JP2006006743A - Absorbent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve restorability from a packed state of an absorbent used for a body fluid absorbing article such as a paper diaper and a sanitary napkin without increasing weight, thickness or costs. <P>SOLUTION: In the absorbent 10 provided with a fiber assembly 1, the one composed of tow (fiber bundles) constituted of fibers is used for the fiber assembly 1, and compression resilience is turned to 45-60%. Further, it contains the one whose compression energy is in the range of 4.0-7.0gf/cm/cm<SP>2</SP>and the one whose fiber density when the thickness is 10mm is ≤0.0075g/cm<SP>3</SP>. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an absorbent body used for a body fluid absorbent article such as a paper diaper or a sanitary napkin.

  Conventionally, an absorbent body incorporated in a body fluid absorbent article is generally a dispersion of superabsorbent polymer particles in a staple fiber stack. Such body fluid-absorbing articles are sold in the form of vinyl packaging, especially in the field of disposable diapers, in order to accommodate a larger number of body fluid-absorbing articles in one package or in a compact state. It is packed in a compressed state to allow transportation. When using, take out the required number from the package. Thereby, the bodily fluid absorbent article is released from the compressed state.

  However, the conventional absorber has room for improvement in resilience when released from the compressed state. If the restoring property of the absorbent body is not good, the intended absorption performance is not fully exhibited, and otherwise it is not preferable because it gives the user anxiety about the absorption performance.

In response to this problem, it has also been proposed to attach a restoration-only member called a cushion material or a foam material to a body fluid absorbent article (see, for example, Patent Document 1), but in this case, the weight, pressure, or cost There was a problem of causing an increase.
JP 2000-316902 A

  Then, the main subject of this invention is improving the restoring property from a packaging state, without causing the increase in a weight, pressure, or cost.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
An absorbent body having a fiber assembly,
The fiber assembly is made of tow composed of fibers, and the compression resilience RC is 45 to 60%.
Absorber characterized by that.

(Function and effect)
The feature of the present invention resides in that the absorbent body itself has sufficient resilience by using a specific “fiber assembly made of tow” having a compression resilience RC of 45 to 60%. Therefore, since it is not necessary to use a member dedicated to restoration, the restoration from the packaged state can be improved without increasing the weight, pressure, or cost.

<Invention of Claim 2>
Compression energy WC are 4.0~7.0gf · cm / cm ^2, claim 1 absorber according.

(Function and effect)
It is preferable that the compression energy WC is in the range described in this section because the compression can be performed in a compact manner at the same level or higher than before when packaging.

<Invention of Claim 3>
The absorbent body according to claim 1 or 2, wherein the fiber assembly has a fiber density of 0.0075 g / cm ³ or less when the thickness is 10 mm.

(Function and effect)
Although it depends on the fineness and material of the fiber assembly and the bonding level between the fibers, it is usually advantageous in terms of resilience and compressibility when the fiber density is within the range described in this section.

<Invention of Claim 4>
The absorbent body according to any one of claims 1 to 3, wherein the basis weight of the fiber assembly is 0.0075 g / cm ² or less.

(Function and effect)
Although it depends on the fineness and material of the fiber assembly and the bonding level between the fibers, in general, if the fiber basis weight is within the range described in this section, it will be easy to restore and compress, increase in weight and cost. This is advantageous.

<Invention of Claim 5>
The absorber according to any one of claims 1 to 4, wherein the weight is 15 g or less.

(Function and effect)
Even if the weight exceeds 15 g, there are the effect of not using a member dedicated for restoration, the suppression of weight increase and the suppression effect of cost increase itself. However, when this weight is reached, the influence of the weight of the dedicated restoration member on the total weight is reduced, and the significance of configuring the absorbent body using a specific fiber assembly having a high restoring force is diminished. Therefore, from this viewpoint, the weight of the absorber is preferably 15 g or less.

<Invention of Claim 6>
The absorber according to any one of claims 1 to 5, wherein a planar projection area is 400 cm ² or more and a thickness is 1 cm or less.

