ABSORBENT ARTICLE

Abstract

Provided is an absorbent article having excellent shape retention of an absorber even when an external force is applied thereto. The present invention is an absorbent article having: an aqueous-liquid absorbing part having crosslinked polymer particles having as essential constitutional units thereof a water-soluble vinyl monomer and/or a vinyl monomer which became the water-soluble vinyl monomer by hydrolysis, and a crosslinking agent; and a nonwoven fabric having porous fibers as an essential constituent thereof, the crosslinked polymer particles preferably absorbing 40 times the weight thereof of physiological saline 40 in 40-150 seconds.

Claims

1. An absorbent article comprising: an aqueous-liquid absorbing part that contains crosslinked polymer particles (A) comprising a water-soluble vinyl monomer (a1) and/or a vinyl monomer (a2) that turns into a water-soluble vinyl monomer (a1) through hydrolysis, and a crosslinking agent (a3) as essential constitutional units; and a nonwoven fabric (B) comprising porous fibers (b1) as an essential constituent.

2. The absorbent article according to claim 1, wherein the crosslinked polymer particles (A) are crosslinked polymer particles that absorb physiological saline 40 times their own weight in 40 to 150 seconds.

3. The absorbent article according to claim 1, wherein the crosslinked polymer particles (A) are crosslinked polymer particles having a basic flowability energy measured by a powder flow analyzer of 500 to 8000 mJ.

4. The absorbent article according to claim 1, wherein the aqueous-liquid absorbing part further contains hydrophilic fibers (c).

5. The absorbent article according to claim 1, wherein the porous fibers (b1) are formed of an acrylonitrile-based polymer that is formed by polymerizing a monomer composition containing acrylonitrile and has an acrylonitrile content of 70% or more based on the total weight of the monomer composition.

6. The absorbent article according to claim 1, wherein the average pore diameter of the porous fibers (b1) is 1 to 1000 nm.

7. The absorbent article according to claim 1, wherein the contact angle with pure water with respect to the porous fibers (b1) is 80 degrees or less.

8. The absorbent article according to claim 1, wherein the percentage elongation of the porous fibers (b1) is 10% or more.

9. The absorbent article according to any one of claims 1 to 8 claim 1, wherein the fineness of the porous fibers (b1) is 0.05 to 20 dtex.

10. The absorbent article according to claim 1, wherein the strength of the porous fibers (b1) is 1.0 cN/dtex or more.

11. The absorbent article according to claim 1, wherein the nonwoven fabric (B) further comprises aqueous-liquid absorbent fibers (b2).

12. The absorbent article according to claim 11, wherein the content of the aqueous-liquid absorbent fibers (b2) is less than 50% based on the total weight of the porous fibers (b1) and the aqueous-liquid absorbent fibers (b2).

13. The absorbent article according to claim 1, wherein the absorbent article has the aqueous-liquid absorbing part at least on one side of the nonwoven fabric (B) and/or in cavities in the nonwoven fabric (B).

14. The absorbent article according to claim 13, wherein the absorbent article has the aqueous-liquid absorbing part at least on one side of the nonwoven fabric (B) and further has a water-permeable sheet between the aqueous-liquid absorbing part and the nonwoven fabric (B).

Description

EXAMPLES

[0155] The present invention is further described by examples below, but the invention is not restricted thereto. Hereafter, unless otherwise stated, “%” means “% by weight” and “part” means “part by weight.”

PRODUCTION EXAMPLES OF CROSSLINKED POLYMER PARTICLES

Production Example 1

[0156] 155 parts (2.15 molar parts) of a water-soluble vinyl monomer (a1) (acrylic acid), 0.6225 parts (0.0024 molar parts) of a crosslinking agent (a3) (pentaerythritol triallyl ether), and 340.27 parts of deionized water were kept at 3° C. under stirring and mixing. After adjusting the dissolved oxygen amount to 1 ppm or less by introducing nitrogen into this mixture, 0.62 parts of a 1% aqueous solution of hydrogen peroxide, 1.1625 parts of a 2% aqueous solution of ascorbic acid, and 2.325 parts of a 2% aqueous solution of 2,2′-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide] were added and mixed, so that polymerization was initiated. After the temperature of the mixture reached 90° C., polymerization was performed at 90±2° C. for about 5 hours, thereby obtaining a hydrous gel (1).

