JP2017036638A - Absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorber, which has a fast water absorption speed and can rapidly exert the performance when being used as a sandbag.SOLUTION: An absorber contains high-absorbent polymer and pulp that is derived from lumber and has fiber length of 1 μm to 24 μm. The absorber can be used as a water absorptive sandbag by being stored in a water permeable bag. It is preferable that the pulp be chemical pulp; average particle diameter of the high-absorbent polymer be 10 μm to 1000 μm; and 2 to 100 w/t parts of the pulp be mixed in the 1 w/t part of the high-absorbent polymer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an absorber that quickly absorbs a liquid such as water. The absorbent body of the present invention can be carried easily and lightly during normal times when used for sandbags to stop running water or change the direction of flow in flood disasters. It can be a sandbag to prevent.

Absorbers that quickly absorb liquids are widely used from personal products such as sanitary goods such as disposable disposable diapers to sandbags in flood disaster situations. In recent years, local floods have frequently occurred due to typhoons and guerrilla heavy rains. Conventionally, sandbags filled with sand or gravel have been used to prevent damage caused by flooding into houses and inflow of water into underground facilities. Since this sandbag is heavy and bulky, it requires labor and time to take a specific storage place and transport it to the target place, so put a super absorbent polymer that does not require labor and time in a hemp bag In the event of an emergency, lightweight sandbags have been developed that can be used by swelling them with water at the target location. However, this lightweight sandbag has a problem that it takes time to swell. In order to solve this problem, Patent Document 1 discloses an invention using a highly water-permeable bag, and Patent Document 2 discloses an invention in which a highly water-absorbing polymer is divided into a plurality of small bags and placed in a large bag. Has been. Patent Document 3 describes an invention in which a water-permeable bag encloses an organic swelling material made of a plant polymer and crushed paper powder or crushed paper pieces of paper. However, even these methods are insufficient from the viewpoint of preventing flooding in the event of a disaster, and a technique for absorbing a large amount of water more quickly is required.
JP 2004-27792 A JP 2002-266330 A JP2002-097614

  Then, an object of this invention is to provide the absorber which absorbs liquids, such as water, very rapidly, and expresses the performance, when used as a sandbag.

  As a result of intensive studies, the present inventors have found that the water absorption speed can be increased by mixing the superabsorbent polymer and the pulp made of wood and having a specific fiber length, and the present invention has been completed. It was. That is, the present invention relates to an absorber including a superabsorbent polymer and wood-derived pulp, wherein the pulp has a fiber length of 1 μm to 24 μm.

  The absorbent body according to the present invention can be easily carried by light weight during normal times when it is used as a sandbag, for example, when it is used as a sandbag, and can absorb water rapidly during a flood and prevent disasters very quickly.

It is the graph which showed the relationship between the water absorption elapsed time and weight in the sandbag produced by the Example and the comparative example.

  Embodiments of the present invention will be described below. In the following description, water is typically assumed as the liquid to be absorbed and expressed as water absorption, water absorption, etc., but the liquid is not limited to water in the present invention.

The present invention is an absorbent body comprising a superabsorbent polymer and a pulp derived from wood and having a fiber length of 1 μm to 24 μm.
The reason why the absorbent of the present invention increases the water absorption rate is not clear, but the interaction between the presence of a high-absorption polymer with a high water-absorbing polymer and pulp derived from wood with a high water absorption rate, The reason may be that the pulp suppresses aggregation in the water absorption process of the polymer.

  The pulp fiber length is 1 μm to 24 μm, and more preferably 2.0 to 10.0 μm. It is considered that the water absorption is greatly affected by the capillary phenomenon, and that the shorter the fiber length, the larger the specific surface area and the larger the contact area with water, thereby increasing the water absorption rate. If the pulp fiber length is longer than 24 μm, the desired water absorption speed is not exhibited, and if it is shorter than 1 μm, for example, when used as a sandbag, it may soar when stored in a bag or may flow out of the eyes of the bag. . Here, the fiber length in the present invention refers to an average value obtained by measuring the length in the length direction of 100 randomly extracted fibers taken with an electron microscope.

  The mixing ratio of the superabsorbent polymer and the pulp is preferably 1 part by weight or more and 100 parts by weight or less with respect to 1 part by weight of the superabsorbent polymer, and the lower limit is more preferably 2 parts by weight or more. As an upper limit, 50 weight part or less is more preferable, and 20 weight part or less is further more preferable. If the blending ratio of the pulp is too small, the desired water absorption speed may not be obtained, and if it is too large, the volume during normal times will increase, making it difficult to store. When the blending ratio of the pulp is too large, the water retention becomes insufficient, and the absorbed water may flow out to the outside again.

