JP2001314444A - Absorbing goods - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide absorbing goods such as a disposable paper diaper which are manufactured continuously with a high efficiency by using a specified paper composing the absorbing body as a base paper in manufacturing the absorbing body, excellent in absorbing properties, and without failure such as leakage of polymer by breaking base paper. SOLUTION: The absorbing goods are provided with a liquid permeable surface sheet 2, a liquid impermeable leakage proof sheet 3 and a liquid retaining absorbing body 4. The absorbing body is provided with a liquid absorbing and retaining layer 43. A skin side and/or reverse side of the liquid absorbing and retaining layer 43 is covered with pieces of paper 44, 45 with an air permeability less than 4.0 seconds (300 ml.32 sheets), a strength in MD direction in dry state more than 500 cN/25 mm and a strength in CD direction in wet state more than 60 cN/25 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorbent article such as a disposable diaper which can be continuously produced efficiently, has excellent absorption performance, and does not cause inconvenience such as polymer leakage during use.

[0002]

2. Description of the Related Art In recent years,
BACKGROUND ART Absorbent articles such as disposable diapers tend to reduce the thickness of the entire product by reducing the thickness of the absorber. In order to reduce the thickness of the absorber, it is effective to reduce the amount of fiber components such as pulp fibers.However, if the amount of fiber components is reduced, it is necessary to disperse the superabsorbent polymer in a desired state in the absorber. Becomes difficult. In order to solve this processing problem, there is a method of directly laminating the fiber component and the superabsorbent polymer on the backing paper. The suction power of the machine is low, and it is not possible to control the mixed pile as desired. For this reason, it is conceivable to use a backing sheet with a coarse mesh and good air permeability, but such a backing sheet tends to be insufficient in strength, causing trouble on the processing machine, or the backing sheet is broken when using absorbent articles. Problems such as leakage of the superabsorbent polymer occur.

[0003] Accordingly, an object of the present invention is to use a predetermined paper constituting an absorbent body as a backing sheet in the manufacture of the absorbent body so that it can be efficiently and continuously produced and has excellent absorption performance. An object of the present invention is to provide an absorbent article such as a disposable diaper which sometimes does not cause inconvenience such as polymer leakage due to a break in the mount.

[0004]

According to the present invention, there is provided an absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable leak-proof sheet, and a liquid-retentive absorbent, wherein the absorbent is a high-absorbent material. A liquid absorption / retention layer containing an absorbent polymer is provided, and the skin contact surface side and / or the non-skin contact surface side of the liquid absorption / retention layer has an air permeability of 4.0 seconds / (300 ml / 32 sheets) or less. The above object has been achieved by providing an absorbent article coated with paper having a strength of 500 cN / 25 mm or more in a dry MD direction and a strength of 60 cN / 25 mm or more in a wet CD direction.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on a preferred embodiment. The disposable diaper 1 as an absorbent article of the present embodiment has a liquid-permeable topsheet 2,
An absorbent body 10 having a liquid-impermeable leak-proof sheet 3 and a liquid-retentive absorber 4, a back part A and an abdominal part B, and the back part A and the abdominal part B Each side edge A
A pants section 11 in which a waist opening and a pair of leg openings are formed by joining 1, B1, A2, and B2. The absorbent main body 10 is fixed to a substantially central portion of the pants portion 11. FIG. 1 shows a state in which the diaper 1 is developed by peeling off joints between the both side edges of the back part A and the both side edges of the abdominal part B in the pants 11.

The disposable diaper 1 will be described more specifically. The absorbent body 4 has a vertically long shape and is sandwiched and fixed between the top sheet 2 and the leak-proof sheet 3. A sheet material for forming a three-dimensional guard having an elastic member 51 on one side edge is located on each side of the absorbent main body 10, and the one side edge is located on the skin contact surface side of the absorber 4. Further, a pair of left and right three-dimensional guards 5 and 5 are formed such that the other side edge is located on the non-skin contact surface side of the absorber 4. Leg elastic members 12 are arranged on the peripheral edges of the pair of leg openings, respectively, to form leg gathers.
Elastic members (not shown) are similarly arranged around the waist opening to form waist gathers.

