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WO2024024706A1 - Composition de résine absorbant l'eau pour la culture de plantes - Google Patents

Composition de résine absorbant l'eau pour la culture de plantes Download PDF

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Publication number
WO2024024706A1
WO2024024706A1 PCT/JP2023/026926 JP2023026926W WO2024024706A1 WO 2024024706 A1 WO2024024706 A1 WO 2024024706A1 JP 2023026926 W JP2023026926 W JP 2023026926W WO 2024024706 A1 WO2024024706 A1 WO 2024024706A1
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Prior art keywords
water
resin composition
mol
weight
calcium
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PCT/JP2023/026926
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English (en)
Japanese (ja)
Inventor
遼 吉本
和宏 糟谷
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Sanyo Chemical Industries Ltd
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Sanyo Chemical Industries Ltd
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Priority to JP2024537697A priority Critical patent/JPWO2024024706A1/ja
Publication of WO2024024706A1 publication Critical patent/WO2024024706A1/fr
Anticipated expiration legal-status Critical
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    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
    • A01G24/00—Growth substrates; Culture media; Apparatus or methods therefor
    • A01G24/30—Growth substrates; Culture media; Apparatus or methods therefor based on or containing synthetic organic compounds
    • A01G24/35—Growth substrates; Culture media; Apparatus or methods therefor based on or containing synthetic organic compounds containing water-absorbing polymers

Definitions

  • the present invention relates to a water-absorbing resin composition for growing plants. More specifically, the present invention relates to a water-absorbing resin composition for growing plants that can be used as a water-retaining material in agriculture (fluid seeding, field cultivation, outdoor cultivation), greening work, gardening, and the like.
  • Nonionic polymers such as acrylamide polymers, or anionic polymers such as acrylic acid polymers have been known as water retaining materials used for growing plants in agriculture, greening work, gardening, etc. .
  • nonionic polymers have a high affinity for plant roots and are excellent in germination, rooting, growth, etc., they have the drawbacks of low water absorption and poor water retention.
  • anionic polymers have a high water absorption capacity and excellent water retention, but they have poor affinity for plant roots and have negative effects such as inhibiting germination, rooting, growth, etc., and have the disadvantage that plants tend to wither. have.
  • Patent Document 1 discloses a hydrogel that is a polyacrylic acid-based polymer that absorbs calcium ions in an amount of less than 50 mg per 1 g of dry weight, and that has an absorption capacity of 100 times or more in ion-exchanged water (room temperature, 25°C).
  • a plant growth water retention carrier containing a forming polymer has been proposed.
  • the calcium ion absorption amount is 0 to 100 mg per 1 g of dry weight
  • the chlorine ion content is 0.07 to 7 mmol per 1 g of dry weight
  • a plant water-retaining carrier containing a hydrogel-forming polymer having 1.0 ⁇ 10 1 to 1.0 ⁇ 10 3 times the amount of water has been proposed.
  • the drawbacks of anionic polymers such as "adverse effects such as inhibiting germination, rooting, growth, etc.”, are avoided by preventing the polymer from depriving plants of calcium ions.
  • the problem of a significant drop in water absorption capacity in fertilized soil (soil containing polyvalent metal ions) remained unsolved, and this was a practical drawback.
  • Patent Document 3 discloses a water-retaining material for plant growth containing a water-insoluble water-absorbing resin having a carboxyl group and a polyvalent metal compound, and which has an absorption rate (water absorption capacity in ion-exchanged water for 10 minutes) of 20. ⁇ 500g/g, and the solubility of the polyvalent metal compound in 100g of ion-exchanged water at 20°C is more than 0 and 10.0g or less, and the polyvalent metal compound is for growing plants that essentially contains calcium.
  • Water retaining materials have been proposed.
  • the water retaining material described in Patent Document 3 is excellent in being able to supply calcium, which is a necessary nutrient for plants, for a long period of time. ), etc., has not been solved, and has had practical drawbacks.
  • Patent Document 4 discloses an agricultural and horticultural water retaining material containing an alkaline earth metal salt of a crosslinked copolymer derived from a monomer component containing an anionic monomer and a nonionic monomer with a specific structure. Proposed. Although the water-retaining material described in Patent Document 4 is not easily affected by the use of fertilizers, the water-absorbing capacity of the crosslinked copolymer is low regardless of the nature of the soil, and as a water-retaining material, it lacks water-retaining properties.
  • Patent No. 4346112 Japanese Patent Application Publication No. 2000-139208 Patent No. 5010276 Japanese Patent Application Publication No. 9-78050
  • the present invention has been made in view of the above-mentioned problems, and the purpose of the present invention is to achieve both water absorption properties (particularly water retention) and plant growth promotion properties, which are conventionally contradictory, and also to have high resistance to the soil environment.
  • the purpose of the present invention is to provide a water absorbent resin composition for growing plants.
  • the present invention provides a crosslinked copolymer (B) containing (meth)acrylic acid and/or (meth)acrylate (b1) and (meth)acrylamide (b2) as essential constituent units. It is a water-absorbing resin composition, the calcium ion content is 5.0 to 80.0 mg per 1.0 g of dry weight of the composition, and the calcium ion absorption amount is 7.0 to 7.0 mg per 1.0 g of dry weight of the composition. It is 76.0 mg.
  • the present invention also provides a method for producing a water-absorbing resin composition for plant growth, which includes the steps (1) and (2) below, and includes the crosslinked copolymer (B) and a water-soluble calcium compound (C). It is.
  • the mixed solution obtained in the step (1) The process of reducing the moisture content of
  • the water-absorbing resin composition for growing plants of the present invention has the effect of achieving both excellent water-absorbing properties (water retention) and plant growth-promoting properties. Furthermore, it is highly resistant to soil environments, and has excellent long-term water retention even in soils containing iron, alkaline soils containing a large amount of magnesia, soils containing polyvalent metal ions that have been fertilized, and the like.
  • excellent water absorption properties (water retention) means that a sufficient amount of water can be supplied for a long period of time for plant growth.
  • plant growth-promoting property means that it does not inhibit plant germination, rooting, elongation, etc., and can supply a sufficient amount of calcium ions that do not cause calcium deficiency in plants.
  • the crosslinked copolymer (B) in the present invention contains (meth)acrylic acid and/or (meth)acrylate (b1) and (meth)acrylamide (b2) as essential structural units.
  • the crosslinked copolymer (B) is substantially water-insoluble and exhibits a water-retaining effect by swelling upon contact with an aqueous solution.
  • (meth)acrylic acid includes acrylic acid and methacrylic acid.
  • (meth)acrylates include alkali metal salts such as sodium (meth)acrylate and potassium (meth)acrylate; alkaline earth metal salts such as calcium (meth)acrylate and magnesium (meth)acrylate; Examples include ammonium meth)acrylic acid salts and organic amine salts of (meth)acrylic acid.
  • (meth)acrylic acid means methacrylic acid and/or acrylic acid.
  • (Meth)acrylate means methacrylate and/or acrylate.
  • the molar ratio of the (meth)acrylate in (b1) above is not particularly limited, but from the viewpoint of water retention capacity and plant growth promoting effect, it is preferably 50 to 100 mol%, and 55 to 100 mol%. %, and even more preferably 60 to 100 mol %.
  • the molar ratio of (meth)acrylate can be adjusted by the neutralization rate of (meth)acrylic acid.
  • (Meth)acrylic acid can be neutralized by adding alkali metal hydroxides (sodium hydroxide, potassium hydroxide, etc.), alkaline earth metal hydroxides (calcium hydroxide, etc.), ammonia, organic amines, etc. It will be done.
  • Polymerization may be performed after neutralization at the monomer stage before polymerization, and alkali metal hydroxides, alkaline earth metal hydroxides, ammonia (aqueous solution), organic amines (aqueous solution), etc. may be added to the hydrogel after polymerization. It may be neutralized by adding
  • the above-mentioned "(meth)acrylate in (b1)" includes those obtained by copolymerizing in the form of (meth)acrylic acid and then converting it into a (meth)acrylate by the method described below.
  • the molar ratio of the calcium (meth)acrylate salt in (b1) above is determined from the viewpoint of water absorption properties and plant growth promoting effect, so that the water-absorbent resin composition for plant growth contains the water-soluble calcium compound (C) described below. The following ranges are preferable for both cases where it is not included and cases where it is included.
  • the molar ratio of the calcium (meth)acrylate salt in (b1) is preferably 20 to 62 mol%. , more preferably 20 to 50 mol%, particularly preferably 20 to 40 mol%.
  • the molar ratio of calcium (meth)acrylate salt in (b1) is preferably 0 to 62 mol%. , more preferably 0 to 50 mol%, particularly preferably 0 to 40 mol%.
  • the above-mentioned "(meth)acrylic acid calcium salt in (b1)” includes (meth)acrylic acid and/or (meth)acrylic acid salt other than calcium salt after copolymerization by the method described below. ) Also includes those converted to calcium acrylate salts.
  • the molar ratio of the calcium (meth)acrylate salt is such that the molar mass of the calcium (meth)acrylate salt is the sum of the mass of 1 mole of anion derived from (meth)acrylic acid and the mass of 0.5 mole of calcium ion. Calculated assuming that there is.
  • the (meth)acrylamide (b2) is acrylamide and/or methacrylamide.
