyleneamidedialkylglycine derivative. 2. An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber disposed between these two sheets, wherein the top sheet is as described in claim 1. An absorbent article characterized by being formed of a hydrophilic nonwoven fabric of the above.