JP2022007305A - Gelation material for aqueous liquid material - Google Patents

Abstract

To provide a gelation material for an aqueous liquid material which more quickly converts an aqueous liquid material into gel than a conventional gelation material.SOLUTION: A gelation material for an aqueous liquid material is obtained by wrapping a powdery and/or granular water-absorbing resin by a sheet, and sealing the resin, in which at least a part of the sheet is water permeable, at least a part of the sealed part is sealed by a water-soluble polymer having a weight average molecular weight of 1,000-1,000,000, a water absorption magnification of the water-absorbing resin for pure water is 80-1,000 times, a content of a water-soluble component is 5 wt.% or less, and the water-absorbing resin is treated with silica.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gelling material for an aqueous liquid material. More specifically, the present invention relates to a gelling material for an aqueous liquid substance containing a specific water-absorbent resin.

Conventionally, as a bag-shaped gelling material that can be put into an aqueous liquid material and gelled (solidified), a water-absorbent resin wrapped in a laminated sheet in which a water-disintegrating paper and a water-soluble film are laminated is used. It is known (for example, Patent Document 1). However, there is a problem that the strength of the laminated sheet is insufficient, and it becomes weak especially when it is dried, and the bag is broken during transportation and handling. To improve this, a gelled material in which a powdery and / or granular water-absorbent resin is wrapped in a sheet and sealed, and at least a part of the sheet is water-permeable and is sealed. A gelling material for an aqueous liquid material (Patent Document 2), which is characterized in that at least a part of the gel is sealed with a water-soluble polymer having a weight average molecular weight of 10 to 1,000,000, has been proposed and used. ..

Japanese Unexamined Patent Publication No. 4-239087 Japanese Patent No. 4123404

However, when the above-mentioned improved gelling material is immersed in the aqueous liquid material, the time until the gelling material collapses and the aqueous liquid material is gelled is delayed, which may cause troubles on the way. It was desired to find a gelling material that gels faster.

An object of the present invention is to provide a gelling material for an aqueous liquid material, which gels an aqueous liquid material even faster than before.

The present inventors have arrived at the present invention as a result of diligent studies to solve the above problems.
That is, the present invention is a gelled material in which a powdery and / or granular water-absorbent resin is wrapped in a sheet and sealed.
At least a part of the sheet is water permeable, and at least a part of the sealed part is sealed with a water-soluble polymer having a weight average molecular weight of 10 to 1,000,000.
The water absorption of the water-absorbent resin with respect to pure water is 80 to 1000 times, and the water-soluble component content is 5% by weight or less.
It is a gelling material for an aqueous liquid material, characterized in that the water-absorbent resin is treated with silica.

Further, the present invention is characterized in that the silica is hydrophilic silica.

Further, the present invention is characterized in that the water-soluble polymer is polyvinyl alcohol.

Further, the present invention is any application selected from a water-absorbing bag, a water-absorbing sandbag, and a sludge volume-reducing bag, which are characterized by using the above-mentioned gelling material for an aqueous liquid material.

The gelling material of the present invention can provide a gelling material for an aqueous liquid material that gels an aqueous liquid material even faster than before.

FIG. 1 (a) is a perspective view showing the configuration of the water-absorbent sandbag in the present invention, and FIG. 1 (b) is a perspective view showing a state in which the water-absorbent sandbag of FIG. 1 (a) is immersed in water and swollen.

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments. Within the same and equal scope as the present invention, various modifications can be made to the following embodiments.

In the present invention, the powdery or granular water-absorbent resin is not particularly limited in whether it is a natural type or a synthetic type, but it is inexpensive, has excellent water absorption characteristics such as safety, durability, water absorption ratio and water retention, and has excellent water absorption characteristics. Those that do not have to worry about spoilage are preferable.
Examples of such a resin include synthetic water-absorbent resins, which are not particularly limited as long as they absorb and retain water, but are not particularly limited, and are, for example, polyacrylic acid partially neutralized cross-linked products and starch-acrylic acid grafts. Polymer neutralizer, starch-acrylonitrile graft polymer hydrolyzate, vinyl acetate-acrylic acid ester copolymer saponified product, isobutylene-anhydrogen maleic acid copolymer crosslinked product, acrylonitrile copolymer or acrylamide copolymer Hydrolyzate or cross-linked products thereof, acrylate-acrylamide copolymer cross-linked product, polyvinyl alcohol cross-linked product, modified polyethylene oxide cross-linked product, acrylamide-2-methylpropanesulfonate copolymer cross-linked product, (meth) acryloyl alkane. Examples thereof include a sulfonate copolymer cross-linked polymer, a cross-linked carboxymethyl cellulose salt, and a cross-linked polymer of a cationic monomer. Of these, the crosslinked product of the partially neutralized polyacrylic acid and the neutralized product of the starch-acrylic acid graft polymer are preferable because they have particularly good water absorption characteristics, safety and economy.