  • the molar ratio [(b1)/(b2)] of the above (b1) and the above (b2), which are essential structural units of the crosslinked copolymer (B), is preferably 10/90 to 50/50, and Preferably it is 20/80 to 40/60.
  • the total amount of (b1) and (b2) is preferably 95.0 mol% or more based on the total number of moles of all structural units of the crosslinked copolymer (B) from the viewpoint of water absorption properties etc. More preferably, it is 99.5 mol% or more.
  • the crosslinked copolymer (B) may contain another ethylenically unsaturated monomer (e) as a structural unit.
  • the content of the ethylenically unsaturated unit (e) should be 10 mol% or less based on the total number of moles of all structural units of the crosslinked copolymer (B). preferable.
  • ethylenically unsaturated monomer (e) hydroxylalkyl (meth)acrylate, sulfoalkyl (meth)acrylate and its salts (alkali metal salts and alkaline earth metal salts, etc.), 2-acrylamido-2-methylpropane
  • sulfonic acid and its salts alkali metal salts and alkaline earth metal salts, etc.
  • maleic acid itaconic acid, etc.; If so, there is no limitation.
  • the method for producing the crosslinked copolymer (B) in the present invention is not particularly limited, but examples include the following methods (i) and (ii).
  • alkali metal hydroxide sodium hydroxide and potassium hydrox
  • carboxylic acid salts alkali metal salts, alkaline earth metal salts, ammonium salts, organic amine salts, etc.
  • a part of the carboxylic acid salts possessed by the crosslinked polymer obtained by the method (i) or (ii) above may be further salted. It may be substituted with a different type of salt by an exchange reaction (for example, a portion of the carboxylic acid sodium salt may be substituted with a calcium salt).
  • the crosslinked copolymer (B) in the present invention has a crosslinked structure.
  • the crosslinked copolymer (B) may be a self-crosslinking type without using a crosslinking agent (b3) or a thermally crosslinking type, but it is preferable that the crosslinking copolymer (B) further contains a crosslinking agent (b3) as a structural unit.
  • the crosslinking agent (b3) By containing the crosslinking agent (b3), the crosslinking density and crosslinking uniformity of the crosslinked copolymer (B) can be easily controlled, and the water absorption rate, absorption capacity, water retention rate, etc. of the crosslinked copolymer (B) can be easily controlled. It becomes easier to balance.
  • crosslinked copolymer (B) there is no particular restriction on the timing of adding the crosslinking agent (b3), for example, when polymerizing the above (b1), the above (b2), and other monomers as necessary.
  • Polymerization may be carried out by adding a crosslinking agent (b3) to the polymer, and after polymerizing the above (b1), the above (b2), and other monomers as necessary to obtain a substantially water-soluble polymer.
  • a crosslinking agent (b3) may be added and a treatment such as heating may be performed to form a crosslink.
  • crosslinking agent (b3) examples include divinylbenzene, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, and polyethylene glycol di(meth)acrylate.
  • crosslinking agents (b3) may be used alone or in combination of two or more.
  • the crosslinking agent (b3) is preferably ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, N,N-methylenebisacrylamide, or polyethylene glycol diglycidyl ether; From the viewpoint of durability (iron decomposition resistance, etc.), trimethylolpropane tri(meth)acrylate and N,N-methylenebisacrylamide are particularly preferred.
  • the content (mol%) of crosslinking agent (b3) units in the crosslinked copolymer (B) is 0.005 to 5 mol% based on the total number of moles of all constituent units of the crosslinked copolymer (B).
  • the amount is preferably 0.01 to 0.5 mol%, more preferably 0.01 to 0.5 mol%.
  • the copolymerization method for obtaining the crosslinked copolymer (B) may be any conventionally known method, and examples include a method using a radical polymerization initiator and a method of irradiating with radiation, electron beams, or ultraviolet rays. Usually, a method using a radical polymerization initiator is used.
  • azo compounds (4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)]propionamide and 2, 2'-azobis(2-amidinopropane) hydrochloride, etc.
  • inorganic peroxides hydrogen peroxide, potassium persulfate, ammonium persulfate, sodium persulfate, etc.
  • organic peroxides di-t-butyl peroxide and cumene hydroperoxide, etc.
  • redox initiators ⁇ reducing agents (alkali metal salt sulfite or bisulfite, ammonium sulfite, ammonium bisulfite, L-ascorbic acid, etc.), peroxides (alkali metal salt persulfate, etc.), salt, ammonium persulfate, hydrogen peroxide, etc.) and combinations of two or more of these.
  • the method of polymerization using a radical polymerization initiator is not particularly limited, and for example, the polymerization temperature varies depending on the type of polymerization initiator used, but is usually -10°C to 100°C, preferably -10°C to increase the molecular weight. ⁇ 80°C.
  • the amount of the polymerization initiator used is not particularly limited, but is usually 0.000001 to 3.0% by weight, preferably 0.000001 to 0.5% by weight, based on the total weight of all structural units of the crosslinked copolymer (B). Weight%.
  • Polymerization methods include known aqueous solution polymerization methods and so-called reverse phase suspension, in which an aqueous monomer solution is dispersed/suspended in a hydrophobic solvent (e.g.
  • the polymerization concentration which is the monomer concentration during polymerization, is usually 10 to 60% by weight, preferably 20 to 50% by weight, based on the weight of the reaction solution. When the polymerization concentration is within the above range, it becomes easier to control the molecular weight of the crosslinked copolymer, the reaction temperature, etc.
  • a hydrogel of the crosslinked copolymer (B) when a hydrogel of the crosslinked copolymer (B) is obtained by aqueous solution polymerization or reverse phase suspension polymerization, it is dried if necessary.
  • the drying method may be a known method.
  • aqueous solution polymerization after dividing the polymerized gel into pieces, air drying (band drying, etc.), ventilation drying (circulating air drying, etc.), or contact drying (drum dryer drying, etc.)
  • examples include a method of performing vacuum drying or aerated drying after solid-liquid separation.
  • the drying temperature of the hydrogel is not particularly limited, but is preferably within the range of 50°C to 180°C, most preferably within the range of 100°C to 170°C.
  • the dried product thus obtained is subjected to operations such as pulverization to make it into fine particles, and then, if necessary, subjected to classification operations such as sieving.
  • the pulverization may be carried out by any known method, for example, an impact pulverizer (pin mill, cutter mill, skillel mill, ACM pulpizer, centrifugal pulverizer, etc.) or an air pulverizer (jet pulverizer, etc.).
  • an impact pulverizer pin mill, cutter mill, skillel mill, ACM pulpizer, centrifugal pulverizer, etc.
  • jet pulverizer jet pulverizer, etc.
  • the shape, average particle diameter, etc. of the crosslinked copolymer (B) are not particularly limited.
  • the hydrogel of the crosslinked copolymer (B) or a dried product thereof may be treated with a reducing agent.
  • the reducing agent include sodium sulfite, potassium sulfite, ammonium sulfite, sodium hydrogen sulfite, potassium sulfite, ammonium hydrogen sulfite, sodium thiosulfate, potassium thiosulfate, ammonium thiosulfate, L-ascorbic acid, ammonia, monoethanolamine, and glucose. can be mentioned.
  • reducing agents may be used alone or in combination of two or more.
  • sodium sulfite, sodium hydrogen sulfite, and atrium thiosulfate are more preferred.
  • the amount of the reducing agent used is not particularly limited, but it is preferably within the range of 0.01 to 2 mol%, based on the total number of moles of all monomers used, and 0.1 to 1 mol%. More preferably within this range.
  • the crosslinked copolymer (B) in the present invention is necessary in consideration of the salt concentration of the soil in which the water-absorbing resin composition for plant growth is used, the properties of the mineral species forming the soil, the quality of water used for irrigation, etc.
  • the surface may be crosslinked depending on the conditions.
  • the cross-linked copolymer (B) improves the ease of mixing with soil, and especially makes it difficult to block the gel absorbed by the cross-linked copolymer (B) when mixed with soil (hereinafter referred to as "blocking resistance").
  • blocking resistance it is preferable that the surface be crosslinked by surface crosslinking.
  • Examples of the surface crosslinking agent include polyhydric glycidyl described in JP-A-59-189103, polyhydric alcohols and polyhydric amines described in JP-A-58-180233 and JP-A-61-16903, etc.
  • Polyvalent aziridine and polyvalent isocyanate, silane coupling agents described in JP-A-61-211305 and JP-A-61-252212, and JP-A-51-136588 and JP-A-61-257235 Examples include polyvalent metals described in publications and the like.
  • polyvalent glycidyl, polyvalent amines and silane coupling agents are preferred, polyvalent glycidyl and silane coupling agents are more preferred, and polyvalent glycidyl is particularly preferred. It is. Furthermore, among the polyvalent glycidyls, the most preferred are ethylene glycol diglycidyl ether and glycerin diglycidyl ether, and the particularly preferred is ethylene glycol diglycidyl ether.
  • the amount (wt%) of the surface crosslinking agent used is preferably 0.01 to 0.20 wt%, more preferably 0.01 to 0.20 wt%, based on the weight of the crosslinked copolymer (B), from the viewpoint of blocking resistance and the like. 0.03 to 0.15% by weight, particularly preferably 0.05 to 0.10% by weight.
