JP3155368B2 - Absorbent articles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorbent article, and more particularly, to an absorbent article such as a disposable diaper or sanitary napkin using a suitable absorbent.

[0002]

2. Description of the Related Art Absorbent articles such as disposable diapers, sanitary napkins, incontinent pads and the like are mainly provided at the center of the body with an absorbent body for absorbing and retaining body fluids such as urine and menstrual blood excreted from the body. A flexible liquid-permeable topsheet disposed on the side in contact with the body, and a liquid-impermeable backsheet disposed on the opposite side in contact with the body. The absorber is usually composed of pulp fibers and a water-absorbing polymer. The absorbent article temporarily holds urine and the like that have entered through the nonwoven fabric with pulp fibers, and then holds body fluid with a water-absorbing polymer. At this time, the water-absorbing polymer swells and the volume of the absorber increases. Generally, when the amount of the absorbent polymer is increased to improve the water absorption of the absorbent, the amount of pulp in the absorbent is relatively reduced, and the entanglement is reduced, so that when the water absorbent polymer swells. In addition, if a compressive or shearing force is applied during the movement of the baby, the absorber may be broken or biased, causing absorption inhibition. As a method of preventing such absorption inhibition, a hot-melt fiber is mixed into pulp fibers to express adhesive force between the hot-melt fibers and between the pulp fiber and the hot-melt fiber, thereby improving shape retention. There are ways to improve it. As proposals for improving the shape stabilization of the absorber by mixing hot-melt fibers, JP-A-63-92701, JP-A-63-318941, and JP-A-63-2
60555 and JP-A-2-74254.

[0003]

However, the incorporation of hot-melt fibers used for the shape-retaining property of the absorber increases the rigidity of the absorber itself and expresses a large resistance to external deformation stress. However, since the hot-melt fiber itself is hydrophobic, there is a possibility that absorption may be impaired. Further, a heat melting system is required on the production line, and the production speed is restricted in consideration of the melting time. Furthermore, depending on the blending type, amount, and melting temperature of the hot-melt fiber, the absorber becomes too hard, and there is a possibility that a problem may occur in terms of texture. Therefore, an object of the present invention is to provide an absorbent article which stably maintains the shape of an absorbent body during absorption of a body fluid without requiring a heat treatment step or the like, has no absorption inhibition, and is further excellent in texture.

[0004]

The present invention comprises a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber interposed therebetween, wherein the absorber is made of pulp fiber and pulp fiber. in the absorbent article has a water-absorbing polymer mainly comprising the absorbent body, a long hydrophilic fibers than pulp fibers fiber length (not including the hot-melt fibers) in the pulp fibers, the pulp
The above object has been achieved by providing an absorbent article characterized by being dispersed in a fiber in an amount of 3 to 12% by weight . Water-absorbing polymer of the upper Symbol absorber on pulp fibers is preferably 100 to 500 wt%, a long fiber length than the "pulp fibers of the absorbent body
The fineness of the “hydrophilic fiber” (hereinafter also referred to as hydrophilic long fiber) is preferably 0.5 to 5 d, and the hydrophilic long fiber is a hydrophilic fiber having a water content (fiber moisture content) of 10% or more. Preferably, there is.

[0005]

In the absorbent article, since the hydrophilic long fibers have an appropriate moisture content and are longer than the pulp fibers, the shape is maintained even before absorbing the body fluid. When the absorbent article absorbs bodily fluid, the bodily fluid is sufficiently retained by the absorbent polymer, and even if the amount of pulp in the absorbent is relatively reduced,
Since the hydrophilic long fibers are entangled with the pulp fibers, even if compression or shearing force is generated during the movement of the wearer, there is no possibility that the absorber will be cracked, and there will be no deviation. In addition, since the hydrophilic long fibers are hydrophilic fibers dispersed without heat treatment,
As a whole, the texture of the absorber is appropriately maintained, and there is little possibility that the body fluid absorption is inhibited.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the absorbent article according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of an absorbent article (disposable diaper) according to the present invention, FIG.
(b) is a sectional view and a partial plan view of the absorbent body of the absorbent article of FIG. 1, and FIG. 3 is a perspective view of a measuring device for measuring the liquid absorbency of the absorbent article according to the present invention. As shown in FIGS. 1 and 2, the absorbent article according to the present invention (disposable diaper 1)
Has a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and an absorber 4 interposed therebetween, and the absorber 4 mainly includes pulp fibers 6 and a water-absorbing polymer 7. In this respect, the configuration is the same as that of the conventional absorbent article. Thus, in the absorber 4, the hydrophilic long fiber 8 having a longer fiber length than the pulp fiber 6 and containing no hot-melt fiber was dispersed in the pulp fiber 6 by 3 to 12% by weight based on the pulp fiber 6 . Things.