The above-mentioned water-absorbent resin may be used alone, or two or more kinds may be appropriately mixed and used. The water-absorbent resin is preferably in the form of particles, and is not limited in shape such as amorphous crushed shape, spherical shape, scaly shape, fibrous shape, rod shape, lump shape, powder shape, etc. preferable.

The average particle size of the particles is not particularly limited, but is preferably 30 to 850 μm, and more preferably 60 to 500 μm.
The water absorption ratio is 80 to 1000 times, more preferably 100 to 800 times. If the water absorption ratio is less than 80 times, the degree of swelling after absorbing water becomes insufficient. If it exceeds 1000 times, it will continue to absorb water during storage, and the water absorption rate will decrease.
The gel strength of the water-absorbent resin is preferably 10,000 to 50,000 dyne / cm ² , more preferably 20,000 to 50,000 dyne / cm ² . When the gel strength is 10,000 dynes / cm ² or more, the force to spread the seal portion of the bag after swelling is strong. Water absorption and gel strength were measured by the following methods.

[Measurement method of water absorption magnification]
In a tea bag (length 20 cm, width 10 cm) made of 250 mesh nylon net, 0.2 g of water-absorbent resin adjusted to a particle size of 30 to 100 mesh (150 to 500 μm) is placed, and 1 in 500 ml of pure water. After being soaked for a time and absorbed, it was hung for 15 minutes and drained, and then the increased mass was measured to determine the water absorption ratio with respect to pure water.

[Measurement method of gel strength]
The amount (Mg / g) of the water-absorbent resin with respect to the physiological saline was measured in advance by the same tea bag method (based on JIS K7223-1996) as in the above-mentioned water absorption magnification measurement. Take (M x 0.75) g of physiological saline in a 100 cc beaker, add 1 g of water-absorbent resin (150-250 microns) while stirring at 600 rps, and absorb evenly to absorb the liquid with a smooth surface. Make a gel. The liquid absorbing gel was kept warm at 25 ° C., and the gel strength was measured using a neocard meter (M302 type manufactured by Iio Electric Co., Ltd.) under the following conditions.
Load: 200g
Pressure-sensitive shaft diameter: 3 mmФ
Pressure-sensitive shaft descent speed: 0.36 cm / sec

The water-soluble component content is usually 5% by weight or less, preferably 1% by weight or less. The smaller the value, the better. If the water-soluble component content exceeds 5% by weight, the aqueous liquid substance cannot be gelled faster than before.
The water-soluble component content can be controlled by the polymerization conditions. As a method for lowering the content of the water-soluble component in the water-absorbent resin, for example, a method for increasing the molecular weight of the water-absorbent resin is preferable, and it can be achieved by taking a method for lowering the polymerization concentration, a method for increasing the cross-linking density, and the like. Further, since the water-soluble component has a small molecular weight and contains a carboxylic acid, these can be crosslinked by post-crosslinking to make them water-insoluble.
The water-soluble component can be measured by a method such as a weight measuring method or an electric droplet method described in JP-A-2005-445. The electric drop method is a method using a calibration curve.

Further, the water-absorbent resin is a crosslinked polymer of water-soluble monomers, and the amount of residual water-soluble monomer (for example, acrylic acid) in the water-absorbent resin is preferably 100 ppm or less, preferably 50 ppm or less. Is more preferable. If it is 100 ppm or less, skin disorders such as itching of the skin in contact with the water-absorbent resin are unlikely to occur. As a method for reducing the amount of residual water-soluble monomer (for example, acrylic acid), a method of adding a reducing substance after polymerization is highly effective, but it can also be achieved by a polymerization condition, for example, a method of increasing the molecular weight of the above-mentioned water-absorbent resin. Can be done. Examples of the reducing substance include sodium sulfite, ascorbic acid, amines (ammonia, monoethanolamine, etc.) and the like. The amount used is preferably 0.001 to 5% by weight with respect to the water-absorbent resin.

