KR0144337B1 - Absorbers and Absorbents - Google Patents

Abstract

An object of the present invention is based on an absorbent polymer and hydrophilic fibers, the absorbent has a density of 0.1 to 0.5 g / cm3, a wet swelling ratio of 200% or more, and the absorber under pressure to physiological saline of 11 to 25 g. It is to provide an absorbent article comprising an absorbent body, a liquid-permeable surface material, a liquid-impermeable backing material, and an absorbent layer sandwiched therebetween, wherein the absorbent polymer has a dropout rate of 45% or less.

Description

Absorbers and Absorbents

1 is a cross-sectional view of an apparatus used in the present invention for measuring the amount of absorption under pressure.

The present invention relates to a novel thin absorber mainly composed of an absorbent polymer and hydrophilic fibers and an absorbent article using the absorbent material.

Background Art Most of the absorbents of absorbent articles such as disposable diapers and sanitary napkins that are currently commercially available have been converted into composites with hydrophilic fibers such as cotton pulp and paper and absorbent polymers. The functions required for these absorbers using relatively large amounts of absorbent polymers include absorption capacity, thin light weight, and shape preservation, and it is necessary to satisfy all of them.

However, currently used absorbers are almost satisfactory in absorbent capacity, but are not satisfied in terms of thin light weight and shape preservation. Therefore, absorbent articles with thin light weight, which have a high absorbent capacity and no leakage, are acceptable to manufacturers and consumers. It could not be manufactured.

It is therefore an object of the present invention to provide novel absorbers and moist articles.

It is another object of the present invention to provide an absorbent article and an absorbent article which are light in weight, have a high absorption capacity, and are free from leakage.

The above object is composed of an absorbent polymer and a hydrophilic fiber as a main component of the absorbent, which has a density of 0.1 to 0.5 g / cm 3, absorbs 11 to 25 g / g of physiological plant under pressure, and the rate of dropping out of the absorbent polymer. Is achieved by the characteristic of being in the range of 45% or less.

Furthermore, these objects are achieved by the fact that the absorbent article consists of a liquid-permeable surface material, a liquid-impermeable surface material, a liquid-impermeable backing material, and an absorbent layer sandwiched therebetween, wherein the absorbent article forms part or all of the absorbent layer with the above-described absorber. Can be.

Furthermore, these objects are achieved as an absorbent having an absorbent polymer and a hydrophilic fiber as main components, characterized in that the absorbed amount of physiological saline solution under pressure is 11 to 24 g / g, the dropout rate of the absorbent polymer is 45% or less, and the wet swelling rate is 200% or more. do.

An object of the present invention consists of an absorbent article comprising a liquid-permeable surface material, a liquid-impermeable backing material and an absorbent layer sandwiched therebetween, which can be achieved by forming part or all of the above-mentioned absorbent layer.

The inventors of the present invention have continued to study the absorber to develop an absorbent article having a light weight, a large absorbent capacity, and no leakage. As a result, the absorber density, absorbency under pressure, and dropout rate of the absorbent polymer are strictly controlled within the aforementioned range. The present invention was completed by using.

Absorbents of the present invention provide an ideal absorbent for absorbent pools useful in medicine and hygiene, such as sanitary napkins, pads for children and adults suffering from disposable diaper urination, pads used for excessive lactation, and the like. In addition, it is useful to apply to various articles required for absorbing and maintaining water, such as freshness maintaining material, agricultural or horticultural water-retaining material, and industrial water-retaining material.

In the present invention, since the absorbent body is mainly composed of the absorbent polymer, it is important that the absorbent polymer has excellent liquid absorbing ability, is sufficiently thin, and that turbidity of the absorbent polymer does not occur after liquid absorption. More importantly, the absorber can absorb and diffuse the liquid without causing gel blocking and must not cause the absorbent polymer to fall off after absorbing the liquid.

The absorbent has a low dropout rate of the absorbent polymer and does not decompose even after absorbing the liquid. Thus, after two or three times liquid absorption, urine or menstrual blood can be absorbed immediately without a decrease in wicking speed. Thus, the absorber is free from the risk of leakage, and guarantees the production of absorbent articles that allow the wearer to always feel smooth. Furthermore, if the amount of liquid absorption of the absorbent under pressure is too high or too small, the absorbent under pressure is an important factor in the production of the absorbent article because the absorbent is prevented from being reduced to the desired weight, and the breakdown of the absorbent causes the risk of leakage. If the density is too small, the absorption and diffusion of the liquid are delayed and the risk of leakage increases, so that the absorber cannot maintain a thin thickness and consequently cannot perform the actual function of the absorber. Therefore, it is possible to use a sufficiently thin and light absorbent article without causing discomfort when wearing the absorbent whose density, absorbed amount under pressure, and absorber dropout rate are adjusted as described above.

