TW201628580A - Absorbent material, and sanitary product equipped with absorbent material - Google Patents

Abstract

The purpose of the present invention is to improve an absorbent material for sanitary products and provide an absorbent material that can be thinned. An absorbent material (1) comprising a absorptive core (4) that contains highly water-absorbable polymer particles (2) and water-absorbable fibers (3) and a sheet member (5) that encloses the absorptive core, wherein the water retaining capacity of the highly water-absorbable polymer particles is 37 g/g or more, the 5 min. DW value, which is an absorption amount achieved when the highly water-absorbable polymer particles are immersed in physiological saline for 5 minutes, is 40 ml/g or more, the late-stage water absorption speed, which is calculated from a time required for increasing the absorption amount in the highly water-absorbable polymer particles from 40 ml/g to 50 ml/g, is 6 ml/g·min or more, the SFC under slightly pressurized conditions, which is a measure for liquid diffusion performance under slightly pressurized conditions, is 5 × 10-6 ·ml·sec or more, and the repeated absorption power index, which is defined by "(water retaining capacity) × (late-stage absorption speed) × (SFC under slightly pressurized conditions × 103)", is 2 or more.

Description

Absorbent body and hygienic article with absorbent body

The present invention relates to an absorbent body and a sanitary article comprising the absorbent body.

In the absorbent body used for sanitary articles such as disposable diapers and sanitary napkins, water-absorbent fibers and superabsorbent polymers (hereinafter referred to as SAP) mixed or laminated with pulp are used. However, as the thickness of the absorber is reduced, the amount of SAP formed accounts for 50% by mass or more. Therefore, SAP does not only have its original liquid storage function, but also has to carry the liquid transport function responsible for the water absorbing fibers such as pulp. Otherwise, the absorption performance, especially the repeated absorption performance, is lowered due to the thinning of the absorbent body. In order to maintain the repetitive absorption performance for a long period of time, even if the absorbent fibers are absorbed to wet the water-absorbent fibers and the SAP is swollen into a hydrogelled state, the excreted urine must be continuously absorbed into the absorbent body, and the liquid is transported to the portion having the excess force. And eventually stay in SAP. However, it is difficult to improve the water absorption performance of SAP, especially the water retention ratio of the basic performance, the absorption speed, and the liquid-liquidity. In order to further improve the water absorption performance of SAP, the state of absorption in the disposable diaper is limited, so that the absorption performance of the trade-off is balanced in an optimum state, and the absorbed state must be achieved. The most effective and efficient absorption performance is exerted. For example, Patent Document 1 discloses an SAP having a telecentric retention capacity (CRC) of at least 26 g/g and a transport value (TW) of at least 15000 cm ³ s. The transport value (TW) is the product of the liquid diffusion performance (SFC) and the core absorption amount (DA ₆₀ ) after 60 minutes and multiplied by 10 ⁷ .

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2008-517116

According to the invention disclosed in Patent Document 1, the liquid diffusion property (SFC: Saline Flow Conductivity) is measured as a liquid permeation amount under a pressure load of 0.3 psi (2.07 kPa) for a hydrogel layer which has been swollen for 60 minutes. The SFC can be said to indicate the liquid permeation performance between the hydrogels which are maximally swollen in the vicinity of the urinary vent in a dense state. However, in the actual diaper absorbent body, the urine excreted repeatedly passes through When the hydrogel layer after the swelling is absorbed by 100%, it spreads so as to swell and expand the upper and lower sides of the hydrogel layer after the absorption capacity is lowered, and is absorbed in the region where the residual absorption force remains. In order to obtain such a flow of urine, a liquid diffusion layer (ADL layer) is obtained in combination with a liquid retention layer in which SAP is present, and an absorbent structure in which a liquid is kept in a liquid division is mainstream. Further, according to Patent Document 1, the core absorption amount (DA60) is such that 70 g of the water-absorbing polymer particles are filled to a thickness of 3 cm, and the absorption of the sodium chloride solution flowing out from the tube for 60 minutes is measured. the amount. The core absorption amount (DA60) is a sufficient amount of hydrogel to be measured at a sufficient absorption time. Although it is excellent as a method for evaluating the potential of the absorption amount of the hydrogel, the diffusion retention force measured at a thickness of 3 cm is In the same manner as the SFC described above, the absorption performance of the hydrogel in a dense state is obtained, and the diffusion layer (ADL layer) is obtained by using a liquid in combination, and the liquid is obtained as a premise of the structure of the absorber which maintains the division of the liquid.