[0007] The present invention will be described in more detail, disposable
The diaper 1 includes a top sheet 2, a back sheet 3, an absorber 4,
And the fasteners 5a and 5b, and the absorber 4 is covered with the top sheet 2 and the back sheet 3 on the upper surface. The surface sheet 2 is not particularly limited as long as it has a sufficient liquid permeability, and examples thereof include a woven fabric, a nonwoven fabric, and a porous sheet. Examples of the material include pulp, rayon, polyester, polyethylene, Polypropylene and the like. Core / sheath type thermally binder fibers consisting of polyester / polyethylene is found using the surface sheet 2 of FIG. Backsheet 3, a liquid if the sheet liquid-impermeable conventionally used in absorbent articles that are particularly limited by stretching by adding filler to <br/> a bur, a thermoplastic resin not A vapor-permeable sheet that is permeable and allows vapor to pass therethrough is preferable, and a sheet having a feeling close to the skin, for example, a composite material of the above-described film and nonwoven fabric, or a composite material of a film and woven fabric may be used. it can.

As shown in FIG. 2, the absorber 4 is composed of pulp fibers 6, a water-absorbing polymer 7, and a hydrophilic long fiber 8 having a longer fiber length than the pulp fibers, and has a predetermined shape according to the purpose of the absorbent article. For example, an hourglass type is preferable for a disposable diaper, and the disposable diaper 1 of the present embodiment is a long one. Also, the thickness of the absorber 4 is formed to an appropriate thickness according to the purpose of the absorbent article. The pulp fiber 6 is not particularly limited as long as it has been conventionally used for the absorbent, but the average fiber length of the pulp fiber is usually 0.8 in consideration of pulverization, lamination, compression treatment and the like.
It is desirably in the range of 3 mm. The water-absorbing polymer 7 is not particularly limited as long as it has been conventionally used for the absorber. In the present invention, it is particularly preferable to use a super-absorbing polymer, and the liquid absorption of the super-absorbing polymer is 20 watts. / W or more. Specific water-absorbing polymers include sodium polyacrylate, vinyl alcohol acrylate copolymer, sodium polyacrylate cross-linked product, starch-acrylic acid graft polymer, isobutylene-maleic anhydride copolymer or a saponified product thereof, Powders such as potassium polyacrylate and cesium polyacrylate are preferred. 100 to 500% by weight, especially 130 to 400% by weight, based on the pulp fiber
When used in this range, the body fluid of the absorber is sufficiently absorbed and the shape retention of the absorber is sufficiently maintained.

[0009] The length of the hydrophilic long fibers 8, ones used fiber length is longer than the fiber length of the pulp fibers 6, the pulp fibers 6
It is distributed to. Such a long fiber length makes pulp fiber and fiber entanglement sufficient ,
Even if the hot-melt fibers are not used, the shape retention of the absorber 4 can be sufficiently exhibited. The specific fiber length of the hydrophilic long fiber 7 is
It is desirable to be as long as possible from the viewpoint of the fixing effect,
5mm considering both dispersibility to pulp and fixing effect
５０50 mm, preferably about 7 mm〜30 mm.
The hydrophilic long fibers 8, it is important that the moisture content is a hydrophilic fiber is 10% or more, when the moisture content is 10% or more, the liquid in the fiber at the point where the absorber 4 has absorbed the body fluid At the same time, the fibers adhere to each other due to the moisture on the fiber surface, and the entanglement between the fibers is synergistically contributed to the shape retention of the absorber 4. When the moisture content of the hydrophilic long fibers 8 falls below 10%, it becomes difficult to take in bodily fluid into the fibers, and as a result, the adhesive force between the fibers is reduced, and the fixing effect is reduced. Also,
The hydrophilic long fibers 8 are desirably as thin as possible from the viewpoint of the fixing effect of the absorber 4, but the fiber diameter is 0.5 to 5 in consideration of the productivity of the fibers and the dispersibility in pulp.
d, particularly preferably 0.7 to 4d.