[0157] Then, while 502.27 parts of the hydrous gel (1) was chopped with a mincing machine, 128.42 parts of a 48.5% aqueous solution of sodium hydroxide was added and mixed, and subsequently 1.9 parts of a hydrophobic substance (a4) (Mg stearate) was added and mixed, so that a chopped gel (2) was obtained. Moreover, the chopped gel (2) was dried in a through-flow band type drier (at 150° C., wind speed: 2 m/second), so that a dried material was obtained. The dried material was pulverized with a juicing blender and then was adjusted to have particle sizes of 150 to 710 μm by using sieves having sizes of opening of 150, 300, 500, 600, and 710 μm, respectively, so that particles of the dried material were obtained. Under stirring 100 parts of the dried material particles at a high speed, 5 parts of a 2% water/methanol mixed solution of ethylene glycol diglycidyl ether (the weight ratio of water/methanol=70/30) was added and mixed by spraying, followed by leaving the mixture to stand at 150° C. for 30 minutes to perform surface crosslinking. Then, 0.10 parts of silica (Aerosil 200) under stirring at a high speed was added, so that crosslinked polymer particles (A-1) were obtained. The crosslinked polymer particles (A-1) had a weight average particle diameter of 400 μm and an apparent density of 0.56 g/ml. The weight average particle diameter and the apparent density were measured by the following methods, respectively.

<Measurement of Weight Average Particle Diameter>

[0158] Standard sieves having sizes of opening of 1000 μm, 850 μm, 710 μm, 500 μm, 425 μm, 355 μm, 250 μm, 150 μm, 125 μm, 75 μm, and 45 μm, respectively, were piled one on another in order, and were combined on a bottom tray. About 50 g of the crosslinked polymer particles (A-1) was put on the top sieve and then shaken for 5 minutes by a RO-TAP sieve shaker . Then, the particles remaining on the respective sieves and the bottom tray were weighed and the weight fractions of the particles on the respective sieves were calculated with the total weight of the particles considered to be 100% by weight. The calculated values were plotted on a logarithmic probability sheet {taking the size of openings of a sieve (particle diameter) as an abscissa and the weight fraction as an ordinate} and then a line connecting the respective points was drawn. Subsequently, a particle diameter that corresponded to a weight fraction of 50% by weight was determined and this was defined as a weight average particle diameter.

<Measurement of Apparent Density>

[0159] Measurement was performed under an environment at 25° C. in accordance with JIS K7365:1999.

Production Example 2

[0160] Crosslinked polymer particles (A-2) were obtained in the same manner as in Production Example 1 except changing “be adjusted to have particle sizes of 150 to 710 μm by using sieves having sizes of opening of 150, 300, 500, 600, and 710 μm, respectively” to “be adjusted to have particle sizes of 150 to 600 μm by using sieves having sizes of opening of 150, 300, 500, and 600 μm, respectively.” The weight average particle diameter and the apparent density of the crosslinked polymer particles (A-2) measured in the same manner as in Production Example 1 were 350 μm and 0.60 g/ml, respectively.

Production Example 3

[0161] Crosslinked polymer particles (A-3) were obtained in the same manner as in Production Example 1 except changing “be adjusted to have particle sizes of 150 to 710 μm by using sieves having sizes of opening of 150, 300, 500, 600, and 710 μm, respectively” to “be adjusted to have particle sizes of 150 to 500 μm by using sieves having sizes of opening of 150, 300, and 500 μm, respectively.” The weight average particle diameter and the apparent density of the crosslinked polymer particles (A-3) measured in the same manner as in Production Example 1 were 300 μm and 0.64 g/ml, respectively.

Production Example 4

[0162] Crosslinked polymer particles (A-4) were obtained in the same manner as in Production Example 1 except changing “0.1 parts of silica (Aerosil 200)” to “0.5 parts of silica (Aerosil 200).” The weight average particle diameter and the apparent density of the crosslinked polymer particles (A-4) measured in the same manner as in Production Example 1 were 400 μm and 0.54 g/ml, respectively.