However, in Patent Document 1, the SAP is densely arranged and a high-density liquid-retaining layer is used, and an absorbent layer of a diffusion layer (ADL layer) is obtained by a bulky liquid which temporarily holds a liquid in an effective manner, and SAP is used for allowing water to be condensed. The permeability of the glue is improved, and the use of the high water weight reduces the water retention rate to a low water retention high-pass liquefaction, and the combination with the bulky ADL layer counteracts the thin effect of the absorber, and there is a so-called thinning effect. problem.

In view of the above, the present invention provides an absorbent body for improving a sanitary article, and a thinner absorbent body is an object of the invention.

For example, in the case of an absorbent body used in a diaper, a relatively large amount of urine is temporarily stored in the inside and the outside of the absorbent body in a region where the body pressure of the baby is not applied, with respect to the region where the body pressure is applied. The urine that is temporarily stored is continuously associated with the water-absorbent material (a) "absorbed in the urine outside the body" (b) and (b) the gas excreted. (3) Three-stage urine that is held in the hydrophilic fibers and the "absorbent body in the absorbent body" of the SAP, which is not absorbed by the water and the water pressure. Excretion of 1-2 times, because the absorption capacity of pulp and SAP is large, there is less "retaining urine in the body" and "retaining urine in the body". However, if the absorption is repeated, the absorption rate is reduced. The increase in the retention of urine in the body, especially the absorption of urine in the body, increases the risk of leakage to the outside of the diaper due to changes in posture and deformation of the absorbent body. In order to reduce the risk of leakage, it is necessary to minimize the absorption of urine in the body. Therefore, it is necessary to allow the "absorption of urine in the body" to migrate as much as possible to the state of "absorption of urine in the body". The "absorption of urine in the body" is a urine that is temporarily held in a space between the absorbent materials formed in the absorbent body. Conventionally, a bulky material is placed between the absorbent body and the surface material to form an ADL layer to store and absorb. The space in which the urine is retained in the body may have a problem that the absorbent body becomes thick. Here, the strength of the water swell of SAP is to optimize the swelling particle diameter (A) and the swelling rate (B) and the swelling efficiency (C), and the swelling of the SAP can be used to "retain the retained urine in the body". The space is effectively produced around the SAP swollen in the thin absorbent body, and the case where the absorption power of the reverse is maximized is found.