  • Surface crosslinking can be performed by a known method (for example, the method disclosed in JP-A-13-2935, JP-A-2003-147005, and JP-A-2003-165883).
  • the surface crosslinking step may be repeated two or more times. That is, the crosslinked copolymer (B) obtained by surface crosslinking with a surface crosslinking agent can be subjected to additional surface crosslinking with a surface crosslinking agent of the same type or different from the first surface crosslinking agent.
  • the content of the additional surface crosslinking agent, treatment method, treatment temperature, treatment time, etc. are the same as in the first case.
  • the water-absorbing resin composition for plant growth of the present invention contains the above-mentioned crosslinked copolymer (B), has a calcium ion content of 5.0 to 80.0 mg per 1.0 g of dry weight of the composition, and has a calcium
  • the water absorbent resin composition has an ion absorption amount of 7.0 to 76.0 mg per 1.0 g of dry weight of the composition.
  • the content of the crosslinked copolymer (B) is preferably 80 to 100% by weight, more preferably 80 to 99% by weight, particularly preferably 80 to 98% by weight, based on the dry weight of the water absorbent composition. % by weight, most preferably 85-97% by weight. Within this range, the physical properties of the water-absorbing resin composition for plant growth of the present invention can be easily controlled within the desired range.
  • the water absorbent resin composition for plant growth of the present invention has a calcium ion content of 5.0 to 80.0 mg, preferably 7.5 to 50.0 mg, per 1.0 g of dry weight of the composition, and further Preferably it is 24.0 to 40.0 mg, particularly preferably 10.0 to 40.0 mg. If the content of calcium ions per 1.0 g of dry weight is less than 5.0 mg, the effect of promoting plant growth will be reduced, and if it exceeds 80.0 mg, the water absorption capacity will be reduced and the water retention capacity will be poor.
  • the water-absorbing resin composition for plant growth of the present invention has the above-mentioned crosslinked copolymer (B) as an essential component, and may or may not contain the water-soluble calcium compound (C) described below.
  • the crosslinked copolymer (B) contains calcium ions, and the crosslinked copolymer (B) Contains calcium ion as a counter ion of the structural unit. That is, the crosslinked copolymer (B) contains calcium (meth)acrylate salt as a part of the essential monomer (b1).
  • the water-absorbent resin composition for plant growth contains a water-soluble calcium compound (C)
  • only the water-soluble calcium compound (C) may contain calcium ions
  • the water-soluble calcium compound (C) and the crosslinked Both copolymers (B) may contain calcium ions.
  • the calcium ion content per 1.0 g of dry weight of the water absorbent resin composition for growing plants is measured by the following method.
  • Atomic absorption spectrometer AA-6500 auto system (manufactured by Shimadzu Corporation) Lighting condition: Ca#8 Current: 10mA/0mA Wavelength: 422.7nm Slit width: 0.5 ⁇ m
  • the calcium ion absorption amount of the water-absorbent resin composition for plant growth of the present invention is 7.0 to 76.0 mg, preferably 7.0 to 70.0 mg, and more preferably 7.0 to 70.0 mg per 1.0 g of dry weight of the composition. 7.0 to 65.0 mg, particularly preferably 7.0 to 60.0 mg. If the absorbed amount of calcium ions per 1.0 g of dry weight exceeds 76.0 mg, the water-absorbing resin will take away calcium ions necessary for plant growth, thereby inhibiting plant growth. Moreover, if the amount of calcium ion absorbed is less than 7.0 mg, the water absorption capacity of the water-absorbing resin composition decreases, making it difficult to supply sufficient water to plants.
  • the calcium ion source in (1) above known calcium salts and the like can be used, but the water-soluble calcium salt (C) described below is particularly preferred.
  • Other polyvalent metal ions include Mg 2+ , Al 3+ , Ba 2+ , Sr 2+ , B 3+ , Be 2+ , Fe 2+ , Fe 3+ , Mn 2+ , and especially Mg 2+ , Al 3+ , Ba 2+ , Sr 2+ , B 3+ and Be 2+ are preferred.
  • the amount of calcium ion absorbed per 1.0 g of dry weight of the water absorbent resin composition for plant growth is measured by the following method.
  • the swollen water-absorbent resin composition is separated, and the concentration of calcium ions in the remaining supernatant (excess amount in the calcium chloride aqueous solution) is measured by atomic absorption spectrometry (Amg/L).
  • Amg/L atomic absorption spectrometry
  • an ultrafiltration membrane with a molecular weight cutoff of about 1,000 to 3,000 is used to avoid the possibility that uncrosslinked water-soluble polymers may be dissolved in the supernatant. It is preferable to carry out separation by ultrafiltration using .
  • Atomic absorption spectrometer AA-6500 auto system (manufactured by Shimadzu Corporation) Lighting condition: Ca#8 Current: 10mA/0mA Wavelength: 422.7nm Slit width: 0.5 ⁇ m
  • the water absorbent resin composition for plant growth of the present invention satisfies the following conditions (a) or (b).
  • the calcium ion content is 10.0 to 40.0 mg per 1.0 g of dry weight of the composition, and the calcium ion absorption amount is 7.0 to 30.0 mg per 1.0 g of dry weight of the composition.
  • the calcium ion content is 24.0 to 40.0 mg per 1.0 g of dry weight of the composition, and the calcium ion absorption amount is 30.0 to 60.0 mg per 1.0 g of dry weight of the composition.
  • the physical properties of the water-absorbing resin composition for plant growth of the present invention can be easily controlled within the desired range, and the plant growth promoting effect (particularly in the early stage as typified by the cracking test described below) (during growth) is particularly good.
  • the water-absorbent resin composition for plant growth of the present invention further contains a water-soluble calcium compound (C) from the viewpoint of the effect of promoting plant growth.
  • the water-soluble calcium compound (C) is a salt of calcium, and includes halogen compounds, inorganic salts such as nitrates, acetates, and the like.
  • the water-soluble calcium compound (C) in the present invention is a compound having a solubility of 30 g or more in 100 g of ion-exchanged water at 20° C. under normal pressure.
  • the solubility is preferably 50 g or more, more preferably 70 g or more, and even more preferably 100 g or more.
  • solubility is 30 g or more, calcium ions easily penetrate into the crosslinked copolymer (B), and metal crosslinking with the carboxyl group of the (meth)acrylic acid unit of the crosslinked copolymer (B) may occur. can.
  • the water-soluble calcium compound (C) examples include halogen compounds (calcium chloride, calcium bromide, calcium iodide, etc.), nitrates (calcium nitrate, etc.), acetates (calcium acetate, etc.), and the like.
  • halogen compounds calcium chloride, calcium bromide, calcium iodide, etc.
  • nitrates calcium nitrate, etc.
  • acetates calcium acetate, etc.
  • calcium chloride and calcium nitrate are preferred from the viewpoint of the effect of promoting plant growth, and calcium nitrate is more preferred.
  • the content of the water-soluble calcium compound (C) in the water-absorbent resin composition for plant growth is The calcium ion content per 1.0 g of dry weight of the polyester resin composition is within the above range (5.0 to 80.0 mg per 1.0 g of dry weight), and from the viewpoint of water retention, it is suitable for plant growth.
  • the content of calcium ions derived from the water-soluble calcium compound (C) per 1.0 g of dry weight of the water-absorbing resin composition is preferably 5.0 to 45.0 mg, more preferably 7.5 to 40.0 mg, Particularly preferred is a range of 10.0 to 35.0 mg.
  • the calcium ion content derived from the water-soluble calcium compound (C) is 5.0 to 5.0 per 1.0 g of dry weight of the water-absorbent resin composition for growing plants. 80.0 mg, and on the other hand, when the crosslinked copolymer (B) contains 4.0 mg of calcium ions per 1.0 g of dry weight of the water-absorbent resin composition for plant growth, the amount of calcium ions derived from the water-soluble calcium compound (C) The calcium ion content is 1.0 to 76.0 mg per 1.0 g of dry weight of the water absorbent resin composition for growing plants.
  • the water-absorbing resin composition for plant growth contains a water-soluble calcium compound (C), it is preferably contained in a form in which the water-soluble calcium compound (C) is attached to the particle surface of the crosslinked copolymer (B).
  • the method for adhering the water-soluble calcium compound (C) to the surface of the crosslinked copolymer (B) include a method of homogeneous mixing using a general mixer. Examples of equipment used include a cylindrical mixer, a screw mixer, a screw extruder, a turbulizer, a Nauta mixer, a double-arm kneader, a fluid mixer, a V-type mixer, and a ribbon mixer. Mixers, fluid mixers, airflow mixers, rotating disk mixers, conical blenders, roll mixers, and the like can be mentioned.
  • the water-absorbing resin composition for plant growth used in the present invention may further contain an inorganic powder (D) from the viewpoint of blocking resistance.
  • the inorganic powder (D) include hydrophilic inorganic particles (D1) and hydrophobic inorganic particles (D2).
  • hydrophilic inorganic particles (D1) examples include particles of glass, silica gel, silica, clay, and the like.
  • hydrophobic inorganic particles (D2) examples include particles such as carbon fiber, kaolin, talc, mica, bentonite, sericite, asbestos, and shirasu. Among these, hydrophilic inorganic particles (D1) are preferred from the viewpoint of blocking resistance, and silica is most preferred.