In the present invention, the powdery and / or granular water-absorbent resin is treated with silica. When treated with silica, the water absorption rate of the powdery and / or granular water-absorbent resin can be improved, and the gelation rate of the aqueous liquid substance can be improved.

As the hydrophilic silica, known hydrophilic silica can be widely used, and among them, fumed silica having a silanol group (Si—OH group) on the surface is preferable.

Examples of the hydrophobic silica include hydrophobic fine powder silica obtained by covalently bonding an alkyl group or the like to a silanol group on the surface of the fine powder hydrophilic silica and modifying it, and the methyl group is covalently bonded and modified. This is preferable because the hydrophobized fine powdery silica can obtain appropriate hydrophobicity. Examples of the surface treatment agent for covalently bonding an alkyl group to a silanol group include dimethyldichlorosilane, hexamethyldisilazane, (meth) acrylicsilane, octylsilane (for example, trimethoxyoctylsilane), and aminosilane. One or more selected from.

As a method of covalently bonding a methyl group to a silanol group on the surface, for example, a method of reacting a silanol group with dimethyldichlorosilane or the like can be mentioned. The number of methyl groups covering the surface of silica can be controlled by the amount of dimethyldichlorosilane or the like to be reacted. The number is not particularly limited, but from the viewpoint of adjusting the hydrophobicity of silica and from the viewpoint that the gelation rate when the gelling material is put into the aqueous liquid material is faster than before, the surface area of silica is used as a reference. , 1.0 to 4.0 pieces / nm ² , more preferably 1.5 to 3.8 pieces / nm ² , and particularly preferably 2.0 to 3.5 pieces / nm ² .
The number of methyl groups can be measured by infrared spectroscopic analysis from the relative ratio of the peak intensities of the silanol groups and the methyl groups on the silica surface. The surface area is determined by the BET method.

As the silica, hydrophilic silica is preferable. More preferably, it is a combination of hydrophilic silica and hydrophobic silica. Treatment with hydrophilic silica further improves the water absorption rate of the water-absorbent resin and further improves the gelation rate. When used in combination, the water absorption rate of the water-absorbent resin is further improved, and the gelation rate is further improved.

As a method for treating the powdery and / or granular water-absorbent resin with silica, silica is blended with the powdery and / or granular water-absorbent resin, and the temperature is preferably 0 to 50 ° C., more preferably 10 to 30 ° C. It can be easily obtained by mixing. It is preferable to mix 1 to 20 parts by weight, more preferably 2 to 7 parts by weight of silica with respect to 100 parts by weight of the water-absorbent resin. The mixing method is obtained by putting both in a container and stirring and mixing, or shaking.

The sheet for wrapping the powdery and / or granular water-absorbent resin used in the present invention is at least partially water-permeable. Such a sheet may be flexible, but when the water-absorbent resin is wrapped and sealed by the sheet and immersed in an aqueous liquid material, even if the water-absorbent resin swells by water absorption, its swelling power is sufficient. The form and material are not particularly limited as long as they have a wet strength that does not tear immediately. In addition, it is necessary to have a certain level of normal strength that does not break even during work such as transportation.

Here, the water permeability is 30 seconds or less, preferably 15 seconds or less, and particularly preferably 5 seconds or less, in terms of the time (seconds) for 100 ml of 25 ° C. ion-exchanged water to pass through an area of 100 cm ² . Point to that. The normal strength needs to be 2 kg / cm or more in both vertical and horizontal directions, preferably 3 kg / cm or more, and the wet strength (tensile strength after being immersed in ion-exchanged water at 25 ° C. for 1 minute) is 0.05 kg / cm. As mentioned above, preferably 0.1 kg / cm or more is required. Conventional water-disintegrating paper and the like are not always preferable because their wettability is too small.

