JP2003158919A - Reusable water-retainable resin-containing mat and method for reusing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-retainable resin-containing cold holding mat for animals reusable as a humectant for plant-raising, using the water-absorbing resin in the mat after used. <P>SOLUTION: This water-retainable resin-containing mat comprises the powder of the water-retainable resin (A) and a bag-like cloth to put the powder in. The calcium ion-absorbing amount of the resin (A) is 0-100 mg per dry weight, the water-absorbing capacity thereof is 10-1,000 times in ion-exchanged water at 25°C and the average particle diameter thereof is 10-1,000 μm. The ventilation rate of the cloth is 0.1-30 cm<SP>3</SP>/cm<SP>2</SP>.sec. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold insulation mat for animals having a water absorbent resin contained in a cloth bag. More specifically, it relates to a cold insulation mat for animals containing a reusable water absorbent resin and a method of recovering the water absorbent resin in the mat after use and reusing it as a water retaining agent for plant growth.

[0002]

2. Description of the Related Art As a mat containing a water-absorbent resin used for a cushion for keeping cold of pets such as dogs, the air permeability is conventionally 1 to 8c.
There is a cushion that absorbs water during use by putting a water-absorbent resin in a cloth bag made of a m ³ / cm ² · sec cloth. (For example,
(Patent Document 1)

[0003]

[Patent Document 1] Japanese Patent Laid-Open No. 10-295499

[0004]

However, even if the mat containing the water absorbent resin is repeatedly used as a cold insulating mat, it is only discarded after one season of use, and the water absorbent resin in the mat containing the water absorbent resin is used. That is, a gel or powdery water absorbent resin is not reused and is a waste as a resource, and a mat containing a water absorbent resin that can be reused after use has been desired. .

[0005]

Means for Solving the Problems As a result of intensive investigations by the present inventors to obtain a water-retaining mat for animals containing a water-absorbent resin, the water-absorbent resin usable as a water retaining agent for growing plants can be obtained. It was found that the gel- or powder-like water-absorbent resin recovered after use can be reused as a water retaining agent for growing plants by constructing a mat containing water-absorbent resin by using the above. That is, the present invention provides a mat comprising a powder of a water-absorbent resin (A) and a bag-shaped cloth in which the powder is absorbed, wherein the (A) has a calcium ion absorption amount of 0 to 100 mg per 1 g of dry weight. ℃
Has a water absorption capacity of 10 to 1,000 times in ion-exchanged water, has an average particle diameter of 10 to 1,000 μm, and has a gas permeability of 0.1 to ³⁰ cm ³ / cm ² · sec. A water-absorbent resin-containing mat; a water retaining agent for plant growth, which uses the water-absorbent resin in the used mat;
In this method, the water absorbent resin in the used mat is recovered and reused as a water retaining agent for plant growth.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Water-absorbent resin (A) in the present invention
, The calcium ion absorption is 0 to 100 mg per 1 g of dry weight, the water absorption capacity in ion-exchanged water at 25 ° C. is 10 to 1,000 times, and the average particle size is 10 to 1,000 μm. There is no particular limitation as long as it is an anionic, nonionic or cationic water absorbent resin as long as it is a certain water absorbent resin. Specifically, for example, the water absorbent resin (a) of the following (1) to (5) The thing which adjusted the absorption amount is mentioned. (1) 1 selected from a polysaccharide (a-1) and / or a monosaccharide (a-2) such as starch or cellulose, a water-soluble monomer and / or a monomer which becomes water-soluble by hydrolysis
A water-absorbent resin obtained by polymerizing at least one kind of monomer (b) and a cross-linking agent (c) as essential components and performing hydrolysis if necessary. Examples of (a-1) include sucrose, cellulose, CMC, starch and the like, and examples of (a-2) include pentaerythritol, diglycerin, sorbitol, xylitol, mannitol, dipentaerythritol, glucose and fructose. .

Examples of (b) include a carboxyl group,
Radical-polymerizable water-soluble monomers having a sulfonic acid group and a phosphoric acid group and salts thereof, and radical-polymerizable water-soluble monomers having a hydroxyl group, an amide group, a tertiary amino group, and a quaternary ammonium salt group Can be mentioned. Examples of the radically polymerizable water-soluble monomer having a carboxyl group include unsaturated mono- or poly (divalent to hexavalent) carboxylic acid [(meth) acrylic acid (acrylic acid and / or methacrylic acid. The same applies hereinafter. Description is used), maleic acid, maleic acid monoalkyl (C1-9) ester, fumaric acid, fumaric acid monoalkyl (C1-9) ester, crotonic acid, sorbic acid, itaconic acid, itaconic acid monoalkyl. (C1-9) ester, itaconic acid glycol monoether, cinnamic acid, citraconic acid, citraconic acid monoalkyl (C1-9) ester, etc.] and their anhydrides [maleic anhydride, etc.] and the like. To be

Examples of the radical-polymerizable water-soluble monomer having a sulfonic acid group include aliphatic or aromatic vinyl sulfonic acids (vinyl sulfonic acid, allyl sulfonic acid, vinyl toluene sulfonic acid, styrene sulfonic acid, etc.), 2 −
Hydroxy-3- (meth) acryloxypropyl sulfonic acid, (meth) acrylalkyl sulfonic acid [(meth)
Sulfoethyl acrylate, sulfopropyl (meth) acrylate, etc.], (meth) acrylamidoalkylsulfonic acid [2-acrylamido-2-methylpropanesulfonic acid, etc.] and the like. Examples of the radical-polymerizable water-soluble monomer having a phosphoric acid group include (meth) acrylic acid hydroxyalkyl phosphoric acid monoester [2-hydroxyethyl (meth) acryloyl phosphate, phenyl-2-acryloyloxyethyl phosphate, etc.] Etc. Salts of water-soluble monomers containing the above-mentioned carboxyl group, sulfonic acid group, and phosphoric acid group [for example, alkali metal salts (sodium salt, potassium salt, etc.), alkaline earth metal salts (calcium salt, magnesium salt, etc.), amine Salt or ammonium salt] and the like.

Hydroxyl group-containing radically polymerizable water-soluble monomer [hydroxyalkyl mono (meth) acrylate having 2 to 3 carbon atoms in the alkyl group, polyethylene glycol (weight average molecular weight Mw: 100 to 4,000) mono (meth ) Acrylate, polypropylene glycol (Mw:
100-4,000) mono (meth) acrylate, methoxy polyethylene glycol (Mw: 100-400)
0) mono (meth) acrylate and the like]; amide group-containing radical-polymerizable water-soluble monomer [eg (meth) acrylamide, N-alkyl (C 1 to C 3) substituted (meth) acrylamide (N-methyl acrylamide, N , N-dimethylacrylamide, etc.)]; Tertiary amino group-containing radical-polymerizable water-soluble monomer [eg, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylamide, etc.]; Quaternary ammonium base-containing radical polymerization Water-soluble monomer [eg quaternized compound of the above-mentioned tertiary amino group-containing monomer (quaternized using a quaternizing agent such as methyl chloride, dimethyl sulfate, benzyl chloride, dimethyl carbonate), etc.] An epoxy group-containing radically polymerizable water-soluble monomer [eg glycidyl (meth) acrylate]; Radically polymerizable water-soluble monomers [4-
Vinyl pyridine, vinyl imidazole, N-vinyl pyrrolidone, N-vinyl acetamide, etc.] and the like.

As the monomer which becomes water-soluble by hydrolysis, at least one hydrolyzable group [an acid anhydride group, a lower alkyl (C1 to C3) ester group, a nitrile group, etc.] is used.
Radical polymerizable monomers having Examples of the radical-polymerizable monomer having an acid anhydride group include a radical-polymerizable monomer having 4 to 20 carbon atoms such as maleic anhydride, itaconic anhydride, and citraconic anhydride, and a radical-polymerizable monomer having an ester group. As the monomer, for example, lower alkyl (C1 to C3) of monoethylenically unsaturated carboxylic acid
Esters [eg, methyl (meth) acrylate, ethyl (meth) acrylate, etc.], esters of monoethylenically unsaturated alcohols [eg, vinyl acetate, acetic acid (meth)]
And the like] and the like. Examples of the radically polymerizable monomer having a nitrile group include (meth) acrylonitrile and the like. These may be hydrolyzed during the polymerization or after the polymerization, and usually they are hydrolyzed to form a salt and become water-soluble. Examples of the salt include the same salts as those described above for the salt-forming group. These monomers are
They may be used alone or in combination of two or more if necessary. Of these, water-soluble monomers are preferable. More preferred are a hydroxyl group-containing radical-polymerizable water-soluble monomer, an amide group-containing radical-polymerizable water-soluble monomer, a carboxyl group-containing radical-polymerizable water-soluble monomer and salts thereof, and particularly preferably (meta ) Acrylic acid and its salts.

Examples of the cross-linking agent (c) include cross-linking agents having two or more radically polymerizable unsaturated groups, cross-linking agents having radically polymerizable unsaturated groups and reactive functional groups, and two reactive functional groups. Examples of the crosslinking agent include one or more. Specific examples of the compound having two or more radically polymerizable unsaturated groups include N, N′-methylenebis (meth) acrylamide,
Ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, glycerin (di or tri) acrylate, trimethylolpropane triacrylate, triallylamine, triallyl cyanurate, triallyl isocyanurate , Tetraallyloxyethane and pentaerythritol triallyl ether.