If the swelling ratio is too low, the absorption and diffusion of the liquid are delayed and the risk of leakage increases, so that the absorber cannot maintain a thin thickness and consequently cannot perform a practical function. Therefore, the wet swelling ratio, the liquid absorption amount under pressure, and the dropout ratio are used only when the absorbent is adjusted as described above, so that there is no discomfort in wearing, and the absorbent article can be used sufficiently thin and light.

More importantly in the present invention, a mixture of absorbent polymer and synthetic pulp (100: 1-30 weight ratio) in the presence of water and hydrophilic oil in a weight ratio of 100: 5-500, preferably 100: 10-200 relative to the absorbent polymer The adsorbents described above should be prepared to mix and heat compress the resulting mixture to have a density of 0.1 to 0.5 g / cm, preferably 0.15 to 0.4 g / cm 3.

In order to reduce the dropout rate of the absorbent polymer, a method of solidifying the absorbent polymer using various adhesives, a method of enclosing the absorbent polymer with a fiber matrix, and the like may be used. The absorbers produced by these methods are inversely proportional to the drop off rate and the absorbed amount under pressure.

None of the commercially available absorbers satisfies the above-mentioned physical properties: density of 0.1 to 0.5 g / cm 3, absorption of physiological saline under pressure of 11 to 25 g / g, and dropping rate of absorbent polymer of 45% or less. .

None of the currently available absorbers satisfies the above-mentioned physical properties, namely the absorption of physiological saline under pressure of 11-25 g / g, the dropout rate of the absorbent polymer of 45% or less, the wet swelling rate of 200% or more.

In order to satisfy these physical properties, the absorbent polymer is mixed with the hydrophilic fiber at 100: 5 to 500 weight ratio with respect to the absorbent polymer and the synthetic pulp at 100: 1 to 30 weight ratio with respect to the absorbent polymer in the presence of water. The absorber should be made to have a density of 0.5 g / cm 3.

Absorbent polymers used in the present invention generally only need to be absorbent. Such absorbent polymers include (meth) acrylic acid or salts thereof as the main component, and in addition to the water-soluble etheric unsaturated monomer optionally containing a crosslinking agent, crosslinked derivatives of polyethylene oxide, polyvinylpyrrolidone, sulfonated polystyrene, polyvinyl Pyridine, starch-poly (meth) atrylonitrile graft copolymer, (and crosslinking derivatives thereof), starch-poly (meth) acrylic ester graft copolymers (and crosslinking derivatives thereof), starch-poly (meth ) Acrylic ester graft copolymer hydrolyzate etc. are mentioned. Among the above-mentioned absorbent polymers, crosslinked polymers of water-soluble ethylenically unsaturated monomers containing acrylic acid or acrylate as a main component are preferred, and crosslinked polymers of acrylic acid and salts thereof are more preferable.

The present invention does not distinguish between absorbent polymers due to the method used to produce the absorbent polymers. In some cases, two or more absorbent polymers may be used in combination. The absorbent polymer used consists of a sufficiently dried position capable of absorbing physiological saline at a rate of at least 5 g / g, preferably 20 to 80 g / g, more preferably 35 to 60 g / g. Inherently absorbent polymers contain water to some extent. Sufficiently dry as used herein means that the individual particles cannot stick together in normal weather.

The shape of the particles effectively used herein may include various types of powders such as spherical, granular, irregular particles, foamed particles, fibrous particles, and the like. These particles may be single particles or pellet particles. These particles are allowed to crosslink at the surface site. In the case of powder, the mass has a diameter of 10 to 1000 µm, preferably 100 to 700 µm, of average weight particles.

Examples of hydrophilic fibers effectively used in the present invention include wood pulp fibers such as mechanical pulp, chemical pulp, degraded pulp and the like and artificial cellulose fibers such as rayon and acetate. In the present invention, synthetic fibers such as nylon, polyester, and polyolefin may be partially added to the hydrophilic fiber. Preferred hydrophilic fibers are wood pulp fibers. The amount of hydrophilic fiber used in the present invention is 5 to 500 parts by weight, preferably 10 to 200 parts by weight with respect to 100 parts by weight of the absorbent polymer.

Hydrophilic fibers in the present invention can be used with synthetic pulp. The amount of synthetic pulp additionally used is 1 to 30 parts by weight, preferably 2 to 25 parts by weight, relative to 100 parts by weight of the absorbent polymer. Synthetic fibers used in the present invention are known in the art. For example, Kirk Othmer, Encyclopedia of Chemical Technology, Vol. 3, Vol. 420, 435, Pulp, Synthetic. Pulp is a fine, branched, discontinuous fibrils made from thermoplastic resins. The appearance and dimensions of the pulp are very similar to wood pulp. Thermoplastic resins that can be effectively used in the production of synthetic pulp in the invention include polyolefins, polyesters, polyatrylonitrile, and other hydrophobic thermoplastic resins. Among the above-mentioned thermoplastic resins, polyolefins selected from one or more α-olefins of polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-1 part-butene copolymer, and ethylene-4-methyl-1-pentene copolymer are It is particularly preferable because it significantly improves the hydrophilicity of the hydrophilic fibers. Methods for producing synthetic pulp from thermoplastic resins are Japanese Patent Publication 47-21,898 (1972), Japanese Patent Publication 47-32,133 (1972), Japanese Patent Publication 3-180,504 (1991), Japanese Patent Publication 52-47,049 (1977). Products produced in this manner are marketed under the trademarks of Mitsui Petrochemical Industries. Ltd. (SWP), E.I du Pont de Nemours Company (PULPLUS), and Hercules Incorporated (PULPEX). For example, the absorber of the present invention is produced by the following method.