In detail, the swelling particle diameter (A) is positively correlated with the water retention ratio. Since SAP swells SAP particles by inhaling internal urine, the hydrogel particle diameter is enlarged. The water retention ratio is measured as a telecentric retention capacity (CRC). Further, the swelling rate (B) was measured as the water absorption speed of SAP and the Demand Wettability (DW). The DW value is measured by the rate at which no physiological load is applied to attract physiological saline as absorption, and the amount of physiological saline absorbed per hour is quantified by weight or capacity. The DW value is generally expressed as a representative value of a 2-minute value, a 5-minute value, and a 15-minute value, but is further measured as a 60-minute value in which the SAP is near saturation, and has a positive correlation with the absorption rate. Although the DW5 minute value has a high relationship with the repeated absorption performance, the higher the relationship is the water absorption speed and the later water absorption speed in a state after hydrogelation to some extent. Because of the high water absorption rate in the late stage of absorption, it is formed in parallel with the "absorption of residual urine in the body" to absorb the residual force in the body. The "absorbed urine in the body" is quickly inhaled into the SAP hydrogel and converted into "absorbent body to maintain urine". It allows the "absorption of residual urine in the body" to be rapidly reduced. After the absorption body is more repeatedly absorbed, since the absorption capacity of the water absorbing fibers such as pulp is almost absent, the late absorption speed of the SAP hydrogel becomes important. The late absorption rate of the SAP hydrogel was calculated from the time when the absorption amount of the SAP particles was from 40 ml/g to 50 ml/g. The efficiency (C) for swelling is measured as a liquid permeability. In terms of liquid permeability, it is known that there is a case where a hydrogel in which SAP water swells to a saturated state is measured under a pressurized state; and a Saline Flow Conductivity (SFC) measured under a pressurized state, However, in order to continue the liquid transport in the "absorption of urine in the body" as "absorption of urine in the body", it was found that there is a correlation between the micro-pressurized SFC measured by the hydrogel after the water is absorbed in the micro-pressurized state. Liquid transport between SAP hydrogels in a state where SAP hydrogel is fully saturated is almost impossible to occur in an actual absorbent body. Further, since the liquid transport between the SAP hydrogels under the pressurized state by the large body pressure is too severe, the contribution rate of the entire absorbent body of the actual diaper is not large. The most suitable absorption of the absorbent body is the liquid transport in a state in which the SAP hydrogel which is maximally swollen under the pressure corresponding to the body pressure of the baby is depressurized and is in a state of being slightly pressurized, that is, micro Liquid permeability at the time of pressurization (micro-pressurized SFC). As described above, it is important that the absorbent body continues to absorb stably and repeatedly, and it is important for the water retention ratio, absorption speed (DW5 minute value, late absorption speed) and liquid permeability (micro-pressurization SFC) of the SAP. However, these are the trade-offs of each other, and the "reverse absorption index" obtained by the water retention ratio × the late absorption rate × the absorption under the slight pressure × 10 ³ is set to 2 or more, and the "absorption body" is found. The method of maximizing the formation speed of the retained urine space and further maximizing the absorption performance of the thin absorbent body can be achieved by the present invention.

The present invention for solving the above problems is an absorbent body comprising: an absorbent core comprising superabsorbent polymer particles and an absorbent core; and an absorbent body of a sheet member covering the absorbent core, characterized in that: high water absorbability The water retention ratio of the polymer particles is 37 g/g or more, and the superabsorbent polymer particles are exposed to physiological saline for 5 minutes under no load, and the DW 5 minute value of the absorption amount when absorbed is 40 ml/g or more, and the water absorption property is high. The late absorption rate of the DW value of the polymer particles from 40 ml / g to 50 ml / g is 6 ml / g. Above minute, the micro-pressurized SFC of liquid diffusion performance under micro-pressurization is 5×10 ^-6 . Ml. In the second or more, the repeated absorption index defined by the water retention ratio × the late absorption speed × the micro-pressurization SFC × 10 ³ is 2 or more.

According to the present invention, it is possible to provide an absorbent body which is capable of combining a SAP and a water-absorbent fiber which exhibit a specific absorption behavior, which is thinner and has superior absorption performance, and a sanitary article including the absorbent body.

1‧‧‧ absorber

2‧‧‧SAP particles

3‧‧‧Water-absorbent fiber

4‧‧‧Absorbent core

5‧‧‧Sheet members

The drawings show a specific embodiment of the present invention, and are not only indispensable structures of the invention, but also include a form of selectivity and ideal implementation.

Fig. 1 is a partially broken perspective view showing the absorbent body of the invention.

Fig. 2 is a view showing a cross-sectional shape of a U-shaped test apparatus.

The embodiment to be described below relates to the absorbent body of the present invention, and it is not only indispensable for the invention, but also includes a selective and desirable structure.

