JP2006225277A - Granular agrochemical wettable powder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a granular agrochemical wettable powder which has excellent disintegrability in water, dispersibility and a reduced deterioration with time and is readily produced. <P>SOLUTION: The powder-like agrochemical wettable powder is obtained by mixing at least one kind of an agrochemical active ingredient with a water-swellable carboxymethyl cellulose or its salt. The carboxymethyl cellulose or its salt has preferably 0.05-0.50 degree of carboxymethyl substitution based on the glucose residue and the carboxymethyl cellulose or its salt has preferably 5-1,000 mPas viscosity of 1% water suspension. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a granular pesticide wettable powder, and more particularly to a granular pesticide wettable powder that is excellent in water disintegration and dispersion stability, is less likely to deteriorate with time, and is easy to produce.

  As for agricultural chemicals, various dosage forms have been developed in which the effects of the active ingredients of agricultural chemicals are maximized and the usage method and safety of users are taken into consideration. One type of agrochemical formulation is a wettable powder. The agrochemical wettable powder is a chemical in which a pesticide active ingredient that is hardly soluble in water is made into fine particles and a surfactant or an auxiliary agent is added, and is diluted with a predetermined amount of water and sprayed as a pesticide. Other agrochemical formulations that are diluted with water and sprayed include emulsions, wettable powders and flowables.

  Since the emulsion uses an organic solvent as a carrier, it has problems such as toxicity, irritation, flammability, odor, and environmental burden.

  Initially, the wettable powder was developed as a fine powder formulation that passes almost all of the 45 μm sieve. However, if it is fine powder, there is a negative effect on the human body due to powder formation when preparing the spray liquid, and the weighing work is complicated. Is a problem.

  On the other hand, a flowable preparation is a preparation that eliminates the problems of powdering of wettable powder and inconvenience of measurement by making a finely pulverized agricultural chemical active ingredient into a suspension preparation. However, since it is a viscous liquid preparation, a small amount of the preparation remains in the container, which may hinder the disposal of the container.

  Therefore, attempts have been made in recent years to granulate the wettable powder in order to eliminate the drawbacks of the above-mentioned preparations. By granulating the wettable powder, the powdering and metering difficulty of the wettable powder is improved, the problem of remaining on the packaging container is also eliminated, and the packaging container is excellent in terms of disposal.

  The granulated wettable powder (the above-mentioned granule wettable powder for agricultural chemicals; hereinafter simply referred to as granule wettable powder) is diluted with water to prepare a spray liquid. (I) Minimal stirring Rapidly disintegrates into fine particles (disintegrating in water), (ii) the fine particles are stably dispersed (dispersion stability), and (iii) are easily redispersed even if precipitates are formed (redispersibility) It is important to have the physical properties of

  If the disintegration property in water is poor, undisintegrated particles cause clogging of the sprayer nozzle. In addition, if the dispersion stability is poor, particles in the spray liquid agglomerate and settle with time, and the agrochemical active ingredient in the spray liquid becomes non-uniform, resulting in variations in the spraying amount of the agricultural chemical. In particular, when the pesticidal active ingredient settles and a hard cake (precipitate which is difficult to redisperse) is generated, the pesticidal active ingredient in the spray liquid becomes extremely uneven.

  In particular, since a large amount of concentrated spray solution is prepared during pest control of pests, the generation of a hard cake by storing the prepared solution causes a reduction in work efficiency in the spraying situation, which is a very big problem. Further, such rapid disintegration in water, dispersion stability and redispersibility (hereinafter, in the background art, dispersion stability and redispersibility are simply referred to as dispersibility) The pesticide composition must be retained for a minimum of 3 years, which is the effective age, and must not degrade over time.

  Various techniques for producing a granular wettable powder having excellent physical properties as described above have been proposed so far. For example, a combination of diatomaceous earth as a bulking agent (see, for example, Patent Document 1); a disintegrating preparation containing a combination of a water-soluble inorganic salt or organic acid salt and a sulfonic acid-based or sulfate-based anionic surfactant; Those having good dispersibility and little deterioration over time (for example, see Patent Document 2); those containing a natural glassy foam pulverized product have improved dispersibility and disintegration, and have little deterioration over time (for example, Patent Document 3) 4); those with improved hydration and solubility by adding ammonium sulfate or saccharose (for example, see Patent Document 5); those containing talc and a surfactant that are disintegrating in water and suspended. Excellent and stable even after long-term storage (for example, see Patent Document 6); excellent disintegration and dispersibility due to incorporation of porous calcium carbonate compound No deterioration over time (for example, see Patent Document 7); one having good disintegration and dispersibility by combining an alkenyl sulfonate as a surfactant and combining with a carrier such as lactose (for example, patents) Reference 8); Similarly, a granular wettable powder having good storage stability by combining an orthophosphate and a sulfonic acid surfactant (see, for example, Patent Document 9); Bacillus thuringiensis as an agrochemical active ingredient In a composition containing a product derived from a fungus, there are granule wettable powders (for example, see Patent Document 10) in which hydration properties and the like are improved by blending inorganic salts or sugars as a bulking agent.