Production Example 5

[0163] Crosslinked polymer particles (A-5) were obtained in the same manner as in Production Example 1 except not “adding 1.9 parts of a hydrophobic substance (a4) (Mg stearate)” and not using “0.1 parts of silica (Aerosil 200).” The weight average particle diameter and the apparent density of the crosslinked polymer particles (A-5) measured in the same manner as in Production Example 1 were 400 μm and 0.64 g/ml, respectively.

[0164] For the crosslinked polymer particles (A-1) through (A-5) obtained in Production Examples 1 through 5, the time taken to absorb physiological saline 40 times their own weight [physiological saline (40 times) absorption time], the basic flowability energy, the water retention capacity, and the gel elastic modulus were measured by the following methods, and they were shown in Table 1 together with the weight average particle diameter and the apparent density.

TABLE-US-00001 TABLE 1 Production Example 1 2 3 4 5 Crosslinked polymer particles A-1 A-2 A-3 A-4 A-5 Physiological saline Second 70 55 40 65 150 (40 times) absorption time Basic flowability energy mJ 1000 1500 2000 8000 500 Weight average particle μm 400 350 300 400 400 diameter Apparent density g/ml 0.56 0.6 0.64 0.54 0.64 Water retention capacity g/g 37 35 33 37 36 Gel elastic modulus N/m.sup.2 2600 2400 2075 2850 2500
<Measurement of Physiological Saline (40 times) Absorption Time>

[0165] To each of 100-ml beakers containing 1.00 g of the crosslinked polymer particles (A-1) through (A-5) obtained in Production Examples 1 through 5, respectively, was added 40 g of physiological saline (salt concentration=0.9% by weight). Then, they were left to stand without stirring, and the time taken by the complete absorption of the physiological saline (at the tail end of absorption, the beaker was inclined slightly to check whether the physiological saline remained or not) was measured and the time was taken as a physiological saline (40 times) absorption time. The temperature of the physiological saline used and that of the measurement atmosphere were adjusted to 25° C.±2° C.

<Measurement of Basic Flowability Energy>

[0166] Using a Powder Rheometer FT4 manufactured by Sysmex Corporation and set to a basic flowability energy measuring mode, measurement was repeated seven times under a measurement environment of −25° C. and 50% RH while the blade width and the rotation speed were set at 48 mm and 100 m/s, respectively, and the arithmetic average of the measurements was taken as a basic flowability energy. The measurement samples used were fixed to have a volume of 160 ml and were obtained by naturally dropping the crosslinked polymer particles (A-1) through (A-5) obtained in Production Examples 1 through 5 individually into 160-ml split containers having an inner diameter of 50 mm.

<Measurement of Water Retention Capacity>

[0167] The crosslinked polymer particles (A-1) through (A-5) obtained in Production Examples 1 through 5 (1.00 g) were each put in a tea bag (20 cm long, 10 cm wide) formed of nylon net with an opening size of 63 μm (JIS Z8801-1:2006) and immersed in 1,000 ml of physiological saline (salt concentration: 0.9% by weight) for 1 hour without stirring. Then, the sample was lifted out of the physiological saline, followed by draining off physiological saline by hanging the sample for 15 minutes, and the sample with the tea bag was put in a centrifuge and was centrifugally dewatered at 150 G for 90 seconds to remove excessive physiological saline. The weight (h1) including the weight of the tea bag after the dewatering was measured. Moreover, the weight (h2) of a tea bag that was obtained by performing the same operation as above except not putting crosslinked polymer particles in the tea bag was measured, and then the water retention capacity was calculated from the following formula.

Water retention capacity (g/g)=(h1)−(h2)

[0168] The temperature of the physiological saline used and that of the measurement atmosphere were adjusted to 25° C.±2° C.