Referring to Fig. 1, an absorbent body 1 comprising: an absorbent core 4 comprising SAP (superabsorbent polymer) particles 2 and water absorbent fibers 3; and a sheet member 5 encasing the absorbent core 4. The SAP particles 2 contained in the absorber 1 are preferably 50 to 100% by mass, and the water absorbent fibers 3 are preferably 0 to 50% by mass. In the water-absorbent fiber 3, a cellulose-based fiber can be used, and it is preferred to use a pulp. Although the SAP particles 2 are particles of crosslinked sodium polyacrylate, the details of the SAP particles 2 of the present invention will be described later. In the wrapped absorbent core 4 The sheet member 5 is made of a liquid permeable sheet, and the liquid impermeable sheet can be arbitrarily combined with the liquid permeable sheet. That is, the entire core of the absorbent core 4 can be individually wrapped with a liquid permeable sheet. Further, the absorbent core 4 may be held between the liquid permeable sheet and the liquid impermeable sheet. In this case, the liquid permeable sheet is placed on the skin facing surface side facing the skin of the user of the absorbent body, and the liquid impermeable sheet is placed on the non-skin facing surface facing the skin. side. Examples of the water-permeable sheet may be a nonwoven fabric, a thin paper, or a film having many minute openings, but are not limited thereto. Examples of the liquid-impermeable sheet may be a resin film or a non-woven fabric after the water repellency treatment, but are not limited thereto.

The SAP particles 2 used in the absorber 1 of the present invention satisfy any or all of the following conditions.

(1) The water retention ratio of the SAP particles 2 is 37 g/g or more, and preferably 39 g/g or more.

(2) The DW5 minute value of the SAP particles 2 is 40 ml/g or more, preferably 50 ml/g or more, and more desirably larger than 60 ml/g.

(3) The late absorption rate calculated from the time when the absorption amount of the SAP particle 2 in the DW method was from 40 ml/g to 50 ml/g was 6 ml/g. Points, ideally at 7ml/g. Above, more preferably at 10ml/g. More than or equal to, more ideally at 14ml / g. More than above.

(4) The micro-pressurized SFC of liquid diffusion performance under micro-pressurization is 5×10 ^-6 . Ml. More than two seconds, the ideal is at 7×10 ^-6 . Ml. More than two seconds.

The amount of particles having a particle diameter of less than 300 μm in the SAP particles 2 is preferably 10% by mass or less, more preferably 9% by mass or less. Further, it is more preferably 8% by mass or less, still more preferably 7% by mass or less, and most preferably 6% by mass or less. Further, the amount of the SAP particles 2 in the absorbent core 4 is 50 to 100% by mass, preferably 50 to 90% by mass, more preferably 50 to 80% by mass, and still more preferably 50 to 70% by mass. More ideally, it is 50 to 65 mass%. At this time, the components other than the SAP particles 2 in the absorbent core 4 are water-absorbent fibers. Although the upper limit of the particle diameter of the SAP particles 2 is not limited, it is preferably 1000 μm or less, more preferably 900 μm or less, and still more preferably 800 μm or less.

The SAP particles 2 used in the present invention are not particularly limited as long as the above conditions are satisfied. For example, either or both of the SAP particles 2 obtained by the following two methods can be used.

In the first method, in order to satisfy the above conditions, in the polymerization crosslinking reaction of the acrylic polymer, a small azo-based radical polymerization initiator which uses a self-crosslinking reaction is used as a radical polymerization initiator, and at the time of polymerization, The SAP particle 2 used in the present invention can be obtained by adding a chain lock transfer agent to allow it to react. Specifically, the polymerization method described in Japanese Patent No. 5162634 can be used. Moreover, it is desirable to use a reverse phase suspension polymerization method from the point of control of precise polymerization reaction and control of a wide particle diameter. For example, the polymerization method described in Japanese Patent No. 4969778 can be used. In the present invention, the internal cross-linking agent can be used in the presence of a plurality of epoxy propyl compounds, using a water-soluble azo-based radical polymerization initiator for 2 to 3 stages of reverse phase suspension polymerization, after use Cross-linking the cross-linked water-absorbent resin to obtain a cross-linking density of the portion near the surface higher than the interior SAP Particle 2. The obtained SAP particles 2 have high water retention capacity, high absorption energy under load, excellent absorption speed, and low water soluble fraction.