In the present invention, as a method of imparting water permeability to a sheet, in addition to forming a through hole in the sheet to allow water to pass through, the portion having the through hole is laminated with a water-soluble sheet to have high water solubility. It also includes those coated with molecules so that the water-soluble resin dissolves in water and immediately penetrates the pores to develop water permeability. The size of the through hole is not particularly limited as long as water can pass through it, but it is preferably 0.1 to 1 mm, particularly preferably 0.1 to 0.5 mm, and the powder and / or particles of the water-absorbent resin are less likely to leak. Anything is fine. Examples of the sheet having through holes as described above include cloths such as knitted fabrics, woven fabrics, and non-woven fabrics; mesh films such as polyethylene and polypropylene sheets having many fine holes formed therein. The thickness of the sheet is preferably 0.1 to 5 mm.

Examples of the material forming the sheet include synthetic resins or fibers such as polyester, nylon, acrylic, polyethylene, polypropylene, and polystyrene and their modified products, semi-synthetic fibers such as rayon and acetate, cotton, wool, silk, and pulp fibers. Natural fibers and all fiber materials such as these blended and woven products can be applied. Of these, a sheet made of hydrophilic fibers such as cotton, linen, pulp fibers and nylon is preferable, and a sheet made of cotton and / or pulp is more preferable. This is because the material forming the sheet is hydrophilic, so that water easily enters the through holes. Sheets made of non-hydrophilic materials are preferably treated with a surfactant or the like before use. Here, as an index of hydrophilicity, a material such as a fiber may be cut into a size of 1.5 cm × 1.5 cm, floated on ion-exchanged water at 25 ° C., and completely wet or settled within 10 minutes. Good, non-hydrophilic ones do not get wet with water even for 10 minutes.

As the water-soluble polymer that covers the portion where the through hole is formed, the same water-soluble polymer as the following water-soluble polymer can be used. The sheet used in the present invention constitutes a part or the whole by the sheet as described above. Further, two or more types of sheets as described above may be used in combination.

In the present invention, in order to enclose the powdery and / or granular water-absorbent resin, at least a part of the sealing portion is sealed with a water-soluble polymer, that is, the water-soluble polymer is present between the sheets of the sealing portion. Seal after. The water-soluble polymer used for the seal needs to be water-soluble after the sheet is adhered by the seal and have a weight average molecular weight of 10 to 1,000,000. The weight average molecular weight is preferably 2000 to 500,000, and particularly preferably 5000 to 200,000. If the weight average molecular weight is less than 1000, the adhesive strength is weak and the gelled material is peeled off during transportation or work. If it exceeds 1 million, it will dissolve slowly in water and the gelation time of the aqueous liquid will be delayed. Specific examples of such a water-soluble polymer include the following (1) to (3).

(1) Synthetic polymer Polyvinyl alcohol (Poval; the degree of saponification is not limited as long as it is soluble in water, but is preferably 70 to 98 mol%, particularly preferably 75 to 95 mol%), polyacrylamide, and water-soluble acrylic. Resins (single or copolymers of water-soluble monomers such as sodium acrylate and hydroxyethyl acrylate), water-soluble polyurethane resins (polyisocyanates such as isophorone diisocyanate and hexamethylene diisocyanate and polyols such as polyethylene oxide having a molecular weight of 400 to 4000, etc. Water-soluble epoxy resin (reaction product of polyol such as polyethylene oxide having a molecular weight of 400 to 4000 and polyepoxide such as ethylene glycol diglycidyl ether), polyethyleneimine, polyethylene oxide, polyvinylpyrrolidone, etc.;

(2) Semi-synthetic polymer Cellulose-based such as carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose; starch-based such as oxidized starch and modified starch;

(3) Natural high molecular weight starches such as corn starch, wheat starch, tapioca starch, horse bell starch; sugars such as konjac mannan and pectin; seaweeds such as glue, agar and sodium alginate; gum arabic, guar gum, locust bean gum, carrageenan, Plant mucilages such as trolley aoi and traganth gum; mucilages produced by microorganisms such as dextran and purulan; proteins such as glue, gelatin and casein;
Two or more of these may be used in combination.
Of these, a synthetic polymer is preferable, and polyvinyl alcohol is particularly preferable.

Examples of the form of the water-soluble polymer before sealing, that is, the form present between the sheets, include those selected from water-soluble films, water-soluble coating agents, and adhesives.
As the water-soluble film, a water-soluble thermoplastic film is preferable. The weight average molecular weight of the water-soluble polymer is preferably 5,000 to 1,000,000, particularly preferably 10,000 to 500,000. The thickness of the film is not particularly limited, but is preferably 10 μ to 4 mm, particularly preferably 50 μ to 2 mm. As the water-soluble coating agent, a water-soluble polymer having a weight average molecular weight of preferably 1,000 to 500,000, particularly preferably 5,000 to 200,000 can be used. Water-soluble adhesives are also included in this.