(Function and effect)
In the present invention, when the size of the absorber is within such a range, the above-described characteristic configuration of the present invention is extremely advantageous in improving the resilience without increasing the weight, pressure, and cost. It is.

  As described above, according to the present invention, it is possible to improve the recoverability from the packaging state without increasing the weight, pressure, or cost.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
<Example structure of absorber>
FIG. 1 schematically shows an example of the structure of an absorbent body according to the present invention. This absorbent body 10 includes a fiber assembly 1 made of tow composed of fibers, a superabsorbent polymer 2, and these. And a wrapping sheet 3 for wrapping.

  More specifically, in the form shown in FIG. 1, a layer made of the superabsorbent polymer 2 is provided on the inner surface of the packaging sheet 3 via an adhesive 4, and a fiber assembly is further provided thereon via an adhesive 5. 1 is provided, and a packaging sheet 3 is bonded onto the fiber assembly 1 via an adhesive. The packaging sheet 3 in the illustrated example is configured so as to wrap the fiber assembly 1 and the superabsorbent polymer 2 by being folded back on both sides, but a form in which the packaging sheet 3 is sandwiched between two upper and lower packaging sheets can also be adopted. .

  When the superabsorbent polymer 2 is bonded to the packaging sheet 3, it is preferable to apply the adhesive 4 in a continuous surface form on the entire surface or substantially the entire surface of the packaging sheet 3 where at least the superabsorbent polymer is provided. . Note that “substantially the entire surface” means 80% of the portion where the superabsorbent polymer is provided. In this case, part or all of the superabsorbent polymer 2 is bonded and fixed to the packaging sheet 3 by the adhesive 4. Moreover, the part which apply | coated the adhesive agent and the part which does not have the some adhesive agent enclosed by the part which apply | coated the adhesive agent are provided, and it adhere | attached with respect to the sheet | seat 3 by the part which apply | coated the adhesive agent It is also preferable to have a superabsorbent polymer and a superabsorbent polymer that exists in a portion that does not have an adhesive. In this case, most of the superabsorbent polymer 2 is constrained in a closed space that does not have an adhesive surrounded by a portion to which the adhesive is applied. In the case of applying the adhesive 4 in a continuous surface shape, curtain coating or roll coating can be used, and it does not have a plurality of adhesives surrounded by a portion where the adhesive is applied and a portion where the adhesive is applied. Spiral coating can be used when providing the portion.

  It is also preferable that part or all of the superabsorbent polymer 2 is bonded and fixed to the fiber assembly 1 with an adhesive 5. In addition, the code | symbol 6 has shown the adhesive agent which adhere | attaches the surface on the opposite side to the polymer side surface of the fiber assembly 1, and the packaging sheet 3. FIG. As these adhesives, an adhesive made of a thermoplastic resin described in the section of the fiber assembly described later can be used.

  2 to 4 show other applications. The form shown in FIG. 2 is different from the form shown in FIG. 1 in that the superabsorbent polymer 7 is held in the fiber assembly 1. The form shown in FIG. 3 is different from the form shown in FIG. 1 in which the superabsorbent polymer 2 is provided only on one side (lower side) of the fiber assembly 1. 2 and 9 are different. In this case, the superabsorbent polymer 9 positioned on the upper side of the fiber assembly 1 can be bonded and fixed to the fiber assembly 1 with the adhesive 8. In the form shown in FIG. 4, the superabsorbent polymer 7 is held in the fiber assembly 21 in the form shown in FIG. 3 as in the case shown in FIG.

  Moreover, when using these absorbers for a body fluid absorbent article, whichever may be used as the body fluid receiving side, in particular, in the form shown in FIGS. 1 and 3, the fiber assembly 1 side is the body fluid receiving side. It is preferable to use for.

  Moreover, FIG. 5 has shown the application example with respect to the paper diaper DP and sanitary napkin NP of the absorber of this invention. As shown in FIGS. 5 (a) and 5 (b), the absorbent body 10 is preferably provided so that the fiber continuous direction of the tow is along the longitudinal direction (front-rear direction) of the article. ), The fiber continuous direction of the tow can be provided along the width direction of the article.