The second method is to derive the relationship between the above-mentioned "reverse absorption index" = water retention ratio × late absorption rate × micro-pressurization SFC × 10 ³ by removing the superabsorbent polymer without pressure DW (refer to comparison) In the portion having a small particle diameter in Example 5), the SAP particles 2 used in the present invention can be obtained (see Examples 2 and 3). The portion having a small particle size contributes to the absorption rate, and on the other hand, the liquid permeability is lowered, and the repeated absorption index does not become high. Here, by reducing the particles having a particle diameter of less than 300 μm contained in the SAP particles 2, the pressure-free DW is not lowered, and the liquid-passing property can be improved to increase the "late absorption rate" and the "reverse absorption index". Further, since the internal crosslinking ratio of the water-absorbing polymer is also increased by removing the small particle diameter portion, the water retention ratio can be improved.

<Measurement of water retention ratio>

In the water retention ratio, 1 gram of SAP particles were weighed in a tea bag, and immersed in physiological saline at 25 ° C for 1 hour, and the amount of absorption was measured, and then centrifuged at 450 G to obtain a water retention ratio. Further, unless otherwise specified, the measurement in this case was carried out in a constant temperature and humidity chamber at 20 ° C and 65% RH.

<Measurement of DW5 minute value>

Weigh 1.000 g of SAP particles and spread them as evenly as possible on a nylon mesh of 250 mesh installed in a DW measuring device to read physiological salt. The amount of water absorbed. In terms of initial absorption, the amount absorbed in 5 minutes (ml/g) was read as a DW 5 minute value. The DW measuring device used for the measurement was a Demand Wettability Tester manufactured by Scientific Machine & Supplies Co., Ltd., a nylon mesh of 250 mesh, which was N-NO. 250 HD manufactured by NBC Industries.

<late absorption speed>

The relationship between the absorption time and the absorbed amount is graphed, and the time T ₄₀ (minutes) required for absorbing the particles of SAP 1.00 g to absorb 40 ml of physiological saline and the time T ₅₀ (minutes) required for absorbing 50 ml are obtained, and T _{50 is} obtained. -T ₄₀ = ΔT, and 10/ΔT (ml/g. min.) is defined as the late absorption rate.

<Micro-pressurized SFC>

Regarding the liquid permeability, although the SFC is well known, it is measured under a load, and it is easy to become a low water retention ratio. On the other hand, although the liquid permeability in the non-pressurized state measured by the maximum swelling ratio is known, in the absorber, since the maximum swelling ratio is not obtained, the correlation with the performance of the absorber is low. Here, a liquid permeability evaluation method under micro-pressure is conceived as an evaluation index. The evaluation of the micro-pressurized SFC was carried out in the following order.

0.200 g of SAP particles were weighed and spread evenly on a mesh screen of a cylinder having an inner diameter of 26 mm which was adhered to the bottom surface of a 250 mesh nylon mesh. Next, a piston (mass 30 g) having an outer diameter of 25 mm in which a nylon mesh of 250 mesh was adhered to the bottom surface was inserted into the cylinder. Thereafter, the substrate was placed on a bottom surface of a cylinder having a height of 2 mm, which was placed in a petri dish containing physiological saline, and placed on the bottom surface of the cylinder into which the piston was inserted, and allowed to absorb water for 30 minutes. Next, the cylinder was taken out from the physiological saline solution, and a 200 g weight was placed on the piston and allowed to stand for 3 minutes. Thereafter, the weight and the piston were taken out from the cylinder, and the cylinder was filled with physiological saline, and the amount of liquid permeated by the scale for 1 minute was used as the liquid passing speed F under the micro load. The micro-pressurized SFC is obtained by the following formula. Further, the thickness L _{0 of the} Gel layer was determined by measuring the thickness of the swollen SAP with a gauge.

<Evaluation of particle diameter of SAP>

The particles of SAP were screened using a sieve specified in JIS Z 8801, and the particle diameter of the SAP was evaluated by measuring the mass of the sample remaining on each sieve. The mesh of the sieve used was 850 μm, 710 μm, 600 μm, 500 μm, 355 μm, 300 μm, 250 μm, and 150 μm.