The concentration of the coating agent is not limited as long as it can be applied with a brush, a roller, or the like, but is preferably 10 to 100% by mass. Solvents and water commonly used when diluting coating agents can be used. The powder may be applied, melted by heat, and adhered.
The coating amount of the coating agent is the mass of the solid content, preferably 0.1 to 50 g / m ² , and particularly preferably 0.2 to 20 g / m ² . The adhesive is a water-soluble polymer having a weight average molecular weight of preferably 1,000 to 300,000, particularly preferably 3,000 to 150,000. The concentration of the adhesive, the amount of coating, and the like may be the same as those of the coating agent.
Among these forms, a water-soluble film and a water-soluble coating agent are preferable, and a water-soluble film is particularly preferable.

The gelled material of the present invention is formed by wrapping a powdery and / or granular water-absorbent resin in a sheet, sealing it, and enclosing it. The encapsulation form is not particularly limited, and examples thereof include a method of forming a sheet into a bag shape. The method for producing the gelled material is not particularly limited. When the sheets are made into a bag shape, the bag may be made into a bag shape by stacking two sheets and sealing them, or may make a bag shape by stacking three or more sheets. After putting the water-absorbent resin in a bag-shaped object from the beginning when the part is opened, the opened part may be sealed to make a bag. As a method of making a bag, there is a method of putting a water-absorbent resin after sealing except a part of the sheet and then sealing the rest, a method of putting a water-absorbent resin on the sheet and sealing the surroundings. Can be mentioned.

The sealing method is not particularly limited as long as the sealed portion is sealed to the extent that the sealed portion does not come off during transportation or handling of the gelled material, but it is usually performed by heat sealing (heat fusion), pressure bonding, or the like. As for the temperature of heat fusion, the pressure of pressure bonding, etc., the conditions normally implemented can be used.
The adhesive strength of the sheet is preferably 0.1 kgf / 25 mm or more, and more preferably 0.2 kgf / 25 mm or more. The gelling agent may be adhered to such an extent that the sealed portion does not come off during transportation or handling. The adhesive strength can be measured by the following method.

[Adhesive strength] The peel strength (180 ° peel peel strength, tensile speed 100 mm / min, unit; kgf / 25 mm) is measured with an adhesive strength measuring device.

When a water-soluble film or coating agent is used as the sealing material, whether the water-soluble film or coating surface of the sheet should be inside the sealing portion after the water-soluble film is bonded or coated on one side of the sheet. , The water-soluble film of one sheet or the coating surface may be on the inside and sealed together with one sheet. Further, a water-soluble film may be inserted between the sheets for sealing, or in the case of coating, the coating surface may be sealed before it dries. When a glue is used, it is the same as the coating, but it is particularly preferable to apply the glue only to the seal portion. Insert the adhesive between the sheets or apply the adhesive to one or both sheets, then align the adhesive-applied surfaces of the sheets and seal. It is also possible to combine these methods. Of these, preferably, it is a method of sealing sheets to which a water-soluble film is bonded or sheets coated with a coating agent together. These methods are also efficient in terms of workability.

Of the total area of the sheet used for encapsulating the powdery and / or granular water-absorbent resin, the area occupied by the water-permeable portion is preferably 25% or more, more preferably 50% or more, and particularly preferably 75% or more. preferable. Most preferably 100%. If it is 25% or more, the amount of water quickly absorbed by the water-absorbent resin is supplied sufficiently quickly. The part other than the part having water permeability means that it does not have water permeability, and it does not have a through hole through which water passes, or even if it has a through hole and is breathable, water can pass through. It means something that does not exist. The material may be the same as that of the portion having water permeability.