  However, such granule wettable powders according to the prior art have deteriorated with time during storage and storage, have not been able to obtain good disintegration and dispersibility in water, and have not been sufficiently satisfactory for practical use.

  Water-soluble extenders such as inorganic salts typified by ammonium sulfate and ammonium dihydrogen phosphate, organic acid salts typified by sodium benzoate and potassium benzoate, saccharides typified by glucose and saccharose, etc. Incorporating is an effective means to some extent in obtaining good disintegration in water and dispersibility. However, blending these water-soluble extenders sufficiently to improve the disintegration property and dispersibility in water tends to cause problems such as physical deterioration due to moisture absorption and reduction in production efficiency due to increased viscosity during granulation. Furthermore, for example, in the case of ammonia odor or benzoate due to an ammonium salt, generation of a specific odor becomes a problem in industrial processes such as granulation. Further, simply adding a water-soluble extender hardly contributes to prevention of hard cake formation by sediment.

Japanese Patent Laid-Open No. 06-128102 Japanese Patent Laid-Open No. 06-219903 Japanese Patent Laid-Open No. 08-143403 Japanese Patent Application Laid-Open No. 09-301801 Japanese Patent Laid-Open No. 10-218704 Japanese Patent Application Laid-Open No. 11-049604 JP 2000-191406 A Japanese Patent Laid-Open No. 10-279403 JP 2000-076022 A JP 2001-010915 A

  As described above, the granular agrochemical wettable powder has good disintegration in water, dispersion stability, and redispersibility, and is less deteriorated with time, and further requires easy handling in production. It was difficult to satisfy all of these. The present invention was devised to solve the above-mentioned problems of the prior art, and has granules that disintegrate in water, have dispersion stability and redispersibility, have little deterioration over time, and are easy to produce. It is an object to provide a pesticide wettable powder.

  As a result of intensive studies to solve the above problems, the present inventors have abbreviated CMC as water-swellable carboxymethyl cellulose or a salt thereof (hereinafter referred to as “carboxymethyl cellulose or a salt thereof”). It was found that good disintegration in water, dispersion stability, and redispersibility can be obtained, and that agrochemical active ingredients can be sprayed well without causing deterioration over time during storage and storage. Further, it has been found that even when a predetermined amount of water-insoluble CMC is blended, there is no problem of a decrease in productivity and a specific odor due to an increase in viscosity. The present invention has been completed based on such findings.

[1] A granular pesticide wettable powder comprising one or more active ingredients of pesticide and water-swellable carboxymethylcellulose or a salt thereof.
[2] The granular pesticide wettable powder according to the above [1], wherein the degree of carboxymethyl substitution per glucose residue of carboxymethylcellulose or a salt thereof is 0.05 to 0.5.
[3] The granular agrochemical wettable powder according to the above [1] or [2], wherein the viscosity of 1% aqueous suspension of carboxymethylcellulose or a salt thereof is 5 to 1000 mPa · s.
[4] The above-mentioned [1] to [3], wherein the content of water-swellable carboxymethylcellulose or a salt thereof is 0.1 to 30 parts by weight with respect to the granular pesticide wettable powder. The granular pesticide wettable powder according to any one of the above.
[5] The granular pesticide wettable powder according to any one of [1] to [4] above, further comprising a surfactant.

[Action]
Even when water-swellable CMC obtained by mild carboxymethylation is added to the granule wettable powder, the production efficiency is hardly lowered due to an increase in viscosity during the production process, and the agglomeration of agrochemical active ingredients in the granule Can be prevented. Water-swellable CMC is water-insoluble and has water absorption. Therefore, by adding water-swellable CMC to the granule wettable powder, the water absorption inside the granule when it is poured into water increases, and the water-swellable CMC absorbs water and swells, so that Helps disintegrate granule wettable powder. Therefore, it can be set as the granule excellent in water disintegration by mix | blending water-swellable CMC. In addition, fibrous or particulate water-insoluble CMC swollen in water builds a three-dimensional network structure, prevents sedimentation of the agrochemical active ingredient, and improves dispersion stability. Further, even when the sprayed chemical solution is left for a long time and the agrochemical active ingredient or the like is settled, since the fibrous or particulate CMC swollen in water is contained, the formed precipitation layer is bulky with fluidity. Is. That is, by blending water-swellable CMC, it is possible to suppress the formation of a hard cake due to sedimentation of agrochemical active ingredients and the like, and it is possible to improve redispersibility. In addition, since the water-swellable CMC is excellent in storage stability, the above performance can be maintained for a long time.