<Method for preparing absorbent body 1 and simple diaper used for measurement>

The pulp which was torn into 5 cm width (Weyerhaueser, NB416) was supplied to a pulp mill (Kamas Cell-mill) and pulverized. Next, the SMS formed by PP fibers is laid on the metal mesh attached to the suction box. Non-woven fabric, on which a wooden frame is placed, and the pulverized pulp is fed to a predetermined basis weight for a predetermined time T.

(2) A scattering pipe of a screw feeder that supplies particles of SAP is inserted between the pulp mill and the suction box, and the number of rotations and the supply time are set to a predetermined basis weight at the time of stacking. SAP is supplied after 1/4 × T seconds after the supply of pulp, and a pulp skin layer containing no SAP is formed. Thereafter, SAP was spread at 1/2 × T seconds, and was fed into the air stream of the pulverized pulp to form a 1/2 thick SAP mixed layer of the laminate.

(3) In the pulp. The SAP laminate was placed on the SMS non-woven fabric, pressed into a predetermined thickness by a hydraulic press, and the absorbent body was cut into a width of 120 mm × a length of 350 mm. After removing the lower SMS on the SAP mixed layer, the hot melt adhesive was applied to the spiral mixed 16 g/m ² tissue (width 120 mm) on the SAP mixed layer, and the hot melt material was subsequently coated. Spiral 16 g/m ² tissue (150 mm wide). Next, the lower side of the 150 mm wide tissue was folded back to each other by 15 mm, and the front and rear ends were cut so that the width of the absorbent body 1 was 120 mm and the length was 350 mm. The thickness of the obtained absorbent body 1 was 2.4 mm. Thus, the absorbent body 1 having an SAP content of 65% by mass (SAP basis weight: 300 g/m ² and a pulp basis weight of 160 g/m ² ) was prepared to have an SAP content of 55% by mass (SAP basis weight: 280 g/m ² , pulp). Absorber 1 having a basis weight of 230 g/m ² ).

(4) Finally, a hot-melting material is applied to the upper surface of the absorber 1 to form a spiral PE film, and a hot-melt adhesive is applied to the lower surface of the absorber 1 to form a spiral hydrophilic hot air non-woven fabric to form a repetitive absorption. Simple diaper for performance evaluation (width 190mm, length 400mm).

<Method for Evaluating the Absorbing Property of the Absorber (Measurement Method of U-Word Absorption Rate)>

1) The simple diaper for absorbability evaluation was placed symmetrically before and after in the U-shaped test apparatus shown in Fig. 2 . Further, the U-shaped test apparatus was formed by bending a rigid vinyl chloride sheet having a width of about 170 mm. In Fig. 2, R is 90 mm, L1 is 230 mm, and L2 is 210 mm. In the evaluation of the absorbability, the test device was supported by a jig, and the U-shaped opening portion was oriented vertically upward.

2) After injecting 80 ml into the center portion of the simple diaper, the time (seconds) until the artificial urine on the surface of the simple diaper was not visually observed was measured as the absorption speed.

3) Place for 3 minutes to mark the diffusion position of the artificial urine.

4) Place it for another 7 minutes, inject the second artificial urine, and mark the absorption rate measurement and diffusion position as the first time. This operation is repeated until the number of injections reaches four. The time (seconds) until the fourth injection of 80 ml of artificial urine was not observed by visual observation, and the time (second) was used as an index for evaluating the absorption performance of the absorber, and Tables 1 and 2 indicate "U". The word absorption speed is the fourth time."

Table 1 shows the results of evaluation of the absorption performance of the simple diaper which was prepared using the SAP particles 2 obtained by the above-described first method.

As shown in Table 1, even if only the particles of the SAP of Example 1 having a reciprocal index of 2 or more were repeated, and the SAP content in the absorber 1 was 55 mass% or 65 mass%, the U word The absorption speed is below 60 seconds for the fourth time. This means that even if the SAP content is increased, the ability to rapidly absorb 80 ml of artificial urine can be maintained. Therefore, the thinning of the absorber 1 becomes possible.