(1) While adding 1 to 40 parts by weight of water, 100 parts by weight of the absorbent polymer is mixed with 1 to 30 parts by weight of synthetic pulp, and 5 to 500 parts by weight of hydrophilic fibers such as the resulting mixture and ground pulp are dried and combined. A method of producing by heat compression after molding into a shape until a density of 0.1 to 0.5 g / cm 3.

(2) 100 parts by weight of the absorbent polymer was mixed with 1 to 30 parts by weight of synthetic pulp moistened with 1 to 40 parts by weight of water, and 5 to 500 parts by weight of the hydrophilic fibers such as the resulting mixture and the ground pulp were dried and molded into a web form. The method of production by heat-compressing until it reaches a density of 0.1-0.5 g / cm <3>.

The absorbent produced as described above has a density of 0.1 to 0.5 g / cm 3 (preferably 0.15 to 0.4 g / cm 3) and an absorption amount of physiological saline of 11 to 25 g / g (preferably 12 to 20 g / g) under pressure. , 45% or less (preferably 30% or less), and have specific physical properties such as dropout rate of the absorbent polymer.

The absorbent produced as described above has an absorption of 11 to 25 g / g (preferably 12 to 20 g / g), a dropping rate of the absorbent polymer of 45% or less (preferably 30% or less), 200% or more (preferably Preferably 220-600%).

The absorber may have an absorption amount of 30 g / g or more by suitably changing the mixing ratio of the constituent materials. However, for the reasons described above, the absorbent having such a large amount of absorption is not preferable because it lacks stability against the wet effect and the absorption efficiency is low. If the dropout rate of the absorbent polymer used in the absorbent is 45% or more, the disposable diaper used by the infant has, for example, a defect in which the absorbent is destroyed when the infant's body moves and the urine continues to leak. Absorbents having a water absorption amount of 11 g / g or less under pressure cannot be reduced to an appropriate thickness and weight because they are insufficient. In view of the various factors described above, it is concluded that the most desirable water absorbency to be provided as an absorber is a density of 0.1 to 0.5 g / cm 3, an absorbed amount under pressure of 11 to 25 g / g, and a dropout rate of the absorbent polymer of 45% or less.

In view of the above factors, it is concluded that the most desirable water absorbency to be provided as an absorbent is in the range of 11-25 g / g of absorbed water under pressure, 45% or less of the absorbent polymer and 200% of the wet swelling ratio.

Application of the absorbent of the present invention to the absorbent article which satisfies these absorption characteristics is to simply insert the absorbent of the present invention between the liquid-permeable sheet and the liquid-impermeable sheet which are other essential components of the absorbent article, An effect can also be obtained by using the absorbent of the present invention together with an absorber well known as an absorbent film such as pulp.

Examples of the liquid impermeable sheet that can be effectively used in the present invention include polyethylene, polypropylene, vinyl chloride resin, nylon, vinylon and the like. The liquid-permeable surface material effectively used in the present invention includes nonwoven fabrics of natural fibers (eg, wood fibers or cotton fibers), synthetic fibers, porous plastic films, porous foams, network foams, and the like.

The above-mentioned absorber and absorbent article are specific examples of the present invention. However, the present invention is not limited to these examples unless departing from the gist of the present invention.

Hereinafter, the present invention will be described in detail with reference to the following examples. Unless otherwise specified, parts in the following Reference Examples, Examples and Comparative Examples represent parts by weight.

[Performance test]

The resulting absorbents were evaluated by the following method.

1. Absorption amount under pressure

As shown in FIG. 1, the external air suction pipe 2 is provided on the balance 1, and the container 4 and the physiological saline receptacle of the user device 4 contain 0.9% physiological saline solution 3. It becomes the reverse rod 6 which is communicated by the conduit 5, the absorber 8 is placed on the glass filter 7 in the government of this reverse rod 6, the polymer 9 is put on it, and 30 minutes The absorption amount (g / g) of the absorber of a later load of 30 g / cm 2 was measured. In addition, the absorber used what was previously cut into the 5.5 cm diameter round.

2.density of absorber

The height z (mm) under 7 g / cm <2> load was measured about the absorber cut | judged to 10x10 cm <2>, and it was set as the density with the value which divided the weight x (g) by the volume of 10z (cm <3>).