  The granular agrochemical wettable powder of the present invention exhibits good disintegration in water, dispersion stability, and redispersibility, and the physical properties thereof are not deteriorated with time during storage and are stable over a long period of time. Maintain physical properties. Therefore, it does not cause troubles such as nozzle clogging during spraying, and exhibits a stable effect. In addition, in the manufacturing process, it is difficult for production efficiency to decrease due to increased viscosity.

  Furthermore, CMC added to the granular pesticidal hydrate of the present invention is a natural product in which a regenerative recycling system in the natural world using cellulose, which is a constituent of a plant, as a raw material, is biodegradable. Even if it accumulates in the soil, it has no impact on the crops and has a low environmental impact.

1. The granular agrochemical wettable powder of the present invention is a granule containing at least one agrochemical active ingredient and water-swellable carboxymethylcellulose or a salt thereof (CMC). As a preferable form, a mixture of these components is processed into granules. The CMC used in the present invention has water swellability. Water-swellable CMC is insoluble in water. Carboxymethylcellulose may or may not be in the form of a salt, and preferably carboxymethylcellulose sodium salt is used. Carboxymethylcellulose sodium salt is preferably used from the viewpoint of production such as availability of raw materials and production cost.

  Water-swellable CMC can be obtained by lightly carboxymethylating cellulose, and the degree of substitution of carboxymethyl groups per glucose residue (ether) as an indicator of the degree of water solubility or water swellability. (Hereinafter sometimes abbreviated as CM-DS). As CMC used by this invention, CM-DS becomes like this. Preferably it is 0.05-0.50, More preferably, it is 0.10-0.45, More preferably, it is 0.10-0.40. is there. When the CM-DS is less than the above lower limit, the degree of swelling of the water-swellable CMC becomes insufficient, and the water-swellable CMC itself also forms a hard cake, and the tendency for excellent redispersibility to be hardly obtained is increased. In addition, when CM-DS exceeds the above upper limit, the solubility in water is increased, and it becomes difficult to generate a bulky precipitated layer with fluidity, so it is difficult to suppress the formation of a hard cake, which is favorable. The tendency that it becomes difficult to obtain redispersibility increases.

  Moreover, it is preferable to adjust the viscosity of the water-swellable CMC used in the present invention mainly from the viewpoint of redispersibility and ease of handling in the production process. The water-swellable CMC used in the present invention preferably has a 1% aqueous suspension viscosity of 5 to 1000 mPa · s, more preferably 10 to 500 mPa · s. If the viscosity of the 1% aqueous suspension is less than the above lower limit, the effect of reducing the sedimentation rate of the particulate matter due to the thickening action is hardly exhibited, it becomes difficult to suppress the formation of hard cake, and excellent dispersion stability is difficult to obtain. The tendency to become stronger. Moreover, when 1% aqueous suspension viscosity exceeds the said upper limit, possibility that it will lead to the fall of the production efficiency by a thickening effect | action and the fall of the work efficiency at the time of dispersion | spreading arises.

  In this specification, the viscosity for CMC is a value 3 minutes after the start of measurement when an anhydrous 1% aqueous suspension is measured at 25 ° C. with a B-type rotational viscometer. A method for preparing a 1% aqueous suspension in terms of anhydride is, for example, stirring a predetermined amount of water with a flat fixed triangular stirring blade at 600 rpm, and adding a predetermined amount of sample thereto. It is prepared by stirring for 3 hours at the same rotational speed. Next, it is a value measured with an appropriate rotor and number of revolutions according to the viscosity of the obtained 1% aqueous suspension in terms of anhydride. Specifically, for example, when the viscosity of the obtained 1% aqueous suspension in terms of anhydride is 0 to 100 mPa · s, the rotor no. In the case where the value measured at 60 rpm at 1 and the viscosity of the obtained 1% aqueous suspension in terms of anhydride is 100 to 200 mPa · s, the rotor no. In the case where the value measured at 30 rpm at 1 rpm and the viscosity of the obtained 1% aqueous suspension in terms of anhydride is 200 to 1000 mPa · s, the rotor no. 2 and measured at 30 rpm.