Compounds having at least one functional group capable of reacting with the functional groups of (a) and (b) and having at least one radically polymerizable unsaturated group [eg hydroxyethyl (meth) acrylate, N -Methylol (meth) acrylamide, glycidyl (meth) acrylate and the like]. Specific examples of the compound having two or more functional groups capable of reacting with the functional groups (a) and (b) include polyhydric alcohols (for example, ethylene glycol, diethylene glycol, glycerin, propylene glycol, trimethylolpropane, etc.), Examples thereof include alkanolamines (eg diethanolamine etc.), polyamines (eg polyethyleneimine etc.) and the like. Two or more kinds of these crosslinking agents may be used in combination. Among these, preferred are copolymerizable cross-linking agents having two or more radically polymerizable unsaturated groups, more preferably N, N'-methylenebisacrylamide, ethylene glycol diacrylate, trimethylolpropane triacrylate, Tetraallyloxyethane, pentaerythritol triallyl ether, triallylamine. The ratios of (a), (b) and (c) and the method for producing the water absorbent resin are not particularly limited.

Examples of the method for producing the water absorbent resin include an aqueous solution polymerization method, a reverse phase suspension polymerization method, a spray polymerization method, a photoinitiated polymerization method and a radiation polymerization method. A preferred polymerization method is a method of aqueous solution polymerization using a radical polymerization initiator. In this case, the type and amount of the radical polymerization initiator used and the radical polymerization conditions are not particularly limited and can be the same as usual. If necessary, various additives, chain transfer agents (eg, thiol compounds, etc.) may be added to these polymerization systems. The amount of the cross-linking agent is 0.00
When it is less than 1%, it becomes a sol at the time of absorbing water, and the water absorbing / water retaining ability which is a function of the water absorbing resin becomes small. Also,
The drying property is very poor and the productivity is inefficient. While 5
On the other hand, if it exceeds%, the crosslinking will be too strong and the water absorption / water retention capacity will not be exhibited sufficiently. If necessary, various additives, chain transfer agents (for example, thiol compounds, etc.), surfactants, etc. may be added to these polymerization systems.

In the case of cross-linking, the above-mentioned cross-linking agent (C) is used for cross-linking, or the cross-linking agent is not used and heated to a specific temperature to utilize the reactivity of functional groups such as hydroxyl groups and amide groups. There is a case of crosslinking by the above-mentioned thermal crosslinking. Examples of preferred polymers that can be thermally crosslinked include (meth) acrylamide and polymers containing a hydroxyalkyl mono (meth) acrylate having an alkyl group with 2 to 3 carbon atoms, and specifically (meth) acrylamide. Examples thereof include / (meth) acrylic acid (alkali metal salt) copolymers and hydroxyalkyl mono (meth) acrylate / (meth) acrylic acid (alkali metal salt) copolymers.

As a method of performing thermal crosslinking, the polymer is heated to a predetermined temperature to be thermally crosslinked before being adjusted to a desired particle size, and then pulverized if necessary to adjust the particle size to a desired particle size. Although it may be, preferably, after the particle size of the polymer is adjusted to a powder or particle size having a desired particle size, by heating at a predetermined temperature to thermally crosslink, the internal crosslink density is increased by the so-called surface crosslink principle. This is a method for obtaining a water absorbent resin that is low and has a high external crosslinking density. The heating temperature at the time of thermal crosslinking is preferably 120 ° C to 230 ° C, more preferably 140 ° C to 2 ° C.
It is 20 ° C. A heating temperature of 120 ° C. to 230 ° C. is preferable because thermal crosslinking proceeds rapidly, the polymer is not thermally decomposed, and the quality does not deteriorate. The heating time varies depending on the degree of crosslinking desired to be achieved, but preferably 1 to 600 minutes, more preferably 5 to 600 minutes after reaching the target temperature.
It's 300 minutes. If the heating time is less than 1 minute, thermal crosslinking may not occur well, while if the heating time exceeds 600 minutes, partial decomposition may start depending on the heating temperature and the composition of the polymer.

The drying temperature of the hydrogel polymer is preferably 60 to 230 ° C, more preferably 100 to 20.
It is 0 degreeC, Especially preferably, it is 105-180 degreeC.
When the drying temperature is 60 ° C or higher, it does not require much time for drying and is economical. On the other hand, when the drying temperature is 230 ° C or lower, side reactions and resin decomposition are less likely to occur, and the absorption performance and absorption rate are low. Does not fall. The device for drying may be an ordinary device, for example, a drum dryer, a parallel flow band dryer (tunnel dryer), an aeration band dryer, a jet flow (nozzle jet) dryer, a box hot air dryer, an infrared dryer, etc. Is mentioned. The heat source is not particularly limited. These dryers may be used in combination. After drying, it is pulverized, and if necessary, the particle size is adjusted to obtain a water absorbent resin. A conventionally known one can be used as the pulverizer, and a conventionally known one such as a sieve shaker can be used for the particle size adjustment. The method for producing the water-absorbent resin is the same as those described in detail in JP-A-52-25886, JP-B-53-46199, JP-B-53-46200 and JP-B-55-21041. To be

(2) Polymerization of (a) and (b) (hydrolyzate of starch-acrylonitrile graft polymer, hydrolyzate of cellulose-acrylonitrile graft polymer, etc.); (3) above ( (A) Crosslinked product (eg, carboxymethylcellulose crosslinked product); (4) Copolymer of (b) and (c) above (partial hydrolyzed product of crosslinked polyacrylamide, crosslinked acrylic acid-acrylamide copolymer) Polymers, crosslinked polysulfonates (crosslinked sulfonated polystyrene, etc.), crosslinked polyacrylate / polysulfonate copolymers,
Saponified vinyl ester-unsaturated carboxylic acid copolymer (JP-A-52-14689 and JP-A-52-2745)
No. 5, etc.), crosslinked polyacrylic acid (salt), crosslinked acrylic acid-acrylic acid ester copolymer, crosslinked isobutylene-maleic anhydride copolymer, crosslinked Polyvinylpyrrolidone, and crosslinked carboxylic acid-modified polyvinyl alcohol); and (5) the polymer (b) having self-crosslinking property (self-crosslinking polyacrylate, etc.); You may use together 2 or more types of the water absorbent resin illustrated above. There is no particular limitation on the type of salt and the degree of neutralization in the case of a water-absorbent resin in the form of a neutralized salt, but the type of salt is preferably an alkali metal salt, more preferably a sodium salt and a potassium salt. And the degree of neutralization with respect to the acid group is preferably 50 to 90 mol%, more preferably 60 to 80 mol%. Two or more kinds of the water absorbent resins (a) exemplified above may be used in combination.

Of these water-absorbent resins (a), preferred are nonionic water-absorbent resins such as cross-linked polyacrylamide copolymers; cross-linked polyacrylic acid (salt), cross-linked acrylic acid-acrylic acid ester. An anionic water-absorbing resin such as a copolymer, a crosslinked isobutylene-maleic anhydride copolymer, and a crosslinked carboxylic acid-modified polyvinyl alcohol. A crosslinked polyacrylamide copolymer and a crosslinked polyacrylic acid (salt) are more preferable, and a crosslinked polyacrylic acid (salt) is particularly preferable. The water absorption capacity of (a) depends on the above-mentioned crosslinked structure, particularly the crosslink density. Generally, the lower the crosslink density,
The water absorption ratio tends to increase. The crosslink density of (a) is a mol% of branch points with respect to all monomers, preferably 0.01 to 10 mol%, more preferably 0.05 to 5
It is mol%. When introducing a crosslinked structure with a crosslinking agent, the copolymerization weight ratio of the crosslinking agent to all monomers (including the crosslinking agent itself) is preferably 0.005 to 3 wt.
%, Preferably 0.01 to 2 wt.%.

When the crosslink density of (a) is 10 mol% or less, the water absorption capacity of (a) becomes large, so that the water absorbing / water retaining effect of the water absorbent resin becomes large. On the other hand, when the crosslinking density is 0.01 mol% or more, the mechanical strength of the (a) becomes strong and the handling becomes good. The average particle size of (a) thus obtained is usually 10 to 1,000.
μm, preferably 50 to 800 μm, and more preferably 100 to 700 μm. Average particle size is 10
If it is less than μm, the water-absorbent resin particles are likely to spill out of the mat before absorbing water, and if it exceeds 1,000 μm, the water absorption time becomes long. As described above, the average particle size can be controlled by grinding and sieving. In the case of reverse phase suspension polymerization, it can be controlled by the polymerization conditions. The average particle size means the mass average particle size, and the mass average particle size is the particle size distribution of each cross-linked polymer, the horizontal axis is the particle size, and the vertical axis is plotted on a logarithmic probability paper of the content on a mass basis. It is measured by the method of determining the particle size at which 50% of the mass is reached.

In the present invention (A), it is necessary that the calcium ion absorption amount is 0 to 100 mg per 1 g of dry weight. It In the present invention, the “calcium ion absorption amount” can be suitably measured, for example, by the following method. (Measurement of Calcium Ion Absorption Amount) 1 g of dried water-absorbent resin (A) was added to a calcium ion concentration of 200 mg / L.
Was added to 1 L of the aqueous solution of calcium chloride and left in a constant temperature bath for 48 hours at 25 ° C. with occasional stirring to swell the (A) and absorb calcium ions. The swollen (A) is separated, and the calcium ion concentration in the remaining supernatant (excess of the above calcium chloride aqueous solution) is quantified by atomic absorption spectrometry (α mg / L).

