JPS6243964B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improved powder herbicide composition with good shape retention and a method for producing the same. In order to solidify an aqueous herbicidal bipyridylium salt solution, the present inventors first used metal salts that can remove a large amount of crystal water, such as sodium sulfate, magnesium sulfate, aluminum sulfate, iron sulfate, and various alums. I suggested getting it. Also, UK patent
No. 1086937 discloses the use of water-absorbing inorganic salts such as calcium citrate, calcium nitrate, potassium aluminum sulfate, potassium hydrogen phosphate, magnesium nitrate, sodium acetate, sodium pyrophosphate, and sodium sulfate. . However, although these water-absorbing inorganic salts are extremely useful for simply solidifying a herbicidal bipyridylium salt aqueous solution, they pose various problems in actual industrial production, and they also have various drawbacks as commercial products. It has become clear that there is. For example, when anhydrous magnesium sulfate is added to an aqueous solution of N・N'-dimethyl-4,4'-bipyridylium salt, the magnesium sulfate dissolves in water and becomes a mushy liquid; however, if it is allowed to stand at room temperature for more than 12 hours, solidify. When industrially producing a powdered herbicide composition using this method, it takes a long time to solidify.
Furthermore, it is necessary to take out the solidified material and crush it, making it difficult to improve productivity. Furthermore, it has become clear that when a pulverized powder herbicide composition is left in the air for a long time or when mechanical pressure is applied, it becomes sticky and difficult to handle, causing various inconveniences in the manufacturing process and in use. The present inventors investigated various methods to overcome the above-mentioned drawbacks of powdered herbicidal compositions obtained by adding water-absorbing inorganic salts to an aqueous solution of herbicidal active ingredients. In addition, it has been found that by adding an anti-caking agent, a powder herbicide composition with excellent manufacturability and easy handling can be obtained. The powder herbicide composition according to the present invention has the formula (i) and (In the formula, R ¹ and R ² may be the same or different, and are a hydroxyl group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, a carbamoyl group, or an N-alkyl substituted carbamoyl group. , or an alkyl group having 1 to 4 carbon atoms, or an alkenyl group which may be substituted with a halogen atom, X ^n- represents an anion, and n represents an integer from 1 to 4). Herbicidal bipyridylium salt 5-25% by weight,
(ii) 15-35% by weight of water, (iii) 15-35% by weight of water-absorbing inorganic salts
and (iv) 1 to 20% by weight of an anti-caking agent. When R ¹ and R ² in the above formula are an alkoxy group, the number of carbon atoms is preferably 1 to 4, and when they are an alkylcarbonyl group and an alkoxycarbonyl group, the number of carbon atoms is preferably 2 to 5. Further, preferred N-alkyl-substituted carbamoyl groups are those in which the alkyl group bonded to the nitrogen atom has 1 to 4 carbon atoms. Examples of the herbicidal bipyridylium diquaternary salt represented by the above formula are as follows. 1,1'-ethylene-2,2'-bipyridium dibromide, 1,1'-dimethyl-4,4'-bipyridylium dichloride, 1,1'-di-2-hydroxyethyl-4, 4'-bipyridylium dichloride, 1,1'-bis-3,5-dimethylmorpholinocarbonylmethyl-4,4'-bipyridylium dichloride, 1-(2-hydroxyethyl)-1'-methyl- 4,4′-bipyridylium dichloride,
1,1'-Dicarbamoylmethyl 4,4'-bipyridylium dichloride, 1,1'-bis-N,N-dimethylcarbamoylmethyl-4,4'-bipyridylium dichloride, 1,1'- Bis-N・N-diethylcarbamoylmethyl-4,4'-bipyridylium dichloride, 1,1'-di-(piperidinocarbonylmethyl)-4,4'-bipyridylium chloride, 1,1 '-Diacetonitrile-4,4'-bipyridylium dichloride, 1,1'-diethoxycarbonylmethyl-4,4'-bipyridylium dibromide, 1,1'-diaryl-4'-bipyri Zylium dibromide. Among the above-mentioned herbicidal bipyridylium quaternary salts, a particularly preferred example is 1,1'-dimethyl-4,
4'-bipyridylium dichloride. The herbicidal effect of bipyridylium quaternary salts is independent of anions, so almost any type of anion can be selected, but macromolecular anions often form salts that are insoluble in water.
Low molecular weight anions are more preferred. Anions that can be used in the present invention include, for example, fluoride ion, chloride ion, bromide ion, iodine ion, sulfate group, nitrate group, phosphoric acid group, chlorate group, perchlorate group, fluorosilicic acid group, methoxysulfate group. , trifluoromethane sulfate, methanesulfonate, benzenesulfonate, benzoate, acetate, formate, citric, oxalate, tartrate, thiocyanate, salicylate,
These include succinic acid radical, hydroborofluoric acid radical, etc.
Particularly preferred examples of these anions include chloride, sulfate, and methoxysulfate. Examples of water-absorbing inorganic salts that can be used in carrying out the present invention include sodium sulfate, magnesium sulfate, aluminum sulfate, iron sulfate, ammonium aluminum sulfate, ammonium magnesium sulfate, potassium sulfate, ammonium iron sulfate, sodium magnesium sulfate. , calcium citrate, calcium nitrate, monopotassium hydrogen phosphate, magnesium nitrate, sodium acetate, sodium pyrophosphate, copper sulfate, and magnesium chloride. These water-absorbing inorganic salts are usually used as anhydrous salts that do not have water of crystallization, but those having water of crystallization below saturation can also be used. For example, magnesium sulfate takes up to 7 molecules of water of crystallization, but magnesium sulfate monohydrate can take up an additional 6 molecules of water of crystallization, so it can be used as a water-absorbing inorganic salt. Among the above-mentioned water-absorbing inorganic salts, magnesium sulfate is the most preferred when comprehensively evaluating water absorption rate, water absorption amount, properties after water absorption, environmental pollution problems when sprayed on fields, price, etc. Examples of anti-caking agents that can be used in carrying out the present invention include finely powdered mineral substances mainly composed of silicon oxide, such as white carbon, diatomaceous earth, silica sand, activated clay, silica gel, and colloidal silica. . Finely powdered minerals mainly composed of metal salts of silicic acid, such as sodium silicate and calcium silicate, can also be used, although their properties after water absorption are somewhat inferior. Mineral fine powder mainly composed of silicon oxide should preferably contain 60% or more, preferably 80% or more of silicon oxide, and if a powder with a small silicon oxide content is used, the resulting herbicidal composition will be It has a tendency to become humid and form lumps. In addition, the particle size of the above-mentioned fine powder mineral substance is preferably 100 mμ or less, preferably 30 mμ or less. If the particle size is large, it will not be sufficiently dispersed and suspended when dissolved in water, resulting in an uneven spraying liquid. This is not desirable. As mentioned above, the powdered herbicide composition of the present invention