  The average particle size of the water-swellable CMC of the present invention is preferably 0.1 to 500 μm, more preferably 5 to 100 μm. If the average particle size is less than the above lower limit, enormous pulverization energy is required to achieve the average particle size, the pulverization cost and the manufacturing cost are likely to increase, and the fine powder tends to scatter, making the work environment more rigorous. The need to do is likely to occur. Moreover, when the average particle diameter exceeds the above upper limit, the work efficiency is liable to decrease due to entanglement between particles, and when spraying agricultural chemicals using a spray nozzle, the possibility of causing nozzle clogging increases. Moreover, when it is in the above-mentioned range, properties such as disintegration in water, dispersion stability, and redispersibility of the granule can be improved.

  In this specification, the particle size of CMC was measured using a “laser diffraction scattering particle size distribution analyzer” (Microtrack Model-9220-SRA, manufactured by Nikkiso Co., Ltd.), and the value at D50 was defined as the average particle size.

  The shape of the water-swellable CMC used in the present invention in the dry state is not particularly limited. For example, the shape of fiber, powder, fine powder, granule, pellet, sheet or the like can be selected depending on the application. It is possible to select appropriately.

  The granular agrochemical wettable powder of the present invention is a mixture of various raw materials, granulated and processed into granules. The average particle size of the granular agrochemical wettable powder may be the same as that of the conventional preparation used in the form of wettable powder, and is usually 0.1 to 3 mm in diameter, preferably 0.5 to 2 mm, and a length of 0. It is adjusted to a range of 1 to 10 mm, preferably 0.5 to 5 mm. The particle size can be adjusted using a sieve.

  The amount of water-swellable CMC is 0.1 to 30 parts by weight, preferably 0.5 to 20 parts by weight, based on the granular agrochemical wettable powder of the present invention. Below 0.1 parts by weight, the water disintegration and dispersion stability may be insufficient in some cases. In addition, when the blending amount is 30 parts by weight or more, in some cases, production efficiency may be reduced due to an increase in viscosity during granulation.

  The granular agrochemical wettable powder of the present invention contains at least one agrochemical active ingredient. In addition, the granular agrochemical wettable powder of the present invention may be mixed with auxiliary components generally used in agricultural chemical formulations such as surfactants as optional components.

  The pesticidal active ingredient used in the present invention is broadly classified into herbicides, insecticides, fungicides, and the like, for example, but is not particularly limited, but is used alone or in combination of two or more. The blending amount is desirably 1 to 90% by weight, more preferably 10 to 80% by weight, based on the granular wettable powder of the present invention. Below, the representative example of an agrochemical active ingredient is given.

Herbicide (1) methyl α- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -O-toluate (generic name: bensulfuronmethyl); (2) (RS) -2- [2- ( 3-chlorophenyl) -2,3-epoxypropyl] -2-ethylindan-1,3-dione (generic name: indanophan); (3) (RS) -2- (2,4-dichloro-m-tolyloxy) (4) 1- (α, α-dimethylbenzyl) -3- (p-tolyl) urea (generic name: Daimlone); (5) 2-chloro-N- (3- Methoxy-2-thienyl) methyl-2 ′, 6′-dimethylacetanylide (generic name: tenyl chlor); (6) 2-chloro-5- (4-chloro-5-difluoromethoxy-1-methyl-1H— Razol-3-yl) -4-fluorophenoxyacetic acid ethyl (generic name: pyraflufen-ethyl); (7) (RS) -N- [2- (3,5-dimethylphenoxy) -1-methylethyl] -6 -(1-Fluoro-1-methylethyl-1,3,5-triazine-2,4-diamine (generic name: triadifram); (8) Isopropylammonium = N- (phosphonomethyl) glycine (generic name: glyphosate isopropylamine) Salt); (9) 2-chloro-4,6-bis (ethylamino) -s-triazine (generic name: simazine); (10) 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (Generic name: atrazine)

Insecticide (11) 2-tertiarybutylimino-3-isopropyl-5-phenyl-1,3,5-thiadiazin-4-one (generic name: buprofezin); (12) 1-naphthyl-N-methylcarbamate ( (General name: NAC); (13) 1,3-dimethyl-5-phenoxy-4- (4′-butoxycarboxy-benzyloxyminomethyl) pyrazole (generic name: fenpyroximate); (14) N-tertiarybutyl- N ′-(4-ethylbenzoyl) -3,5-dimethylbenzohydrazide (generic name: tebufenozide); (15) 2- (4-ethoxyphenyl) -2-methylpropyl-3-phenoxybenzyl ether (general Name: etofenprox); (16) 1- (6-Chloro-3-pyridylmethyl) -N-nitro (imidazolidine) - ylidene) amine (common name: imidacloprid)