  • the shapes of the hydrophilic inorganic particles (D1) and the hydrophobic inorganic particles (D2) may be any of amorphous (crushed), spherical, film, rod-like, fibrous, etc.; Spherical shapes are preferred, and spherical shapes are more preferred.
  • the specific surface area (m 2 /g) of the hydrophilic inorganic particles (D1) and the hydrophobic inorganic particles (D2) is preferably 5 to 700 m 2 /g, more preferably 20 to 500 m 2 /g, particularly preferably 40 to 700 m 2 /g. 400 m 2 /g, most preferably 150-250 m 2 /g.
  • the content (wt%) of the inorganic powder (D) is preferably 0.010 to 5.000 wt%, more preferably 0.10 to 5.000 wt%, based on the weight of the crosslinked copolymer (B). %, next preferably from 0.20 to 5.000% by weight, particularly preferably from 0.275 to 5.000% by weight, most preferably from 0.300 to 3.000% by weight. Within this range, the blocking resistance becomes even better.
  • the water-absorbent resin composition for plant growth contains the inorganic powder (D), it is preferably contained in the form that the inorganic powder (D) is attached to the particle surface of the crosslinked copolymer (B).
  • the method for adhering the inorganic powder (D) to the surface of the crosslinked copolymer (B) include a method of uniformly mixing using a general mixer. Examples of equipment used include a cylindrical mixer, a screw mixer, a screw extruder, a turbulizer, a Nauta mixer, a double-arm kneader, a fluid mixer, a V-type mixer, and a ribbon mixer.
  • the mixing temperature (°C) is not particularly limited, but is preferably 20 to 120°C, more preferably 30 to 100°C, particularly preferably 40 to 90°C. Within this range, the inorganic powder (D) will have good adhesion to the surface of the crosslinked copolymer (B).
  • the step of adhering the inorganic powder (D) to the surface of the crosslinked copolymer (B) is different from each step of producing the crosslinked copolymer (B) ⁇ polymerization step, shredding step, It is preferable to carry out before and after the drying step, the grinding step, the surface cross-linking step, the calcium addition step, etc., and more preferably, It is preferable to carry out the treatment after the calcium compound addition step.
  • additives can be added to the water-absorbent resin composition for plant growth of the present invention as long as the performance is not impaired.
  • Other additives include inorganic compounds containing elements that provide nutrients for plants [low water-soluble calcium salts other than water-soluble calcium compounds (C), potassium salts, phosphates, nitrogen compounds (urea, etc.) , sulfur compounds, magnesium salts (magnesium chloride and magnesium sulfate, etc.), iron salts (iron chloride, etc.), aluminum salts, zinc salts, manganese salts, boron salts, molybdenum salts, copper salts, nickel salts, chlorine compounds, silicon compounds, etc.
  • inorganic compounds containing elements that provide nutrients for plants [low water-soluble calcium salts other than water-soluble calcium compounds (C), potassium salts, phosphates, nitrogen compounds (urea, etc.) , sulfur compounds, magnesium salts (magnesium chloride and magnesium sulfate, etc.), iron salts (iron chloride, etc.), aluminum salts
  • additives preservatives, fungicides, antioxidants, ultraviolet absorbers, colorants, deodorants, organic fibrous materials, etc.
  • additives for example, JP 2003-225565A
  • these may be used alone or in combination of two or more.
  • an inorganic compound containing an element other than the above-mentioned calcium salt in addition to the water-soluble calcium compound (C) germination, rooting, growth, etc. of plants may be further improved.
  • timing of adding these additives is not particularly limited, and can be added at any stage in the production process of the crosslinked copolymer (B) (polymerization process, drying process, surface crosslinking process, calcium compound addition process, and/or before or after these processes) ) can be added.
  • the water retention amount (g/g) of ion-exchanged water of the water-absorbent resin composition for plant cultivation of the present invention is more than 50 g/g and less than 1000 g/g from the viewpoint of water supply ability to plants and block resistance.
  • the amount is preferably 60 to 1000 g/g, particularly preferably 70 to 1000 g/g, and most preferably 80 to 1000 g/g.
  • the water retention amount (g/g) of ion-exchanged water of the water-absorbent resin composition for plant growth of the present invention is measured by the following method.
  • the weight (H2) of the tea bag after centrifugal dehydration is measured in the same manner as above except that no measurement sample is used, and the water retention amount is calculated from the following formula.
  • Water retention amount of ion-exchanged water (g/g) [(H1)-(H2)]/0.100
  • the water retention amount of ion-exchanged water of the water-absorbing resin composition for plant cultivation of the present invention is determined by the polymerization conditions of the crosslinked copolymer (B) used (monomer concentration during polymerization, etc.), the crosslinking agent (b3), and the surface crosslinking agent. It can be adjusted by controlling the type and amount.
  • methods to increase water retention include lowering the monomer concentration during polymerization, using crosslinking agents and surface crosslinking agents with low reactive group concentration (the number of moles of functional groups having crosslinking reactivity based on the unit weight of the crosslinking agent). Examples include methods of reducing the amount of crosslinking agent and surface crosslinking agent selected.
  • methods for lowering the water retention amount include increasing the monomer concentration during polymerization, selecting a crosslinking agent and surface crosslinking agent with a high concentration of reactive groups, and increasing the amounts of the crosslinking agent and surface crosslinking agent.
  • the water retention amount (g/g) of the 1% by weight calcium chloride aqueous solution of the water absorbent resin composition for plant growth of the present invention is larger than 5 g/g and 50 g/g from the viewpoint of water supply ability to plants and block resistance. It is preferably less than 10 g, more preferably 6 to 50 g/g, particularly preferably 7 to 50 g/g, and most preferably 8 to 50 g/g.
  • the water retention amount of the 1% by weight calcium chloride aqueous solution of the water absorbent resin composition for plant growth is measured by the following method.
  • the water retention amount of the 1% by weight calcium chloride aqueous solution of the water-absorbent resin composition for plant growth of the present invention is determined by the molar ratio of the structural units of the crosslinked copolymer (B) used [(b1)/(b2)], (b1) It can be adjusted by controlling the molar ratio of acrylate in, polymerization conditions (monomer concentration during polymerization, etc.), the type and amount of crosslinking agent and surface crosslinking agent, etc.
  • Methods for increasing the water retention amount include, for example, lowering the molar ratio [(b1)/(b2)] of the constituent units of the crosslinked copolymer (B), lowering the molar ratio of acrylate in (b1), and increasing the amount of water retained during polymerization.
  • Select crosslinking agents and surface crosslinking agents with low reactive group concentrations number of moles of functional groups having crosslinking reactivity based on the unit weight of crosslinking agent
  • crosslinking agents and surface crosslinking agents are examples of surface crosslinking agents.
  • methods for lowering the water retention amount include increasing the molar ratio [(b1)/(b2)] of the structural units of the crosslinked copolymer (B), increasing the molar ratio of acrylate in (b1), and Methods include increasing the monomer concentration of , selecting a crosslinking agent and surface crosslinking agent with a high concentration of reactive groups, and increasing the amount of the crosslinking agent and surface crosslinking agent.
  • the water absorption rate of the water absorbent resin composition for plant growth of the present invention is preferably 1800 seconds or less, more preferably 3 to 1200 seconds, and particularly preferably 4 to 600 seconds. Within this range, water retention is particularly good, making it easy to supply a sufficient amount of water for plant growth over a long period of time. Note that the water absorption rate (seconds) is a value determined by the following measurement method.
  • Water absorption rate (seconds) is measured at 25°C in accordance with JIS K7224. (Test solution: ion exchange water)
  • the water absorption rate of the water absorbent resin composition for plant growth of the present invention can be adjusted by controlling the apparent density, surface treatment of the crosslinked copolymer (B), and the like.
  • the apparent density (g/ml) of the water absorbent resin composition for plant growth of the present invention is preferably 0.3 to 0.9 g/ml, more preferably 0.4 to 0.9 g/ml, particularly preferably 0. .5 to 0.9 g/ml.
  • the apparent density of the water-absorbent resin composition for plant growth is a value measured at 25°C in accordance with JIS K7365:1999.
  • the water content (wt%) of the water-absorbent resin composition for plant growth of the present invention is preferably 20% by weight or less, more preferably 1 to 20% by weight, based on the weight of the water-absorbent resin composition for plant growth. Particularly preferably from 2 to 18% by weight, most preferably from 3 to 17% by weight. Within this range, the water absorption performance becomes even better.
  • the water retention rate (wt%) of the water absorbent resin composition for plant growth of the present invention in a water retention test is preferably 80% or more, more preferably 85% or more, particularly preferably 90% or more. It is.
  • the water retention amount maintenance test was conducted by comparing the initial water retention amount (water retention amount of ion-exchanged water) with the assumption that water absorption and dehydration were repeated multiple times when the water absorbent resin composition for plant cultivation was used in soil etc. If the water retention rate is within the above range, it will be sufficient for plant growth even after repeated water absorption and dehydration multiple times when used in soil etc. It is possible to maintain water retention over a long period of time.