At this time, the following conditions can be used in the calcium ion analysis by the atomic absorption spectrometry. <Measurement conditions of atomic absorption spectrometry> Atomic absorption spectrometer: Shimadzu Corporation, trade name: AA-6
500 Auto system lighting condition: Ca # 8 Current: 10 mA / 0 mA Wavelength: 422.7 nm Slit width: 0.5 μm Based on the quantitative value (α) of the calcium ion concentration measured in this manner, 1 g of the water-absorbent resin (A) The amount of absorbed calcium ion is calculated by the following equation. When separating (A) and the supernatant, the uncrosslinked water-soluble polymer may be dissolved in the supernatant. Therefore, if necessary, a weight average molecular weight of about 1,000 to 3,000 may be used. Separation by ultrafiltration using an ultrafiltration membrane is performed. Calcium ion absorption amount (mg / g) per 1 g of water absorbent resin (A) = 200-α

[Calcium salt measured by the above method]
On-absorption amount is 100 per 1 g of dry weight of water-absorbent resin
When it exceeds mg, it is used as a water retention agent for plant growth.
Plants that come into contact with the water-absorbent resin (A)
It is easy to cause "calcium ion deficiency"
It is easy to run out of things. Water retention for plant growth in the present invention
In order to be effectively exhibited as an agent, this "calcium
The "ion absorption amount" is 0 per 1 g of the dry weight of the water absorbent resin.
˜100 mg, preferably 0-80 mg.
In the case of polyacrylic acid type water absorbent resin,
Calcium ion absorption of fat (A) is 100 mg or less
In order to do so, the (A) is a “polyvalent metal having a carboxyl group.
It is a preferred embodiment to contain "salt". The multivalent
As the ion of the metal salt, for example, Ca²⁺, Mg²⁺, A
l³⁺, Ba²⁺, Sr²⁺, B³⁺, Be²⁺, Fe²⁺, F
e³⁺, Mn²⁺Etc. Among them, Ca²⁺, M
g²⁺, Al³⁺, Ba ²⁺, Sr²⁺, B³⁺, Be²⁺Is preferred
Ku, Ca²⁺Is particularly preferable. The content of the polyvalent metal salt is
It is preferably 0.1 to 7 per 1 g of dry weight of the water absorbent resin.
mmol, more preferably 0.5 to 6.5 mmo
1 and particularly preferably 1.0 to 6.0 mmol
It

Particularly when a polyacrylic acid salt-based water-absorbing resin is used, a method of cross-linking and polymerizing acrylic acid and an alkali metal salt of acrylic acid and then adding the polyvalent metal salt is preferably used. . Particularly when calcium chloride or magnesium chloride is used as the polyvalent metal salt, the Ca absorption amount of the water absorbent resin can be suppressed by substituting Ca and Mg for the alkali metal salt. Further, as will be described later, chlorine ions can also be introduced into the water absorbent resin. Specific examples of these production methods and water absorbent resin,
Japanese Patent Application No. 10-316440, Japanese Patent Application No. 11-290
No. 552.

The above-mentioned "content of polyvalent metal salt of carboxyl group" can be measured, for example, by the following method. (Method for measuring content of polyvalent metal salt of carboxyl group) Water-absorbent resin (A) was thoroughly washed with ion-exchanged water and dried, and 0.2 g of dried (A) was weighed in a platinum crucible, After ashing in an electric furnace, it is dissolved in 5 ml of 1N hydrochloric acid, distilled water is added to a constant volume of 50 ml, and the polyvalent metal ion concentration (EmM) is determined by atomic absorption spectrometry. The content of carboxyl group polyvalent metal salt in 1 g of dried (A) was E
Calculated as x valence / 4 (mmol). Valence of this polyvalent metal ion (for example, if Mg ion, valence =
In 2), when the polyvalent metal ions are mixed, the valence obtained by "weighted average" of the valences of each polyvalent metal ion is used.

At this time, the same conditions as in the above-mentioned "calcium ion analysis" can be used for the cations by the atomic absorption analysis method. Conventional hydrogels composed of "crosslinked products of alkali metal salts of polyacrylic acid" have significantly higher water absorption capacity than hydrogels composed of nonionic hydrophilic polymer crosslinked products. Therefore, it has been conventionally used as a water absorbent resin in the agricultural field. However, this hydrogel has a very large introduction amount of dissociative ionic groups (for example, the introduction amount of alkali metal salt of acrylic acid is about 8 mmol or more per 1 g of dry resin), and calcium ion which is essential for plant growth. Heavily adsorbed heavy metal ions such as the above, and tended to significantly inhibit plant growth. As described above, when the carboxyl group is a heavy metal salt, the water absorption capacity decreases, and it becomes impossible to supply sufficient water as a water retention agent.
Therefore, while the carboxyl group is converted to a heavy metal salt, it is necessary to introduce a certain amount of a dissociative ionic group (for example, an alkali metal salt or ammonium salt of a carboxyl group) to secure the water absorption capacity. When 0.3 to 7 mmol of the dissociative ionic group is introduced per 1 g of the dry water-absorbent resin, a sufficient water retention effect (in ion-exchanged water) to grow plants without causing calcium ion deficiency in the plants It has been found to be preferable because it exhibits a water absorption capacity of 10 to 1,000 times.

As described above, when the polyvalent metal salt is used as the carboxyl group, the water absorption capacity is reduced. Therefore, in order to improve the water absorption capacity, it is necessary to use a certain amount or more of the carboxyl group as the alkali metal salt. As the alkali metal salt of carboxyl group, sodium salt or potassium salt is desirable. When (A) is an anionic water absorbent resin having a carboxyl group, the content of the alkali metal salt or ammonium salt of the carboxyl group is preferably 0.3 to 7 mmol per 1 g of dry weight. When it is 0.3 mmol or more, the water absorption capacity of the water absorbent resin can be made 10 times or more, and when it is 7 mmol or less, the amount of absorbed calcium ions hardly exceeds 100 mg per 1 g of the dry water absorbent resin.

(Measuring Method of Content of Alkali Metal Salt of Carboxyl Group) The water-absorbent resin (A) was thoroughly washed with ion-exchanged water and then dried, and 0.2 g of the dried (A) was placed in a platinum crucible. After weighing and ashing in an electric furnace, 1N hydrochloric acid 5m
Dissolve in 1 and add distilled water to a constant volume of 50 ml to determine the cation concentration (DmM) by atomic absorption spectrometry. The content of the carboxyl group salt in 1 g of dried (A) was D /
Calculated as 4 (mmol = molar concentration in 1 liter). The concentration of the dried (A) in the solution for atomic absorption analysis used here was 0.2 g / 50 ml as described above.
= 4 g / 1 L (liter), it was dried (A)
The content of carboxyl group salt in 1 g is (D / 4) mm
ol.

Further, in the present invention, the content of the chlorine ion (A) is 0.07 to 7 mm per 1 g of dry weight.
ol is preferred. The chlorine ion content can be measured, for example, by the following method. (Measurement of chlorine ion content) 0.2 g of (A) in a dry state is immersed in 200 ml of ion-exchanged water and left for 2 days. This supernatant was filtered with a filter, and the chlorine ion concentration in the filtrate was measured with an ion analyzer (Ion Analyzer IA-10).
0, Toa Denpa Kogyo). Based on the chlorine ion concentration thus obtained, the ion-exchanged water 200
The amount of chlorine ions in ml is calculated and the calculated value is used as the amount of chlorine ions in 0.2 g of the dry water absorbent resin (A).

At this time, the following conditions can be used in the chlorine ion analysis by the above ion analyzer. <Measurement conditions of ion analyzer> Column: Anion column PCI-201S (manufactured by Toa Denpa Kogyo Co., Ltd.) and card column PCI-201SG (manufactured by Toa Denpa Kogyo Co., Ltd.) Solvent: Anion eluent (Toa Denpa Kogyo Co., Ltd.) Column tank temperature: 40 ± 4 ° C. The “chlorine ion content” measured by the above method is 0.07 to 7 mmo per 1 g dry weight of the water absorbent resin (A).
When it is 1, it becomes possible to suppress the above-mentioned "calcium ion deficiency" as shown in Examples described later.
The "chlorine ion content" is more preferably 0.5 to 6.5.
mmol, particularly preferably 1.0 to 6.0 mmo
It is l. There are no particular restrictions on the type of counter cation for chlorine ions, but Na, K, Ca, and NH ₄ ions are preferred. Among them, Na ion is particularly preferable.

The water-absorbent resin (a) may contain chlorine ions by absorbing an aqueous solution containing chlorine ions into the water-absorbent resin (a). Also,
When (A) is synthesized in water, it is more preferable to add chloride ions to this aqueous solution. At this time, the amount of chlorine ions added is set to be 0.07 to 7 mmol per 1 g of the dry weight of the water absorbent resin (A) obtained. When (a) already contains 7 mmol or more of chlorine ion per 1 g of dry weight, the chlorine ion content can be increased by washing this with water that does not contain chlorine ion (or low chlorine ion concentration). Can be reduced to a desired set value.

