JPH06293607A - Aqueous suspension type herbicide for paddy field - Google Patents

Abstract

PURPOSE:To obtain an aqueous suspension type herbicide for paddy field, good in formulation stability while keeping an essentially possessed wide weeding spectrum and the safety for crops and having excellent spreadability when spraying. CONSTITUTION:The characteristic of this aqueous suspension type herbicide for paddy field is to disperse 2-chloro-N-(3-methoxy-2-thenyl)-2',6'- dimethylacetanilide (NSK-850), a surfactant and a viscosity modifier in water and has 100-230cP viscosity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-suspended herbicide for paddy fields, which is excellent in formulation stability and spreadability during spraying.

[0002]

2. Description of the Related Art The present dosage forms of herbicide for paddy fields are predominantly granules and emulsions for both pre-rice planting and post-rice planting treatments. Of these, the major components in emulsions are xylene and the like. Since they are organic solvents, these xylenes and other organic solvents are now being restricted in use because of their adverse effects on the environment. In addition, the effect of granules may vary due to the uneven distribution of the powder during spraying. Therefore, a water-suspended herbicide for paddy fields has been developed to solve these problems and is now in the spotlight. On the other hand, 2-chloro-N- (3-methoxy-2-thenyl) -2 ', 6'-dimethylacetanilide (hereinafter also referred to as NSK-850) has a low dose and a broad herbicidal spectrum, and has no phytotoxicity. It has no medicinal properties,
Moreover, it is considered to be suitable as a water-suspended paddy field herbicide because it has low water solubility and high melting point.

Therefore, in the preparation of the water-suspended paddy field herbicide of the present invention, there is a description of a method for preparing a water-suspended paddy field herbicide of oxadiazone as a medicinal component.
According to the report of 501, NSK- which is the medicinal ingredient of the present invention.
When 850 was similarly formulated, there was no spread of the medicinal component on the water surface and in the water at the time of spraying, and the result was that the medicinal component was not observed on the surface of the paddy soil.
No satisfactory agent was obtained in the spreadability during spraying. That is, it was found that the optimum formulation of the water-suspended herbicide for paddy fields varies depending on the type of medicinal component.

[0004]

For this reason, the present inventors have conducted intensive studies in order to develop an optimum water-suspended herbicide for paddy fields containing NSK-850 as a medicinal component.

[0005]

[Means for Solving the Problems] As a result, by paying attention to the viscosity of a water-suspended herbicide for paddy fields and adjusting the viscosity within a specific range, a stable formulation can be obtained and high spreadability at the time of spraying. The present invention has been completed and the present invention has been completed.

That is, the present invention relates to 2-chloro-N- (3
-Methoxy-2-enyl) -2 ', 6'-dimethylacetanilide, a surfactant and a viscosity modifier dispersed in water, and having a viscosity of 100 to 230 cP for a water-suspended paddy field It is a herbicide.

The medicinal component used in the present invention is NSK-8.
As described above, it is a medicinal component having a low dose, a broad herbicidal spectrum and no phytotoxicity, and is characterized by low water solubility and high melting point. The shape of the medicinal component is not particularly limited, but it is usually preferable to pulverize it in advance to a particle size of 300 μm or less, and it is particularly preferable to use the one pulverized to a particle size of 150 μm or less.

As the surfactant used in the present invention, known anionic surfactants, nonionic surfactants, cationic surfactants or amphoteric surfactants can be used without any limitation.

Specific examples of the anionic surfactant include:
Lignin sulfonate, alkyl allyl sulfonate,
Examples thereof include dialkyl sulphosuccinate, polyoxyethylene alkyl allyl phosphate, polyoxyethylene alkyl allyl ether sulfate, alkyl naphthalene sulfonate, polyoxyethylene styryl phenyl ether sulfate and alkyl sulfate.

Specific examples of the nonionic surfactant include:
Examples thereof include polyoxyethylene alkyl allyl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene sorbitan alkylate, polyoxyethylene glycol, polyoxyethylene alkyl ester, and polyoxyalkylene glycol.