  • the mechanism of the decrease in water holding capacity that may occur when the water-absorbent resin composition for plant growth is used in soil or the like and is repeatedly absorbed and dehydrated multiple times is not known, for example, the water-absorbent resin composition for plant growth
  • the water solubility of the calcium ion source and other polyvalent metal ion sources in the resin composition the selection of the crosslinking means of the crosslinked copolymer (B), the selection of the type of crosslinking agent (b3), the selection of the type of crosslinking agent (b3), and during polymerization or surface crosslinking. It is possible to adjust the water retention rate by controlling the degree of crosslinking, etc.
  • Methods for increasing the water retention rate include, for example, using highly water-soluble calcium ion sources and other polyvalent metal ion sources, and increasing the concentration of reactive groups (functional groups with crosslinking reactivity based on the unit weight of the crosslinking agent). Methods include selecting a crosslinking agent and a surface crosslinking agent with a high number of moles) and increasing the amounts of the crosslinking agent and surface crosslinking agent. On the other hand, methods for lowering the water retention rate include, for example, using calcium ion sources and other polyvalent metal ion sources with low water solubility, selecting crosslinking agents and surface crosslinking agents with low reactive group concentrations, and selecting crosslinking agents and surface crosslinking agents.
  • Methods include reducing the amount of surface crosslinking agent or not using it, and shortening the thermal crosslinking time in the thermally crosslinkable crosslinked copolymer (B).
  • the water retention rate (% by weight) in the water retention rate retention test of the water absorbent resin composition for plant growth is a value determined by the following measurement method.
  • the gel residual rate (wt%) of the water-absorbent resin composition for plant growth of the present invention in the iron decomposition resistance test is preferably 50% by weight or more, more preferably 75% by weight or more, particularly preferably 90% by weight or more. be.
  • the gel residual rate is within the above range, even if the water absorbent resin composition for plant growth of the present invention is used in soil containing a large amount of iron, the performance will not deteriorate and the amount of water supplied to the plants will not decrease. , and its water retention properties tend to last for a long time.
  • the cause of the performance deterioration of the water-absorbent resin composition for plant growth that may occur when the soil used is iron-containing soil has not been clearly identified, but the crosslinked copolymer (B) and water absorption This is thought to be due to the decomposition of the plastic resin.
  • the residual rate of gel can be adjusted by, for example, selecting the type of crosslinking agent for the crosslinked copolymer (B), controlling the degree of crosslinking during polymerization, and the degree of crosslinking during surface crosslinking. Is possible.
  • methods for increasing the gel residual rate include selecting a crosslinking agent and surface crosslinking agent with a high reactive group concentration (the number of moles of functional groups having crosslinking reactivity based on the unit weight of the crosslinking agent); One example is a method of increasing the amount of crosslinking agent.
  • methods for lowering the gel residual rate include using a crosslinking agent that has an ester bond as part of the crosslinking agent, selecting a crosslinking agent and surface crosslinking agent with a low concentration of reactive groups, and selecting the amount of crosslinking agent and surface crosslinking agent. There are ways to reduce this.
  • the gel residual rate (weight %) in the iron decomposition resistance test of the water-absorbent resin composition for plant growth is a value determined by the following measurement method.
  • the weight particle diameter of the water-absorbent resin composition for plant cultivation of the present invention is not limited and can be appropriately selected depending on the intended use and the environment of the land in which it is used.
  • the diameter (D50) is preferably 100 to 10,000 ⁇ m, more preferably 300 to 5,000 ⁇ m, particularly preferably 500 to 2,000 ⁇ m.
  • the weight average particle diameter (D50) of the water absorbent resin composition for plant growth is measured by the following method.
  • JIS Japanese Industrial Standards
  • standard sieves are 5,600 ⁇ m, 4,750 ⁇ m, 4,000 ⁇ m, 3,350 ⁇ m, 2,800 ⁇ m, 2,360 ⁇ m, 2,000 ⁇ m, 1,700 ⁇ m, 1,400 ⁇ m, 1, 000 ⁇ m, 850 ⁇ m, 600 ⁇ m, 500 ⁇ m, 425 ⁇ m, 300 ⁇ m, 212 ⁇ m, 150 ⁇ m, 106 ⁇ m, 75 ⁇ m, and the saucer in this order.
  • ⁇ Method for producing a water-absorbing resin composition for plant growth comprising the steps (1) and (2) below and containing a crosslinked copolymer (B) and a water-soluble calcium compound (C)>
  • the water-absorbent resin composition for plant growth of the present invention contains a water-soluble calcium compound (C), the crosslinked copolymer (B), the water-soluble calcium compound (C), and optionally the above-mentioned inorganic powder (D) and It can be manufactured by mixing / or other additives.
  • the above-mentioned water-soluble calcium compound (C) may be mixed. Similar to the method of adhering to the surface of the crosslinked copolymer (B), a method of uniformly mixing using a general mixer can be mentioned.
  • the method for producing a water-absorbing resin composition for plant growth containing the crosslinked copolymer (B) and water-soluble calcium compound (C) of the present invention preferably includes the steps (1) and (2) below. .
  • the mixed solution obtained in the step (1) The process of reducing the moisture content of
  • the water-soluble calcium compound (C) is preferably mixed as an aqueous solution of the water-soluble calcium compound (C).
  • the concentration of the aqueous solution is not particularly limited, but it is preferably 20 to 60% by weight, more preferably 30 to 50% by weight, particularly preferably 35 to 40% by weight. Within this range, the adhesion of the calcium compound (C) to the surface of the crosslinked copolymer (B) becomes even better.
  • the temperature (°C) during mixing is not particularly limited, but is preferably 10 to 120°C, more preferably 15 to 100°C, particularly preferably 20 to 90°C. Within this range, the adhesion of the calcium compound (C) to the surface of the crosslinked copolymer (B) becomes even better.
  • the step of mixing the calcium compound (C) with the crosslinked copolymer (B) is performed from the viewpoint of adhesion efficiency of the calcium compound (C) to the surface of the crosslinked copolymer (B).
  • steps after manufacturing ⁇ pulverization step, surface crosslinking step, drying step, etc. ⁇ it is preferable to perform the treatment before or after the crushing step and the surface crosslinking step, and more preferably after the crushing step and the surface crosslinking step. It is preferable to do so.
  • a drying step may be performed if necessary.
  • the water-soluble calcium compound (C) is mixed as an aqueous solution of the water-soluble calcium compound (C)
  • the mixed liquid obtained by mixing has a high water content, and the water-absorbing resin composition and crosslinked copolymer (B) Since the water content also increases, it is preferable to perform a drying step (a step of reducing the water content).
  • the temperature (°C) during drying is not particularly limited, but for example, when drying with hot air, it is usually carried out in the range of 60°C to 250°C, preferably 100°C to 220°C, more preferably 120°C to 200°C.
  • the water-absorbing resin composition for growing plants of the present invention has the effect of achieving both excellent water absorption properties (water retention) and plant growth promoting properties. Furthermore, it is highly resistant to soil environments, and has excellent long-term water retention even in soils containing iron, alkaline soils containing a large amount of magnesia, soils containing polyvalent metal ions that have been fertilized, and the like. More specifically, it can supply sufficient moisture for a long period of time for plant growth, and since the water-absorbing resin composition does not take away calcium ions necessary for plant growth, it does not inhibit plant germination, rooting, elongation, etc. Furthermore, it can supply a sufficient amount of calcium ions to prevent plants from becoming deficient in calcium, thereby promoting plant growth.
  • the absorbent resin composition for plant growth of the present invention can be used in agriculture (fluid seeding, field cultivation, etc.).
  • the water-absorbent resin composition for plant growth of the present invention does not inhibit plant growth, so it can be used at high concentrations in soil.
  • Direct cultivation using a swollen gel of the absorbent resin composition for plant growth of the present invention filling a hole in which the absorbent resin is swollen with water or fertilizer water is placed in a hole dug in the soil, etc., and then A cultivation method in which plants are directly planted) is also possible.
  • the water-absorbing resin composition for plant growth of the present invention may be used together with other plant growth substrates as necessary.
  • Other plant growing substrates include soil, gravel, sand, pumice, carbide, peat, vermiculite, bark, porous inorganic materials (perlite, zeolite, filton (porous ceramic, Kuntan), rock wool). , sponge, sphagnum moss, coconut shell, cryptomoss, powdered styrene resin foam, crushed urethane foam, foam pulp of various synthetic resins, and mixtures of two or more of these.
  • the ratio of the water absorbent resin composition for plant growth of the present invention to other plant growth substrates is not particularly limited, and can be adjusted as appropriate depending on the type of other plant growth substrates and the environment in which they are used.
  • the water-absorbing resin composition for plant growth of the present invention is usually used in dry weight of 0.01 to 100 parts by weight, preferably 0.1 to 50 parts by weight, per 100 parts by weight of the plant growth substrate. It is more preferable to use 0.2 to 40 parts by weight, particularly preferably 0.2 to 10 parts by weight.
  • the present disclosure is a plant containing a crosslinked copolymer (B) containing (meth)acrylic acid and/or (meth)acrylate (b1) and (meth)acrylamide (b2) as essential constituent units. It is a water-absorbent resin composition for growth, and the calcium ion content is 5.0 to 80.0 mg per 1.0 g of dry weight of the composition, and the calcium ion absorption amount is 7.0 mg per 1.0 g of dry weight of the composition. This is a water-absorbing resin composition for growing plants with a weight of 0 to 76.0 mg.