The water absorption capacity of the water absorbent resin (A) in the present invention is usually 10 to 1,000 times, preferably 20 times.
˜900 times, and more preferably 50 to 800 times. If the water absorption ratio is less than 10 times, it will not have sufficient cold storage capacity and elasticity after absorbing water, and it will be impossible to supply sufficient water when used as a water retention agent for plant growth when recovered from the mat. Become. When it exceeds 1,000 times, the gel after absorbing water becomes soft and lacks elasticity. The amount of water absorption can be controlled by various production conditions of the above water-absorbent resin.
In the present invention, the above “water absorption capacity in ion-exchanged water” can be measured, for example, by the following method. (Measurement of water absorption capacity in ion-exchanged water) A fixed amount (W1g) of the dry water-absorbent resin (A) was weighed and an excess amount (for example,
Immersion in ion-exchanged water (electrical conductivity: 5 μS / cm or less) of 1.5 times or more the expected water absorption amount of the water-absorbent resin, and leaving it in a constant temperature bath at 25 ° C. for 48 hours, and )
To swell. After removing excess water by filtration, the weight (W2g) of the water-swelled (A) is measured, and the water absorption capacity is determined by the following formula. Water absorption capacity = (W2-W1) / W1 When measuring this water absorption capacity, the weights W1 and W2 are measured, for example, by using a precision electronic balance (Shimadzu Corporation, LIBROR A
EG-220; LIBROR EB-3200-D, etc.) is preferably used.

The water retention / water absorption ratio of the water absorbent resin (A) is preferably 0.55 to 1.00, more preferably 0.65 to 1.00. When the water retention / water absorption ratio is 0.55 or more, normal pets, domestic animals and the like swing around the mat and do not release water even with respect to their weight. The water retention / water absorption ratio can be controlled by the type of monomer and the crosslinking conditions.

The water-soluble component content of the water absorbent resin (A) is preferably 10% by weight or less, more preferably 6% by weight or less, and particularly preferably 3% by weight or less. When the content of the water-soluble component is 10% by weight or less, the water-soluble component does not appear on the mat surface through the cloth, and a slimy feeling does not appear. Therefore, the water-soluble component does not adhere to animal hair and become dirty.
The water-soluble component content can be controlled by the polymerization conditions. As a method for decreasing the content of the water-soluble component in the water absorbent resin, for example, a method of increasing the molecular weight of the water absorbent resin is preferable, and it can be achieved by a method of decreasing the polymerization concentration, a method of increasing the crosslink density, or the like.

In addition to the above physical properties, the water absorbent resin (A) preferably has a physiological saline solution absorbent gel strength of 10,
It is preferably 000 to 50,000 dynes / cm ² , more preferably 20,000 to 45,000 dynes / cm ² because deformation of the gel due to the body weight of the animal is suppressed. Gel strength can be improved, for example, by surface cross-linking the particles. The method for measuring the gel strength will be described later. In addition to the above physical properties, the water absorbent resin has a physiological saline solution absorption gel elastic modulus measured by a creep meter of preferably 5 × 10 ^{3 to} 20 × 10 ³ N / m ² , and more preferably 6 × 10 ³ to 15. It is preferable that the density is × 10 ³ N / m ^{2 because the} gel returns to its original state due to elasticity when the animal separates after the gel is deformed due to the weight of the animal and the mat feels good. The gel elastic modulus can be achieved by, for example, polymerization conditions (balance between molecular weight and degree of crosslinking). The gel elastic modulus is an elastic modulus determined by the amount of instantaneous compression deformation when a constant load (stress) is applied to the swollen gel of the water absorbent resin, and the measuring method will be described later. The amount of the water-absorbent resin used in the mat of the present invention is preferably 20 to 2,000 g / m ² , and particularly preferably 40 to 800 g / m ² because it expands to an appropriate size when absorbing water. .

The bag-like cloth forming the mat of the present invention has an air permeability of usually 0.1 to ³⁰ cm ³ / cm ² · sec,
It is preferably 0.3 to 25 cm ³ / cm ² · sec,
It is more preferably 0.5 to ²⁰ cm ³ / cm ² · sec, and particularly preferably 1 to 8 cm ³ / cm ² · sec. If the air permeability is less than 0.1 cm ³ / cm ² · sec, the moisture absorption by the water-absorbent resin gradually evaporates through the cloth, and the vaporization rate is too slow, resulting in an insufficient cooling effect. When the air permeability of the cloth exceeds 30 cm ³ / cm ² · sec, the water-absorbent resin powder before water absorption spills to the outside, or the water vaporization rate of the water-absorbent resin after water absorption is too fast, and the cold insulation duration time becomes longer. It gets shorter.

Further, even within the above range of air permeability,
It is preferable that the cloth has an air permeability of 0.1 to ¹ cm ³ / cm ² · sec because the vaporization rate is relatively slow and the effect of relatively long keeping the cold is obtained. When the air permeability of the cloth is 8 to ³⁰ cm ³ / cm ² · sec, the vaporization rate is relatively fast and the cold insulating effect is excellent, which is preferable. Also,
A value between 1 and 8 cm ³ / cm ² · sec, which is intermediate between the ^two , is preferable because a cold insulation effect and a cold insulation duration time are relatively balanced.

Examples of the cloth include woven cloth, knitted cloth, and non-woven cloth, and woven cloth is preferable. The material is not particularly limited, and examples thereof include cotton, rayon, polyester, acryl, nylon, polyethylene, polypropylene and the like, and mixed spinning thereof. Among these, cotton, polyester, and a blend thereof are preferable. In the case of cotton or a mixed spinning containing mainly cotton, it is a cloth having a fiber density of 200 fibers / inch or more, preferably 200 to 280 fibers / inch, which is crushed after refining. In the case of the mixed spinning, the proportion of cotton is preferably 60% by mass or more, particularly preferably 70% by mass or more. Before scouring, cotton is hydrophobic due to stains, etc., but it is hydrophilic in nature, and hydrophilicity is exhibited by scouring. This is because it can be easily adjusted. In the case of polyester, the fiber density is preferably the same as above. In addition, polyester is advantageous in that it has excellent water resistance and chemical resistance and is resistant to mold, and the cost is relatively low. Further, the cloth may be subjected to other treatments if necessary. For example, there are hydrophilic treatment, antibacterial treatment, insect repellent treatment and the like.

Further, in the present invention, in addition to the water absorbent resin, if necessary, an antibacterial agent, an insect repellent, a bactericide, a deodorant, an aromatic agent, a component having an odor preferred by animals, or a substance disliked when the animal bites. Ingredients, anti-blocking agents (for example, inorganic anti-blocking agents such as silica, talc, titanium oxide, calcium carbonate, etc., organic anti-blocking agents such as polyurethane resins having a particle size of 100 μ or less, epoxy resins, poly (meth) acrylate resins, etc. Etc.), surfactants, and other absorbents (pulp, cotton, silica gel, etc.) can be added. The addition amount is not particularly limited as long as it does not hinder the absorption of the water absorbent resin, but is preferably 50 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the water absorbent resin. Further, the cloth may be covered with an outer bag having high air permeability. This is because it is mechanically reinforced and the outer bag can be freely decorated. The material and shape of the outer bag are not particularly limited.

The mat is a bag-shaped cloth in which a water-absorbent resin is enclosed, and the joining means for forming the bag is not particularly limited, but for example, sewing, heat sealing, adhesive,
There is a method in which a heat-sealing tape is interposed between cloths and heat-bonded by heat. Preferred are sewing and heat sealing. The size of the mat is determined by the size of the animal to be used, preferably 100cm ² ~20,000cm ^2, more preferably 400cm ² ~5,000cm ^2, the shape is not particularly limited, square, Rectangular, circular,
There are oval shapes.

The cloth is sewn or heat-sealed between the upper and lower parts so that the inner space is divided into a plurality of spaces, preferably 2 to 8, and each divided space has a unit width. It is preferable that the water absorbent resin is evenly filled. This is because the water absorbent resin can be prevented from being biased to one side in the bag. In addition, in order to prevent unevenness of the water-absorbent resin, a sheet in which a water-absorbent resin is applied to a base material such as a non-woven fabric instead of the water-absorbent resin is put in a cloth bag, or when two cloths are formed when the cloth bag is made. A mat may be created by sandwiching and sewing. In order to prevent the powder of the water-absorbent resin from falling off around the mat, the ends may be bent and sewn, or if necessary, a hem may be attached and sewn. Further, it is preferable to use a thin needle and a thin thread in order to prevent the powder from falling off from the seam. If necessary, the seams can be crushed later by resin processing or the like.

The water-absorbent resin-containing mat of the present invention is usually used as a cool mat for one season, but after use, the water-absorbent resin can be recovered without reuse and reused as a water retaining agent for growing plants. The water-absorbent resin (A) used for the water-absorbent resin-containing mat of the present invention has a calcium ion absorption amount of 0 to 100 mg per 1 g of dry weight, and a water absorption capacity of 10 to 10 in ion-exchanged water at 25 ° C. 1,
Since it is 000 times, and preferably, the content of chloride ion is 0.07 to 7 mmol per 1 g of dry weight, it does not cause root inhibition of plants or inhibition of root elongation,
It can be used as a water retention agent for growing plants that does not cause so-called "calcium ion deficiency". Conventional water-absorbent resins absorb water but have a poor ability to supply water to plants, and when used in large amounts, they may inhibit rooting of plants or inhibit root elongation, so they cannot be recovered and used as water retention agents for growing plants. It was

The water-absorbent resin in the mat containing the water-absorbent resin of the present invention which has been used can be recovered and the gel-like substance in the mat can be used as it is by mixing it with the soil. You can also do it. In that case, the water absorbent resin (A) may be further mixed, or the water absorbent resin (A) may be mixed and used. Moreover, you may add the additive normally added as a water retention agent for plant growth. The mixing ratio when the gel-like material is mixed with the soil as it is depends on the concentration of (A) in the gel, the type of soil, etc., but is preferably 1/9 by mass ratio.
9-90 / 10, more preferably 2 / 98-50
/ 50. When used by mixing with the carrier (D),
It may be variously changed depending on the type of (A), the type of (D), and the optimum water content of the plant, but (the total amount of the recovered gel-like material (G) and the new (A)) / ( The ratio with D) is a weight ratio, preferably 0.1: 99.9 to 80:20,
It is more preferably 5:95 to 70:30, and particularly preferably 10:90 to 65:35. When the total amount of (G) and (A) is 0.1 or more, the water retention capacity is sufficient, and when it is used at 80 or less, the moldability is good and it is preferable from the economical viewpoint.