Fungicide (17) α, α, α-trifluoro-3′-isopropoxy-O-toluanilide (generic name: flutolanil); (18) diisopropyl 1,3-dithiolane-2-ylidene malonate (generic name: (19) 8-hydroxyquinoline copper (generic name: oxine copper); (20) methyl (E)-(2- [6- (cyanophenoxy) pyrimidin-4-yloxy] phenyl) -3-methoxyacrylate (Generic name: azoxystrobin); (21) N-trichloromethylthiotetrahydrophthalimide (generic name: captan); (22) 5-methyl-1,2,4-triazolo [3,4-b] benzothiazole ( (Generic name: tricyclazole)

The granular agrochemical wettable powder of the present invention preferably contains a surfactant.
Examples of the surfactant used in the present invention include those generally used in agricultural chemical preparations as wetting agents and dispersants, and anionic surfactants such as sulfonates, sulfates, and carboxylates are particularly preferable. .

  Typical sulfonates include alkyl naphthalene sulfonate, formalin condensate of naphthalene sulfonate, formalin condensate of alkyl naphthalene sulfonate, lignin sulfonate, special sulfonate polymer and the like. Representative sulfates include alkyl sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkyl phenyl ether sulfates, and the like.

  Typical carboxylates include polyacrylates, styrene-maleate copolymers, special carboxylate polymers and the like. Examples of these salts include alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts.

  The blending amount of the surfactant is desirably 0.5 to 20% by weight, more preferably 1 to 10% by weight, based on the granular agrochemical wettable powder of the present invention. In addition, other surfactants can be used as required. For example, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polystyryl phenyl ether can be used for nonionic surfactants. , Polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester, etc., anionic surfactants such as dioctyl sulfosuccinate, polyoxyethylene polystyryl phenyl ether phosphate, cationic or amphoteric surface activity Examples of the agent include tetraalkylammonium salts and alkylcarboxybetaines.

  These surfactants may be used alone or in admixture of two or more, and the selection and blending ratio thereof must be determined so as to match the properties of the agrochemical active ingredient to be used. is there.

  In the granular agrochemical wettable powder of the present invention, if necessary, other ingredients commonly used in granule production, such as an auxiliary agent for facilitating granulation into granules, an auxiliary agent for adjusting the properties of granules, You may mix | blend in the range which does not inhibit the effect of this invention. Specific examples of other components that can be blended include, for example, grinding aids (eg, white carbon, diatomaceous earth, fatty acids, phosphate esters, etc.), granulating agents, binders, absorbents, decomposition inhibitors, water surface floatation agents. , Coloring agents or antifoaming agents, bulking agents and the like.

  As a bulking agent, diatomaceous earth, talc, clay, bentonite, hydrous silicic acid, calcium carbonate, inorganic salts and organic acid salts, saccharides and the like are blended. These bulking agents may be used alone or in combination of two or more.

2. Production of water-swellable CMC and granular agrochemical wettable powder The water-swellable CMC used in the present invention can be produced by carrying out a light carboxymethylation reaction using cellulose as a raw material. As the cellulose raw material in the present invention, natural cellulose such as cellulose produced by microorganisms such as bleached or unbleached wood pulp, refined linter, acetic acid bacteria, etc., cellulose is dissolved in some solvent such as copper ammonia solution, morpholine derivative, and so on. Spinned regenerated cellulose, and fine cellulose obtained by depolymerizing the cellulose raw material by acid hydrolysis, alkali hydrolysis, enzymatic decomposition, explosion treatment, vibration ball mill treatment, or the like, or mechanically processed fine cellulose, and the like can be used. .

For example, water-swellable CMC is obtained by mercerizing cellulose raw material with an alkali such as sodium hydroxide and then connecting CH ₂ COOH (carboxymethyl group) to OH group of cellulose by ether bonding. Or it can manufacture by the method of performing etherification reaction using monochloro sodium acetate.

  Specifically, for example, cellulose is used as a raw material, and the solvent is 3 to 20 times lower alcohol, specifically methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, isobutanol, tertiary butanol. Or a mixture medium of two or more and water. The ratio of the lower alcohol to the total of the lower alcohol and water is preferably 60 to 95% by weight.

As a mercerizing agent for mercerizing cellulose, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is preferred.
Mercerizing agent is added to the above solvent so as to be 0.5 to 20 times mol per glucose residue of cellulose, mixed, and reaction temperature is 0 to 70 ° C., preferably 10 to 60 ° C., 15 minutes to The reaction is carried out for 8 hours, preferably 30 minutes to 7 hours to form merceres.