3.dropping rate of absorber

The absorbent cut to 2cm × 4cm in a 100cc beaker was added to the mixture at 100 rpm using a 45 mm stirrer in 100 cc physiological saline, and after 10 minutes, the absorber was taken out and the weight of the absorbent polymer dropped into physiological saline was measured. Then, the dropping rate of the absorbent polymer was calculated according to the following formula.

Reference Example 1

4,000 parts of 37% acrylic monomer aqueous solution of 74.98 mol% of sodium acrylate, 25 mol% of acrylic acid, and 0.02 mol% of trimethylolpropane triacrylate were polymerized under stirring in nitrogen atmosphere using 2.0 parts of sodium persulfate and 0.08 parts of 1-ascorbic acid. About 5 mm of granular gelled hydrous polymer was obtained. The gel hydrous polymer was dried in a hot air dryer at 150 ° C., pulverized with a hammer-type grinder, sieved through a 20-mesh gold mesh, and an aliquot of 20 mesh was passed. (Average particle diameter: 405 µ) Then, 0.5 part of glycerol was added to 100 parts of the aliquot. 2 parts of water and 2 parts of ethyl alcohol were added and mixed, followed by heat treatment at 210 ° C. to obtain a water absorbent polymer A having a secondary crosslinked surface. The amount of physiological leaves of this polymer was 50 g / g.

Reference Example 2

4000 parts of a solution of 74.95% sodium acrylate, 25 mol% acrylic acid and 0.05 mol% trimethylolpropane triacrylate were polymerized under stirring in a nitrogen atmosphere using 2.0 parts of sodium persulfate and 0.08 parts of 1-ascorbic acid in a granulated gel having a particle diameter of about 5 mm. The water-soluble polymer was obtained, and the gel-like water-containing polymer was dried in a 150 ° C. hot air dryer, pulverized with a hammer-type grinder, sieved through a 20-mesh gold mesh, and the 20-mesh pass-through was fractionated to obtain an absorbent polymer B (average particle size 350 µ). The physiological saline uptake amount of this polymer was 46 g / g.

Reference Example 3

The absorbent polymer B obtained in Reference Example 2 was mixed with 0.5 part of glycerol and 2 parts of mole 2 parts ethyl alcohol, and then the resulting mixture was heated at 210 ° C. to obtain a second crosslinked absorbent polymer near the surface. The physiological saline uptake amount of this polymer was 43 g / g.

Reference Example 4

The water absorbent polymer C obtained in the reference example 3 was classified into 60-100 mesh, and the water absorbent polymer D (diameter 149-250 micrometers) was fractionated. The physiological saline absorption amount of the water absorbing polymer D was 42 g / g.

Example 1

100 parts of absorbent polymer A and 25 parts of synthetic pulp (SWP UL-415, product of Sanji Chemical Co., Ltd.) were mixed, adding 25 parts of water. Subsequently, the mixture was dry mixed with 125 parts of pulverized pulp in a mixer, and compression-molded into a sheet form on a wire screen using a batch type air compression mold apparatus to obtain an area of 14 cm x 40 cm and a weight of 0.047 g / cm 2. Made a web. The obtained web was compressed and heated at 150 ° C. for 10 minutes to obtain an absorbent body 1 of the present invention having a density of 0.16 g / cm 3. The absorption amount under pressure of the obtained absorber 1 was 16.5 g / g, the dropping rate of the absorbent polymer was 19%, and the wet swelling rate was 256%.

Example 2

In Example 1, except that the amount of water was 32 parts, the amount of synthetic pulp was 17 parts, and the amount of ground pulp was changed to 133 parts, the weight was 0.051 g / cm 2 and the density was 0.13 g / cm 3 of the present invention. The absorber 2 was produced. The absorbent under pressure of this absorbent body was 16.0 g / g, the dropping rate of the absorbent polymer was 22%, and the wet swelling rate was 210%.

Example 3

To 100 parts of absorbent polymer A, 7 parts of synthetic pulp previously wetted with 5 parts of water were mixed. The mixture was dry mixed with 67 parts of ground pulp. The resulting mixture was compression molded into a sheet form on a wire mesh with a batch air compression mold apparatus to produce a web of 14 cm x 40 cm area with a unit weight of 0.42 g / cm 2. The web was heat-compressed at 150 DEG C for 10 minutes to produce an absorbent body 3 of the present invention, which was 0.20 g / cm &lt; 3 &gt;. The absorbent under pressure of this absorbent body 3 was 15.8 g / g, the dropping rate of the absorbent polymer was 20%, and the wet swelling rate was 270%.

Example 4

100 parts of water-absorbing polymer C and 13 parts of synthetic pulp (SWP UL-415, manufactured by Nippon Sankai Chemical Co., Ltd.) were mixed while adding 20 parts of moles. The mixture was then dry mixed with 100 parts of ground pulp in a mixer. The resulting mixture was compression molded into a sheet form on a wire mesh with a batch air compression mold apparatus to produce a web having an area of 14 cm x 40 cm. The web was inserted into two tissue papers having a weight of 0.0013 g / cm 2, and then embossed at 150 ° C. for 1 minute to obtain an absorbent body (4) of the present invention having a weight of 0.054 g / cm 2 and a density of 0.27 g / cm 3. The absorbent under pressure of this absorbent body was 14.4 g / g, the dropping rate of the absorbent polymer was 6%, and the wet swelling rate was 300%.