The absorbent body 4 of the disposable diaper 1 is provided with a liquid absorption / retention layer 43 containing the superabsorbent polymer 41, and the liquid absorption / retention layer 43 is in contact with the skin (FIG. 2).
Is covered with a first sheet 44 as the paper, and the non-skin contact surface side (the lower side in FIG. 2) of the liquid absorption / retention layer 43 is covered with a second sheet 45 which is another paper. I have. The first sheet 44 covers the entire surface of the liquid absorption / retention layer 43 on the skin contact surface side. In addition, the second sheet 45 covers the entire surface of the liquid absorbing and retaining layer 43 on the non-skin contact surface side and both edge portions in the diaper width direction. The holding layer 43 is adhered to the first sheet 44 on the skin contact surface side.

The first sheet 44 covering the skin contacting surface side of the liquid absorption / retention layer 43 has an air permeability of 4.0 seconds / (300 ml × 32 sheets) or less according to JIS-P8117. It is preferably 3.0 seconds / (300 ml × 32 sheets) or less. The absorber 4 in the present embodiment includes a first sheet 4
4 was obtained as a mount for stacking, specifically,
A superabsorbent polymer 41 and a fiber component 42 as another component constituting the liquid absorption / retention layer 43 are directly formed on the first sheet 44 to form the first sheet 4.
If the air permeability of Sample No. 4 is higher than 4.0 seconds / (300 ml, 32 sheets), the suction force of the processing machine is reduced during stacking, and the mixed stacking cannot be controlled as desired. Therefore, the air permeability of the first sheet 44 is 4.0 seconds / (300 ml × 32 sheets).
If it is higher than this, a high-quality absorber cannot be obtained, and the quality of the diaper, such as absorbency and shape retention, will deteriorate. The first
The air permeability of the sheet 44 is preferably 0.8 seconds / (300 ml × 32 sheets) or more from the viewpoint of obtaining a predetermined strength described later.

Here, the air permeability can be measured as follows according to JIS-P8117. That is,
The first sheet 44 is cut into 70 × 70 mm,
The time required for 300 ml of air to pass through is measured using an air permeability meter [GURLEY DENSOMETER (trade name) manufactured by Kumagaya Riki Kogyo Co., Ltd.].

The first sheet 44 has a strength in the MD direction in a dry state of 500 cN / 25 mm or more, preferably 800 cN / 25 mm or more. M in dry state
If the strength in the direction D is less than 500 cN / 25 mm, the sheet 44 may be torn or cut when the first sheet is fed from the roll and supplied to the diaper production line.

The first sheet 44 has a strength in the CD direction in a wet state of 60 cN / 25 mm or more, preferably 90 cN / 25 mm or more. If the strength of the first sheet 44 in the wet state in the CD direction is less than 60 cN / 25 mm, there is a possibility that the sheet 44 will be broken when used as a diaper, and inconveniences such as leakage of the water-absorbing polymer will occur. The strength in the MD direction in the dry state and the strength in the CD direction in the wet state of the first sheet 44 are each preferably as high as possible, and there is no particular upper limit. However, considering the balance with the preferable air permeability, the strength is 2500 cN / 25 mm or less in order. 250c
It is preferable that it is N / 25 mm or less. The first sheet 44 has a dry strength of 200 cN / 2 in the CD direction.
5 mm or more, MD strength in wet state is 200 cN /
It is preferably 25 mm or more.