Specific examples of the cationic surfactant include:
Examples thereof include tetraalkylammonium salt, trialkylbenzylammonium salt, alkylpyridinium salt, N, N-dialkylmorpholinium salt, and polyethylene polyamine fatty acid amide salt.

Specific examples of the amphoteric surfactant include:
Examples thereof include N, N-dimethyl-N-alkyl-N-carboxymethylammonium betaine, N, N-dialkylaminoalkylenecarboxylic acid salt, N, N, N-trialkyl-N-sulfoalkyleneammonium betaine and the like.

Even if these surfactants are used alone,
You may mix 2 or more types of a different kind or the same kind of surfactant in arbitrary ratios. In particular, it is preferable to use a mixture of an anionic surfactant and a nonionic surfactant in terms of suspension stability and spreadability.

As the viscosity modifier used in the present invention, known ones can be used without any limitation. Usually, a water-soluble polymer is preferably used as the viscosity modifier. As the water-soluble polymer, all natural, semi-synthetic and synthetic products can be used.

Specific examples of the natural water-soluble polymer include guar gum, locust bin gum, gum arabic, tragacanth gum, xanthan gum (xanthan gum), dextran, gelatin and casein.

Specific examples of the semi-synthetic water-soluble polymer include methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose,
Methyl hydroxypropyl cellulose, soluble starch, sodium alginate and the like can be mentioned.

Specific examples of the synthetic water-soluble polymer include polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, ethylene oxide propylene oxide block polymer and the like.

The water-suspended herbicide for paddy field of the present invention may contain an anti-caking agent and an anti-freezing agent as other components within a range that does not impair the performance thereof.

The anti-caking agent is usually used to prevent aggregation of the finely divided raw material. Specific examples of the anti-caking agent include clay minerals such as bentonite and hydrous magnesium silicate. Further, examples of the antifreezing agent in the cold season include ethylene glycol, propylene glycol, glycerin, methanol, ethanol, isopropanol, urea, and alkali halide salts.

Further, for example, components such as a silicone type defoaming agent and an antifungal agent may be added.

A typical formulation of the water suspension type herbicide for paddy field of the present invention is shown below.

NSK which is a medicinal component used in the present invention
When the total amount of -850 is 100 parts by weight, it is preferably 1 to 10 parts by weight, and particularly 3 to 6 parts by weight from the viewpoint of herbicidal activity and effect sustainability.

The surfactant may be blended in any proportion, but usually when the total amount is 100 parts by weight,
It is added in a proportion of 0.1 to 10 parts by weight. From the viewpoint of improving the dispersibility of the medicinal component, it is particularly preferably 3 to 8 parts by weight.

Since the viscosity modifier contributes most to the adjustment of the viscosity specified in the water suspension type herbicide for paddy field of the present invention,
The blending amount is determined in consideration of other components so that the viscosity range of the present invention is 100 to 230 cP. Usually the total amount is 1
When the amount is 00 parts by weight, the proportion is 0.01 to 2 parts by weight, preferably 0.05 to 1 part by weight.

When an anti-caking agent or an anti-freezing agent is blended, the anti-caking agent is generally 0.1 to 3 parts by weight when the total amount of the anti-caking agent is 100 parts by weight, and the total amount of the anti-caking agent is 100% by weight. When the amount is 100 parts by weight, 4 to 10 parts by weight is added.

The formulation of the water-suspending herbicide according to the present invention is generally carried out by mixing the above-mentioned components in predetermined amounts and then adding water so that the total amount becomes 100 parts by weight. However,
It is preferable that a predetermined amount of the viscosity modifier is dissolved in water and then mixed, in order to prevent generation of a sparingly water-soluble viscous mass.