Table 2 shows the results of evaluation of the absorption performance of the simple diaper which was prepared using the SAP particles 2 obtained by the above-described second method.

As shown in Table 2, the amount of particles having a particle diameter of less than 300 μm contained in the SAP particles 2 is 10% by mass or less, preferably 9% by mass or less, more preferably 8% by mass or less, and still more preferably 7 The mass% or less is most preferably 6% by mass or less, and the DW5 minute value is 50 ml/g or more, preferably larger than 60 ml/g, and the late absorption speed is 6 ml/g. In the above-described Examples 1 to 3, the U-shaped absorption rate was 60 seconds or less in the fourth time even when the SAP content in the absorbent body 1 was 55% by mass or 65% by mass. This means that even if the SAP content is increased, the ability to rapidly absorb 80 ml of artificial urine can be maintained. Therefore, the thinning of the absorber 1 becomes possible.

As described above, by reducing the amount of particles having a particle diameter of less than 300 μm in the SAP particles 2, the repeated absorption performance of the absorber 1 can be maintained. On the other hand, the SAP particles 2 having a particle diameter of less than 300 μm have a large ratio of surface area to volume, and therefore have a low absorption performance and a high absorption rate. Therefore, the amount of particles having a particle diameter of less than 300 μm in the particles of the SAP disposed on the skin-facing surface side of the absorbent body 1 is reduced to 10% by mass or less, and the surface is faced from the opposite side of the skin toward the non-opposing surface. When the particle diameter of the SAP particles 2 is reduced, the absorber 1 having both high repetitive absorption performance and high absorption speed can be obtained. In the absorbent body 1, for example, the particles of the SAP are sieved using a sieve having an opening of 300 μm, and the SAP particles 2 having no sieve are disposed on the skin-facing surface side of the absorbent body 1, and the SAP particles 2 passing through the sieve are disposed. Obtained on the opposite side of the skin.

The absorbent body 1 of the present invention can be used in the use of containing SAP The entire hygiene product of the absorbent body 1. In the case of the sanitary article, a disposable disposable diaper, a sanitary napkin, a incontinence pad, and a breast milk pad are known, but are not limited thereto.

In the present invention described above, at least the following items can be arranged.

An absorber comprising: an absorbent core comprising superabsorbent polymer particles and water-absorbent fibers; and an absorbent body of a sheet member encasing the absorbent core, wherein the superabsorbent polymer particles have a water retention ratio of 37 g/g or more, which is highly absorbent The DW5 minute value of the absorption amount of the polymerizable particles after immersion in physiological saline for 5 minutes is 40 ml/g or more, and the late absorption calculated from the time when the absorption amount of the superabsorbent polymer particles reaches 40 ml/g from 40 ml/g. The speed is 6ml/g. Above minute, the micro-pressurized SFC of liquid diffusion performance under micro-pressurization is 5×10 ^-6 . Ml. In the second or more, the repeated absorption index defined by the water retention ratio × the late absorption speed × the micro-pressurization SFC × 10 ³ is 2 or more.

The invention disclosed in paragraph 0034 may include at least the following embodiments. The form of this embodiment is separable or combined with each other.

(1) The water retention ratio is above 39 g/g.

(2) The DW 5 minute value is above 50 ml/g.

(3) The absorption rate in the later stage is 7ml/g. More than above.

(4) Micro-pressurized SFC at 7×10 ^-6 . Ml. More than two seconds.

(5) The absorbent body contains 50 to 100% by mass of superabsorbent polymer particles and 0 to 50% by mass of water-absorbent fibers.

(6) The superabsorbent polymer particles contain a particle diameter of less than 300 μm. The amount of particles is 10% by mass or less.

(7) The absorbent body has a skin-facing surface that faces the skin surface of the user, and a non-skin-facing surface that faces the skin, and is located in the highly water-absorptive polymer particles on the opposite side of the skin. The amount of particles having a particle diameter of less than 300 μm is 10% by mass or less, and the particle diameter of the superabsorbent polymer particles decreases from the skin facing surface to the non-opposing surface.