<Fiber assembly>
The fiber assembly 1 used in the present invention is composed of tows (fiber bundles) composed of fibers. Examples of tow fibers include polysaccharides or derivatives thereof (cellulose, cellulose ester, chitin, chitosan, etc.), synthetic polymers (polyethylene, polypropylene, polyamide, polyester, polylactamamide, polyvinyl acetate, etc.), and the like. In particular, cellulose esters and cellulose are preferable.

  As cellulose, cellulose derived from plants such as cotton, linter, and wood pulp, bacterial cellulose, and the like can be used. Regenerated cellulose such as rayon may be used, and the regenerated cellulose may be a spun fiber. The shape and size of cellulose is a continuous fiber that can be regarded as a substantially infinite length and has a long diameter of several millimeters to several centimeters (for example, 1 mm to 5 cm), and a particle diameter of about several microns (for example, 1 to 100 μm). Can be selected from various sizes up to a fine powder. Cellulose may be fibrillated, such as beaten pulp.

  Examples of cellulose esters include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate; mixed acid esters such as cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate acetate; and polycaprolactone Cellulose ester derivatives such as grafted cellulose ester can be used. These cellulose esters can be used alone or in admixture of two or more. The viscosity average degree of polymerization of the cellulose ester is, for example, about 50 to 900, preferably about 200 to 800. The average substitution degree of the cellulose ester is, for example, about 1.5 to 3.0 (for example, 2 to 3).

  The average degree of polymerization of the cellulose ester can be, for example, 10 to 1000, preferably 50 to 900, more preferably about 200 to 800, and the average degree of substitution of the cellulose ester is, for example, about 1 to 3, preferably 1 to 1. 2.15, more preferably about 1.1 to 2.0. The average degree of substitution of the cellulose ester can be selected from the viewpoint of enhancing biodegradability.

  As the cellulose ester, an organic acid ester (for example, an ester with an organic acid having about 2 to 4 carbon atoms), particularly cellulose acetate is suitable. The degree of acetylation of cellulose acetate is often about 43 to 62%, but about 30 to 50% is particularly preferable because it is excellent in biodegradability.

  The tow constituent fiber may contain various additives such as a heat stabilizer, a colorant, an oil agent, a yield improver, a whiteness improver, and the like.

  The fineness of the tow constituent fibers can be, for example, about 1 to 16 denier, preferably about 1 to 10 denier, and more preferably about 2 to 8 denier. The tow constituent fiber may be a non-crimped fiber, but is preferably a crimped fiber. The crimped degree of the crimped fiber can be, for example, 5 to 75, preferably 10 to 50, and more preferably about 15 to 50 per inch. Further, a crimped fiber that is uniformly crimped is often used. When crimped fibers are used, a bulky and light absorbent body can be produced, and a tow with high unity can be easily produced by entanglement between the fibers. The cross-sectional shape of the tow constituting fiber is not particularly limited, and may be any one of, for example, a circular shape, an oval shape, an irregular shape (for example, a Y shape, an X shape, an I shape, an R shape) or a hollow shape. Also good. The tow constituent fibers can be used, for example, in the form of tows (fiber bundles) formed by bundling about 3,000 to 1,000,000, preferably about 5,000 to 1,000,000 single fibers. The fiber bundle is preferably formed by bundling about 3,000 to 1,000,000 continuous fibers.

  Since the entanglement between fibers is weak, a binder having an action of adhering or fusing the contact portions of the fibers can be used mainly for the purpose of maintaining the shape. The binder includes triacetin, triethylene glycol diacetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, citric acid triethyl ester, and other plastic resins, as well as various resin adhesives, especially thermoplastic resins. Can be used.

  The thermoplastic resin is a resin that exhibits an adhesive force when melted and solidified, and includes a water-insoluble or hardly water-soluble resin and a water-soluble resin. A water-insoluble or poorly water-soluble resin and a water-soluble resin can be used together as necessary.