<Measurement of Gel Elastic Modulus>

[0169] In a 100 ml-volume beaker (inner diameter: 5 cm), 60.0 g of artificial urine [200 parts by weight of urea, 80 parts by weight of sodium chloride, 8 parts by weight of magnesium sulfate (7 hydrate), 3 parts by weight of calcium chloride (dihydrate), 2 parts by weight of ferric sulfate (7 hydrate), 9,704 parts by weight of ion-exchange water] was weighed, and in the same manner as in the operation described in JIS K 7224-1996, 2.0 g of each of the crosslinked polymer particles (A-1) through (A-5) obtained in Production Examples 1 through 5 was precisely weighed and charged into the beaker to prepare a 30-fold swollen gel. Subsequently, the beaker containing the 30-fold swollen gel was wrapped with wrapping film, and then was allowed to stand in an atmosphere at 40±2° C. for 3 hours and further in an atmosphere at 25±2° C. for 0.5 hours. Then, the gel elastic modulus of the 30-fold swollen gel was measured under the following conditions using a Curd-Meter MAX ME-500 manufactured by Itec Techno Engineering K. K.

(Conditions of Card Meter)

[0170] Pressure-sensitive shaft: 8 mm

[0171] Spring: for 100 g

[0172] Load: 100 g

[0173] Elevation rate: 1 inch/7 seconds

[0174] Test property: breakage

[0175] Measurement time: 6 seconds

[0176] Atmospheric temperature for measurement: 25±2° C.

PRODUCTION EXAMPLE OF NONWOVEN FABRIC

Production Example 6

[0177] A monomer mixture of acrylonitrile (90 parts), methyl acrylate (9.7 parts), and sodium methallylsulfonate (0.3 parts) was subjected to aqueous suspension polymerization, and a polymer A was thereby obtained. A monomer mixture of acrylonitrile (28 parts) and methoxypolyethylene glycol (30 mol) methacrylate (72 parts) was subjected to aqueous suspension polymerization, and a polymer B was thereby obtained. The polymer A (97 parts) and the polymer B (3 parts) were dissolved in a50% aqueous solution of sodium rhodanate (900 parts) to form a spinning solution, and then spinning was performed using this solution to obtain porous fibers (b1-1). The fineness, the strength, the percentage elongation, the contact angle, and the average pore diameter of the resulting porous fibers (b1-1) were found to be 2 dtex, 3 cN/dtex, 50%, 46 degrees, and 10 nm, respectively. Using the porous fibers (b1-1), a nonwoven fabric (B-1) having a weight per unit area of 40 g/m.sup.2 was produced by a needle punch method.

[0178] The fineness, the strength, the percentage elongation, the contact angle, and the average pore diameter of the porous fibers (b1-1) were measured by the following methods.

<Fineness>

[0179] The fineness was measured in accordance with Method A provided for in “8.5 Fineness” of JIS L1015 (2010).

<Strength and Percentage Elongation>

[0180] The strength and the percentage elongation were measured in accordance with the standard tests provided for in “8.7 Tensile Strength and Elongation” of JIS L1015 (2010).

<Contact Angle>

[0181] One fiber was sampled out of a fiber bundle and then was immersed in and lifted from pure water using pure water as a solvent. Then, a contact angle was measured with Sigma 701 manufactured by Biolin Scientific AB.

<Average Pore Diameter>

[0182] The average pore diameter was measured by the mercury press-injection method of JIS R1655 (2003).

Production Example 7

[0183] Porous fibers (b1-2) were obtained in the same manner as in Example 5 except using a spinning solution prepared by dissolving the polymer A (95 parts) and the polymer B (5 parts) in 900 parts of a 50% aqueous solution of sodium rhodanate. The fineness, the strength, the percentage elongation, the contact angle, and the average pore diameter of the resulting porous fibers (b1-2) were found to be 1 dtex, 2 cN/dtex, 30%, 46 degrees, and 20 nm, respectively. Using the porous fibers (b1-2), a nonwoven fabric (B-2) having a weight per unit area of 40 g/m.sup.2 was produced by a needle punch method.

Production Example 8

[0184] A monomer mixture of acrylonitrile (75 parts) and methyl acrylate (25 parts) was subjected to aqueous suspension polymerization, and a polymer C was thereby obtained. The polymer C (97 parts) and polymer B (3 parts) were dissolved in 900 parts of a 50% aqueous solution of sodium rhodanate to form a spinning solution, and then spinning was performed using this solution to obtain porous fibers (b1-3). The fineness, the strength, the percentage elongation, the contact angle, and the average pore diameter of the resulting porous fibers (b1-3) were found to be 6 dtex, 5 cN/dtex, 70%, 50 degrees, and 40 nm, respectively. The porous fibers (b1-3) (80 parts) and polyester-based heat-fusible fibers (MELTY #4080 manufactured by UNITIKA LTD.) (20 parts) were mixed, and then a nonwoven fabric (B-3) having a weight per unit area of 40 g/m.sup.2 was produced using a needle punch method and a heat press method in combination.