(8) Hygiene articles having the absorbent body of the present invention

Further, the present invention may include the following embodiments. The form of this embodiment is separable or combined with each other.

(1) An absorber comprising: an absorbent core comprising superabsorbent polymer particles and water-absorbent fibers; and a sheet member encasing the absorbent core, wherein the superabsorbent polymer particles are immersed in physiological saline for 5 minutes. The post-absorption amount has a DW5 minute value of 50 ml/g or more, preferably more than 60 ml/g, and a late absorption rate calculated from the time when the absorption amount of the superabsorbent polymer particles reaches 40 ml/g from 40 ml/g. 6ml/g. More than a minute, ideally 14ml/g. Above, more preferably 16ml/g. In the above, the amount of particles having a particle diameter of less than 300 μm in the superabsorbent polymer particles is 10% by mass or less, preferably 9% by mass or less, more preferably 8% by mass or less, and even more preferably 7 mass%. Below %, the most desirable is less than 6% by mass.

(2) The absorbent body contains 50 to 100% by mass of superabsorbent polymer particles and 0 to 50% by mass of water-absorbent fibers.

(3) The absorbent body has a skin facing surface opposite to the skin surface of the user, and a non-skin opposing surface facing the skin, which is located in the skin pair The amount of particles having a particle diameter of less than 300 μm in the superabsorbent polymer particles on the surface side is 10% by mass or less, and the particle diameter of the superabsorbent polymer particles decreases from the skin facing surface toward the non-opposing surface.

(4) Hygiene articles having the absorbent body of the present invention

1‧‧‧ absorber

2‧‧‧Superabsorbent polymer particles

3‧‧‧Water-absorbent fiber

4‧‧‧Absorbent core

5‧‧‧Sheet members

Claims (9)

An absorbent body comprising: an absorbent core comprising superabsorbent polymer particles and an absorbent core; and an absorbent body of the sheet member covering the absorbent core, wherein the water-absorbent ratio of the superabsorbent polymer particles is 37 g/g or more, the DW5 minute value of the absorption amount of the superabsorbent polymer particles after immersing in physiological saline for 5 minutes is 40 ml/g or more, and the absorption amount of the superabsorbent polymer particles reaches 40 ml/g. The late absorption rate calculated at a time of 50 ml/g was 6 ml/g. Above minute, the micro-pressurized SFC of liquid diffusion performance under micro-pressurization is 5×10 ^-6 . Ml. In the second or more, the repeated absorption index defined by the water retention ratio × the late absorption speed × the micro-pressurization SFC × 10 ³ is 2 or more. The absorbent body according to claim 1, wherein the water retention ratio is 39 g/g or more. The absorber according to claim 1 or 2, wherein the DW 5 minute value is 50 ml/g or more. 1. The absorbent body according to claim 1 or 2, wherein the aforementioned late absorption rate is 7 ml/g. More than above. The absorbent body according to claim 1 or 2, wherein the micro-pressurized SFC is 7 × 10 ^-6 . Ml. More than two seconds. The absorbent body according to the first or second aspect of the invention, wherein the absorbent body contains 50 to 100% by mass of the high water absorbability. The polymer particles and the water-absorbing fibers of 0 to 50% by mass. The absorbent body according to the first aspect of the invention, wherein the amount of particles having a particle diameter of less than 300 μm contained in the superabsorbent polymer particles is 10% by mass or less. The absorbent body according to the first or second aspect of the invention, wherein the absorbent body has a skin facing surface facing the skin surface of the user; and a non-skin opposing surface facing the skin surface, The amount of the particles having a particle diameter of less than 300 μm in the superabsorbent polymer particles on the skin-facing surface side is 10% by mass or less, and the particle diameter of the superabsorbent polymer particles is from the skin facing surface. The reduction toward the aforementioned non-opposing surface. A sanitary article comprising the absorbent body according to any one of claims 1 to 8.