  Examples of water-insoluble or hardly water-soluble resins include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer and other olefinic homo- or copolymers, polyvinyl acetate, polymethyl methacrylate, methacryl Acid methyl-acrylic acid ester copolymer, acrylic resin such as copolymer of (meth) acrylic monomer and styrene monomer, polyvinyl chloride, vinyl acetate-vinyl chloride copolymer, polystyrene, styrene monomer ( Styrenic polymers such as copolymers with (meth) acrylic monomers, polyesters that may be modified, nylon 11, nylon 12, nylon 610, nylon 612 and other polyamides, rosin derivatives (for example, rosin esters), Hydrocarbon resin (eg terpene tree , Dicyclopentadiene resins, and petroleum resins), and hydrogenated hydrocarbon resins. One or two or more of these thermoplastic resins can be used.

  Examples of water-soluble resins include various water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, vinyl monomers, and copolymerizable monomers having a carboxyl group, a sulfonic acid group, or a salt thereof. Vinyl water-soluble resins such as copolymers, acrylic water-soluble resins, polyalkylene oxides, water-soluble polyesters, water-soluble polyamides, and the like can be used. These water-soluble resins can be used alone or in combination of two or more.

  Various additives such as stabilizers such as antioxidants and ultraviolet absorbers, fillers, plasticizers, preservatives, and antifungal agents may be added to the thermoplastic resin.

  The fiber assembly of the present invention made of tow can be produced by a known method, and if necessary, it can be opened in a strip shape so as to have a desired size and bulk. The opening width of the tow is arbitrary and can be, for example, about 100 to 2000 mm, preferably about 150 to 1500 mm. Moreover, the density of an absorber can be adjusted by adjusting the degree of tow opening.

  As a method for opening a tow, for example, a method in which a tow is passed over a plurality of opening rolls and the width of the tow is gradually expanded as the tow progresses, and tension (elongation) and relaxation of the tow ( (Shrinkage) can be repeated, and a method of widening and opening using compressed air can be used.

  FIG. 6 is a schematic diagram showing an example of the opening facility. In this example, the tow 21 serving as a raw fabric is sequentially fed out, and in the conveying process, a widening means 22 using compressed air and a plurality of spread nip rolls 23, 24, 25 having a faster peripheral speed as the downstream roll is combined. After passing through the opened portion and widened / opened, the fiber is passed through the binder addition box 26, and a binder is added (for example, the box is filled with mist of triacetin), and the fibers are made of tow having a desired width and density. The assembly 1 is formed.

The fiber assembly of the present invention, the fiber density at the time of a thickness of 10mm is 0.0075 g / cm ³ or less, is suitable as a particularly 0.0060~0.0070g / cm ^3. Although it depends on the fineness and material of the fiber assembly and the bonding level between the fibers, in the usual case, the fiber density within this range is advantageous in terms of resilience and ease of compression. The fiber density can be adjusted by the degree of opening described above.

The basis weight of the fiber assembly of the present invention is preferably 0.0075 g / cm ³ or less, particularly 0.0060 to 0.0070 g / cm ³ . Usually, when the fiber basis weight is within this range, it is advantageous in terms of resilience and ease of compression, as well as weight and cost. The fiber basis weight can be adjusted by selecting a tow serving as a raw fabric or manufacturing conditions thereof.

<About superabsorbent polymer>
The superabsorbent polymer 2 can be used without any particular limitation, but preferably has a water absorption of 60 g / g or more. Examples of the superabsorbent polymer 2 include starch-based, cellulose-based and synthetic polymer-based polymers, such as starch-acrylic acid (salt) graft copolymer, saponified starch-acrylonitrile copolymer, and sodium carboxymethylcellulose crosslinking. Or an acrylic acid (salt) polymer can be used. As the shape of the superabsorbent polymer, a commonly used granular material is suitable, but other shapes can also be used.

  As the superabsorbent polymer 2 of the present invention, a polymer having a water absorption rate of 40 seconds or less is preferably used. When the water absorption speed exceeds 40 seconds, so-called reversal that the body fluid supplied into the absorbent body returns to the outside of the absorbent body tends to occur.