Example 5

An absorbent body 5 of the present invention having a weight of 0.044 g / cm 2 and a density of 0.22 g / cm 3 was obtained in the same manner as in Example 4 except that the amount of the ground pulp was 66 parts. The absorbent amount under pressure of this absorbent body was 17.3 g / g, the dropout rate of the absorbent polymer was 7%, and the wet swelling rate was 325%.

Example 6

An absorbent body 6 of the present invention having a weight of 0.029 g / cm 2 and a density of 0.30 g / cm 3 was obtained in the same manner as in Example 4 except that the amount of the synthetic pulp was 15 parts and the amount of the ground pulp was 34 parts. The absorbent 6 had a water absorption amount under pressure of 16.3 g / g, an absorbent polymer dropping rate of 19%, and a wet swelling rate of 300%.

Example 7

100 parts of absorbent polymer C and 12 parts of synthetic pulp (SWP UL-415, manufactured by Nippon Sankai Chemical Co., Ltd.) were mixed while adding 20 parts of moles. The resulting mixture was dry mixed with 131 parts of the ground pulp in a mixer. The resulting mixture was compression molded into a sheet form on a wire mesh with a batch air compression mold apparatus to produce a web of area 14 cm × 40 cm. The web was inserted into two tissue papers having a weight of 0.0013 g / cm 2, and then embossed at 150 ° C. for 1 minute to obtain an absorbent body 7 of the present invention having a weight of 0.047 g / cm 2 and a density of 0.24 g / cm 3. The water absorption amount under pressure of this absorber 7 was 12.5 g / g absorptive polymer dropping rate of 8%, and wet swelling rate of 275%.

Example 8

The absorber 8 of the present invention was obtained in the same manner as in Example 7 except that the amount of the synthetic pulp was 5 parts and the amount of the pulverized pulp was 0.050 g / cm 2 and the density 0.25 g / cm 3. The absorbent 8 had a water absorption amount under pressure of 15.3 g / g, an absorbent polymer dropping rate of 13%, and a wet swelling rate of 225%.

Example 9

Except having made the amount of synthetic pulp 23 parts and the amount of pulverized pulp 133 parts, it carried out similarly to Example 7, and obtained the absorber 9 of this invention which is a weight 0.060 g / cm <2> and density 0.30 g / cm <3>. The absorbent under pressure of this absorbent body was 13.5 g / g, the absorbent polymer dropping rate was 12%, and the wet swelling rate was 400%.

Example 10

The absorber 10 of the present invention was obtained in the same manner as in Example 7, except that the amount of the synthetic pulp was 24 parts and the amount of the ground pulp was 167 parts, and the weight was 0.070 g / cm 2 and the density was 0.35 g / cm 3. The absorbent under pressure of this absorbent 10 was 12.3 g / g, the dropping rate of the absorbent polymer was 15%, and the wet swelling rate was 400%.

Example 11

An absorbent body 11 of the present invention was obtained in the same manner as in Example 9 except that the amount of the ground pulp was 67 parts, with a weight of 0.044 g / cm 2 and a density of 0.33 g / cm 3. The absorbent under pressure of this absorbent 11 was 14.2 g / g, the dropping rate of the absorbent polymer was 10%, and the wet swelling rate was 333%.

Example 12

100 parts of absorbent polymer D and 13 parts of synthetic pulp (SWP UL-415, manufactured by Nippon Sankai Chemical Co., Ltd.) were mixed while adding 20 parts of a 30% by weight polyaluminum chloride solution. The resulting mixture was dry mixed with 100 parts of the ground pulp with a blender. The resulting absorbent mixture was compression molded into a sheet form on a wire mesh with a batch air compression mold apparatus to produce a web having an area of 14 cm x 40 cm. The web was inserted into two pieces of tissue paper having a weight of 0.0013 g / cm 2, and then embossed at 150 ° C. for 1 minute to produce an absorbent body 12 of the present invention having a weight of 0.042 g / cm 2 and a density of 0.21 g / cm 3. Under water absorption of this absorbent 12, 13.2 g / g, the absorptivity of the absorbent polymer were 5%, and the wet swelling rate was 350%.

Example 13

100 parts of absorbent polymer B and 13 parts of synthetic pulp (SWP UL-415, manufactured by SEIKO, Japan) 1% by weight of ethylene glycol diglycidyl ether (manufactured by Denaco., Ex-810, Nagase Kasei KK) It mixed while adding 20 parts of aqueous solution. The resulting mixture was dry mixed with 67 parts of the ground pulp in a blender. The resulting mixture was compression molded into a sheet form on a wire mesh with a batch air compression mold apparatus to produce a web having an area of 14 cm x 40 cm. The web was inserted into two tissue papers having a weight of 0.0013 g / cm 2, and then embossed at 150 ° C. for 1 minute to obtain an absorbent body 13 of the present invention having a weight of 0.047 g / cm 2 and a density of 0.23 g / cm 3. The absorbent amount under pressure of the absorbent body 13 was 13.7 g / g, and the dropping rate of the absorbent polymer was 3%, and the swelling swelling rate was 250%.