Here, the carrier (D) used is
It may be one generally used as a substance suitable for growing plants and is not particularly limited. As the substance suitable for growing plants, for example, powders of inorganic substances and / or organic substances, porous substances, pellets, fibrous substances and water-insoluble solid substances such as foams can be used. Various additives described later are excluded. As inorganic substances, inorganic powders (soil, sand,
Fly ash, diatomaceous earth, clay, talc, kaolin,
Bentonite, dolomite, calcium carbonate, alumina, etc.); Inorganic fibers (rock wool, glass fibers, etc.); Inorganic porous materials [Filton (porous ceramic, kuntan), vermiculite, pumice, volcanic ash, zeolite,
Shirasu balloon and the like]; inorganic foams (perlite and the like) and the like.

As the organic substance, organic powder [coconut shell, chaff, peanut shell, tangerine shell, wood waste,
Wood powder, coconut dry powder, synthetic resin powder (polyethylene powder, polypropylene powder, ethylene-vinyl acetate copolymer powder, etc.); organic fiber [natural fiber [cellulosic one (cotton, sawdust, straw, etc. ) And others, grass charcoal, wool, etc.), artificial fibers (cellulosics such as rayon, acetate, etc.), synthetic fibers (polyamide, polyester, acrylic, etc.), pulp [mechanical pulp (ground wood from logs, asplund method ground wood pulp, etc.] ), Chemical pulp (sulfurous acid pulp, soda pulp, sulfate pulp, nitric acid pulp, chlorine pulp, etc.), semi-chemical pulp, recycled pulp (for example, mechanically crushed or crushed paper made from paper once made, or waste paper Mechanically crushed or pulverized recycled waste paper pulp, etc.), and other waste materials (waste from the production of disposable diapers) Etc.), etc.]; organic porous material (coconut shell activated carbon, etc.); organic foams [cereals, synthetic resin or rubber foam (polystyrene foams, polyvinyl acetal sponge, rubber sponge, polyethylene foam,
Polypropylene foam, urethane foam, etc.), etc.];
Examples include organic pellets [rubber and synthetic resin pellets, etc.]. The above-mentioned carrier for growing a plant may be used alone or in combination of two or more as required. Of these, preferred are inorganic porous materials, inorganic foams, organic fibers, rubbers and synthetic resins. The density of the foam is 0.01-1 g / cm ³ .

The rubber and / or synthetic resin may be those generally used, but specific examples include the following. Examples of the rubber include ordinary natural rubber (NR) and styrene-butadiene rubber (SB).
R), butadiene rubber (BR), isoprene rubber, butyl rubber (IIR), ethylene propylene rubber, ethylene propylene non-conjugated diene rubber, polychloroprene rubber (CR), nitrile rubber, acrylonitrile-butadiene rubber and the like. Examples of the synthetic resin include a thermoplastic resin and a thermosetting resin. As the thermoplastic resin, soft or hard, for example, ethylene-vinyl acetate copolymer or a saponified product thereof, ethylene-acrylic acid salt copolymer, ethylene-acrylic acid ester copolymer,
Chlorosulfonated polyethylene, chlorinated polyethylene,
Urethane resin, styrene resin, vinyl chloride resin,
Examples include olefin-based resins, polyester-based resins, polyamide-based resins, etc., but those having flexibility such that the volume can swell due to water absorption are preferable, and when a hard one is used, it is flexible by using an appropriate plasticizer. It is preferable to impart the property.

As the urethane resin, linear polyurethane obtained by bulk polymerization or solution polymerization of polyol, diisocyanate and chain extender is pelletized and extrusion-molded, injection-molded or solution-polymerized. It is produced by a method of shaping a polyurethane solution to volatilize and remove the solution, or by contacting with a coagulation bath to coagulate. As styrene resin,
For example, styrene polymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-
Examples thereof include a styrene block copolymer and a styrene-ethylene-propylene-styrene block copolymer. Examples of vinyl chloride resins include high polymerization degree vinyl chloride resins, partially crosslinked vinyl chloride resins, nitrile rubber (NB
R), blends of urethane resin or polyester resin and vinyl chloride resin, urethane-vinyl chloride copolymer, nitrile rubber (NBR) -vinyl chloride copolymer and the like. Examples of the olefin resin include polyethylene, polypropylene, a mixture of ethylene-propylene rubber and polyolefin, a polymer obtained by grafting polyolefin on ethylene-propylene rubber, and the like.

Examples of polyester resins include aromatic polyester-polyether block copolymers and aromatic polyester-aliphatic polyester block copolymers. Examples of polyamide resins include polyether-polyamide block copolymers and polyester-polyamide block copolymers. Although the molecular weights of these thermoplastic resins and rubbers are not particularly limited, the softening point is preferably 30 to 300 ° C,
The temperature is more preferably 40 to 200 ° C, and particularly preferably 50 to 150 ° C. These may be used alone or in combination of two or more. Examples of the thermosetting resin include formalin condensation resin type, epoxy resin type, urethane resin type and the like. As formalin condensation resin system, urea resin (reaction product of urea and formalin), melamine resin (reaction product of melamine and formalin, phenol resin (reaction product of phenol and formalin), resorcinol resin (resoninol and formalin) Reaction products and the like can be mentioned.

The epoxy resin system is produced by combining an oligomer having a reactive epoxy group at a terminal and having a molecular weight of several hundred to about 10,000 with an appropriate curing agent and curing the same. For example, a glycidyl ether type epoxy resin, Epoxy resin (epoxy equivalent; 65-1000) such as glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin, and curing agent (polyamine,
Examples thereof include reaction products with acid anhydrides, polyisocyanates, polyols, polymercaptans, etc. (the molar ratio of epoxy groups to functional groups is 1:10 to 10: 1) and the like.

As the urethane resin system, a linear polyester, polyether or polyesteramide is used as a base, and a polyisocyanate is reacted to prepare an NCO-terminated prepolymer (NCO%: 1 to 10%). A prepolymer method in which a polymer is polymerized and cured by heat or an appropriate crosslinking agent and a one-shot method in which a polyol, a diisocyanate, a chain extender and a crosslinking agent are simultaneously mixed and reacted to obtain a polyurethane (active hydrogen such as isocyanate / polyol = 0.8 / 1 to 10/1) and molded by a casting method or a kneading method.

The number average molecular weights of the rubber and the thermoplastic resin are usually 10,000 or more, preferably 21 to 1,000,000.
The number average molecular weight of the thermosetting resin before curing is usually 10
It is 10,000 or less, preferably 50,000 or less. The number average molecular weight can be measured by gel permeation (GPC method). or,
The size of the form of (D) is not limited, but the particle size (major axis) of these powders is usually 1 to 800 μ, preferably 5 to 200 μ, and the sizes of the porous body, the fiber and the foam are usually. 0.001 to 20 mm, preferably 0.01
-10 mm. Pellets are usually 1 to 1,000 mm
Is.

Further, the binder (E) may be used when the carrier (D) is used. As (E), those commonly used may be used, and any of them may be used regardless of whether they are water-soluble or water-insoluble. The (G) has some water content in a normal state and has an adhesive property by itself, but depending on the water state, the shape, the specific gravity, etc. of the (G), the molding effect of the (G) and the (D) If necessary, a binder (E) is used to increase the The shape of (E) is not particularly limited, but it is used in a state where the viscosity at 25 ° C. has a fluidity of 1,000,000 or less, preferably 100,000 or less, and is, for example, dissolved or dispersed in a solvent and / or water. Those that have been used can be preferably used. Further, a binder can be selected and used depending on the molding method, and examples thereof include natural polymers, semi-synthetic polymers, synthetic resins and synthetic rubbers. (Excluding the additives described below)

Examples of the thermoplastic resin and those which can be dissolved or dispersed in the solvent include rubber and synthetic resins. Examples of the rubber and the synthetic resin are the same as those described in (D) above. In the present invention, the amount of the binder (E), which is optionally used in the present invention and has a role of binding (D) and (A), is usually 0 to 20% by weight based on the total amount of (A) and (D) in terms of solid content. , Preferably 0.5 to 15% by weight.

When the recovered gel-like material is reused, since the water content in the gel-like material is unknown, once the gel-like material is dried to remove water, the recovered gel-like material is used. As a method for producing a water retaining agent for plant growth using (D) using the dried product (G) of (1), for example, (i) the above-mentioned (G), (D) and, if necessary, a stirred mixture of (E) Method of pressure molding into pellets in a mold of appropriate shape and size, (ii) pressure molding of the mixture and cutting into an appropriate size
A method of crushing, (iii) a method of sprinkling (A) and optionally (E) on the surface of the cut / crushed product obtained in (i) above, and then press-molding again, and cutting / crushing, (iv) (iii) A method of pressure-molding the product before pressure-molding into a pellet shape in a mold having an appropriate shape and size, (v) once pressure-molding into a sheet shape, rod shape or block shape, and then appropriate A method of cutting or crushing into various sizes, (vi) a method of heat-molding the mixture into a sheet, rod or block, and then cutting or crushing, (vii) the mixture in a mold of suitable shape and size. Examples thereof include a method of heat-molding into a pellet shape, (viii) a method of foaming the mixture into a sheet shape, a rod shape or a block shape, and then cutting or crushing. If necessary, foaming may be performed in the above method. When (G), (D) and, if necessary, (E) are mixed, 1 to 50% of the total amount of (G), (D) and (E) is added to the mixture to thicken and mix the gel. Is also good. Among these methods, (ii), (vi), (vii) and (viii) are preferable.