(i) 5-25% by weight of the herbicidal bipyridylium salt of the above formula, (ii) 15-35% by weight of water, (iii) 15-35% by weight of a water-absorbing inorganic salt, and (iv) 1-20% by weight of an anti-caking agent. %, and if the content of herbicidal bipyridylium salt is less than 5% by weight, handling efficiency will decrease, and if it exceeds 25% by weight, it will not be possible to suppress the hygroscopicity of the herbicidal bipyridylium salt. The proportions of water, water-absorbing inorganic salt and anti-caking agent in the herbicidal composition are almost uniquely determined by the concentration of the herbicidal bipyridylium salt aqueous solution used. That is, the water-absorbing inorganic salt is used in an amount necessary to absorb water or in a slightly excessive amount, and the anti-caking agent is used in an amount sufficient to prevent caking of the herbicidal composition or in a slightly excessive amount. use Furthermore, the amount of the anti-caking agent is as follows:
It is preferably 1 to 100 g per mole, and 10 to 100 g.
More preferably, it is 50g. If the amount of the anti-caking agent is less than 1% by weight, the anti-caking effect will not be sufficient, and if it exceeds 20% by weight, the uniformity of the liquid will tend to deteriorate when dissolved in water, which is not preferred. Herbicidal active ingredients other than the herbicidal bipyridylium salt, surfactants, etc. can be added to the herbicidal composition of the present invention. Examples of other suitable herbicides include, for example, urea herbicides such as Monyuron, Linyuron, Fenyuron, Duyuron, simazine,
Triazine herbicides such as atrazine, propazine, and ametrine, uracil herbicides such as bromacil, renacil, and terbacil, phenoxy herbicides such as 2,4-D, and dinitroaniline herbicides such as trifluralin, nitraline, and beslozin. be. Further, as surfactants that can be used in the present invention, there are many compounds belonging to the anionic type, cationic type, and nonionic type. for example,
Glycerin esters of higher fatty acids, glycol esters, higher alcohol condensates, higher fatty acid condensates, higher alkylamine condensates, alkylphenol condensates, polypropylene oxide condensates,
Examples include amine salts, alkyl quaternary ammonium salts, aminocarboxylic acids, and alkylalanines. The powder herbicidal composition of the present invention usually contains a mixed powder of a water-absorbing inorganic salt, an anti-caking agent, and in some cases, a surfactant and other herbicidal active ingredients in the herbicidal bipyridylium salt aqueous solution. The respective components can be added together or in any order.
When the herbicidal bipyridylium salt aqueous solution and the above mixed powder were mixed, the water-absorbing inorganic salt first dissolved to form a mushy liquid, and then as water was incorporated into the water-absorbing inorganic salt, the composition gradually became smooth and powdery. Things are generated. The resulting powdered herbicide composition does not solidify or become wet due to pressure or friction, and does not become sticky even when left in the air, so it can be stored stably for a long period of time. Moreover, when added to water during spraying, it dissolves quickly and produces a homogeneous aqueous solution in which fine particles of the anti-caking agent are suspended, so it can be sprayed without any problems and is extremely easy to handle. Therefore, its commercial value as a powder herbicide composition is extremely high. The powder herbicide composition according to the present invention can be suitably used as a general-purpose herbicide for weed control in fields, paddy fields, orchards, tea plantations, mulberry fields, and open spaces, and usually per 10 ares.
Dissolve 100-1000g in 100-1000 times the amount of water and spray. Hereinafter, the present invention will be explained in more detail with reference to Examples, but it goes without saying that the technical scope of the present invention is not limited to these Examples. Example 1 (Production Example) 16.2 g of N・N′-dimethyl-4・4′-bipyridylium dichloride was dissolved in 24.6 g of water, and 6.8 g of polyoxyethylene nonyl phenyl ether was added as a surfactant to this aqueous solution. g was added to prepare an aqueous solution. Next, separately from this, anhydrous magnesium sulfate
23.1g, white carbon 5.7g, and DCMU
Thoroughly mix 23.6 g of [3-(3,4-dichlorophenyl)-1,1-dimethylurea] to prepare a uniform powder, add the powder to the aqueous solution prepared earlier, and immediately stir with a spatula. Mixed. After that,
By allowing the powder to stand until the liquid was uniformly soaked into the powder, 100 g of a powdered herbicide composition could be obtained. Example 2 (Production Example) 24 g of N・N′-ethylene-2・2′-bipyridylium dibromide was dissolved in 21.3 g of water, and 6.8 g of polyoxyethylene dodecyl phenyl ether was added to prepare an aqueous solution. . Similarly to Example 1, in addition to this, 20.0 g of anhydrous magnesium sulfate, diatomaceous earth
7.9 g and 20.0 g of CAT [2-chloro-4,6-bis(ethylamino)-S-triazine] were combined to prepare a thoroughly mixed powder. The powder was added to a previously prepared aqueous solution, stirred and mixed well, and then left to stand until water absorption by the inorganic salt was completed. As the water absorption progressed, 100 g of a smooth reddish-brown powder herbicide composition was obtained. The effect of the anti-caking agent in the production process as described above will be explained in more detail using the following experimental examples. Experimental Example 1 (Anti-caking effect) A composition containing an anti-caking agent and a composition not containing an anti-caking agent having the compositions shown in Table 1 were prepared using an operating method similar to Example 1, and the compositions were evaluated over time. A comparative study of their properties was carried out. As a result, as shown in Table 1, the composition containing the anti-caking agent maintains a smooth powder state immediately after preparation, whereas the composition containing no anti-caking agent remains viscous immediately after preparation. Furthermore, after the water absorption was completed, it became a solid that firmly adhered to the preparation container. The abbreviations used in Table 1 are as follows.
DCMU represents the above-mentioned compound. PQCl ₂ : N・N′-dimethyl-4・4′-bipyridylium dichloride POE: Polyoxyethylene nonyl phenyl ether MG: Anhydrous magnesium sulfate WHC: White carbon