Example 14

Except having made the amount of the synthetic pulp 7 parts, it carried out similarly to Example 8, and obtained the absorber 14 of this invention of the weight 0.043g / cm <2> and density 0.22g / cm <3>. The absorbent 14 had a water absorption amount under pressure of 15.3 g / g, an absorbent polymer dropping rate of 14%, and a wet swelling rate of 300%.

Example 15

100 parts of absorbent polymerization C and 13 parts of synthetic pulp (SWP UL-415, manufactured by Nippon Sankai Chemical Co., Ltd.) were mixed while adding 20 parts of water. The resulting mixture was dry mixed with 100 parts of the ground pulp with a blender. The resulting mixture was compression molded into a sheet form on a wire mesh with a batch air compression mold apparatus to produce a web having an area of 14 × 40 cm. The web was inserted into two tissue papers having a weight of 0.002 g / cm 2, and then embossed at 200 ° C. for 10 seconds to produce an absorbent body 15 of the present invention having a weight of 0.052 g / cm 2 and a density of 0.26 g / cm 3. The absorbing amount of this absorber 15 was 14.5 g / g, the dropping rate of the absorbent polymer was 11%, and the wet swelling rate was 300%.

Example 16

100 parts of absorbent polymer C and 10 parts of synthetic pulp (SWP UL-415, manufactured by Nippon Sankai Chemical Co., Ltd.) were mixed while adding 20 parts of water. The resulting mixture was dry mixed with 133 parts of powder pulp with a blender. The resulting mixture was compression molded into a sheet form on a wire mesh with a batch air compression mold apparatus to produce a web 14 cm × 40 cm. The web was inserted into two tissue papers having a weight of 0.002 g / cm 2, and then embossed at 150 ° C. for 10 minutes to prepare an absorber 16 of the present invention having a weight of 0.092 g / cm 2 and a density of 0.23 g / cm 3. This absorbent body 16 had a water absorption amount under pressure of 13.5 g / g, a dropping rate of the absorbent polymer of 29%, and a wet swelling ratio of 350%.

Example 17

100 parts of absorbent polymer A and 8 parts of synthetic pulp were mixed while adding 20 parts of water. This mixture was dry mixed with 70 parts of powder pulp with a blender. The resulting mixture was compression molded into a sheet form on a wire mesh with a batch air compression mold apparatus to produce a web. On the other hand, another web composed of 35 parts of powdered pulp and 0.7 parts of synthetic pulp was prepared, and the produced web was sandwiched between two webs to make a web having an area of 14 cm x 40 cm and a weight of 0.046 g / cm 2. The web was heat-compressed at 150 ° C. for 1 minute to obtain an absorbent body of the present invention having a density of 0.23 g / cm 3. The absorbent under pressure of this absorber 17 was 13.5 g / g, the dropping rate of the absorbent polymer was 20%, and the wet swelling rate was 352%.

Example 18

100 parts of absorbent polymer D and 20 parts of synthetic pulp were mixed with 20 parts of water. This mixture was dry mixed with 18 parts of pulverized pulp with a blender. The resulting mixture was compression molded into sheet form on a wire mesh with a batch air compression mold apparatus to make a web. An absorbent body of the present invention having a weight of 0.019 g / cm 2 and a density of 0.25 g / cm 3 was prepared by embossing at 150 ° C. for 1 minute by inserting two tissue papers of 0.0013 g / cm 2. The absorbent 18 had a water absorption amount under pressure of 18.0 g / g, an absorbent polymer dropping rate of 35%, and a wet swelling rate of 375%.

Example 19

100 parts of the water absorbent polymer A were mixed while adding 13 parts of synthetic pulp (SWP UL-415, manufactured by Nippon Sankai Chemical Co., Ltd.) and 10 parts of water. The resulting mixture is sandwiched between two webs of 33 parts of ground pulp to make a web 14 cm x 40 cm in weight and 0.052 g / cm 2 in weight. The resulting web was heat compressed at 150 ° C. for 1 minute to obtain an absorbent body 19 of the present invention having a density of 0.17 g / cm 3. Under water absorption of the absorbent body 19, the dropping rate of the 12.5 g / g absorbent polymer was 33% and the wet swelling ratio was 233%.