In order to increase the mixing efficiency of the mixed liquid, a predetermined amount of glass beads is added, and the rotation number is 100 to 3000.
Usually, it is preferable to carry out wet pulverization at 25 ° C. or lower for 1 to 10 hours in an r.p.m. sand glider. The glass beads in the liquid are filtered and separated from the suspension which has been wet-milled to obtain the water-suspended paddy field herbicide of the present invention.

The water-suspending herbicide for paddy field obtained in the present invention plays an important role in the viscosity of the formulation stability and spreadability during spraying. Factors that determine the viscosity include not only the viscosity modifier but also a water solubility of the medicinal component itself, a surfactant that increases the dispersibility of the medicinal component and promotes the water solubility of the medicinal component.

In the present invention, the viscosity is 100 to 230 cP by changing the kinds and amounts of these components while taking the above factors into consideration.
A water-suspended paddy field herbicide is prepared so that If the viscosity is less than 100 cP, the suspension layer separates and the medicinal components and the anti-caking agent settle out after long-term storage, and a uniform preparation cannot be obtained. On the other hand, when the viscosity exceeds 230 cP, not only it becomes difficult to take it out of the container at the time of spraying, but also the spreadability on the water surface and in the water is lowered, so that the chemical damage to paddy rice is likely to occur.

Among the above viscosity ranges, the most suitable viscosity range for carrying out the present invention is 130 to 180 cP, and within this range, separation of the suspension layer is hardly observed even after long-term storage, Since the solid content does not deposit (cake) on the low surface and the spread of the medicinal component on the water surface, water and the surface of the paddy soil is excellent at the time of spraying, the medicinal effect of NSK-850, which is the medicinal component of the present invention, is shown. Can be demonstrated without regret.

[0031]

EFFECTS OF THE INVENTION The water-suspended herbicide for paddy field according to the present invention has a broad herbicidal spectrum and is safe for crops. By adjusting the viscosity to 100 to 230 cP, a water-suspending herbicide for paddy fields which has good formulation stability and spreadability at the time of spraying can be obtained. Therefore, like the emulsion,
It has a high herbicidal effect not only in hand-spraying in paddy fields, but also in hand-spraying from ridges, which has been attracting attention in recent years in terms of labor saving in spraying work. It could be an excellent water-suspended herbicide for paddy fields.

[0032]

EXAMPLES Examples of the present invention are shown below, but it goes without saying that the present invention is not limited to these.

The methods for measuring each physical property are as follows.

[Viscosity] A conical-plate type rotational viscometer [E-type viscometer manufactured by Tokyo Keiki Co., Ltd.] was used and the rotation speed was 2.5 r.
It was measured at pm at a liquid temperature of 23 ° C.

[Surface Tension] The surface tension was measured using a Wilhelmy surface tension meter [Kyowa Interface Science Co., Ltd., FACE powder dynamic wetting-penetration speed meter PHW type].

[Preparation Stability] 10 ml of a sample was placed in a sedimentation tube, sealed and stored at 40 ° C. for 1 month, and the ratio (%) of the suspension layer to the total amount and the presence or absence of caking were observed.

[Spreadability] 60 cm × 60 cm × 10 cm
Water of 20 ° C. is filled up to a height of 5 cm in the acrylic water tank of No. 3, and after standing still, a height of 10 cm from the water surface is 0.03 to 0.0.
A drop of 05 ml was dropped with a pipette and evaluated by the following five-stage evaluation. 5: Rapidly spreads on the surface of water and water 4: Spreads well on the surface of water and water, droplets do not settle to the bottom 3: Spreads on the surface of water and water, but some droplets reach the bottom Sedimentation 2: Poor spreadability on water surface and water, mostly settles to the bottom as droplets 1: Not spread on water surface and water, sediments to the bottom as droplets [stability of conformation] The amount of the drug substance in the sample stored at 40 ° C. for 1 month was quantified using a high performance liquid chromatograph and its stability was evaluated.