[Table] Experimental Example 2 (Dispersibility Experiment) According to Examples 1 and 2, 100 g of a powdery composition having the following manufacturing ratio was prepared.

【table】

[Table] In order to examine the dispersibility of the above composition in water, a comparative test was conducted with a commercially available Bromasil wettable powder (manufactured by Dupont Far East). That is, put the water in step 1 into the beaker in step 3, stir the water sufficiently with a magnetic stirrer, add 100 g each of the above and Bromasil wettable powder, and stir for another 30 seconds to form a suspension. Obtained. Immediately, both suspensions were visually observed and their dispersibility was compared and examined. As a result, both had good dispersibility. Furthermore, in order to confirm the dispersibility of these suspensions, they were sprayed using a normal sprayer, but the spraying was successful without any problems. Experimental Example 3 (Hygroscopicity Experiment) Samples Nos. 1 to 7 prepared in Experimental Example 1 were placed in a weighing bottle and left in a desiccator kept at 25°C and relative humidity of 80% to observe changes in weight and appearance. Changes in properties were observed. Note that sample No. 7 prepared as a comparative example became a solidified substance after water absorption was completed, so it was crushed in a mortar and then finely ground in a blender for use in the experiment. The results are shown in Table 2, and according to this experiment,
Although the anti-caking agent itself had little effect on preventing moisture absorption under high humidity conditions, the appearance was smooth, indicating that it is extremely advantageous in practical handling.