The reusable plant water-retaining agent obtained by the above method is a pressure-molded product in which the molded product is a pellet, the sheet-shaped product,
Rod-shaped or block-shaped cut or crushed product, sheet-shaped, rod-shaped or block-shaped cut or crushed product, pellet-shaped heat-molded product, sheet, rod-shaped or block-shaped It is a water retention agent for plant growth selected from the group consisting of cut or crushed products of foam.
Preferably, the cut or crushed product of the sheet-shaped, rod-shaped or block-shaped pressure-molded body or the heat-molded body, the pressure-molded body in which the molded body is in a pellet form, the sheet, the bar-shaped or block-shaped foam cut body, or It is a crushed product.

In obtaining the recycled water-absorbent resin foam of the present invention, when the above (D) is a thermoplastic resin and rubber,
It is produced by blending (G) and (D) with a foaming agent and, if necessary, a foaming accelerator or a foaming inhibitor, and then heat-foaming. Examples of the foaming agent used include diazoamino derivatives, azonitriles, azodicarboxylic acid derivatives, dinitropentamethylenetetramine (DPT), benzene monohydrazole, oxybisbenzenesulfonyl hydrazide (OBBH), ammonium carbonate, ammonium bicarbonate, propane and petroleum. Examples thereof include ethers, which may vary depending on the expansion ratio of the foam or the application, but (D) 1
A range of 1 to 80 parts by mass is desirable for 00 parts by mass.
If necessary when preparing a mixture of (G) and (D), a plasticizer, a stabilizer, a lubricant, a filler, a colorant, a flame retardant,
An antistatic agent or an antifungal agent may be mixed. or,
When rubber is used as (D), a rubber chemical such as a vulcanizing agent, a vulcanization accelerator, a vulcanization aid or an activator, a rubber reinforcing agent, a tackifier, a processing aid, an antioxidant, an infrared absorber. , (Ozone) antiaging agent or the like may be mixed. The compounding amount is 0.01 to 10 parts with respect to 100 parts by mass of (D). In addition, foaming is performed by ordinary one-step foaming or two-step foaming. The density of the obtained foam is not particularly limited.

When the above (D) is a thermosetting resin, for example, in the foaming of a urethane resin containing (G), (G) and (D) are mixed in advance when a usual urethane foam is produced. What is necessary is just to manufacture it, and it can be manufactured by the same operation as that for manufacturing a normal urethane foam. Conventional polyurethane foams are prepared by a one-shot method in which a polyisocyanate and a polyhydroxyl compound are reacted in a single step in the presence of a blowing agent and a suitable auxiliary agent, or an excess amount of the polyisocyanate and a polyhydroxyl compound are reacted. By a total prepolymer method in which the obtained prepolymer and water are reacted in the presence of a suitable auxiliary agent, or by reacting an excess amount of polyisocyanate with a polyhydroxyl compound and an additional amount of polyhydroxyl compound It can be obtained by a semi-prepolymer method in which and are reacted in the presence of a foaming agent and other suitable auxiliary agents. The blowing agent includes a reactive blowing agent such as water and a non-reactive blowing agent such as a low boiling point halogenated hydrocarbon. The other auxiliary means a catalyst, a foaming regulator (foam stabilizer), a colorant and the like.

The above-mentioned mixing device may be any device as long as it can uniformly mix the mixture, and examples thereof include a Heschel mixer, a ribbon blender, a planetary mixer, a tumbler and a universal mixer. For kneading the mixture, for example, a twin-screw extruder, a single-screw extruder,
There are devices such as a co-kneader, a Banbury mixer, a kneader, and an open roll that can be kneaded under shear while heating. Examples of the pressure molding method include a dry pressure molding method, a direct powder pressure molding method, and a wet pressure molding method. Pressure molding can be performed using a roll-type pressure molding machine (such as a briquette machine), a piston-type pressure molding machine, a screw-type pressure molding machine, or a perforated plate molding machine (such as a disk pelleter). . Of the above pressure molding machines, a roll pressure molding machine and / or a perforated plate molding machine are preferable. Further, the pressure during the pressure molding is usually performed at room temperature, but it may be performed under heating (for example, 30 to 300 ° C.). The pressure at the time of pressure molding can be appropriately selected according to the type, size (particle size), properties, etc. of the base material, but is usually 1 to 3000 kg / cm ² , preferably 10 to 2,0.
It is 00 kg / cm ² . The obtained pressure-molded product may have any shape, for example, a sheet shape, a spherical shape, a cylindrical shape, a plate shape,
Various shapes such as a lump shape, a rectangular parallelepiped shape, a cone shape, a pyramid shape, and a rod shape can be given. The size thereof is, for example, a thickness of 0.1 to 30 mm in the case of a sheet, and a maximum diameter of 0.1 to 30 mm in the case of a ball to a rod. The size of the cut product may be arbitrary, and the size of the crushed product is usually 0.001 to 20 mm,
It is preferably 0.01 to 10 mm. The cutting may be performed by a known method, for example, using a cutter or a pelletizer, and the crushing may be performed by a known method. (Jet mill, etc.)
Etc.

In the case of the heating and / or dry molding method, various methods such as extrusion molding, press molding, combined use of extrusion molding and press molding, and centrifugal molding can be applied without any particular limitation. As a typical example, in the case of the extrusion molding method,
Using the mixture of the present invention, a screw-type vacuum extrusion molding machine, a screw-type extrusion molding machine, a plunger-type extrusion molding machine, and the like, extruded into a desired shape through a die or the like attached to its tip, a cutter or a crusher Using, cut into a desired length and size, and crush. The extruded mixture is then heated and / or dried to obtain the desired molded product. The drying method may be a known method,
For example, a method of performing air drying (band drying, etc.), aeration drying (circulation drying, etc.), contact drying (drum dryer drying, etc.), reduced pressure drying, etc. can be exemplified. Also, heating and /
Or, the temperature at the time of dry molding depends on the type of substrate, size (particle size),
It can be appropriately selected according to the nature, etc., but is usually 30
-300 degreeC, Preferably it is 50-200 degreeC. In the above, the drying is usually performed under atmospheric pressure, but under reduced pressure (750 to 5
There is no problem even if it is performed under mmHg). The shape of the obtained heated and / or dried molded product is the same as that in the case of pressure molding. The water content of the dried product is 10% or less, preferably 7
% Or less.

In addition, as a water retention agent for plant reuse for reuse, if necessary, a fertilizer, a pesticide, an insecticide, a bactericide, a deodorant, an aromatic, a fungicide, a preservative, an antiblocking agent, an interface, A drug such as an activator can be used in combination. These agents may be present in the water retaining agent for growing plants, and may be added to the carrier for growing plants and / or the water absorbent resin in advance, or may be added before or after the molding step. Good. This water retention agent may or may not be colored, but is preferably colored with a pigment and / or dye from the visual effect.

The reusable water retaining agent for growing plants may be used alone as a cultivation bed material, or may be mixed with a cultivation bed material such as soil, or a specific place apart from the plant. Examples thereof include a method of burying the seedlings in the soil, and a method of burying them in a layered manner at an appropriate depth of the cultivation bed. That is,
Any location in the soil may be used as long as the water retained by the cultivated plant can be effectively used by forming a water retaining layer or water retaining mass by using the reused water retaining agent for growing plants. In addition, the water retention agent for plant growth of the present invention, vegetation zone, vegetation mat, vegetation bag,
It can also be used by incorporating it into materials such as vegetation boards. The water retaining agent for reusing the plant is water or an aqueous solution (for example,
Aqueous liquid obtained by dissolving fertilizer components in water is absorbed, and preferably 5 to 200 relative to the mass of the water retaining agent for growing plants.
It has a property of swelling twice, more preferably 10 to 100 times. The “dispersion liquid” retained in the cross-linking or network structure is not particularly limited as long as it is a liquid containing water as a main component. More specifically, for example, the dispersion liquid may be water itself, or an aqueous solution (for example,
It may be either an aqueous solution in which a water-soluble fertilizer or the like is dissolved) and / or a water-containing liquid (for example, a mixed liquid of water and a monohydric or polyhydric alcohol).

[0061]

EXAMPLES In each of the following examples and comparative examples, each physical property measuring method and evaluation criteria are as follows. [Water absorption amount] [Water retention amount] [Water-soluble component content] is for pure water, and [Gel strength] [Gel elastic modulus] is for physiological saline.

[Water Absorption] A tea bag made of 250 mesh nylon net, having a size of 10 × 20 cm and a heat sealing width of 5 mm or less, and pure water are prepared. Water absorbent resin is JI
It is sieved with an S standard sieve, and those having a particle size of 30 to 100 mesh are collected and used as a measurement sample. 0.20 g of the sample is put into a tea bag, and it is immersed in pure water about 15 cm from the bottom of the tea bag. After left for 1 hour, the tea bag is pulled up, hung vertically and drained for 15 minutes. The weight (Ag) is measured. The weight (Bg) is measured by performing the same operation using an empty tea bag containing no sample.
The measurement is performed 3 times and averaged. Water absorption (g / g) = (A-
Calculate from B) /0.2.