  • the present disclosure (ii) is the water-absorbing resin composition for plant growth according to the present disclosure (i), which further contains a water-soluble calcium compound (C).
  • the present disclosure (iii) provides that the molar ratio [(b1)/(b2)] of the above (b1) and the above (b2) in the structural units of the crosslinked copolymer (B) is 10/90 to 50/50. , the water-absorbing resin composition for plant cultivation according to the present disclosure (i) or (ii).
  • the present disclosure (iv) provides plant cultivation in any combination with any of the present disclosures (i) to (iii), wherein the molar ratio of the (meth)acrylate in the above (b1) is 50 to 100 mol%.
  • This is a water-absorbing resin composition for use.
  • the present disclosure (v) provides plant cultivation in any combination with any of the present disclosures (i) to (iv), wherein the molar ratio of the calcium (meth)acrylate salt in the above (b1) is 0 to 40 mol%. This is a water-absorbing resin composition for use.
  • the present disclosure is a water-absorbing resin composition for plant growth, which further contains an inorganic powder (D) and is in any combination with any of the present disclosures (i) to (v).
  • the present disclosure (vii) is a water-absorbing resin composition for plant cultivation in any combination with any of the present disclosure (i) to (vi), which has a water retention capacity retention rate of 80% by weight or more in a water retention capacity maintenance test. be.
  • the present disclosure (viii) is a water-absorbing resin composition for plant growth that satisfies the following conditions (a) or (b) and is any combination of the present disclosure (i) to (vii): (a) the calcium ion content is 10.0 to 40.0 mg per 1.0 g of dry weight of the composition and the calcium ion absorption amount is 7.0 to 30.0 mg per 1.0 g of dry weight of the composition; (b) The calcium ion content is 24.0 to 40.0 mg per 1.0 g of dry weight of the composition, and the calcium ion absorption amount is 30.0 to 60.0 mg per 1.0 g of dry weight of the composition.
  • the present disclosure (ix) is a method for producing a water-absorbing resin composition for plant growth, which is any combination of any of the present disclosures (ii) to (viii) and includes the following steps (1) and (2).
  • the mixed solution obtained in the step (1) The process of reducing the moisture content of
  • the shredded gel was dried in a ventilation type band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly pulverized dried product [crosslinked copolymer (B-1)].
  • a juicer mixer OEM BLENDER manufactured by Oster
  • the particle size of the dried body [water-absorbent resin composition (A -1)] was obtained.
  • Example 2 The amount of ammonium acrylate charged was changed from 68.2 g (0.766 mol) to 133.7 g (1.50 mol), and the amount of calcium acrylate was changed from 112.4 g (1.234 mol) to 45.5 g (0 mol).
  • a hydrous gel was obtained in the same manner as in Example 1, except that the amount of deionized water was changed from 872.7 g to 868.8 g.
  • 750.00 g of this water-containing gel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • the shredded gel was dried in a ventilation band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly crushed dried product [crosslinked copolymer (B-2)].
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles.
  • hydrophilic fumed silica [trade name "Aerosil 200", manufactured by Nippon Aerosil Co., Ltd., specific surface area 200 m 2 /g] as hydrophilic inorganic particles (D1) was added to 100 g of the dried particles, and the mixture was heated in a conical blender.
  • a water absorbent resin composition (A-2) was obtained by uniformly mixing at 80° C. using a water absorbent resin composition (manufactured by Hosokawa Micron Co., Ltd.).
  • Example 3 220.3 g (2.000 mol) of potassium acrylate as (b1), 142.2 g (2.000 mol) of acrylamide as (b2), 0.4934 g (0.0 mol) of N,N-methylenebisacrylamide as crosslinking agent (b3) 0032 mol) and 980.0 g of deionized water were kept at 5° C. while stirring and mixing.
  • the shredded gel was dried in a ventilation band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly crushed dried product [crosslinked copolymer (B-3)].
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles. While stirring 100 g of these dry particles at high speed (Hosokawa Micron high speed stirring turbulizer: rotation speed 2000 rpm), a 35% by weight aqueous solution (51.7 g) of calcium nitrate (C-1) as a water-soluble calcium compound (C) was added. ) was added while spraying, mixed, and allowed to stand at 150°C for 30 minutes to obtain a water absorbent resin composition (A-3).
  • a juicer mixer OEM BLENDER manufactured by Oster
  • Example 4 68.2 g (0.766 mol) of ammonium acrylate was changed to 57.6 g (0.800 mol) of acrylic acid and 88.1 g (0.800 mol) of potassium acrylate, and the amount of calcium acrylate charged was 112.
  • a hydrogel was prepared in the same manner as in Example 1, except that the amount of deionized water was changed from 4 g (1.234 mol) to 36.4 g (0.400 mol) and from 872.7 g to 876.9 g. Obtained. Next, 750.00 g of this water-containing gel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • the shredded gel was dried in a ventilation type band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly crushed dried product [crosslinked copolymer (B-4)].
  • a juicer mixer OEM BLENDER manufactured by Oster
  • the particle size of the dried body [water-absorbent resin composition (A -4)] was obtained.
  • Example 5 The amount of ammonium acrylate charged was changed from 68.2 g (0.766 mol) to 89.1 g (1.000 mol), and the amount of calcium acrylate was changed from 112.4 g (1.234 mol) to 54.6 g (0 mol). .600 mol), the amount of acrylamide charged from 142.2 g (2.000 mol) to 170.6 g (2.400 mol), and the amount of deionized water charged from 872.7 g to 849.8 g. Except for this, a hydrogel was obtained in the same manner as in Example 1. Next, 750.00 g of this water-containing gel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • a mincing machine (12VR-400K manufactured by ROYAL
  • the shredded gel was dried in a ventilated band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly pulverized dried product [crosslinked copolymer (B-5)].
  • a juicer mixer OEM BLENDER manufactured by Oster
  • the particle size of the dried body [water-absorbent resin composition (A -5)] was obtained.
  • Example 6 68.2 g (0.766 mol) of ammonium acrylate was changed to 57.6 g (0.800 mol) of acrylic acid and 44.6 g (0.500 mol) of ammonium acrylate, and the amount of calcium acrylate charged was 112. 4 g (1.234 mol) to 27.3 g (0.300 mol), acrylamide charge from 142.2 g (2.000 mol) to 170.6 g (2.400 mol), deionized water charge A hydrous gel was obtained in the same manner as in Example 1 except that the amount was changed from 872.7 g to 811.4 g.
  • Example 7 The amount of potassium acrylate was changed from 220.3 g (2.000 mol) to 176.2 g (1.600 mol), and the amount of acrylamide was changed from 142.2 g (2.000 mol) to 170.6 g (2.400 mol).
  • a hydrogel was obtained in the same manner as in Example 3, except that the amount of deionized water charged was changed from 872.7 g to 937.7 g.
  • 750.00 g of this hydrogel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • the shredded gel was dried in a ventilation type band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly pulverized dried product [crosslinked copolymer (B-7)].
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles.
  • Example 8> The crosslinked copolymer (B-7) obtained in the same manner as in Example 7 was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then sieved with a particle size of 150 to 710 ⁇ m using a sieve with openings of 150 ⁇ m and 710 ⁇ m. By adjusting the temperature, dried particles were obtained. While stirring 100 g of these dry particles at high speed (Hosokawa Micron high speed stirring turbulizer: rotation speed 2000 rpm), a 35% by weight aqueous solution (22.9 g) of calcium chloride (C-2) as a water-soluble calcium compound (C) was added. ) was added while spraying, mixed, and allowed to stand at 150° C. for 30 minutes to obtain a water-absorbing resin composition (A-8) in the form of irregularly pulverized particles.
  • a juicer mixer OEM BLENDER manufactured by Oster
  • Example 9 The crosslinked copolymer (B-7) obtained in the same manner as in Example 7 was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then sieved with a particle size of 150 to 710 ⁇ m using a sieve with openings of 150 ⁇ m and 710 ⁇ m. By adjusting the temperature, dried particles were obtained. 100 g of these dry particles were stirred at high speed (high-speed stirring turbulizer manufactured by Hosokawa Micron: rotation speed 2000 rpm), and a 35% by weight aqueous solution (32.5 g) of calcium acetate (C-3) as a water-soluble calcium compound (C) was stirred. ) was added while spraying, mixed, and allowed to stand at 150°C for 30 minutes to obtain a water absorbent resin composition (A-9).
  • a juicer mixer OEM BLENDER manufactured by Oster
  • Example 10 68.2 g (0.766 mol) of ammonium acrylate was changed to 14.4 g (0.200 mol) of acrylic acid and 66.1 g (0.600 mol) of potassium acrylate, and the amount of calcium acrylate was changed to 112. 4 g (1.234 mol) to 36.4 g (0.400 mol), acrylamide charge from 142.2 g (2.000 mol) to 199.0 g (2.800 mol), deionized water charge A hydrous gel was obtained in the same manner as in Example 1 except that the amount was changed from 872.7 g to 854.2 g.
  • this water-containing gel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel. Further, the shredded gel was dried in a ventilation type band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly pulverized dried product [crosslinked copolymer (B-8)].
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles.