  Thereafter, a carboxymethylating agent is added in an amount of 0.05 to 2.0 moles per glucose residue of cellulose, and the reaction temperature is 30 to 90 ° C, preferably 40 to 80 ° C, 30 minutes to 10 hours, preferably 1 hour. React for ~ 4 hours to effect etherification. Thus, CM-DS and viscosity in CMC can be adjusted by adjusting the addition amount of the carboxymethylating agent. When the amount of the carboxymethylating agent is large, the viscosity increases.

  When the viscosity of CMC exceeds 1000 mPa · s, the viscosity can be lowered using a method such as a method of adding various salts or a method of reducing the swelling property of CMC by setting the pH of CMC to 6 or less. . Industrially, the method of adding various salts is simple and suitable. Examples of the various salts include sodium salts such as sodium chloride and sodium sulfate. The amount of each salt added may be any amount within the range that does not change the physical properties of CMC, but is preferably 0.5 to 30% by weight (vs. CMC solid content weight).

  The water-swellable CMC produced as described above may undergo a washing process, a drying process, a pulverizing process, and a classification process as necessary.

The granular agrochemical wettable powder of the present invention can be produced, for example, as follows.
First, an agrochemical active ingredient, a water-swellable CMC, a surfactant, and other auxiliary agents and extenders as necessary are added, mixed uniformly, and then finely pulverized as necessary.
The fine pulverization can be performed by a known pulverizer, for example, a dry pulverizer such as an impact pulverizer, a medium mill, or an airflow mill. Next, an appropriate amount of water is added to the fine powder obtained and kneaded, followed by granulation using a granulator and drying to obtain a granulated wettable powder.

  Granulation can be performed by a granulator such as an extrusion granulator, a pressure granulator, a fluidized bed granulator, a stirring granulator, or a rolling granulator.

  Alternatively, an agrochemical active ingredient, a surfactant and other adjuvants are added to an appropriate amount of water, finely pulverized with a wet pulverizer such as a ball mill or a sand grinder, and then the resulting aqueous suspension is swollen with water. CMC, and if necessary, a surfactant and other adjuvants and a bulking agent are added and mixed, and this is spray dried with a spray dryer to obtain a granulated wettable powder.

  Another method is to add agrochemical active ingredients, surfactants and other adjuvants to an appropriate amount of water, finely pulverize with a wet mill such as a ball mill or sand grinder, and then swell the resulting aqueous suspension with water. After adding a kneading agent CMC and, if necessary, a surfactant and other auxiliary agents and a bulking agent and kneading, the mixture is granulated using a granulator and dried to obtain the desired product.

  Granulation can be performed by a granulator such as an extrusion granulator, a pressure granulator, a fluidized bed granulator, a stirring granulator, or a rolling granulator. In particular, granule wettable powder produced using an extrusion granulator can obtain cylindrical particles having a constant diameter and a substantially constant length by appropriately determining the opening of the extrusion screen in advance. This is preferable because the physical properties of the wettable powder, such as hardness and disintegration in water, are uniform, the content of fine powder is small, and the appearance is good. The diameter and length are not particularly limited, but are usually 0.1 to 3 mm in diameter, preferably 0.5 to 2 mm, and 0.1 to 10 mm in length, preferably 0.5 to 5 mm. Further, the ratio (% by weight) of passing through a sieve having an opening of 100 μm is preferably less than 10%, more preferably 5% or less.

3. Application of granular pesticide wettable powder As a method of applying the granular pesticide wettable powder of the present invention, a diluted solution is usually diluted with water to prepare a uniform diluted solution, which can be sprayed in the form of a mist such as a nozzle or an atomizer. Spread with a pressure spreader. Of course, it is possible to disperse with a riding machine such as a speed sprayer equipped with such a spreader, a pan ride cruiser, or a helicopter.

  In addition, irrigate the diluted solution into the soil, mix it with the soil, fill it into a plastic bottle with a discharge hole, etc., and spray it on the flooded sewage paddy. Is also possible. Furthermore, encapsulate the granulated wettable powder in a bag-like water-soluble film, and put this water-soluble film package into the water in the chemical preparation tank for dilution spraying, or directly into the flooded sewage paddy field. It can also be used.

  Hereinafter, the embodiments of the present invention will be described by way of examples, but the present invention is not limited thereto. In the following, “parts” indicating the blending amount means “parts by weight” unless otherwise specified.

<Measurement method of degree of etherification (CM-DS)> (nitric acid methanol method)
About 2.0 g of the sample was precisely weighed and placed in a 300 ml Erlenmeyer flask with a stopper. 100 ml of methanol nitric acid (a solution obtained by adding 100 ml of special concentrated nitric acid to 1 liter of anhydrous methanol) was added and shaken for 3 hours to replace the carboxymethylcellulose sodium salt with hydrogen to prepare carboxymethylcellulose (H-CMC).