[Water retention amount] 150 G (1100 rpm, r
A centrifugal separator capable of exerting a centrifugal force of 10 cm). A tea bag containing the sample after measuring the water absorption amount is set in a centrifuge, an empty tea bag is set diagonally with the tea bag, and centrifugation is performed at 150 G × 90 seconds. The weight of each tea bag was measured, and the water retention capacity (g / g) = (AB) /
Calculate from 0.2.

[Water-Soluble Component Content] 10.00 g of the sample was put in an excess amount of pure water with respect to the amount of water absorbed and stirred for 24 hours. Then, the liquid is filtered, the mother liquor is concentrated by an evaporator, and then evaporated to dryness in a 120 ° C. constant temperature bath. The ratio of the evaporation residue to the amount of the sample used for the measurement is calculated in% by weight.

[Gel Strength] The liquid absorption amount (Mg / g) of the water-absorbent resin with respect to physiological saline was previously measured by the same tea bag method (JIS K7223-1996) used in the measurement of the water absorption amount. [(M × 0.75) -1] g of physiological saline is added to 100
Place in a cc beaker and stir at 600 rps for 1
g of a water-absorbent resin (60 to 100 mesh) is added and uniformly absorbed to prepare a liquid-absorbent gel having a smooth surface. The liquid-absorbent gel was kept warm at 25 ° C., and the gel strength was measured using a neocard meter (M302 type, manufactured by Iio Denki Co., Ltd.) under the following conditions. Load: 200g Diameter of pressure sensitive shaft: 8mmφ Descent speed of pressure sensitive shaft: 0.36cm / sec

[Gel Elastic Modulus] The water-absorbent resin, which has been sieved with a sieve of 26 to 30 mesh, is swollen 50 times with physiological saline and measured with a creep meter. Set the following measurement conditions by the creep analysis program of the computer. Initial height (H ₀ ) condition setting: 0.01 mm Measuring height (H ₀ -h ₁ ) during compression: 0.01 mm Load (stress): 30 g Plunger descending speed (at initial height measurement and compression Time): 1 mm / sec Swelling sample 0.20 ± 0.10.
Place g flat (so that there is one layer) and measure. The measurement is performed 3 times and averaged. The elastic modulus is calculated by the following formula. Elastic modulus E ₀ = P ₀ / h ₁ / H ₀ (N / m ² ) where stress P ₀ = F × 98 / S (N / m ² ) load F = 30 g cross-sectional area S = V ₀ / (H _0- h ₁ ) Sample volume V ₀ = Sample weight W 0 ∴ Elastic modulus E ₀ = 2940 × H ₀ × (H ₀ −h ₁ ) / W ₀
× h ₁

[Air Permeability] An air permeability test according to JIS L-1096 was carried out using a Frazier type fabric air permeability tester, and the amount of air passing through the cloth (cm ³ / cm ² · sec).
Was taken as the air permeability.

[Evaluation Criteria] (Water Absorption Time) ... The water absorption time was defined as the time required to immerse the mat containing the water absorbent resin in a tub containing 2 liters of water (water temperature 25 ° C.) and absorb all the water. (Smelling test) ... The mat containing the water-absorbent resin that had absorbed water to the above-mentioned certain amount was gripped with fingers, and the slimy feeling at that time was examined. (Stability test) ... A bucket containing 25 kg of water, which is equivalent to a large dog, is placed on a mat containing water-absorbent resin that has absorbed water to the above-mentioned certain amount for 24 hours, during which gel squeeze out and water separation I checked. (Surface temperature) ... The mat containing water-absorbent resin that has absorbed water to the above-mentioned certain amount is left in a room at a temperature of 32 ° C. and a humidity of 60%, and a temperature sensor is attached to the surface of the mat. The temperature was measured. (Cold keeping duration) ...... The mat containing the water-absorbent resin that has absorbed water up to the above-mentioned fixed amount is left in a room at a temperature of 32 ° C and a humidity of 60%, and moisture evaporates to reduce the mat weight by half. The period (number of days) was examined.

Production Example 1 To a 1 L beaker, 230 g of acrylic acid, 133 g of 48% aqueous sodium hydroxide solution, 1.0 g of pentaerythritol triallyl ether, and 636 g of water were added.
Cooled to 0 ° C. This solution was placed in an adiabatic polymerization tank, and dissolved oxygen in the solution was adjusted to 0.1 ppm (measured by Orient Electric Co., trade name dissolved oxygen meter DO220PB) through nitrogen, and then 0.023 g of 35% hydrogen peroxide solution, 0.00575 g of L-ascorbic acid and 0.23 g of potassium persulfate were added. The polymerization reaction started about 30 minutes after the addition, and reached the maximum temperature of 72 ° C. about 2 hours later. Furthermore, it was aged at this temperature for 5 hours to complete the polymerization. The obtained polymer had a hydrogel state. This polymer is kneader (made by Irie Shosha Co., Ltd., trade name BENCH KNEADERPN
V-1: Rotation speed 70 rpm), the mixture was stirred for about 2 hours and shredded, and 35.5 g of a 50% calcium chloride aqueous solution was further added, and the mixture was stirred by a kneader for about 2 hours and mixed. Subsequently, it is dried by heating at 110 ° C., and then pulverized to have an average particle diameter of 370 microns (manufactured by Nikkiso Co., Ltd., trade name: Microtrac FRA).
Particle size analyzer), calcium ion absorption 85.4 (mg / g), chloride ion content 1.6 (mm
ol / g), water absorption capacity 309 (g / g), gel strength 3
50,000 (dyne / cm ² ), gel elastic modulus 10.3
A water-absorbent resin (A) having a water-soluble component content of × 10 ³ (N / m ² ) of 3.0 (%) and a water retention / water absorption ratio of 0.8 was obtained.

Production Example 2 When 10 g of a commercially available water-absorbent resin (manufactured by Sanyo Kasei Co., Ltd., trade name: Sunfresh ST-500D) was swollen with 4 L of distilled water, 1 L of a CaCl 2 solution (Ca containing 1
g; concentration 0.28%) was added and well stirred. After leaving for 2 hours with occasional stirring, the gel was filtered off with a net (fineness of mesh: nylon mesh filter cloth, 250 mesh, manufactured by Azumi Filter Paper Co., Ltd., trade name N-No250HD), and then dried (120 ° C). In air for 1 hour. After drying, it was ground in a mortar to give a gel powder, average particle size 330 microns, calcium ion absorption 62.9 (mg / g), chloride ion content 0.6 (mmol / g), water absorption capacity 24
4 (g / g), gel strength 35,000 (dyne / cm
² ), a gel elastic modulus of 11.0 × 10 ³ (N / m ² ), a water-soluble component content of 3.0 (%), and a water retention / water absorption ratio of 0.75 were obtained.

Production Example 3 0.29 g of acrylic acid (0.0
4 mol) and 48% aqueous sodium hydroxide solution 0.33
g, 508.4% acrylamide aqueous solution 278.4 g (1.9
6 mol) and 278 g of water were added, and the mixture was cooled to 5 ° C. This solution was placed in an adiabatic polymerization tank, and the amount of dissolved oxygen in the solution was adjusted to 0.1 ppm through nitrogen, and then 0.0001 g of 35% hydrogen peroxide solution and 0.00005 g of L-ascorbic acid.
And 0.025 g of 4,4'-azobis (4-cyanovaleric acid) were added. Polymerization started after about 30 minutes, reached the maximum reached temperature of about 75 ° C. after about 5 hours, and the polymerization was completed, and a hydrogel polymer was obtained. This gel is subdivided with a meat chopper, and then 120 ° C. using a band dryer (air dryer, manufactured by Inoue Metal Co., Ltd.).
And dried for 1 hour and pulverized to obtain an uncrosslinked dry powder having an average particle size of 500 microns. 100 g of this uncrosslinked dry powder
In a stainless steel vat with a thickness of 3 mm, 160 ℃
Heated for 120 minutes in a circulating air dryer to thermally crosslink, calcium ion absorption amount 3.3 (mg / g), chloride ion content 0 (mmol / g), water absorption capacity 55 (g / g), gel Strength 40,000 (dyne / cm ² ), gel elastic modulus 9.8 × 10 ³ (N / m ² ), water-soluble component content 3.5
(%), Water retention resin / water absorption ratio of 0.8 (A)
Got

Example 1 Air permeability 4 cm ³ / cm ² · sec, size 40 × 40c
m, two pieces of 100% cotton white cloth, the same size and air permeability of 30
Two pieces of dyed cloth of cm ³ / cm ² · sec were prepared. Then, two sheets of white cloth were placed inside, and two pieces of colored cloth were placed outside respectively, so that a total of four sheets were superposed and three sides were sewn. In addition, the inner space was divided into four equal parts by stitching also on three lines parallel to the two opposite sides that were sewn. Each of the divided spaces was filled with 15 g of the water absorbent resin A obtained in Production Example 1 from the unsewn side, and the side was also sewn to manufacture a mat containing the water absorbent resin.

As shown in FIG. 1 as a cross-sectional view, the obtained mat has upper and lower white cloths (1) and (2) and 4 surrounded by them.
One space (3), (4), (5), water-absorbent resin (7) evenly filled in (6), and a white cloth (1), (2) dyeing cloth to reinforce from the outside (8),
(9) consists of When this mat is immersed in 2 liters of water to absorb water, the water-absorbent resin expands with the absorption of water, and as a result, the whole expands in the thickness direction. The water absorption time of this mat was 4 minutes, there was no slimy feeling in the slime test, and neither swelling of the gel nor water separation was observed in the stability test. The surface temperature of the mat was 23 ° C. The cold preservation duration was 6 days.