  • Example 11 68.2 g (0.766 mol) of ammonium acrylate was changed to 84.6 g (0.900 mol) of sodium acrylate, and the amount of calcium acrylate was changed from 112.4 g (1.234 mol) to 27.3 g ( 0.300 mol), the amount of acrylamide charged from 142.2 g (2.000 mol) to 199.0 g (2.800 mol), and the amount of deionized water charged from 872.7 g to 840.8 g. Except for the above, a hydrogel was obtained in the same manner as in Example 1. Next, 750.00 g of this water-containing gel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • a mincing machine (12VR-400K manufactured by ROYAL
  • the shredded gel was dried in a ventilation band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain a dried product in the form of irregularly crushed pieces.
  • Product (A-11) was obtained.
  • Example 12 68.2 g (0.766 mol) of ammonium acrylate was changed to 110.2 g (1.000 mol) of potassium acrylate, and the amount of calcium acrylate was changed from 112.4 g (1.234 mol) to 18.2 g ( 0.200 mol), the amount of acrylamide charged from 142.2 g (2.000 mol) to 199.0 g (2.800 mol), and the amount of deionized water charged from 872.7 g to 885.1 g. Except for the above, a hydrogel was obtained in the same manner as in Example 1. Next, 750.00 g of this hydrogel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • a mincing machine (12VR-400K manufactured by ROYAL
  • the shredded gel was dried in a ventilation band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain a dried product in the form of irregularly crushed pieces.
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles. While stirring 100 g of these dry particles at high speed (Hosokawa Micron high speed stirring turbulizer: rotation speed 2000 rpm), a 2% water/methanol solution (water/methanol weight ratio) of ethylene glycol diglycidyl ether as a surface crosslinking agent was added.
  • Example 13 220.3 g (2.000 mol) of potassium acrylate was changed to 106.9 g (1.200 mol) of ammonium acrylate, and the amount of acrylamide charged was changed from 142.2 g (2.000 mol) to 199.0 g (2.0 mol).
  • a hydrogel was obtained in the same manner as in Example 3, except that the amount of deionized water charged was changed from 980.0 g to 827.2 g. Next, 750.00 g of this hydrogel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • the shredded gel was dried in a ventilation band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain a dried product in the form of irregularly crushed pieces.
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles.
  • Example 14 68.2 g (0.766 mol) of ammonium acrylate was changed to 55.1 g (0.500 mol) of potassium acrylate, and the amount of calcium acrylate was changed from 112.4 g (1.234 mol) to 27.3 g ( 0.300 mol), the amount of acrylamide charged from 142.2 g (2.000 mol) to 227.5 g (3.200 mol), and the amount of deionized water charged from 872.7 g to 837.7 g. Except for the above, a hydrogel was obtained in the same manner as in Example 1. Next, 750.00 g of this water-containing gel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • a mincing machine (12VR-400K manufactured by ROYAL
  • the shredded gel was dried in a ventilated band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an amorphous crushed dried product [crosslinked copolymer (B-12)].
  • a juicer mixer OEM BLENDER manufactured by Oster
  • the particle size of the dried body [water-absorbent resin composition (A -14)] was obtained.
  • Example 15 The amount of potassium acrylate was changed from 220.3g (2.000 mol) to 88.1g (0.800 mol), and the amount of acrylamide was changed from 142.2g (2.000 mol) to 227.5g (3.200 mol).
  • a hydrogel was obtained in the same manner as in Example 3, except that the amount of deionized water charged was changed from 980.0 g to 853.2 g.
  • 750.00 g of this hydrogel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel. Further, the shredded gel was dried in a ventilated band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an amorphous crushed dried product [crosslinked copolymer (B-13)].
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles. While stirring 100 g of the dried particles at high speed (Hosokawa Micron high speed stirring turbulizer: rotation speed 2000 rpm), a 35% by weight aqueous solution (14.9 g) of calcium nitrate (C-1) was added and mixed while spraying. A water absorbent resin composition (A-15) was obtained by allowing the mixture to stand at 150° C. for 30 minutes.
  • a juicer mixer OEM BLENDER manufactured by Oster
  • Example 16 220.3 g (2.000 mol) of potassium acrylate was changed to 14.4 g (0.200 mol) of acrylic acid and 56.4 g (0.600 mol) of sodium acrylate, and the amount of acrylamide charged was changed to 142.2 g ( A hydrous gel was obtained in the same manner as in Example 3, except that the amount of deionized water was changed from 980.0 g to 806.5 g. . Next, 750.00 g of this hydrogel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • a mincing machine (12VR-400K manufactured by ROYAL
  • the shredded gel was dried in a ventilation type band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly pulverized dried product [crosslinked copolymer (B-14)].
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles. While stirring 100 g of these dry particles at high speed (Hosokawa Micron high speed stirring turbulizer: rotation speed 2000 rpm), a 35% by weight aqueous solution (10.6 g) of calcium chloride (C-2) was added and mixed while spraying. A water absorbent resin composition (A-16) was obtained.
  • Example 17 68.2 g (0.766 mol) of ammonium acrylate was changed to 14.4 g (0.200 mol) of acrylic acid and 10.7 g (0.120 mol) of ammonium acrylate, and the amount of calcium acrylate charged was 112. 4 g (1.234 mol) to 7.3 g (0.080 mol), acrylamide charge from 142.2 g (2.000 mol) to 255.9 g (3.600 mol), deionized water charge A hydrous gel was obtained in the same manner as in Example 1 except that the amount was changed from 872.7 g to 779.4 g.
  • Example 18 220.3 g (2.000 mol) of potassium acrylate was changed to 35.6 g (0.400 mol) of ammonium acrylate, and the amount of acrylamide was changed from 142.2 g (2.000 mol) to 255.9 g (3.600 mol). ), a hydrous gel was obtained in the same manner as in Example 3, except that the amount of deionized water charged was changed from 980.0 g to 788.2 g. Next, 750.00 g of this water-containing gel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • a mincing machine (12VR-400K manufactured by ROYAL
  • the shredded gel was dried in a ventilated band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an amorphous crushed dried product [crosslinked copolymer (B-16)].
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles. While stirring 100 g of the dried particles at high speed (Hosokawa Micron high speed stirring turbulizer: rotation speed 2000 rpm), a 35% by weight aqueous solution (6.4 g) of calcium nitrate (C-1) was added and mixed while spraying. A water absorbent resin composition (A-18) was obtained.
  • Example 19 Potassium acrylate 220. g (2.000 mol) was changed to 14.4 g (0.200 mol) of acrylic acid and 22.0 g (0.200 mol) of potassium acrylate, and the amount of acrylamide charged was 142.2 g (2.000 mol).
  • a hydrogel was obtained in the same manner as in Example 3, except that the amount of deionized water was changed from 980.0 g to 790.4 g. Next, 750.00 g of this water-containing gel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • the shredded gel was dried in a ventilated band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an amorphous crushed dried product [crosslinked copolymer (B-17)].
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles.
  • 100 g of the dried particles were mixed with high-speed stirring (Hosokawa Micron high-speed stirring turbulizer: rotation speed 2000 rpm) and spraying a 35% by weight aqueous solution (6.4 g) of calcium nitrate (C-1).
  • a water absorbent resin composition (A-19) was obtained.
  • Example 20 100 g of "AQUASORB 3005 KB", an acrylamide-potassium acrylate cross-linked copolymer manufactured by SNF Co., Ltd., was used as the cross-linked copolymer (B-18) and stirred at high speed (high-speed stirring turbulizer manufactured by Hosokawa Micron).
  • a water-absorbing resin composition was prepared by adding and mixing a 35% by weight aqueous solution (13.5 g) of calcium nitrate (C-1) while spraying at a rotation speed of 2000 rpm), and leaving it to stand at 150°C for 30 minutes. (A-20) was obtained.
  • Example 21 100 g of "AQUASORB 3005 KB", an acrylamide-potassium acrylate cross-linked copolymer manufactured by SNF Co., Ltd., was used as the cross-linked copolymer (B-18) and stirred at high speed (high-speed stirring turbulizer manufactured by Hosokawa Micron).
  • a water-absorbent resin composition was prepared by adding and mixing a 35% by weight aqueous solution (9.1 g) of calcium chloride (C-2) while spraying at a rotational speed of 2,000 rpm), and allowing it to stand at 150°C for 30 minutes. (A-21) was obtained.
  • Example 22 The amount of ammonium acrylate charged was changed from 68.2 g (0.766 mol) to 106.8 g (1.200 mol), and the amount of calcium acrylate was changed from 112.4 g (1.234 mol) to 72.8 g (0 mol).
  • a hydrous gel was obtained in the same manner as in Example 1, except that the amount of deionized water was changed from 872.7 g to 871.7 g.
  • 750.00 g of this hydrogel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel.
  • the shredded gel was dried in a ventilated band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an amorphous crushed dried product [crosslinked copolymer (B-19)].
  • a juicer mixer OEM BLENDER manufactured by Oster
  • the particle size of the dried body [water-absorbent resin composition (A -22)] was obtained.
  • Example 23 A hydrous polymer was obtained in the same manner as in Example 4 except that the crosslinking agent (b3) was not used.
  • this water-containing polymer was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded products. This was further dried in a ventilated band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly pulverized dried product.