The sheet is sealed after adding powdery and / or granular water-absorbent resin, but when the sheet is bag-shaped, the part sealed with the water-soluble polymer occupies the length of the entire outer circumference to be sealed. The ratio is preferably 25% or more, more preferably 50% or more, and particularly preferably 75% or more of the total outer peripheral length of the bag. Most preferably 100%. This is because if it is 25% or more, the time for the water-absorbent resin to come out after opening the seal portion is reduced. It is preferable to seal the entire outer circumference of the bag with a water-soluble polymer. The remaining portion not sealed with the water-soluble polymer may be sealed or sewn with a non-water-soluble polymer sealing material (ordinary polyethylene sheet, polypropylene sheet, etc.), but is not particularly limited. The width of the seal is not particularly limited as long as the water-absorbent resin does not leak from the bag during handling, but is preferably 1 to 30 mm, and particularly preferably 5 to 15 mm.

The shape of the gelling material may be set according to the intended use, and may be any shape such as a circle, a quadrangle (rectangle, square, rhombus, trapezoid, etc.), a triangle, etc. It is a rectangle. The size is not particularly limited, but one side of a quadrangle (particularly a rectangle or the like) is preferably 5 to 30 cm, and particularly preferably 7 to 20 cm. If one side is 5 cm or more, the efficiency of producing a gelling agent is good, and if it is 30 cm or less, it is not too large and difficult to handle.

The amount of the water-absorbent resin enclosed in one of the gelling materials is preferably 0.01 to 0.6 g / cm ² , more preferably 0.05 to 0.5 g / cm ² , and particularly preferably. Is 0.1 to 0.4 g / cm ² .

In addition to the water-absorbent resin, the gelling material of the present invention contains known deodorants, fragrances, bactericides, fungicides, preservatives, defoamers, foaming agents, and blocking prevention, if necessary. Agents, surfactants, oxygen scavengers, bulking agents (CMC, etc.) and the like can be added. The amount added is not particularly limited as long as it does not hinder the water absorption and swelling of the water-absorbent resin, but is preferably 50 parts by mass or less, more preferably 20 parts by mass or less, and particularly preferably 20 parts by mass with respect to 100 parts by mass of the water-absorbent resin. It is 10 parts by mass or less.

The gelling material of the present invention provides a gelling material for an aqueous liquid material that gels an aqueous liquid material even faster than before. The reason for this is considered as follows.
When the gelling material of the present invention is immersed in an aqueous liquid substance, the water-soluble polymer as an adhesive on the sheet surface begins to dissolve in water, and at the same time, the water that has entered the bag through the water-permeable portion of the sheet is powdered. And / or the granular water-absorbent resin absorbs water and swells, and as a result, the adhesive surface of the sheet is expanded by the swelling pressure, and the sealed portion made of the water-soluble polymer is easily opened. When the seal is opened, the water-absorbent resin goes out of the bag and absorbs water and swells at once, gelling the water-based liquid.

The powdery and / or granular water-absorbent resin is an aggregate of the water-absorbent resin. When water invading from the water-permeable part of the sheet swells the powdery and / or granular water-absorbent resin, if there is silica on the surface of the water-absorbent resin, the water-absorbent resin and water-absorbent in the powder and / or granules If the water-soluble component of the water-absorbent resin is 1% by weight or less, the water on the surface of the water-absorbent resin will be the water-absorbent resin itself when it enters the water-absorbent resin itself. It can get inside quickly, and as a result, the water-absorbent resin itself can be swollen quickly. If the water-soluble component exceeds 1% by weight, the water-soluble component interferes with water entering the water-absorbent resin, so that swelling is delayed.
That is, since the water-absorbent resin in the gelling material swells faster than before, the bag can be expanded and opened quickly, and the outer aqueous liquid material can be further gelled.

The aqueous liquid substance to which the gelling material of the present invention is used may be a hydrous liquid substance, and is not particularly limited. The ratio of water in the aqueous liquid material is not particularly limited, but is preferably 50% by mass or more. Specific examples of the aqueous liquid material include rainwater, tap water, well water, river water, pond / lake water, seawater, muddy water and other general water; mines, civil engineering / construction sites, paper and pulp factories, textile / dyeing factories, etc. Hedro-like wastewater and effluent generated from machinery / metal processing factories, ore scouring factories, chemical factories, electrical / electronic related factories, medical industry facilities such as hospitals, food processing factories, ceramics, water purification plants, sewage treatment plants, households, etc. And so on. The liquid material may be in a stationary state or may be in a flowing state.