The H-CMC was completely dried and 1.5 to 2.0 g was precisely weighed and placed in a 300 ml Erlenmeyer flask with a stopper. H-CMC was moistened with 15 ml of 80% methanol, 100 ml of 0.1N sodium hydroxide was added, and the mixture was shaken at room temperature for 3 hours.
Excess sodium hydroxide was back titrated with 0.1N sulfuric acid using phenolphthalein as an indicator. CM-DS was calculated by the following formulas (I) and (II).

In the above formulas (I) and (II):
A: Amount of 1N sodium hydroxide required to neutralize 1 g of H-CMC (ml)
F: 0.1N sulfuric acid titer F ': 0.1N sodium hydroxide titer

<Measuring method of granule particle size>
In this specification, the particle size of the granule is the residual sample weight on a sieve (aperture 100 μm) using a low-tap sieve shaker (Iwata Kogyo Co., Ltd.) and a sieve with an opening 100 μm (Tokyo Screen Co., Ltd.). Was measured, and the sieve passage rate with an opening of 100 μm was calculated. That is, it can be said that the smaller this value is, the less fine powder is in the granule.

For example, 10 g of the granule sample is placed on a sieve having an opening of 100 μm and sieved for 10 minutes. Thereafter, the weight of the remaining sample on the sieve (aperture 100 μm) is measured, and the sieve passage rate of the sieve 100 μm is calculated by the following formula. The following passage rates were obtained according to this calculation method.
Passage rate = (10 g−residual sample weight) × 100/10 g

[Production Example 1]
To a biaxial kneader whose rotational speed is adjusted to 100 rpm, 911 parts of 99% isopropyl alcohol and 78.7 parts of sodium hydroxide dissolved in 189 parts of water are added, and a commercially available dissolving pulp (trade name “NDPS”, Nippon Paper Industries Co., Ltd.) 200 parts of Chemical Co., Ltd.) were completely dried.

  After stirring and mixing at 30 ° C for 90 minutes to prepare alkali cellulose, 26 parts of monochloroacetic acid dissolved in 90 parts of 90% isopropyl alcohol was added while stirring, and the temperature was raised to 70 ° C in 30 minutes, followed by reaction for 90 minutes. I let you. After completion of the reaction, it was washed twice with 80% methanol, neutralized, drained and dried, CM-DS: 0.11, 1% aqueous suspension viscosity: 15 mPa · s, CMC (1) with an average particle size of 300 μm Got.

[Production Example 2]
To a biaxial kneader whose rotational speed is adjusted to 100 rpm, 1044 parts of 99% isopropyl alcohol and 69.8 parts of sodium hydroxide dissolved in 162 parts of water are added, and a commercially available dissolving pulp (trade name “NDPS”, Nippon Paper Industries Co., Ltd.) 200 parts of Chemical Co., Ltd.) were completely dried. After stirring and mixing at 30 ° C for 90 minutes to prepare alkali cellulose, 66 parts of monochloroacetic acid dissolved in 90 parts of 90% isopropyl alcohol was added while stirring, and the temperature was raised to 70 ° C in 30 minutes, followed by reaction for 90 minutes. I let you. After the completion of the reaction, neutralization, liquid removal, drying and pulverization were performed to obtain CMC (2) having a CM-DS 0.43, 1% aqueous suspension viscosity of 400 mPa · s, and an average particle size of 60 μm.

[Example 1]
Weighed 20 parts by weight of Flaside (Labside drug substance; manufactured by Kureha Chemical Industry Co., Ltd.) and 70 parts by weight of calcined diatomaceous earth into each mixing container, mixed for 5 minutes with a universal mixer, )), And the recovered pulverized product was mixed for 5 minutes.

  89 parts by weight of this finely pulverized product, 10 parts by weight of lignin sulfonate (trade name “Sun Extract P252”; manufactured by Nippon Paper Chemical Co., Ltd.), 1 part by weight of CMC (1), wetting agent (trade name “Nopco Wet 50”) “San Nopco Co., Ltd.) 1 part by weight was mixed in a universal mixer for 30 minutes, then 60 parts of water was added and kneaded, and then an extrusion granulator equipped with a screen with an extrusion diameter of 0.8 mm was used. Granulated. After drying at 50 ° C., the granules were sized with a sieve having an opening of 500 to 850 μm to obtain the granular agrochemical wettable powder of the present invention. The passing rate of the sieve having an opening of 100 μm was 0.5%.