Here, the strength of the first sheet 44 in the MD and CD directions in a dry state can be measured as follows. Here, the dry state refers to a state of being left for 24 hours under the conditions of a temperature of 20 ° C. and a humidity of 65% in accordance with JIS P-8111. The strength in the MD direction was determined by cutting a test piece having a length of 150 mm in the same direction (MD direction) as the flow direction during papermaking and a width of 25 mm in a direction perpendicular to the flow direction (CD direction) from the first sheet. Using a Tensilon tensile tester [manufactured by Orientec Co.]
A tensile test is performed at a tensile speed of 300 mm / min in the MD and MD directions. Then, the breaking strength at that time is measured. CD
The strength in the direction is 25m in the MD direction from the first sheet.
m, a test piece having a length of 150 mm in the CD direction is cut out, and the distance between chucks is set to 50 m using the above Tensilon tensile tester
A tensile test is performed at a tensile speed of 300 mm / min in the m and CD directions, and the breaking strength is measured in the same manner.

The strength of the first sheet 44 in the wet state is as follows. In the MD direction and the CD direction, the first sheet is cut out to the same size as the above-mentioned dry state, and water is sufficiently sprayed by spraying. The strength is measured in the same manner as the strength measurement in a dry state.

The first sheet 44 has a basis weight of 10
It is preferably from 25 to 25 g / m ² , particularly from 15 to 18 g / m ² , from the viewpoint of achieving both air permeability and strength.

The first sheet having the above-described air permeability, strength, and basis weight includes, for example, pulp fibers having an average fiber diameter of 0.3 to 1.5 mm obtained with a beating degree of 550 to 750;
A pulp fiber can be easily produced by making a pulp fiber from a papermaking liquid containing a paper strength enhancer according to a conventional method. As the pulp fiber, the average fiber diameter is 0.3 to 1.5.
mm, especially 0.5 to 1.0 mm, is preferable because preferable air permeability and strength can be easily achieved. Specifically, the product name "Albasel" [Internarional Paper Co.
)) Can be used. As the paper strength agent, a commonly used chemical such as a dry paper strength agent or a wet paper strength agent can be used. Various known materials can be used as the dry paper strength agent, and examples thereof include carboxymethyl cellulose, polyvinyl alcohol, and polyacrylamide. Specifically, commercially available products under the trade names “Gohsenol” (Nippon Gohsei Chemical Industry Co., Ltd.) and “Selogen” (Daiichi Kogyo Seiyaku Co., Ltd.) can be used. As the wet paper strength agent, various known materials can be used, for example, urea-formalin resin, melamine-
Examples include formalin resin, dialdehyde starch, polyethyleneamine, epoxidized polyamide resin, and methylolated polyamide. Specifically, commercially available products such as trade name “Kaimen” (manufactured by Dick Hercules KK) can be used. The amount of the paper strength enhancer is preferably from 0.3 to 4.0%, more preferably from 0.8 to 2 based on the amount of the pulp fiber, from the viewpoint of efficiently exhibiting the effect of the compounding. More preferably, it is 0.0%.

Next, the material for forming the disposable diaper will be described. Top sheet 2, leakproof sheet 3, sheet material and elastic member 51 for forming a three-dimensional guard, leg portion elastic member 12 forming pants portion 11, sheet material 13 and waist elastic member, and height forming absorber 4 As the water-absorbing polymer 41 and the fiber component 42, various known polymers used for absorbent articles such as disposable diapers can be used without particular limitation. As the fiber component 42, a pulp fiber or a nonwoven fabric is preferable. Also, the second
The material for forming the sheet 45 is preferably a paper having the same physical properties as the above-described first sheet 44 in terms of air permeability and strength, but may be paper having different physical properties from the first sheet 44. It may be. The content of the superabsorbent polymer 41 in the liquid absorption holding layer 43 is not particularly limited, but is not less than 60% by weight, particularly 70 to 95% by weight.
It is preferred that

The disposable diaper 1 can be efficiently manufactured through the following steps, ie, a fiber stacking step, an absorbent body manufacturing step, an absorbent main body manufacturing step, and an absorbent main body arranging step. .