Next, various materials used in the absorber of the present invention will be exemplified.
Pulp made from wood of the present invention can be any known pulp as long as it is derived from wood such as mechanical pulp and chemical pulp made from softwood or hardwood, but chemical pulp with less lignin component can be used. preferable.
In the present invention, the pulp can be used after being pulverized by a pulverizer such as a ball mill, an attritor, a sand glider, a micro cutter, or a jet mill. It is preferable to pulverize to the above-described fiber length range because the water absorption speed and workability can be balanced.

  Examples of the superabsorbent polymer used in the present invention include polyacrylic acid and its metal salt, polysulfonic acid and its metal salt, maleic anhydride and its metal salt, polyacrylamide, polyvinyl alcohol, polyethylene oxide, polyaspartic acid and Known superabsorbent polymers such as metal salts thereof, polyglutamic acid and metal salts thereof, polyalginic acid and metal salts thereof, and starch can be used. From the viewpoint of water absorption, polyacrylic acid and sodium polyacrylate are preferred.

  The average particle size of the superabsorbent polymer is preferably 10 μm or more and 1000 μm or less. As a minimum, More preferably, it is 20 micrometers or more, More preferably, it is 40 micrometers or more. As an upper limit, More preferably, it is 500 micrometers or less, More preferably, it is 300 micrometers or less. The amount of water absorption is proportional to the specific surface area of the superabsorbent polymer, and the finer the particle size, the greater the amount of water absorption. On the other hand, there is a problem that the superabsorbent polymer aggregates. On the other hand, in this invention, by mixing the pulp which has specific fiber length, even if the particle size of a super absorbent polymer is small, aggregation is suppressed and water absorption can be improved. The reason for this is not clear, but since the superabsorbent polymer has a low water absorption rate, when it comes into contact with water, the surface swells and stickiness occurs. Therefore, if the superabsorbent polymer is present in an overcrowded state, the superabsorbent polymers are bound to each other, and the absorption rate is rapidly reduced. On the other hand, in this invention, since a pulp exists between superabsorbent polymers, it is thought that the binding of superabsorbent polymers can be inhibited. In addition, the average particle diameter in this invention shows the average value of the superabsorbent polymer particles taken with an electron microscope, the average diameter of 100 randomly selected particles measured.

  Moreover, the absorber of this invention can be accommodated in the water-permeable bag, and can be used as a sandbag. Here, the water-permeable bag is a bag made of nonwoven fabric, hemp or the like as a raw material, and has no particular limitation as long as it has an appropriate network structure, penetrates water, and is insoluble in water. In addition, the use of the absorber of this invention is not limited to a sandbag, It can be used for the use which needs liquid absorption.

  The following examples illustrate the invention but are not intended to limit the invention.

[Comparative Example 1]
A superabsorbent polymer and wood-derived pulp were mixed in the following composition.
Superabsorbent polymer (SAP) crushed to an average particle size of 50 μm by Aisin Nano Technology's Jet Nanomizer Mill: Mixture of polyacrylic acid and sodium polyacrylate (trade name: Aqua Pearl, manufactured by Sundia Polymer Co., Ltd.) 10 g
Kraft pulp (manufactured by Marubeni Paper Pulp Sales Co., Ltd., trade name: bleached kraft pulp, average fiber length 1.5 mm) 20 g
Next, using a wet nonwoven fabric (Nippon Paper Papillia Co., Ltd., basis weight 77.4 g / m ² ), a bag of 300 mm × 300 mm is made (cut into 600 mm × 300 mm, folded in two, and two sides Was sewn with a sewing machine), and one side remaining after the mixture was accommodated therein was sewn to obtain a water-absorbent sandbag.