Production Example 9

[0185] A monomer mixture of acrylonitrile (94 parts), methyl acrylate (5 parts), and sodium methallylsulfonate (1 part) was subjected to solution polymerization using dimethyl sulfoxide as a polymerization solvent, and a polymer D was thereby obtained. A monomer mixture of acrylonitrile (30 parts) and methoxypolyethylene glycol (30 mol) methacrylate (70 parts) was subjected to solution polymerization, and a polymer E was thereby obtained. The polymer D (85 parts) and the polymer E (15 parts) were dissolved in dimethyl sulfoxide to obtain a spinning solution having a solid content of 15%, and then spinning was performed in a mixed solution having a dimethyl sulfoxide/water weight ratio of 1/1. Moreover, the resulting fibers were immersed in a 2% aqueous solution of sodium hydroxide to dissolve the polymer E, and porous fibers (b1-4) were thereby obtained. The fineness, the strength, the percentage elongation, the contact angle, and the average pore diameter of the porous fibers (b1-4) were found to be 2 dtex, 2 cN/dtex, 20%, 45 degrees, and 600 nm, respectively. Using the porous fibers (b1-4), a nonwoven fabric (B-4) having a weight per unit area of 40 g/m.sup.2 was produced by a needle punch method.

Production Example 10

[0186] The porous fibers (b1-1) (90 parts) and “LANSEAL (registered trademark) F” (manufactured by Toyobo Co., Ltd., fineness: 5.6 dtex; fiber length: 51 mm) (10 parts) as aqueous-liquid absorbent fibers (b 2-1) were mixed by airlaying, and then a nonwoven fabric (B-5) having a weight per unit area of 40 g/m.sup.2 was obtained by a needle punch method.

Production Example 11

[0187] The porous fibers (b1-1) (70 parts) and the aqueous-liquid absorbent fibers (b2-1) (30 parts) were mixed by airlaying, and then a nonwoven fabric (B-6) having a weight per unit area of 40 g/m.sup.2 was obtained by a needle punch method.

Production Example 12

[0188] The porous fibers (b1-1) (45 parts) and the aqueous-liquid absorbent fibers (b 2-1) (45 parts) were mixed by airlaying and then further mixed with polyester-based heat-fusible fibers (MELTY #4080 manufactured by UNITIKA LTD.) (10 parts), and then a nonwoven fabric (B-7) having a weight per unit area of 40 g/m.sup.2 was obtained using a needle punch method and a heat press method in combination.

Production Example 13

[0189] The porous fibers (b1-1) (10 parts) and the aqueous-liquid absorbent fibers (b2-1) (90 parts) were mixed by airlaying, and then a nonwoven fabric (B-8) having a weight per unit area of 40 g/m.sup.2 was obtained by a needle punch method.

Production Example 14

[0190] A nonwoven fabric (B-9) having a weight per unit area of 20 g/m.sup.2 was obtained from the porous fibers (b1-1) (100 parts) by a spun lace method.

Example 1

[0191] The crosslinked polymer particles (A-1) were uniformly scattered by hand to a weight per unit area of 200 g/m.sup.2 on the nonwoven fabric (B-1) (weight per unit area: 40 g/m.sup.2), followed by pressing at a pressure of 5 kg/cm.sup.2 for 30 seconds to bury the crosslinked polymer particles (A-1) into cavities (i.e., micropores) in the nonwoven fabric (B-1), and thus an absorber (1) was obtained. The absorber (1) was cut into a rectangle (10 cm×40 cm), and then the absorber (1) was sandwiched between water-permeable sheets (weight per unit area: 15.5 g/m.sup.2; filter paper #2 manufactured by ADVANTEC) having the same size as the absorber (1), and further a polyethylene sheet (polyethylene film UB-1 manufactured by TAMAPOLY CO., LTD.) was arranged on the rear side as a back sheet and a nonwoven fabric (nonwoven fabric weight per unit area: 25 g/m.sup.2; 2.2 T 44-SMK manufactured by Toyobo Co., Ltd.) was arranged on the outermost side, and thus an absorbent article (1) was prepared.