The hydrophilic fiber material used for the hydrophilic long fiber 8 is not particularly limited as long as it can be selected within a desirable range of fiber length, fiber diameter and moisture content. , Rayon, cotton, wool, hemp and the like can be used alone or in combination. Hydrophilic long fibers 8, to the pulp fibers 6, Ru 3 to 12 wt% der. The amount is 3
Fixed effect is less than% by weight is not sufficiently expressed, 12
If the content exceeds% by weight, the thickness of the absorber 4 is increased, which is disadvantageous in cost.

In the disposable diaper 1 constructed as described above, there is no danger that the absorbent body 4 will be biased when worn, and that it will not be broken even if the baby moves under compression or shearing force. Does not occur. Further, in the above embodiment, the absorbent article is described as a disposable diaper. However, in the case of a sanitary napkin or the like, the texture is good and the wearing feeling does not cause a problem. Accordingly, the absorbent article of the present invention, the absorbent product article shape retention is required, it can be suitably applied.

Hereinafter, embodiments according to the present invention will be described, provided that:
The present invention is not limited to the following embodiments. (Example) Rayon fiber as a hydrophilic long fiber in sheet pulp (Example sample 1: 0.8 d × 10 m at a moisture content of 14.8%)
m, Example sample 2: 1.1 at a moisture content of 14.1%.
5 × 30 mm) was added to the pulp at 12% by weight and pulverized. At the same time, the water-absorbing polymer was mixed at 200% by weight with respect to the pulp, laminated and compressed, and the basis weight was 390 g / m ² and the density was 390 g / m ² . An absorbent of 0.2 g / cm ³ was prepared, and its water content, wet strength and maximum absorption were measured. In Example Sample 2, the rayon fibers, even those pulp 6 as added weight% and 3 wt% added pressure, measuring the wet strength and the maximum absorption amount as each sample of Example 3 and Example Sample 4 did. The results are shown in Table 1. As shown in [Table 1], the obtained absorber
All had a moisture content of 12%. (Comparative Example) Comparative Example Sample 1 was prepared in Example (Example Sample 1) without adding rayon fiber.
Further, instead of the rayon fiber, a polyethylene - and as sample 2 which was made by adding polypropylene composite fibers (2d × 50 mm) operation. Instead of rayon fibers, and as sample 3 obtained by made by adding polyethylene terephthalate (2d × 50 mm) operation. Furthermore,
Polyethylene-polypropylene conjugate fiber (2d × 50 mm) was added instead of rayon fiber,
Comparative Example Sample 4
And The results are shown in Table 1.

[Measurement method] (1) Fiber moisture content (moisture content ) The fiber moisture content was determined according to the moisture content test method of JIS L1013. That is, the sample was heated at a temperature of
Pre-dry for hours. The sample is left in a standard test room at a temperature of 20 ± 2 ° C. and a relative humidity of 65 ± 2% to make moisture absorption constant and uniform. Then, leave an interval of one hour or more
And weigh twice before and after, and the difference in weight before and after
Within a certain percentage of (0.1% by weight of cellulosic fiber)
The resulting state is defined as a constant weight in water equilibrium, and the constant weight is defined as a weight before drying. Next, the sample having the constant weight was subjected to temperature 1
Placed in 05 ± 2 ℃ dryer moisture is evaporated until the weight difference before and after the time of dry 10 minutes, is within the weight constant rate after (0.1 wt% cellulose fiber system) Dry
Measuring the absolute dry weight of the sample is, determine the water content by the following equation, further again by the same operation, fiber in the average of two
Represents the moisture content of fibers . Fiber water content (%) = (W−W ′ / W ′) × 100 where W: weight before drying (g), W ′: absolute dry weight (g)