【table】

[Table] * Comparative Example Test Example 1 (Herbicidal Effect Test) The excellent properties of the herbicidal composition are made even more effective by the excellent herbicidal and herbicidal effects.
The herbicidal and herbicidal effects of the sample Nos. 2, 4, and 6 compositions prepared in Experimental Example 1 were confirmed in a field test. At a mandarin orange orchard in Okitsu City, Shizuoka Prefecture, where Italian ryegrass is dominant, a test plot of 2 m ² / plot was set up when the average plant height of Italian ryegrass was 15 to 20 cm, and the samples prepared in Experimental Example 1 were 5g was weighed out and dissolved and suspended in 1000ml of water to prepare a spray solution. The homogeneous suspension was filled into a conventional sprayer and sprayed. The herbicidal effect was visually observed on the 7th day after spraying.
Furthermore, on the 18th day, all types of weeds in the test plot were cut, the weeds were dried using a blow dryer, and their dry weight was measured. Then, on the 36th day after spraying, the weed suppressing effect was visually observed. The effectiveness was judged based on the following criteria.

【table】

[Table] In addition, the herbicidal effect measured by air dry weight was expressed as follows. Air-dry weight ratio (%) = {1-air-dry weight (g) of drug-treated area/air-dry weight (g) of untreated area} x 100 (%) As a comparative example, commercially available gramoxone 300ml/
10a dissolved in 100/10a diluted water was sprayed.
All tests were performed in triplicate and the results are averaged and reported in Table 3.

【table】

Claims (1)

[Claims] 1 Formula (i) and (In the formula, R ¹ and R ² may be the same or different, and are a hydroxyl group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, a carbamoyl group, or an N-alkyl substituted carbamoyl group. , or an alkyl group having 1 to 4 carbon atoms, or an alkenyl group which may be substituted with a halogen atom, X ^n- represents an anion, and n represents an integer from 1 to 4). Herbicidal bipyridylium salt 5-25% by weight,
(ii) 15-35% by weight of water, (iii) 15-35% by weight of water-absorbing inorganic salts
and (iv) a powdered herbicidal composition comprising 1 to 20% by weight of an anticaking agent. 2 Water-absorbing inorganic salts include sodium sulfate, magnesium sulfate, aluminum sulfate, iron sulfate, ammonium aluminum sulfate, ammonium magnesium sulfate, potassium sulfate, ammonium iron sulfate, sodium magnesium sulfate, calcium citrate,
Claim 1, which is at least one member selected from the group of calcium sulfate, potassium hydrogen phosphate, magnesium nitrate, sodium acetate, sodium pyrophosphate, copper sulfate, and magnesium chloride.
Compositions as described in Section. 3 The anti-caking agent is white carbon, diatomaceous earth,
The composition according to claim 1 or 2, which is at least one selected from the group of silica sand, activated clay, silica gel, and colloidal silica. 4 (i) 5 to 25% by weight of the herbicidal bipyridylium salt of the above formula, (ii) 15 to 35% by weight of water, (iii) 15% of magnesium sulfate.
35% by weight and (iv) 1 to 20% by weight of at least one anti-caking agent selected from the group of white carbon, diatomaceous earth and colloidal silica. 5 formula and (In the formula, R ¹ and R ² may be the same or different, and are a hydroxyl group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, a carbamoyl group, or an N-alkyl substituted carbamoyl group. , or an alkyl group having 1 to 4 carbon atoms, or an alkenyl group which may be substituted with a halogen atom, X ^n- represents an anion, and n represents an integer from 1 to 4). A method for producing a powdery herbicidal composition, which comprises adding an anti-caking agent when producing the powdery herbicidal composition by adding a water-absorbing inorganic salt to a herbicidal bipyridylium salt aqueous solution. 6 Water-absorbing inorganic salts include sodium sulfate, magnesium sulfate, aluminum sulfate, iron sulfate, ammonium aluminum sulfate, ammonium magnesium sulfate, potassium sulfate, ammonium iron sulfate, sodium magnesium sulfate, calcium citrate,
Claim 5 is at least one member selected from the group of calcium sulfate, potassium hydrogen phosphate, magnesium nitrate, sodium acetate, sodium pyrophosphate, copper sulfate, and magnesium chloride.
Manufacturing method described in section. 7 The anti-caking agent is white carbon, diatomaceous earth,
The manufacturing method according to claim 5 or 6, which is at least one selected from the group of silica sand, activated clay, silica gel, and colloidal silica. 8. The production method according to claim 5, wherein the water-absorbing inorganic salt is magnesium sulfate, and the anti-caking agent is at least one selected from the group of white carbon, diatomaceous earth, and colloidal silica.