Example 2

[0192] An absorbent article (2) was prepared in the same manner as in Example 1 except changing the “crosslinked polymer particles (A-1)” to the “crosslinked polymer particles (A-2)” and changing the “nonwoven fabric (B-1) to the “nonwoven fabric (B-2).”

Example 3

[0193] An absorbent article (3) was prepared in the same manner as in Example 1 except changing the “crosslinked polymer particles (A-1)” to the “crosslinked polymer particles (A-3)” and changing the “nonwoven fabric (B-1) to the “nonwoven fabric (B-3).”

Example 4

[0194] An absorbent article (4) was prepared in the same manner as in Example 1 except changing the “crosslinked polymer particles (A-1)” to the “crosslinked polymer particles (A-4)” and changing the “nonwoven fabric (B-1) to the “nonwoven fabric (B-4).”

Example 5

[0195] An absorbent article (5) was prepared in the same manner as in Example 1 except changing the “crosslinked polymer particles (A-1)” to the “crosslinked polymer particles (A-5)” and changing the “nonwoven fabric (B-1) to the “nonwoven fabric (B-5).”

Example 6

[0196] An absorbent article (6) was prepared in the same manner as in Example 1 except changing the “nonwoven fabric (B-1)” to the “nonwoven fabric (B-6).”

Example 7

[0197] Hydrophilic fibers (c) (fluff pulp) (20 parts) and 80 parts of the crosslinked polymer particles (A-1) were mixed using an air-flow type mixing apparatus (pad former) to obtain a mixture, and then the mixture was uniformly stacked to a weight per unit area of 250 g/m.sup.2 on an acrylic plate (4 mm thick), followed by pressing at a pressure of 5 kg/cm.sup.2 for 30 seconds, and thus an absorber (2) was obtained. The absorber (2) was cut into a rectangle sized in 10 cm×40 cm, and water-permeable sheets (weight per unit area: 15.5 g/m.sup.2; filter paper #2 manufactured by ADVANTEC) having the same size as the absorber were arranged on both sides of the absorber, and further a polyethylene sheet (polyethylene film UB-1 manufactured by TAMAPOLY CO., LTD.) was arranged on the rear side as a back sheet, a nonwoven fabric (B-7) (weight per unit area: 40 g/m.sup.2) was arranged on the front side, and a nonwoven fabric (nonwoven fabric weight per unit area: 25 g/m.sup.2; 2.2 T 44-SMK manufactured by Toyobo Co., Ltd.) was arranged on the outermost side, and thus an absorbent article (7) was prepared. The weight ratio of the crosslinked polymer particles to the hydrophilic fibers (weight of crosslinked polymer particles/weight of hydrophilic fibers) was 80/20.

Example 8

[0198] An absorbent article (8) was prepared in the same manner as in Example 1 except changing the “nonwoven fabric (B-1)” to the “nonwoven fabric (B-8).”

Example 9

[0199] An absorbent article (9) was prepared in the same manner as in Example 7 except changing the amount of the hydrophilic fibers (c) from 20 parts to 5 parts and the amount of the crosslinked polymer particles (A-1) from 80 parts to 95 parts and also changing the “nonwoven fabric (B-7)” to the “nonwoven fabric (B-1).”

Example 10

[0200] An absorbent article (10) was prepared in the same manner as in Example 7 except changing the “nonwoven fabric (B-7)” to the “nonwoven fabric (B-1).”

Example 11

[0201] An absorbent article (11) was prepared in the same manner as in Example 7 except changing the amount of the hydrophilic fibers (c) from 20 parts to 80 parts and the amount of the crosslinked polymer particles (A-1) from 80 parts to 20 parts and also changing the “nonwoven fabric (B-7)” to the “nonwoven fabric (B-8).”

Example 12

[0202] An absorbent article (12) was prepared in the same manner as in Example 7 except changing the amount of the hydrophilic fibers (c) from 20 parts to 50 parts and the amount of the crosslinked polymer particles (A-1) from 80 parts to 50 parts.