Example 2 In place of the water absorbent resin A in Example 1, Production Example 2
A water-absorbent resin-containing mat was produced under the same conditions as in Example 1 except that the water-absorbent resin A obtained in 1. was used. The average particle size of the resin was adjusted by passing it through a sieve after crushing. The mat had a water absorption time of 5 minutes, a slimy feeling by the slime test was little, and no gel squeeze-out and water separation were observed by the stability test. The surface temperature of the mat is 23 ℃.
Met. The cold preservation duration was 6 days.

Example 3 In place of the water absorbent resin A in Example 1, Production Example 3
A water-absorbent resin-containing mat was produced under the same conditions as in Example 1 except that the water-absorbent resin A obtained in 1. was used. The average particle size of the resin was adjusted by passing it through a sieve after crushing. The mat had a water absorption time of 5 minutes, a slimy feeling by the slime test was little, and no gel squeeze-out and water separation were observed by the stability test. The surface temperature of the mat is 23 ℃.
Met. The cold preservation duration was 6 days.

Comparative Example 1 In Example 1, the water absorbent resin was replaced by A, the average particle size was 400 μm, and the calcium ion absorption amount was 164 (mg /
g), chlorine ion content 0 (mmol / g), water absorption capacity 900 times, gel strength 11,000 (dyne / c)
m ² ), gel elastic modulus 4.7 × 10 ³ N / m ² , water-soluble component content 13.0%, water retention / water absorption ratio 0.8 except that a cross-linked polymer of sodium acrylate was used. A mat containing a water absorbent resin was prepared in the same manner as in Example 1. The water absorption time of the mat was 12 minutes, and there was a slimy feeling in the slime test. No gel swelling or water separation was observed in the stability test. The surface temperature of the mat was 23 ° C. The cold preservation duration was 6 days.

Performance Evaluation The gel-like material in the water-absorbent resin-containing mats of Examples 1 to 3 and Comparative Example 1 was subjected to a test for confirming the degree of plant growth. The results are shown in Table 1.

<Confirmation test of plant growth degree (1)> 3
5 kg of sandy soil (for example, river sand) was put into a 0 cm × 20 cm × 20 cm plastic planter. 2.0 kg of a gel-like material (Examples 1 to 3 and Comparative Example 1) in a mat containing a water absorbent resin and 5.0 kg of sandy soil and a chemical fertilizer (nitrogen: phosphoric acid: potassium = 1: 1: 1). 3 kg was added and the well mixed soil was layered on a planter containing sandy soil and sufficiently watered, and then cucumber, radish and rice were sown. 100 g of tap water was irrigated every 3 days, and the growth status (average value of 12 strains) of each plant was observed for 14 days. Confirmation test of plant growth degree (1)

[0079]

[Table 1]

Example 4 The gel-like material obtained in Example 1 was dried for 3 hours in a dryer whose temperature was adjusted to 120 ° C. to obtain a used water absorbent resin B having a water content of 3.2% by mass. Quartz sand "Natural silica sand No. 4" (grain size 20
˜65 mesh, manufactured by Tsuchiya Kaolin Co., Ltd.) and the used water absorbent resin B in a weight ratio of 85:15, and 2,000 kg / c in a briquette machine (manufactured by Shinto Kogyo Co., Ltd.) at room temperature.
By applying m (linear pressure), a pellet-shaped water retaining agent for growing plants having an average particle size of about 4 mm was prepared.

Example 5 The gel-like material obtained in Example 2 was dried in the same manner with a dryer whose temperature was adjusted to 120 ° C. to obtain a used water absorbent resin B having a water content of 2.8% by mass. A water retaining agent for growing plants was prepared in the same manner as in Example 4 except that the used water absorbent resin B was used instead of the used water absorbent resin in Example 4.

Example 6 The gel-like material obtained in Example 3 was dried in the same manner with a dryer whose temperature was adjusted to 120 ° C. to obtain a used water absorbent resin B having a water content of 3.5% by mass. In Example 4, “natural silica sand 4
No. ":" Used water absorbent resin B "(blending ratio is 85:15 by weight)," Natural silica sand No. 4 ":" Used water absorbent resin B ":" Lack Star CB-2 "(styrene
A water retaining agent for growing plants was prepared in the same manner as in Example 4 except that butadiene rubber, manufactured by Dainippon Ink and Chemicals, Inc. (blending ratio was 85: 15: 1 by weight).

Comparative Example 2 The gel-like material obtained in Comparative Example 1 was similarly dried with a dryer whose temperature was adjusted to 120 ° C. to obtain a used water absorbent resin B having a water content of 2.6% by mass. A water retaining agent for growing plants was prepared in the same manner as in Example 4 except that the used water absorbent resin B was used instead of the used water absorbent resin in Example 4.

The test method for the water retaining agent for growing plants is shown below. <Confirmation test of plant growth degree (2)> 30 cm x 20
5 kg of sandy soil (for example, river sand) was placed in a cm × 20 cm plastic planter. Sandy soil 8.7k
g in the mat containing the water-absorbent resin (Examples 4 to
6, Comparative Example 2) 1.3 kg and 0.5 kg of chemical fertilizer (nitrogen: phosphoric acid: potassium = 1: 1: 1) were added and mixed well, and the soil was laminated on a planter containing sandy soil. After watering, cucumber, radish and rice were seeded. 50 g of tap water was irrigated every 3 days, and the growth status (average value of 12 strains) of each plant was observed for 14 days.

Performance Evaluation With respect to the water-retaining agents for growing plants of Examples 4 to 6 and Comparative Example 2, a confirmation test of the growth degree (2) of plants was conducted. The results are shown in Table 2. Confirmation test of plant growth degree (2)

[0086]

[Table 2]

[0087]

The mat containing the water absorbent resin of the present invention has the following effects. (1) Since the effect of keeping cool is large and the duration of keeping cool is long, it is effective as a measure against summer heat for animals such as large dogs that are particularly vulnerable to heat. (2) The water-absorbent resin in the used mat containing the water-absorbent resin can be reused as a water retention agent for growing plants without collecting and discarding it. (3) Since the reusable water retaining agent for growing plants does not inhibit the growth of plants and has an excellent water absorbing ability, it is possible to replenish the plants with sufficient water. Also, since a lightweight base material can be used in place of natural soil and processed into various shapes, the weight of the implant material can be significantly reduced. In particular, it can be effectively used as a planting material for "pots" such as cell-molded seedlings, community pot seedlings, pot seedlings, etc. whose production and distribution are rapidly increasing in facility horticulture.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state of a water-absorbent resin-containing mat before water absorption.

FIG. 2 is a cross-sectional view showing a state of the water-absorbent resin-containing mat after water absorption.

[Explanation of symbols]

1, 2; cloth 3, 4, 5, 6; Space 7; Water absorbent resin 8, 9; Outer cloth

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 3, 2003 (2003.3.3)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0084

[Correction method] Change

[Correction content]

The test method for the water retaining agent for growing plants is shown below. <Confirmation test of plant growth degree (2)> 30 cm x 20
5 kg of sandy soil (for example, river sand) was placed in a cm × 20 cm plastic planter. Sandy soil 8.7k
g is a water retention agent for growing plants (Examples 4 to 6, Comparative Example 2)
1.3 kg and chemical fertilizer (nitrogen: phosphoric acid: potassium = 1: 1)
1: 1) 0.5 kg was added and well mixed soil was stacked on a planter containing sandy soil and sufficiently watered, and then cucumber, radish and rice were sown. 50 g of tap water was irrigated every 3 days, and the growth status (average value of 12 strains) of each plant was observed for 14 days.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2B022 BA02 BA03 BA04 BA06 BA12                       BA13 BA21 BA22 BA23 BB01                       BB05

Claims (9)

[Claims] 1. A mat comprising a powder of a water-absorbent resin (A) and a bag-shaped cloth containing the powder, wherein the (A) has a calcium ion absorption amount of 0 to 100 m per 1 g of dry weight.
and the water absorption capacity in ion-exchanged water at 25 ° C is 10
~ 1,000 times, and the average particle size is 10 ~ 1,
000 μm, and the cloth has an air permeability of 0.1 to ³⁰ cm ³ /
A mat containing a water-absorbent resin, which has a cm ² · sec. 2. The mat according to claim 1, wherein the content of chlorine ions in (A) is 0.07 to 7 mmol per 1 g of dry weight. 3. The mat according to claim 1, wherein the (A) is a nonionic water absorbent resin and / or an anionic water absorbent resin. 4. The gel strength of the water-absorbent resin is 10,000.
The mat according to any one of claims 1 to 3, which has a density of 0 to 50,000 dynes / cm ² . 5. The cloth is sewn up and down so that an inner space is divided into a plurality of spaces, and each of the divided spaces is uniformly filled with a water absorbent resin per unit area. The mat according to any one of 1 to 4. 6. The outer bag for covering the cloth is further provided.
The mat according to any one of to 5. 7. A cushion or a cushion for animals.
The mat according to any one of to 6. 8. A water retaining agent for growing plants, which uses the water absorbent resin in the mat according to any one of claims 1 to 7 which has been used. 9. A method for recovering the water-absorbent resin in the used mat according to any one of claims 1 to 7 and reusing it as a water retaining agent for growing plants.