  As the superabsorbent polymer 2, a polymer having a gel strength of 1000 Pa or more is preferably used. Thereby, even if it is a case where it is set as a bulky absorber by using tow | toe, the sticky feeling after bodily fluid absorption can be suppressed effectively.

The basis weight of the superabsorbent polymer 2 can be appropriately determined according to the amount of absorption required for the use of the absorber. Thus can not be said sweepingly, typically 0.03 g / cm ² or less, particularly preferably be a 0.025~0.010g / cm ^2. By setting the polymer basis weight to 0.03 g / cm ² or less, it is possible to prevent the lightening effect from being hardly exerted by adopting a fiber assembly made of tow depending on the weight of the polymer.

<Packaging sheet>
As the packaging sheet 3 used for the absorbent body 10, a liquid permeable sheet such as a crepe paper, a nonwoven fabric or a perforated sheet, or a liquid impermeable sheet such as a polyethylene film can be used.

<Absorber size and weight>
On the other hand, the size of the absorber 10 is preferably such that the planar projection area is 400 cm ² or more and the thickness is 1 cm or less. When the size of the absorber is within this range, it is extremely advantageous to improve the resilience without increasing the weight, pressure and cost. Moreover, it is preferable to comprise so that the weight of an absorber may be 15 g or less. When the weight of the absorber is within this range, the advantage of not using a dedicated member becomes particularly remarkable.

<Compressive properties of absorber>
In the present invention, the compression resilience RC of the absorbent body 10 is 45 to 60%, particularly 50 to 60%. Thereby, even if it does not use the member only for restoration like the past, it becomes possible to exhibit sufficient restoration property with the absorber itself.

Furthermore, it is preferable that the compression energy WC of the absorbent body 10 is 4.0 to 7.0 gf · cm / cm ² , since it can be compressed more compactly to the same level as before or during packaging.

  These compression characteristics can be adjusted by adjusting the fiber density of the fiber assembly 1 by opening or the like, selecting a fiber material, selecting a kind of binder such as a plasticizer, adjusting the degree of processing, or a combination thereof.

  Table 1 shows an absorbent body (Example) according to the present invention using a fiber assembly made of cellulose acetate fiber tow, a general absorbent body (conventional example) using short fiber pulp, and cellulose acetate fiber The following measurement was performed about the absorber (comparative example) which is using the fiber assembly which consists of a tow but does not satisfy the conditions of the present invention. In Table 1, the evaluation results are also shown.

(Measurement of water absorption of super absorbent polymer)
In a 1 liter beaker containing a rotor, 500.00 ± 0.10 g of 0.9% sodium chloride aqueous solution (prepared by dissolving 9.00 g of reagent-grade sodium chloride in 991.0 g of ion-exchanged water) was added, and magnetic. While stirring the liquid with a stirrer, add 2.000 ± 0.0002 g of sample, cover with Saran wrap and stir for 1 hour.
The beaker content is filtered using a standard sieve (38 μm, 200 mmφ × 45 mm), the gel remaining on the sieve is drained with a Teflon plate and left for 15 minutes. The weight A of the gel remaining on the sieve is measured, and the amount of water absorption is calculated by the following formula.
C = A / S (1)
Here, C is the amount of raw water absorbed (g / g), A is the weight of the gel remaining on the sieve (g), and S is the sample weight (g).

(Measurement of water content of superabsorbent polymer)
About 80% of 0.9% sodium chloride aqueous solution is put into a stainless steel container.
A sample 2.0000 ± 0.0002 g is precisely weighed and placed in a cotton bag (Membrode # 60 100 mm × 200 mm), then about 100 ml of a 0.9% sodium chloride aqueous solution is poured into the cotton bag, and at the same time Is immersed in an aqueous solution in a stainless steel container.
The upper part of the cotton bag is tied with a rubber band and immersed for 15 minutes, then dehydrated for 1 minute with a dehydrator (167G), and the weight of the cotton bag and gel is measured.
The same operation is carried out without putting a sample, and the wet weight of an empty cotton bag is measured.
The water retention amount is calculated by the following formula.
C = (A−B) / S (2)
Here, C: water retention amount (g / g), A: weight of cotton bag and gel (g), B: weight of wet cotton bag when wet (g), and S: sample weight (g).