Example 13

[0203] An absorbent article (13) was prepared in the same manner as in Example 7 except changing the “nonwoven fabric (B-7)” to the “nonwoven fabric (B-9).”

Example 14

[0204] An absorbent article (14) was prepared in the same manner as in Example 7 except changing the “nonwoven fabric (B-7)” to the “nonwoven fabric (B-3).”

Comparative Example 1

[0205] An absorbent article (H1) was prepared in the same manner as in Example 7 except not using the nonwoven fabric (B-7) containing the porous fibers, and instead using a nonwoven fabric (HB-1) containing no porous fibers (nonwoven fabric weight per unit area : 25 g/m.sup.2, 2.2 T 44-SMK manufactured by Toyobo Co., Ltd.).

Comparative Example 2

[0206] An absorbent article (H2) was prepared in the same manner as in Example 1 except changing the crosslinked polymer particles (A-1) to the hydrophilic fibers (c) (fluff pulp) and the “nonwoven fabric (B-1)” to the “nonwoven fabric (B-8).”

[0207] For the absorbent articles (1 through 14) obtained in Examples 1 through 14 and the comparative absorbent articles (H1 and H2) obtained in Comparative Examples 1 and 2, shape retention was evaluated by the following method and the results are shown in Table 2.

<Measurement of Shape Retention>

[0208] Each of the absorbent articles obtained in Examples 1 through 14 and Comparative Examples 1 and 2 was cut at the center portion into a size of 8 cm×3 cm with scissors and the cut piece was put into a bag with a zipper (10 cm×14 cm). After filling the bags with nitrogen gas, the bags were zipped, and each of the bags was shaken for 10 seconds by hand 10 times. The zipper was opened and the cut sample was allowed to absorb 12 g of physiological saline. After 5 minutes from the charge of the physiological saline, the bag was filled with nitrogen gas again and was zipped, and each of the bags was shaken for 20 seconds by hand 20 times. Then, the shape of the cut sample was checked and was evaluated by classifying into levels 1 to 5 based on the following criteria.

[0209] 1: The sample is in a disjointed form;

[0210] 2: The sample is in a form composed mostly of disjointed parts and partly of massive parts;

[0211] 3: The sample is in a form composed evenly of disjointed parts and massive parts;

[0212] 4: The sample is in a form composed mostly of massive parts and partly of disjointed parts; and

[0213] 5: The sample is in a massive form.

TABLE-US-00002 TABLE 2 Liquid Aqueous-liquid absorbing part diffusion Crosslinked part Absorbent polymer Hydrophilic Nonwoven Retention No. article particles (A) fibers (c) fabric (B) of shape Example 1 1 A-1 No B-1 5 2 2 A-2 No B-2 5 3 3 A-3 No B-3 4 4 4 A-4 No B-4 4 5 5 A-5 No B-5 3 6 6 A-1 No B-6 4 7 7 A-1  20 parts B-7 4 8 8 A-1 No B-8 3 9 9 A-1  5 parts B-1 4 10 10 A-1  20 parts B-1 5 11 11 A-1  80 parts B-8 2 12 12 A-1  50 parts B-7 3 13 13 A-1  20 parts B-9 5 14 14 A-1  20 parts B-3 4 Comparative 1 H2 No 100 parts B-8 1 Example 2 H1 A-1  20 parts HB-1 1

[0214] As shown in Table 2, the absorbent articles of the present invention were superior to comparative absorbent articles in absorber retention after swelling. Therefore, it is easily expected that when the absorbent article of the present invention is used, it is superior in the retention of the shape of an absorber and in the absorbability for an aqueous liquid even when an external force is applied thereto, and even if a certain force is continuously or discontinuously applied to an absorbing site, neither rupture nor twist of the absorbing part occurs and liquid leakage is not caused by degradation of absorption performance, and rash of the skin, etc. derived therefrom are not caused.

INDUSTRIAL APPLICABILITY

[0215] The absorbent article of the present invention is useful for a disposable diaper for children, a disposable diaper for adults, a sanitary napkin, a pet sheet, a pantyliner, an incontinence pad, a sweat absorbent sheet, a blood absorbent article for medical use, a wound-protecting material, a wound-healing agent, a surgical drainage disposal agent, etc.