Example 20

100 parts of water-absorbing polymer C and 20 parts of synthetic pulp (SWP UL-415, manufactured by Nippon Sankai Chemical Co., Ltd.) were mixed while adding 20 parts of water. This mixture was dry mixed with 60 parts of pulverized pulp with a blender. The resulting mixture was compression molded into a sheet form on a wire mesh with a batch air compression mold apparatus to produce a web having an area of 14 cm x 40 cm. Another web consisting of 30 parts of pulverized pulp was placed on one side of the resultant web and placed in two tissue papers weighing 0.0013 g / cm 2 and passed through a heating roller at 200 ° C. for 20 seconds to weigh 0.048 g / cm 2 density 0.16 g / The absorber 20 of this invention which is cm <3> was obtained. The absorbent amount under pressure of this absorbent 20 was 12.2 g / g, the dropping rate of the absorbent polymer was 14%, and the wet swelling rate was 210%.

Comparative Example 1

100 parts of absorbent polymer C and 33 parts of synthetic pulses (SWP UL-415, product of Nippon Sankai Chemical Co., Ltd.) were mixed while adding 20 parts of water. The resulting mixture was mixed with 100 parts of ground pulp with a blender. The resulting mixture was compression molded onto a wire mesh with a batch air compression mold apparatus to produce a web of area 14 cm x 40 cm. The web was inserted into two tissue papers having a weight of 0.0013 g / cm 2 and embossed at 150 ° C. for 1 minute to produce a comparative absorbent body 1 having a weight of 0.048 g / cm 2 and a density of 0.24 g / cm 3. The absorption amount of the comparative absorbent material 1 was 10.2 g / g, the dropping rate of the absorbent polymer was 17%, and the wet swelling rate was 250%.

Comparative Example 2

100 parts of absorbent polymer C and 66 parts of synthetic pulp (SWP UL-415, product of Nippon Sankai Chemical Co., Ltd.) were mixed while adding 20 parts of water. The resulting mixture was mixed with 100 parts of ground pulp with a blender. The resulting mixture was compression molded onto a wire mesh with a batch air compression mold apparatus to produce a web of area 14 cm x 40 cm. These two webs were inserted into two tissue papers having a weight of 0.0013 g / cm 2 and embossed at 150 ° C. for 1 minute to obtain a comparative absorbent body 2 having a weight of 0.056 g / cm 2 and a density of 0.28 g / cm 3. The amount of water absorbed under pressure of the comparative absorber 2 was 8.8 g / g, the dropping rate of the absorbent polymer was 5%, and the wet swelling rate was 275%.

Comparative Example 3

100 parts of absorbent polymer C and 100 parts of ground pulp were dry mixed with a blender. The resulting mixture was compression molded onto a wire mesh with a batch air compression mold apparatus to produce a web of area 14 cm × 40 cm. This web was inserted into two tissue papers having a weight of 0.0013 g / cm 2 and embossed at 150 ° C. for 1 minute to produce a comparative absorber 3 having a weight of 0.043 g / cm 2 and a density of 0.17 g / cm 3. The absorption amount of this comparative absorbent material 3 was 12.3 g / g, the dropping rate of the absorbent polymer was 76%, and the wet swelling rate was 240%.

Comparative Example 4

100 parts of absorbent polymer C, 13 parts of synthetic pulp (SWP UL-415, product of Japan Sankai Chemical Co., Ltd.), and 100 parts of ground pulp were mixed with a mixer. The resulting mixture was compression molded onto a wire mesh with a batch air compression mold apparatus to produce a web of area 14 cm × 40 cm. The web was inserted into two tissue papers having a weight of 0.0013 g / cm 2 and embossed at 150 ° C. for 1 minute to obtain a comparative absorber 4 having a weight of 0.049 g / cm 2 and a density of 0.25 g / cm 3. The comparative absorber 4 had a density of 10.9 g / g, an absorbent polymer dropping rate of 76%, and a wet swelling rate of 250%.

Comparative Example 5

100 parts of absorbent polymer C and 13 parts of synthetic pulp (SWP UL-415, manufactured by Nippon Sankai Chemical Co., Ltd.) were mixed with a mixer while adding 20 parts of moles. The resulting mixture was compression molded onto a wire mesh with a batch air compression mold apparatus to produce a web of area 14 cm × 40 cm. The web was inserted into two tissue papers having a weight of 13 g / m 2 and heated at 150 ° C. for 10 minutes to produce a comparative absorbent body 5 having a weight of 0.050 g / cm 2 and a density of 0.08 g / cm 3. The amount of water absorbed under pressure of the comparative absorber 5 was 13.9 g / g, the absorbent polymer dropping rate was 56%, and the wet swelling rate was 100%.

Example 21

Disposable diaper with liquid-permeable polypropylene top sheet, two tissue papers, invention absorbent (weight: 15 g) dml 9 cm x 35 cm rectangular sample, liquid-impermeable polyethylene sheet containing leg gathers, two tape fasteners Was assembled by hand by tightening each component with a double-sided tape. The total weight of the diaper was 33 g.

The diaper obtained was worn on a 1 year old infant (10 kg), and compared with the diapers (gross weight: 50 g) currently on the market, the diaper using the absorbent of the present invention was remarkably excellent in shape retention after urine absorption, and there was almost no leakage. .