That is, in the stacking process, the first sheet 4
The liquid absorbing and retaining layer 43 is formed on the first sheet 44 by sucking from the back surface side of 4 and depositing the superabsorbent polymer 41 and the fiber component 42 such as pulp fiber on the first sheet 44. Instead of this method, the fiber component 42 such as pulp fiber or non-woven fabric is preliminarily laminated on the first sheet 44 to obtain a laminated sheet, and the superabsorbent polymer 41 is placed on the laminated sheet to form the first sheet 44. It may be suctioned from the back side and deposited.

In the manufacturing process of the absorbent body, the second sheet 45 is arranged on the surface of the liquid absorbing and retaining layer 43 formed in the fiber stacking step opposite to the first sheet 44 side to obtain the absorbent body 4. . And in the manufacturing process of an absorptive main body, the absorber 4 obtained in the manufacturing process of the absorber is
The absorbent body 10 is obtained by holding the sheet between the topsheet 2 and the leakproof sheet 3 such that the 4 side faces the leakproof sheet 3 side. Then, in the step of disposing the absorbent main body, the obtained absorbent main body 10 is disposed and fixed at a predetermined position of the diaper, specifically, substantially at the center of the pants portion 11. Then, both side edges of the back part A and the abdominal part B of the pants part 11 to which the absorbent main body 10 is fixed are joined to obtain the diaper 1.

The diaper 1 of the present embodiment includes a first sheet 44.
However, since it satisfies the above-described conditions of air permeability and strength, the dispersion of the superabsorbent polymer in the fiber-laying step can be easily controlled to a desired state, and in a continuous production line, One sheet 44 can be stably conveyed. Therefore, efficient production is possible, and the absorption performance is excellent. In addition, even during use, the first sheet 44 is not broken, and problems such as leakage of the superabsorbent polymer do not occur.

The first sheet 44 is made of the liquid absorbing and retaining layer 4.
3, the liquid such as urine discharged onto the topsheet 2 is quickly absorbed into the liquid absorption / retention layer 43. Therefore, a diaper having more excellent absorption performance and excellent liquid leakage prevention properties can be obtained.

Although the embodiment of the present invention has been described above, the present invention can be variously modified. For example, instead of the first sheet 44 or together with the first sheet 44, the second sheet 45 disposed on the non-skin contact surface side of the liquid absorption / retention layer 43
May be paper that satisfies the conditions of the air permeability and the strength of the first sheet 44 described above. According to the diaper having such a configuration,
By using the second sheet as the backing sheet in the stacking process, a high-quality absorber 4 can be obtained.
5 does not break during the diaper manufacturing process and when the diaper is used. Therefore, the same effect as in the above embodiment is obtained.

Further, the MD direction of the first sheet may coincide with either the longitudinal direction or the width direction of the diaper. Further, the present invention can be applied to a pants-type disposable diaper, a deployable disposable diaper, an incontinence pad, a sanitary napkin, and the like.

[0024]

EXAMPLE 1 A diaper having the structure shown in FIGS. 1 and 2 was manufactured according to the above-described method of manufacturing a diaper. First
As the sheet, paper having physical properties shown in Table 1 was used.

[0025]

[Table 1]

The following materials were used for forming the liquid absorption holding layer. Super absorbent polymer: Aquaric CAW-90 (trade name), manufactured by Nippon Shokubai Fiber component: Pulp fiber

[Comparative Examples 1 and 2] Diapers were manufactured in the same manner as in Example 1 except that papers having physical properties shown in Table 1 were used as the first sheets.

Comparative Example 3 Using the paper having the physical properties shown in Comparative Example 3 in Table 1 as the first sheet, diaper production was attempted in accordance with the diaper production method described above. However, the diaper could not be manufactured because the MD strength of the paper used for the first sheet in a dry state (MD strength when dried) was 500 cN / 25 mm or less. In the item of the running property of the production line in Table 1, “○” means that the paper ran stably without being cut or torn on the production line, and the diaper could be stably produced continuously. However, "x" means that the diaper could not be manufactured because the paper was cut or torn on the manufacturing line.