[Example 2]
Except that CMC (1) in Example 1 was replaced with CMC (2), all operations were performed in the same manner as in Example 1 to obtain a granulated wettable powder for agricultural chemicals of the present invention. The passing rate of a sieve having an opening of 100 μm was 1%.

[Comparative Example 1]
The same operation as in Example 1 was conducted except that CMC (1) of Example 1 was replaced with powdered cellulose (trade name “KC Flock W-200G”, CM-DS: 0; manufactured by Nippon Paper Chemicals Co., Ltd.). A granular pesticide wettable powder was obtained. The passing rate of the sieve having an opening of 100 μm was 10%.

[Comparative Example 2]
The same operation as in Example 1 was conducted except that CMC (1) of Example 1 was replaced with a commercially available CMC (trade name “Sunrose F10LC”, CM-DS: 0.55; manufactured by Nippon Paper Chemicals Co., Ltd.). A granular pesticide wettable powder was obtained. The passing rate with an opening of 100 μm was 3%.

[Comparative Example 3]
Except for the CMC (1) of Example 1, all operations were performed in the same manner as in Example 1 to obtain a granular pesticide wettable powder. The passing rate with an opening of 100 μm was 7%.

[Test Example 1]
About 10 g of the preparations obtained from Examples and Comparative Examples were sealed in an aluminum bag and stored at 50 ° C. for 1 month. Immediately after production and the above-mentioned preservation samples were subjected to an underwater disintegration test, measurement of the amount of undisintegrated particles, and a dispersion stability and redispersibility test by the following methods.

<Underwater disintegration test>
A 1.0 g sample was accurately weighed. The weighed sample was put into a 250 ml stoppered measuring cylinder containing 250 ml of 3 degree hard water placed in a constant temperature water bath at 20 ° C. After standing for 20 seconds, the graduated cylinder was inverted at a rate of 1 inversion every 2 seconds, and the number of inversions until the sample completely disintegrated was regarded as disintegrating in water. However, the maximum number of cylinder reversals was 20 times. The smaller the number of inversions, the better the disintegration in water. The results are shown in Table 1.

<Measurement of undisintegrated particle amount>
Immediately after completion of the underwater disintegration test, the liquid in the cylinder is passed through a sieve having an opening of 45 μm. The undisintegrated particles remaining on the sieve net were transferred to a petri dish, dried at 105 ° C. for 2 hours, weighed, and expressed as a ratio (% by weight) to 1.0 g of the sample. The smaller the weight percent, the fewer undisintegrated particles and the better the disintegration in water. The results are shown in Table 1.

<Dispersion stability test>
A sample of 0.25 g was accurately weighed. The weighed sample was put into a 250 ml stoppered measuring cylinder containing 250 ml of 3 degree hard water placed in a constant temperature water bath at 20 ° C. After standing for 20 seconds, the graduated cylinder was inverted 30 times at a pace of 1 inversion every 2 seconds. Next, the cylinder was left in a constant temperature water bath at 20 ° C., and after 30 minutes, the upper 225 ml was discharged, and the content of the active ingredient in the remaining lower 25 ml was determined by liquid chromatography. %). The greater the suspension rate, the better the dispersion stability. The results are shown in Table 1.

Suspension rate (%) = [(A−B) / (A × 0.9)] × 100 (III)
In formula (III):
A: Active ingredient weight in the first sample B: Active ingredient weight in the lower 25 ml

<Redispersibility test>
For the redispersibility, a 1000-fold diluted solution of each preparation was prepared, allowed to stand at 50 ° C. for 10 days, and then the number of times required to completely redisperse the sediment was measured with one reciprocal inversion of the cylinder. The smaller the value, the better the redispersibility. The results are shown in Table 1.

  As shown in the results of Table 1, the product of the present invention was very good in water disintegration, dispersion stability and redispersibility immediately after production and one month later.

Claims (5)

  A granular pesticide wettable powder comprising one or more kinds of pesticide active ingredients and water-swellable carboxymethylcellulose or a salt thereof.   The granular agrochemical wettable powder according to claim 1, wherein the degree of carboxymethyl substitution per glucose residue of carboxymethylcellulose or a salt thereof is 0.05 to 0.5.   The granular agrochemical wettable powder according to claim 1 or 2, wherein the viscosity of a 1% aqueous suspension of carboxymethylcellulose or a salt thereof is 5 to 1000 mPa · s.   The granular pesticide wettable powder according to any one of claims 1 to 3, wherein the content of water-swellable carboxymethylcellulose or a salt thereof is 0.1 to 30% by weight.   Furthermore, surfactant is included, The granular agrochemical wettable powder as described in any one of Claim 1 to 4 characterized by the above-mentioned.