[0014] (2) wet strength wet strength index, turn absorber above 70 mm × 60 mm, which was added physiological saline 20 cc, after standing for 5 minutes, between chucks 50 mm, sample width 60 mm, tensile speed of 300mm / Mi
The maximum value of the breaking strength at n. This maximum is 120
When the g / g is 60 mm or more, it has been confirmed that there is actually no crack in the absorber when used as a diaper. (3) Maximum absorption amount The maximum absorption amount is 200 mm x 150 mm, and the above-mentioned absorber is prepared and placed on a 45-degree inclined surface of an inclined table as shown in FIG. (140mm x from the end
75 mm). That is, at that point, 50 cc of physiological saline corresponding to the excretion amount of one infant was injected at a rate of 5 cc / sec at intervals of 5 minutes. Here, the maximum absorption amount is the maximum amount of physiological saline that can be held in the absorber. The maximum absorption required for disposable diapers is four urine volumes (20
0cc), which was our goal. (4) Absorption rate of superabsorbent polymer liquid Superabsorbent polymer kept at a constant temperature and humidity of 65% at 20 ° C.
Weigh 00 g. Add this to excess saline (about 150
cc) and let the polymer equilibrate swell for 30 minutes.
Leave for a minute. Thereafter, a non-woven bag (15 ×
15 cm), centrifugally dehydrated for 3 minutes at a rotation speed of 1420 rpm and a centrifugal acceleration of 250 G, and immediately weigh the weight of the swollen polymer. From this value, polymer weight (1.00 g)
The value obtained by subtracting the value is the absorptivity of the highly absorbent polymer liquid (w / w)
And

[0015]

[Table 1]

From the above results, it can be seen that the sample of Example 4 has a certain amount of wet strength (shape retention of the absorber) although the amount of the hydrophilic long fiber added is small. Further, even if the comparative samples 2 and 3 show some degree of wet strength,
It can be seen that the absorbency deteriorates.

[0017]

The absorbent article according to the present invention stably maintains the shape of the absorbent body when absorbing bodily fluids without requiring a heat treatment step or the like, has no absorption inhibition, and is excellent in texture.

[Brief description of the drawings]

FIG. 1 is a sectional view of a disposable diaper according to the present invention.

FIGS. 2 (a) and (b) are a cross-sectional view and a plan view of an absorbent body of the absorbent article of FIG.

FIG. 3 is a perspective view of a measuring device for measuring the liquid absorbency of the absorbent article according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disposable diaper 2 Top sheet 3 Back sheet 4 Absorber 6 Pulp fiber 7 Superabsorbent polymer 8 Hydrophilic long fiber

──────────────────────────────────────────────────の Continuation of front page (56) References JP-A-61-28003 (JP, A) JP-A-2-74254 (JP, A) Jiko 56-6098 (JP, Y2) 504144 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) A61F 13/53 A61F 5/44 A61F 13/15 A61F 13/49 D04H 1/40

Claims (4)

(57) [Claims] A liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber interposed therebetween;
In the absorbent article, wherein the absorbent is mainly composed of pulp fibers and a water-absorbing polymer, the absorbent includes a hydrophilic fiber having a fiber length longer than that of the pulp fiber (not including a hot-melt fiber), and the pulp fiber includes : The pal
An absorbent article characterized in that it is dispersed in an amount of 3 to 12% by weight with respect to fiber . 2. The water content of the hydrophilic fiber of the absorber is 10%.
% Or more . 3. The absorbent article according to claim 1, wherein the water-absorbing polymer of the absorbent is 100 to 500% by weight based on the pulp fiber. 4. The fineness of the hydrophilic fiber of the absorber is 0.5.
The absorbent article according to claim 1, wherein the number is from 5 to 5d.