[Evaluation of Uniformity of Stacked Fibers] For each diaper of Example 1 and Comparative Examples 1 and 2, the uniformity of the stacked fabrics of the respective absorbents was evaluated according to the following criteria. ：: The superabsorbent polymer and the pulp fiber are uniformly mixed, and the basis weight of the absorber is also uniform. X: A part with many superabsorbent polymers and a part with many pulp fibers are recognized, and the basis weight of the absorber is also non-uniform.

[Evaluation of Absorbing Performance] Example 1 and Comparative Example 2
About each diaper, absorption performance was evaluated as follows. That is, each diaper was developed as shown in FIG. 1, and the angle was inclined to 45 with the skin contact surface side (top sheet 2 side) facing upward. And while holding the diaper in an inclined state,
40 cc of simulated urine was injected onto the topsheet 2 at 5 cc / sec, and the distance that the simulated urine moved on the topsheet 2 was measured. Then, another 80 cc of pseudo urine was added to 40 cc
Injections were made in the same manner at 5 minute intervals, and the migration distance of the pseudo urine was measured when 40 cc was injected (total 80 cc) and when 80 cc was injected (total 120 cc). Table 1 shows the average value of the moving distance in these three injections.

[Evaluation of the difficulty of tearing the mount of the diaper] The diapers of Example 1 and Comparative Examples 1 and 2 were evaluated for the difficulty of tearing the diaper mount in the following manner.
Each diaper was developed, and 80 cc of pseudo urine was injected into the crotch at a time. After standing for 5 minutes, the crotch side portion was squeezed left and right 20 times, and visually observed whether or not the diaper mount (first sheet) was torn. The evaluation was performed in Example 1 and Comparative Examples 1 and 2.
10 diapers were used. Table 1 shows the number of diapers in which the mount was torn out of 10 sheets.

From the results shown in Table 1, it can be seen that the diaper of the present invention, particularly the diaper in which the paper having the above-mentioned physical properties is disposed on the skin contacting side of the liquid absorbing and retaining layer, has excellent absorption performance. . In addition, from the results of the evaluation of the difficulty of tearing the backing sheet, the diaper of the present invention, particularly a diaper in which the paper having the above physical properties is arranged on the skin contacting surface side of the liquid absorbing and retaining layer has a sufficient mounting strength,
It is clear that the superabsorbent polymer does not leak due to the backing being broken, and it is excellent.

[0033]

As described above, the absorbent article of the present invention can be efficiently and continuously produced by using the predetermined paper constituting the absorbent body as a backing sheet for the production of the absorbent body, and has excellent absorption performance. In use, there is no inconvenience such as leakage of polymer due to tearing of the backing paper.

[Brief description of the drawings]

FIG. 1 is a plan view of a disposable diaper as one embodiment of the present invention as viewed from a skin contact surface side in a deployed state.

FIG. 2 is a sectional view taken along line XX of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disposable diaper (absorbent article) 2 Top sheet 3 Leak-proof sheet 4 Absorber 41 Superabsorbent polymer 42 Fiber component 43 Liquid absorption holding layer 44 First sheet 45 Second sheet A Back side B Abdominal side P Skin contact Contact surface Q Non-skin contact surface

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3B029 BA05 BA13 BA18 BD18 4C098 AA09 CC03 CC08 CC12 CE05 CE06 DD03 DD04 DD05 DD06 DD10 DD23

Claims (3)

[Claims] 1. An absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable leakproof sheet, and a liquid-retentive absorber, wherein the absorber has a liquid-absorbent containing a highly absorbent polymer. The liquid absorption / retention layer has a skin contact surface side and / or a non-skin contact surface side with an air permeability of 4.0 seconds / (300 ml · 32
Hereafter, the strength in the MD direction in the dry state is 500 cN / 25.
mm or more, strength in the CD direction in a wet state 60 cN / 25 m
m. Absorbent articles covered with paper of at least m. 2. The paper has a basis weight of 10 to 25 g / m.
^2. The absorbent article according to claim 1, which is ² . 3. The absorbent article according to claim 1, wherein the skin contact surface side of the liquid absorption / retention layer is covered with the paper.