  • the dried product was pulverized using a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m.
  • a crosslinked copolymer (B-20) was obtained by placing 100 g of the obtained uncrosslinked dry powder into a stainless steel vat with a thickness of about 3 mm and heating it in a circulating air dryer at 160°C for 120 minutes to thermally crosslink it.
  • a water absorbent resin composition (A-23) containing the following was obtained.
  • the shredded gel was dried in a ventilated band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an amorphous crushed dried product [crosslinked copolymer (B-21)].
  • a juicer mixer OEM BLENDER manufactured by Oster
  • the particle size of the dried body was adjusted to 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m. (E-1)] was obtained.
  • a mincing machine (12VR-400K manufactured by ROYAL
  • the shredded gel was dried in a ventilated band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly pulverized dried product [crosslinked copolymer (B-22)].
  • a juicer mixer OEM BLENDER manufactured by Oster
  • the particle size of the dried body was adjusted to 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m. (E-2)] was obtained.
  • the shredded gel was dried in a ventilated band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly pulverized dried product [crosslinked copolymer (B-23)].
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles. While stirring 100 g of these dry particles at high speed (Hosokawa Micron high speed stirring turbulizer: rotation speed 2000 rpm), a 35% by weight aqueous solution (3.2 g) of calcium chloride (C-2) was added and mixed while spraying.
  • a comparative water-absorbent resin composition (E-4) was obtained by allowing the mixture to stand at 150° C. for 30 minutes.
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles. While stirring 100 g of these dry particles at high speed (Hosokawa Micron high speed stirring turbulizer: rotation speed 2000 rpm), a 35% by weight dispersion of calcium sulfate (31.3 g) was added in portions and mixed, and the mixture was heated to 150°C. A comparative water-absorbing resin composition (E-8) was obtained by allowing the composition to stand for 30 minutes. Note that the solubility of calcium sulfate in 100 g of ion-exchanged water at 20° C. under normal pressure is less than 30 g, and it does not fall under the category of water-soluble calcium compound (C).
  • ⁇ Comparative example 9 144.1 g (2.000 mol) of acrylic acid and 188.1 g (2.000 mol) of sodium acrylate as (b1), 0.5574 g (0.0032 mol) of ethylene glycol diglycidyl ether as crosslinking agent (b3), and 898.2 g of deionized water was maintained at 5° C. while stirring and mixing.
  • the shredded gel was dried in a ventilation band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain a dried product in the form of irregularly crushed pieces [comparative crosslinked copolymer (B'-2)].
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles.
  • the shredded gel was dried in a ventilation type band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain a dried product in the form of irregularly crushed pieces.
  • Hydrophilic fumed silica as hydrophilic inorganic particles (D1) [trade name "Aerosil 200", Nippon Aerosil Co., Ltd.] was added to the comparative crosslinked copolymer (B'-3) obtained in the same manner as in Comparative Example 10.
  • a comparative water-absorbent resin composition (E-11) was obtained by adding 0.25 g of the product and having a specific surface area of 200 m 2 /g and uniformly mixing at 80° C. using a conical blender ⁇ manufactured by Hosokawa Micron Co., Ltd. ⁇ . .
  • this water-containing gel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel. Further, the shredded gel was dried in a ventilation type band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain a dried product in the form of irregularly crushed pieces. The dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles.
  • a mincing machine (12VR-400K manufactured by ROYAL
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles.
  • a hydrogel was obtained in the same manner as in Example 15, except for changing to Next, 750.00 g of this water-containing gel was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded gel. Further, the shredded gel was dried in a ventilation band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain a dried product in the form of irregularly crushed pieces. The dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles.
  • a mincing machine (12VR-400K manufactured by ROYAL
  • the dried product was pulverized with a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m to obtain dried particles.
  • ⁇ Comparative example 14> A hydropolymer was obtained in the same manner as in Example 3 except that the crosslinking agent (b3) was not used. Next, this water-containing polymer was shredded using a mincing machine (12VR-400K manufactured by ROYAL) to obtain shredded products. Further, this was dried in a ventilation type band dryer ⁇ 150° C., wind speed 2 m/sec ⁇ to obtain an irregularly pulverized dried product. The dried product was pulverized using a juicer mixer (OSTERIZER BLENDER manufactured by Oster), and then adjusted to a particle size of 150 to 710 ⁇ m using sieves with openings of 150 ⁇ m and 710 ⁇ m.
  • a juicer mixer OSTERIZER BLENDER manufactured by Oster
  • compositions of the water absorbent resin compositions (A-1) to (A-23) obtained in the Examples and Comparative Examples and the comparative water absorbent resin compositions (E-1) to (E-13) are shown in Table 1. Shown below. Calcium ion content per 1.0g dry weight (mg/g), calcium ion absorption per 1.0g dry weight (mg/g), water retention amount of ion exchange water (g/g), 1% chloride by weight Calcium aqueous solution water retention capacity (g/g), water absorption rate (seconds), apparent density (g/ml), water content (wt%), weight average particle diameter ( ⁇ m), water retention capacity maintenance rate in water retention capacity test ( Table 2 shows the results of measuring the gel residual rate (weight %) in the iron decomposition resistance test using the above-mentioned method. In addition, the relative value (%) of germination vigor (underground and above-ground parts) was calculated using the following method in the burrowing test, and the results of evaluating the plant growth promoting effect are shown in Table 3.
  • a seed germination test was conducted using a water-absorbing resin composition that had absorbed ion-exchanged water as a medium.
  • the seeds used were commercially available Kaiware radish seeds that can be easily tested for germination in a short period of time.
  • a gel-like medium made of a water-absorbing resin composition that had absorbed ion-exchanged water.
  • Five Kaiware radish seeds (Kaiware radish seeds obtained from Takii Seed Co., Ltd. with a germination rate of 85% or higher) were uniformly sown on the surface of the gel-like medium in each test tube, and the holes with a diameter of 6 mm were stuffed with cotton. Cover with a silicone stopper.
  • the thus-covered test tube was cultured in a culture room (25° C., 2000 Lux, 16 hour photoperiod) for 6 days to cause germination.
  • the germinated daikon radish was taken out, and the stem and leaf length (above-ground length: L 1 (cm)) was measured from the base of the germinated solid (the branching point of the root and stem) to the leaf tip.
  • the length of the underground part was measured as the root length from the base of the germinated solid to the tip of the taproot (length of underground part: L 2 (cm)).
  • the water absorbent resin composition of Comparative Example 10 [(E-10): The crosslinked copolymer does not contain acrylamide as a structural unit and the water absorbent resin composition does not contain calcium ions] was used as a control sample.
  • the water-absorbing composition for growing plants of the present invention has the effect of achieving both excellent water-absorbing properties (water retention) and plant growth-promoting properties. Furthermore, it is highly resistant to soil environments, and has excellent long-term water retention even in soils containing iron, alkaline soils containing a lot of magnesia, soils containing polyvalent metal ions that have been fertilized, etc. , it can be suitably used as a water retaining material for growing plants. More specifically, it can be suitably used as a water retaining material in agriculture (fluid seeding, field cultivation, open field cultivation), greening work, gardening, etc.

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  • Life Sciences & Earth Sciences (AREA)
  • Environmental Sciences (AREA)
  • Cultivation Of Plants (AREA)

Abstract

La présente invention est une composition de résine absorbant l'eau pour la culture de plantes comprenant un copolymère réticulé (B) qui contient, en tant qu'unités constitutives essentielles, un acide (méth)acrylique et/ou un sel d'acide (méth)acrylique (b1), et un (méth)acrylamide (b2). La teneur en ions calcium est comprise entre 5,0 et 80,0 mg pour 1,0 g de poids sec de la composition. La quantité d'absorption d'ions calcium est comprise entre 7,0 mg et moins de 76,0 mg pour 1,0 g de poids sec de la composition. La présente invention permet de fournir une composition de résine absorbant l'eau pour la culture de plantes qui permet d'obtenir des propriétés d'absorption d'eau (en particulier la rétention d'eau) et des propriétés favorisant la croissance des plantes, et qui présente également une résistance élevée aux environnements de sol.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998005196A1 (fr) * 1996-08-01 1998-02-12 M & M Laboratory Co., Ltd. Support de retenue d'eau pour des plantes
JP2009131167A (ja) * 2007-11-29 2009-06-18 Sanyo Chem Ind Ltd 植物生育用保水剤
JP2010022249A (ja) * 2008-07-17 2010-02-04 Iej:Kk 吸水シートを用いて植物を育成する方法
WO2022145274A1 (fr) * 2020-12-28 2022-07-07 株式会社クラレ Matériau de rétention d'eau pour l'agriculture et son procédé de production

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998005196A1 (fr) * 1996-08-01 1998-02-12 M & M Laboratory Co., Ltd. Support de retenue d'eau pour des plantes
JP2009131167A (ja) * 2007-11-29 2009-06-18 Sanyo Chem Ind Ltd 植物生育用保水剤
JP2010022249A (ja) * 2008-07-17 2010-02-04 Iej:Kk 吸水シートを用いて植物を育成する方法
WO2022145274A1 (fr) * 2020-12-28 2022-07-07 株式会社クラレ Matériau de rétention d'eau pour l'agriculture et son procédé de production

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