The gelling material of the present invention can be gelled in a short time (usually about 1 minute) by putting it in an aqueous liquid material and preferably stirring the whole liquid. The ratio of the water-absorbent resin in the gelling material to the water in the target aqueous liquid material is preferably 1: 500 to 1:10 by mass ratio, and particularly preferably 1: 400 to 1:50. .. It is sufficient to stir the whole liquid lightly. A general-purpose stirrer can be used, and there is no particular limitation. If the amount of liquid is 5 liters or less, it is sufficient to stir by hand with a spatula.

INDUSTRIAL APPLICABILITY The present invention is used for any of a water-absorbing bag, a water-absorbing sandbag, and a sludge volume-reducing bag, which are characterized by using the above-mentioned gelling material for an aqueous liquid material. The water absorption bag is used, for example, to absorb and remove water when the ground becomes flooded due to rain, and to dry the ground quickly. Water-absorbing sandbags, like sandbags, are used to block water during floods. A sludge volume reduction bag allows water in sludge to enter the bag and absorbs the water to reduce the amount of water in sludge, resulting in a reduction in the apparent amount of sludge, thus reducing the total amount of sludge. The volume can be reduced. They are all configured with the same structure and can be applied to different applications. The following will be described as a representative of water-absorbing sandbags.

The water-absorbent sandbag is formed by enclosing the gelling material of the present invention in a water-permeable bag. As the material of the water-permeable bag, the same material as that having the above-mentioned sheet water permeability can be used. The size of the bag is not particularly limited as long as it can enclose the gelling material of the present invention, but is preferably a bag having a size of 20 to 50 cm × 50 to 80 cm, and more preferably 30 to 45 cm × 50 to 70 cm. .. The shape of the bag is not limited as well as the gelling agent. The water-absorbent sandbag preferably contains 1 to 10 gelling materials of the present invention, more preferably 1 to 6 pieces, and particularly preferably 1 to 4 pieces. If the gelling material is fixed in the water-absorbent sandbags with double-sided tape so that the intervals are the same, the gelling material does not move and is not biased during transportation, resulting in uniform gelation during use. The width of the interval is preferably 1 to 15 cm, particularly preferably 3 to 10 cm. The ratio of the gelling material of the present invention to the area of the bag constituting the water-absorbent sandbag is preferably 10 to 70%, particularly preferably 20 to 50%.

FIG. 1 (a) is a perspective view showing the configuration of the water-absorbent sandbag in the present invention, and FIG. 1 (b) is a perspective view showing a state in which the water-absorbent sandbag of FIG. 1 (a) is immersed in water and swollen.
When the water-absorbing sandbag 1 of FIG. 1A is immersed in water, the gelling material 2 collapses and the hemp bag 3, which is a sack, is expanded and inflated. The situation is shown in FIG. 1 (b) by the swollen water-absorbing sandbag 5.
The water-absorbing sandbag of the present invention can be used in the same manner as ordinary soil sandbags, but can be suitably used as rainwater intrusion prevention in order to protect embankments, buildings, houses, etc. in the event of a flood, heavy rain, etc., for example.

Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited thereto.
Production Example 1
76.7 g of sodium acrylate, 23 g of acrylic acid, 0.3 g of N, N'-methylenebisacrylamide and 295 g of deionized water were placed in a glass reaction vessel having a capacity of 1 liter, and the temperature of the contents was raised to 5 while stirring and mixing. Keeped at ° C. After inflowing nitrogen into the contents to make the dissolved oxygen amount about 1 ppm, 1 g of a 1% aqueous solution of hydrogen peroxide, 1.2 g of a 0.2% aqueous solution of ascorbic acid and 2,2'-azobis amidinopropane dihydro 2.8 g of a 2% aqueous solution of chloride was added and mixed to initiate polymerization (polymerization concentration 25%). A hydrogel-like polymer was obtained by polymerizing and aging for about 6 hours.
This water-containing gel-like polymer was laminated on a SUS screen having an opening of 850 μm to a thickness of 5 cm, and a small air-permeable dryer (manufactured by Hakkou Denki Seisakusho Co., Ltd.) was used to supply an air temperature of 205 ° C. Under the condition of a wind speed of 1.5 m / sec, the water-containing gel was allowed to permeate for 30 minutes, and the water-containing gel was heated and dried to obtain a dried product having a water content of about 4%. The obtained dried product was crushed using a household mixer, and a product having a particle size of 32 to 710 μm (400 mesh to 22 mesh) was collected using a fluid, and the water-absorbent resin (1) (average particle diameter 420 μm, A water absorption magnification of 220 times, a gel strength of 31,000 dyne / cm ² , and a water-soluble component content of 6.5% by weight) were obtained.