Example 22

Disposable diapers using absorbers with various properties were made the same as the method of Example 21. These diapers were tested by seven mothers for one month. Each mother received 30 random diapers and put them on their children. After the test, the leak rate of the test diaper and the shape retaining ability of the absorbent body were examined. Table 1 shows the results. It is clear from the table that the absorbent article using the absorbent of the present invention has excellent absorption characteristics.

Claims (16)

In the absorbent polymer containing the water-absorbing polymer which is a crosslinked polymer of the water-soluble ethylenic monomer which has acrylic acid or an acrylate as a main component, and a hydrophilic fiber, the density of an absorber is 0.1-0.5 g / cm <3>, and the absorption amount under pressure to physiological saline is 11 It is the range of -25 g / g, and the absorptivity of an absorbent polymer is 45% or less, The absorber characterized by the above-mentioned. The absorbent according to claim 1, wherein the amount of hydrophilic fiber is blended in an amount of 5 to 500 parts by weight per 100 parts by weight of the absorbent polymer. The polymer according to claim 2, further comprising 1 to 30 parts by weight of synthetic pulp with respect to 100 parts by weight of the absorbent polymer. In an absorbent body having a water absorbent polymer and a hydrophilic fiber as a main component, the absorptive polymer has a crosslinked polymer of a water-soluble ethylenic monomer containing acrylic acid or an acrylate as a main component, and the absorber under pressure is 11 to physiological saline. 25 g / g, an absorbent polymer having a dropping rate of 45% or less, and a wet swelling rate of 200% or more. The absorber according to claim 4, wherein 5 to 500 parts by weight of the hydrophilic fiber is blended with respect to 100 parts by weight of the absorbent polymer. The absorbent according to claim 5, further comprising 1 to 30 parts by weight of synthetic pulp with respect to 100 parts by weight of the absorbent polymer. In an absorbent article comprising a liquid-permeable surface material, a liquid-impermeable backing material, and an absorbing layer sandwiched therebetween, the main component is a flaw polymer and a hydrophilic fiber, which are crosslinked polymers of water-soluble ethylenic monomers containing acrylic acid or acrylate as a main component, An absorbent having a density of 0.1 to 0.5 g / cm 3, absorbing pressure under physiological saline under pressure of 11 to 25 g / g, and an absorptivity of the absorbent polymer having an absorption characteristic of 45% or less to form part or all of the absorbent layer. Absorbent article characterized in that. The absorbent article according to claim 7, wherein the amount of the hydrophilic fiber is blended in an amount of 5 to 500 parts by weight based on 100 parts by weight of the absorbent polymer. The absorbent article according to claim 8, further comprising 1 to 30 parts by weight of synthetic pulp with respect to 100 parts by weight of the absorbent polymer. It consists of a liquid-permeable surface material, a liquid-impermeable backing material, and an absorbent layer sandwiched therebetween. The absorbent polymer, which is a crosslinked polymer of water-soluble ethylenic monomer containing acrylic acid or acrylate as a main component, has a low component and hydrophilic fiber, and is pressurized under physiological saline. An absorbent article having an absorption amount of 11 to 25 g / g, an absorbent having a dropping rate of 45% or less and a wet swelling rate of 200% or more, and having a part or all of the absorbent layer formed thereon. The absorbent article according to claim 10, wherein the amount of the hydrophilic fiber is blended in an amount of 5 to 500 parts by weight based on 100 parts by weight of the absorbent polymer. The absorbent article as set forth in claim 11, wherein said absorbent further blends 1 to 30 parts by weight of synthetic pulp with respect to 100 parts by weight of the absorbent polymer. In an absorbent material containing a water absorbent polymer and a hydrophilic fiber as a main component, the absorbent density is in the range of 0.1 to 0.5 g / cm 3, the absorption under pressure to the physiological saline solution is in the range of 11 to 25 g / g, and the dropping rate of the absorbent polymer is 45. An absorbent body, which is% or less. In an absorbent material containing a water absorbent polymer and a hydrophilic fiber as a main component, the absorbent under pressure to the physiological saline solution is 11 to 25 g / g, the dropping rate of the absorbent polymer is 45% or less, and the wet swelling rate is 200% or more. Absorber made. In an absorbent article comprising a liquid permeable surface material, a liquid impermeable backing material, and an absorbent layer sandwiched therebetween, the absorbent polymer and the hydrophilic fiber have a main component, a density of 0.1 to 0.5 g / cm 3, and an absorption amount under pressure to physiological saline. An absorbent article having a portion or all of the absorbent layer formed of an absorbent having an absorption property of 11 to 25 g / g and having an absorptivity of less than 45% of the absorbent polymer. It consists of a liquid-permeable surface material, a liquid-impermeable backing material, and an absorbent layer sandwiched therebetween, and has an absorbent polymer and a hydrophilic fiber as its main components, and the absorption amount under pressure to physiological saline is 11 to 25 g / g, An absorbent article comprising at least part of the absorbent as an absorbent having an absorption characteristic of 45% or less and a wet swelling ratio of 200% or more.