(Measurement of absorption rate of superabsorbent polymer)
Add 50.00 ± 0.01 g of 0.9% aqueous sodium chloride solution to a 100 ml beaker containing a rotor, and keep the temperature constant at 25 ± 0.2 ° C. in a constant temperature water bath.
Stir at a rotational speed of 600 ± 10 rpm using a magnetic stirrer and rotator.
2.000 ± 0.0002 g of sample is weighed and put into a vortex in a beaker, and measurement with a stopwatch is started at the same time. Record the time (seconds) from when the vortex disappears until the liquid level becomes horizontal, and use it as the absorption speed.

(Measurement of absorption amount of superabsorbent polymer under pressure)
As shown in FIG. 7, an acrylic resin cylinder 203 (with an inner diameter of 2 cm, a height of 5 cm, and a 75 μm nylon net 201N attached to the bottom) with the center aligned with the upper and lower through holes in the center of the support base 201, A sample 200 of 0.100 ± 0.0002 g is placed in the cylinder 203, and a cylindrical weight 202 (diameter 1.9 cm, weight 120 g) is placed on the sample 200.
The outlet of the burette 204 is connected to the lower opening of the through hole of the support base 201 by a conduit 206, and the scale value before opening the valves V1 and V2 and the scale value after 30 minutes are read.
The absorption under pressure is calculated by the following formula.
C = (A−B) / S (3)
Here, C: absorption amount under pressure (ml / g), A: scale value (ml) 30 minutes after the start of water absorption, B: scale value (ml) before water absorption, S: sample weight (g).

(Measurement of gel strength of superabsorbent polymer)
20.0 g of urea, 8.0 g of sodium chloride, 0.3 g of calcium chloride, 0.8 g of magnesium sulfate, 970.9 g of ion-exchanged water, and 0.25 g of ferrous sulfate were mixed to make a total of 1 liter of human urine ( Iron ions 50 ppm).
Add 49 ± 0.1 g of artificial urine containing 50 ppm of iron ions to a 100 ml beaker containing a rotor, and stir using a magnetic stirrer. A sample 1.0000 ± 0.0002 g is weighed and put into a vortex in a beaker, and then stirred until the vortex disappears and the liquid level becomes horizontal.
The produced gel is left in a constant temperature and humidity machine of 40 ° C. × 60% RH for 3 hours.
After immersing in a constant temperature water bath at 25 ° C. for 5 minutes, the gel strength is measured with a neo-card meter. The measured value is converted into a unit by the following formula, and the gel strength (Pa) is calculated.
C = A × 0.1 (4)
Here, C: gel strength (Pa), A: gel strength (dyne / cm ² ) obtained from a neo-cardometer, and 0.1: constant.

(Measurement of absorption under pressure in diapers)
First, the weight of the unabsorbed sample is measured.
Next, as shown in FIG. 8, in the sample diaper 100, a portion that shrinks with rubber thread or the like, for example, the waist portion 101, the leg periphery portion 102, and the gather portion 103 are cut at intervals of 2 cm as shown by dotted lines. , Make the diaper flattened unnaturally (naturally).
Human urine with the use surface (inner surface) facing up, a sample sandwiched flat between an acrylic plate and a metal plate, a weight (10 kg) placed on the acrylic plate, and maintained at 37 ° C. (as described above) Immerse in for 30 minutes.
After 30 minutes, the sample is pulled up from the human urine, the weight and the acrylic plate are removed, and then the sample is folded in three and placed on a scale to measure the weight.
The amount of absorption under pressure (g) is calculated by subtracting the unabsorbed sample weight from the sample weight after absorption.