Manufacturing example 2
In Production Example 1, 285 g of deionized water was used instead of 295 g of deionized water, and 3.2 g of the 2% aqueous solution was used instead of 2.8 g of a 2% aqueous solution of 2,2'-azobisamidinopropanedihydrochloride. Water-absorbent resin (2) (average particle size 375 μm, water absorption magnification 205 times, gel strength 35,000 dyne) in the same manner as in Production Example 1 except that the polymerization / aging was performed for about 8 hours instead of the polymerization / aging for about 6 hours. / Cm ² , water-soluble component content 0.9% by weight) was obtained.

Production example 3
Water-absorbent resin (2) Add 1 g of "Aerosil 200CF" (hydrophilic ultrafine silica, average particle diameter of primary particles of about 12 nm, manufactured by Nippon Aerosil Co., Ltd.) to 100 g of the water-absorbent resin, and stir well to make the water-absorbent resin. The water-absorbent resin A of the present invention was obtained by coating the surface of (2) with ultrafine silica.

Production example 4
In Production Example 3, instead of 1 g of "Aerosil 200CF", 0.5 g of "Aerosil 200CF" and "Aerosil R972CF" (hydrophobic ultrafine silica, average particle diameter of primary particles of about 16 nm, manufactured by Nippon Aerosil Co., Ltd.) 0. The water-absorbent resin B of the present invention was obtained in the same manner as in Production Example 3 except that 5 g was used.

Production Example 5
In Production Example 3, a comparative water-absorbent resin C was obtained in the same manner as in Production Example 3 except that 100 g of the water-absorbent resin (1) was used instead of 100 g of the water-absorbent resin (2).

Example 1
10 sheets (a) laminated with "Havix JS45HD-W" (Havix, dry pulp non-woven fabric) and a 30 μm-thick PVA film (Kuraray, CP-1220T10, saponification degree 87-89%). A bag was manufactured by cutting it into a rectangle having a size of × 15 cm, overlapping the PVA film side, and heat-sealing the three ends (sides). 50 g of the above-mentioned water-absorbent resin A was put therein, and then the opening was heat-sealed (sealed) to prepare the gelled material (A) of the present invention.

Example 2, Comparative Examples 1 to 3
In Example 1, gelation is performed in the same manner as in Example 1 except that the same amounts of water-absorbent resin B, water-absorbent resin (2), water-absorbent resin C, and water-absorbent resin (1) are used instead of water-absorbent resin A. A material (B) (Example 2), a gelling material (C) (Comparative Example 1), a gelling material (D) (Comparative Example 2), and a gelling material (E) (Comparative Example 3) were obtained. See Table 1 below.

The following gelation test was performed using the above gelling material.
(Test method)
2 L of tap water was put into a 3 L polybeaker, the liquid temperature was adjusted to 25 ° C., and then the gelling material was added, and the time (seconds) until the entire tap water was gelled was measured.
The results are shown in Table 1.

From Table 1, it can be seen that the gelling material of the present invention can be gelled faster than the conventional gelling material (E).

1. 1. Water-absorbing sandbags 2. Gelling material 3. Hemp bag 4. Sewing part of water-absorbent sandbags 5. Swollen water-absorbing sandbags

Claims (4)

A gelling material in which a powdery and / or granular water-absorbent resin is wrapped in a sheet and sealed.
At least a part of the sheet is water permeable, and at least a part of the sealed part is sealed with a water-soluble polymer having a weight average molecular weight of 10 to 1,000,000.
The water absorption ratio of the water-absorbent resin with respect to pure water is 80 to 1000 times, and the water-soluble component content is 5% by weight or less.
A gelling material for an aqueous liquid material, wherein the water-absorbent resin is treated with silica. The gelling material for an aqueous liquid material according to claim 1, wherein the silica is hydrophilic silica. The gelling material for an aqueous liquid substance according to claim 1 or 2, wherein the water-soluble polymer is polyvinyl alcohol. Any use selected from a water-absorbing bag, a water-absorbing sandbag, and a sludge volume-reducing bag, which comprises using the gelling material for an aqueous liquid material according to any one of claims 1 to 3.

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