Example 1 5.4 g of NSK-850, 3 g of polyoxyethylene polyoxypropylene block polymer (trade name: Newpol PE-64), 2 g of dialkyl sulfosuccinate (trade name: Sanmorin OT-70), 0. 22 wt% carboxymethyl cellulose (trade name: Serogen WS-
C) Aqueous solution 82.9 g, bentonite (trade name: Kunipia-F) 2 g, propylene glycol 4.5 g, silicon emulsion (trade name: Pronal EX-300)
Put 0.2g into sand grinder, then diameter 0.6
mm beads and add 80g, 1500 rp
m for 4 hours at 25 ° C. or lower. Then, the glass beads were separated by filtration to obtain the water-suspended herbicide for paddy field of the present invention.

The measured values of various physical properties and the formulation evaluation of the obtained water-suspended herbicide for paddy field (Formulation No. 1) are summarized in Table 2.

Example 2 As a viscosity modifier, a 0.24 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution was used instead of a 0.21 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution. A formulation was prepared in the same manner as in Example 1 except for the above.

Table 2 shows the measured values of various physical properties and the formulation evaluation of the obtained water-suspended herbicide for paddy field (formulation number: 2).

Example 3 As a viscosity modifier, a 0.30 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution was used instead of a 0.21 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution. A formulation was prepared in the same manner as in Example 1 except for the above.

Table 2 shows the measured values of various physical properties and the formulation evaluation of the obtained water-suspended herbicide for paddy field (formulation number: 3).

Example 4 As a viscosity modifier, a 0.36 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution was used instead of a 0.21 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution. A formulation was prepared in the same manner as in Example 1 except for the above.

Table 2 summarizes the measured values of physical properties and formulation evaluation of the resulting water-suspended herbicide for paddy field (formulation number: 4).

Example 5 As a viscosity modifier, 0.42 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution was used instead of 0.21 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution. A formulation was prepared in the same manner as in Example 1 except for the above.

Table 2 shows the measured values of various physical properties of the obtained water-suspended herbicide for paddy field (formulation number: 5) and the formulation evaluation.

Example 6 A water-suspended paddy field herbicide (formulation numbers 6 to 15) was obtained in the same manner as in Example 1 except that the surfactant and the viscosity modifier were variously changed. The ratio of each component of the water-suspended paddy field herbicide is summarized in Table 1. Table 2 shows the measured values of various physical properties and the formulation evaluation of the obtained water-suspended herbicide for paddy field.

The substances shown in Tables 1 and 2 are 2-chloro-N- (3-methoxy-2-thenyl) -2 ', 6'.
Represents dimethylacetanilide (NSK-850). Further, the surfactant, the viscosity modifier, the anti-caking agent and the defoaming agent in Tables 1 and 2 are described by their trade names, but the general name for each trade name is as follows.

Regarding the surfactant, trade name: Newpol PE-64 is polyoxyethylene polyoxypropylene block polymer, trade name: Neugen EA130A.
Is polyoxyethylene nonyl phenyl ether, trade name: Neugen EA157 and EA167 are polyoxyethylene alkyl allyl ethers, trade name: Neugen EA112 and EA152 are polyoxyethylene octyl phenyl ethers, trade name: Sanmorin OT-7
0 represents a dialkyl sulfosuccinate, trade name: Hitenol N-07, NE-05 represents a polyoxyethylene alkyl ether sulfate, and Neocor YSK represents a dialkyl sulfosuccinate.

Regarding the viscosity modifier, trade name: serogen WS-C is carboxymethyl cellulose, trade name: Genuum gum RL-200 is locust bean gum, trade name: Kelzan is xanthan gum, trade name: Meiprogut 90 is guar gum, Further, regarding the anti-caking agent, the trade name: Kunipia F indicates bentonite, and also an antifoaming agent, the trade name: Pronal EX300.
Indicates a silicone emulsion.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

Example 7 Each of the representative water-suspended herbicides for paddy fields obtained in Examples 1 to 6 was stored at 40 ° C. for 1 month and then tested for herbicidal effect and phytotoxicity by the following methods. The results are summarized in Table 3 and described.