[Example 1]
A water-absorbent sandbag was produced in the same manner as in Comparative Example 1 except that instead of the kraft pulp of Comparative Example 1, a pulp obtained by pulverizing the kraft pulp to an average fiber length of 10 μm using a jet nanomizer was used.
[Example 2]
Instead of the kraft pulp of Comparative Example 1, a water-absorbent sandbag was prepared in the same manner as in Comparative Example 1 except that the kraft pulp was pulverized to 5 μm with a cutter mill.
[Example 3]
Instead of the kraft pulp of Comparative Example 1, a water-absorbent sandbag was prepared in the same manner as in Comparative Example 1 except that paper powder generated at the time of tissue paper slitting (manufactured by Nippon Paper Crecia Co., Ltd., fiber length: 2 μm) was used.
[Example 4]
A water-absorbent sandbag was produced in the same manner as in Comparative Example 1 except that the amount of paper powder blended in Example 3 was 2 g.
[Example 5]
A water-absorbent sandbag was produced in the same manner as in Comparative Example 1 except that the amount of paper powder in Example 3 was changed to 5 g.
[Example 6]
A water-absorbent sandbag was produced in the same manner as in Comparative Example 1 except that the amount of the paper powder blended in Example 3 was 10 g.
[Example 7]
A water-absorbent sandbag was produced in the same manner as in Comparative Example 1 except that the amount of the paper powder in Example 3 was 50 g.
[Example 8]
A water-absorbent sandbag was produced in the same manner as in Comparative Example 1 except that the amount of the paper powder blended in Example 3 was 100 g.
[Example 9]
A water-absorbent sandbag was produced in the same manner as in Example 3 except that a superabsorbent polymer (average particle size 200 μm) that was not pulverized was used.
[Example 10]
A water-absorbent sandbag was produced in the same manner as in Example 3 except that a highly water-absorbing polymer ground to 25 μm with a jet nanomizer was used.
[Example 11]
A water-absorbent sandbag was produced in the same manner as in Example 3 except that a highly water-absorbing polymer pulverized to 10 μm with a jet nanomizer was used.
[Example 12]
A water-absorbent sandbag was produced in the same manner as in Comparative Example 1 except that KC Flock W-400G (average fiber length: 24 μm) manufactured by Nippon Paper Industries Co., Ltd. was used instead of the kraft pulp of Comparative Example 1.
[Example 13]
A water-absorbent sandbag was prepared in the same manner as in Comparative Example 1 except that thermomechanical pulp (manufactured by Nippon Paper Tsusho Co., Ltd., average fiber length: 2 μm) was used instead of the kraft pulp of Comparative Example 1.

[Comparative Example 2]
A water-absorbent sandbag was prepared in the same manner as in Comparative Example 1 except that kraft pulp was not used.
[Comparative Example 3]
A water-absorbent sandbag was produced in the same manner as in Comparative Example 1 except that KC Flock W-100G (average fiber length: 37 μm) manufactured by Nippon Paper Industries Co., Ltd. was used instead of the kraft pulp of Comparative Example 1.

The following evaluation was performed about the produced water absorbent sandbag.
<Water absorption evaluation>
The produced water-absorbing sandbag was poured with tap water for 5 minutes at a water volume of 10 liters per minute in a shower, and the weight (g) was measured every 30 seconds. Then, it was immersed in tap water for 10 minutes, and the weight was measured. The weight at this time was defined as the maximum weight. The time taken to reach 90% of the maximum weight was taken as the water absorption time and was used as a measure of the water absorption rate. The smaller the time number, the faster the water absorption rate. The results are shown in the table and FIG.

The following can be said from the evaluation results shown in Table 1 and FIG.
-Examples 1-3 of this invention which mixed and used the superabsorbent polymer and the pulp whose fiber length is a specific range are the comparative examples 1 and 3 using a pulp with long fiber length, and the comparison which does not use a pulp. Compared to Example 2, it can be seen that the water absorption speed is increased and functions as a sandbag quickly and effectively.
-From Examples 3-8, it turns out that the maximum weight of a sandbag increases and the water absorption ability improves as the compounding ratio of the pulp whose fiber length is a specific range increases. Here, in Example 4, the water absorption rate is similar to that of the comparative example, but the water absorption amount is increased, and it can be seen that the performance as a sandbag is improved.
From Examples 9 to 11, it can be seen that the smaller the average particle size of the superabsorbent polymer, the faster the water absorption rate.
-From the comparison with Example 12 and Examples 1-3, it turns out that a water absorption speed is so quick that the fiber length of a pulp is short.
-From the comparison between Example 13 and Example 3, it can be seen that chemical pulp has a higher water absorption rate than mechanical pulp.

Claims (5)

  An absorbent comprising a superabsorbent polymer and wood-derived pulp, wherein the fiber has a fiber length of 1 μm to 24 μm.   The absorbent according to claim 1, wherein the pulp is a pulp produced by chemical treatment.   The absorber according to claim 1, wherein the superabsorbent polymer has an average particle size of 10 μm to 1000 μm.   2. The absorbent according to claim 1, wherein 2 to 100 parts by weight of pulp is mixed with 1 part by weight of the superabsorbent polymer.   A water-absorbent sandbag comprising the absorbent body according to any one of claims 1 to 4 accommodated in a water-permeable bag.

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