(Measurement of absorption rate in diapers)
A U-shaped instrument is used which is made of a U-shaped plate formed assuming a portion extending from the crotch to the buttocks, and has an injection port formed at the center in the width direction at the lowest position.
Mark the longitudinal center position of the absorbent body in the sample diaper and align the mark position with the inlet to secure the sample to the outer surface of the U-shaped instrument.
Place a U-shaped instrument with a fixed sample on the hammock so that it does not tilt.
A weight (1 kg, 10 cm × 10 cm) having a through hole in the center is placed on the U-shaped instrument. At this time, the through hole of the weight is aligned with the inlet of the U-shaped instrument.
100 cc of artificial urine (as described above) is injected into the sample through the weight through hole and the injection port of the U-shaped instrument, and the time required for absorption of the entire amount is measured to obtain the absorption rate (seconds).

(Measurement of the amount of return in diapers)
A top sheet is placed on an absorber cut to 100 mm × 300 mm, and four sides are sealed to obtain a sample.
A cylindrical instrument (support 150 mm × 150 mm) with an inner diameter of 27 mm is placed in the center of the sample. The cylindrical instrument is weighted as necessary.
Artificial urine is dropped 3 times at an interval of 10 minutes in an amount of 50 cc.
Ten minutes after the third dropping, a filter paper (ADVANTEC No. 2, 10 cm × 10 cm, 30 sheets stacked) was put on, and after applying a load with a 5 kg weight for 10 seconds, the weight of the kitchen paper was measured and measured in advance. By subtracting the weight of the unabsorbed kitchen paper, the amount of human urine transferred to the kitchen paper is calculated and set as the reversal amount (g).

(Measurement of compression resilience RC and compression energy WC)
Using a compression tester manufactured by Kato Tech Co., Ltd., the sample was compressed under the conditions of speed: 0.01 cm / sec, compression area: 2 cm 2, sensitivity: 2 (force meter 200 g / 10 v), compression load: 50 gf / cm 2, The compression resilience RC and the compression energy WC are calculated from the correlation diagram between the pressure and the deformation amount. The compression resilience RC means that the greater the value, the higher the recoverability after compression, and the compression energy WC means that the greater the value, the easier the compression.

(Sensory evaluation of resilience)
Paper diaper samples were manufactured using each absorbent body and using the same structure except for the absorbent body. What was not compressed after manufacture and what was unpacked after being compressed and packaged in a common form were prepared, and the restorability was evaluated visually and touched by 20 subjects. Evaluation was based on the conventional example, and in comparison with this, the case where almost no change was felt was indicated by Δ, and the case where the restoration property was high and the flexibility was high was indicated by ○.

  The present invention is suitable for absorbents of body fluid absorbent articles such as paper diapers and sanitary napkins and the production thereof, but can be applied to other uses within the scope of the present invention.

It is a longitudinal cross-sectional view which shows the structural example of an absorber roughly. It is a longitudinal cross-sectional view which shows the structural example of an absorber roughly. It is a longitudinal cross-sectional view which shows the structural example of an absorber roughly. It is a longitudinal cross-sectional view which shows the structural example of an absorber roughly. It is the schematic which shows the various arrangement | positioning form of an absorber. It is the schematic which shows the manufacturing flow of a fiber assembly. It is a front view which shows roughly the measuring method of the amount of absorption under pressure of a superabsorbent polymer. It is a top view which shows roughly the measuring method of the absorbed amount under pressure in a diaper state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fiber assembly, 2, 7, 9 ... Super absorbent polymer, 3 ... Packaging sheet, 4-6 ... Adhesive, 10 ... Absorber.

Claims (6)

An absorbent body having a fiber assembly,
The fiber assembly is made of tow composed of fibers, and the compression resilience RC is 45 to 60%.
Absorber characterized by that. Compression energy WC are 4.0~7.0gf · cm / cm ^2, claim 1 absorber according. The absorbent body according to claim 1 or 2, wherein the fiber assembly has a fiber density of 0.0075 g / cm ³ or less when the thickness is 10 mm. The absorbent body according to any one of claims 1 to 3, wherein the basis weight of the fiber assembly is 0.0075 g / cm ² or less.   The absorber according to any one of claims 1 to 4, wherein the weight is 15 g or less. The absorber according to any one of claims 1 to 5, wherein a planar projection area is 400 cm ² or more and a thickness is 1 cm or less.

Images