Test method Paddy soil was packed in a plastic pot of 1 / 10,000a, seeded with Novier, larva, and yellow cypress, and the inundation depth was set to 3
cm. Rice plants at the 2.5-leaf stage were transplanted to the 1.5-leaf stage of Nobie, and the prescribed amount of the water-suspended herbicide for paddy fields was treated the next day.
After 20 days from the treatment, evaluation was performed by the following method. The results are shown in Table 3.
It was shown to.

The evaluation of the herbicidal effect in Table 3 has 6 levels, and the numerical values from 0 to 5 are shown below.

0 ・ ・ ・ ・ ・ ・ Weed control rate 0-9% 1 ・ ・ ・ ・ ・ ・ Weed control rate 10-29% 2 ・ ・ ・ ・ ・ ・ Weed control rate 30-49% 3 ・ ・ ・ ・ ・ ・Grass rate 50-69% 4 ・ ・ ・ ・ ・ ・ Weed control rate 70-89% 5 ・ ・ ・ ・ ・ ・ Weed control rate 90-100% Regarding phytotoxicity to paddy rice, the ratio of plant height and total weight (air dry amount) to untreated plot Then, the worst of both factors was set to 5, and the evaluation was made in 6 stages of 0 to 5 below.

0: Ratio of untreated area 100% 1: Ratio of untreated area 90 to 99% 2: Ratio of untreated area 80: 89% 3・ ・ ・ ・ ・ ・ Untreated plot ratio 60-79% 4 ・ ・ ・ ・ ・ ・ Untreated plot ratio 40-59% 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Untreated plot ratio 0-39% Table 2-Chloro-N- (3-methoxy-2-thenyl) -sprayed per 10 are in the dose section in 3.
2 ', 6'-dimethylacetanilide (NSK-85
The dose of 0) is displayed.

[0060]

[Table 4]

Comparative Example 1 As a viscosity modifier, a 0.12 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution was used instead of a 0.22 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution. The same procedure as in Example 1 was performed except that the above was performed.

Table 2 shows measured values of various physical properties and formulation evaluation of the obtained water-suspended herbicide for paddy field (formulation number: ratio 1), and Table 3 shows herbicidal effect and phytotoxicity test results.

The herbicide had large separation and had a problem in stability as a preparation. The herbicidal effect was high and there was no phytotoxicity to paddy rice.

Comparative Example 2 As a viscosity modifier, a 0.72 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution was used instead of a 0.22 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution. The same procedure as in Example 1 was performed except that the above was performed.

Table 2 shows measured values of physical properties and formulation evaluation of the obtained water-suspended herbicide for paddy field (formulation number: ratio 2), and Table 3 shows herbicidal effect and phytotoxicity test results.

Since the herbicide had poor spreadability in water, a decrease in herbicidal effect and phytotoxicity to paddy rice were observed.

Comparative Example 3 As a viscosity modifier, an aqueous solution of 0.72 wt% -carboxymethyl cellulose (trade name: Daicel CMC1150) was used in place of the 0.22 wt% -carboxymethyl cellulose (trade name: Serogen WS-C) aqueous solution. Was performed in the same manner as in Example 1.

Table 2 shows measured values of various physical properties and formulation evaluation of the obtained water-suspended herbicide for paddy field (formulation number: ratio 3), and Table 3 shows herbicidal effect and phytotoxicity test results.

Since this herbicide had poor spreadability in water, a decrease in herbicidal effect and phytotoxicity to paddy rice were observed.

Claims (1)

[Claims] 1. 2-Chloro-N- (3-methoxy-2-
Tenyl) -2 ', 6'-dimethylacetanilide, a surfactant and a viscosity modifier are dispersed in water to give a viscosity of 1
A water-suspended herbicide for paddy fields, which is from 0 to 230 cP.