JPS5824401B2 - Antennarukendakujiyounoyaku - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stable agricultural chemical suspension formulation that simultaneously contains a solid agricultural chemical that is sparingly soluble in water or a solid agricultural chemical that is sparingly soluble in water and a water-soluble solid agricultural chemical. A suspension preparation containing a solid agricultural chemical, using water as a dispersion medium, and containing a surfactant and a water-soluble polymer in an amount sufficient to give the suspension a liquid viscosity of 200 to 500 cp at 20°C. This allows the homogeneous dispersion of the suspension agent to be maintained stably over a long period of time, making it suitable not only for regular concentration spraying on the ground, but also for micro-dose spraying (ULV spraying) in which the suspension formulation is sprayed by air as a undiluted solution. It is an object of the present invention to provide a suspension agent which is suitable and also enables liquid small-volume aerial spraying (LV spraying) in which a suspension preparation is diluted 8 times and sprayed.

Conventional 1-naphthyl N-methyl carbamate, 4, 5, 6
・Solid pesticides such as 7-titrachlorphthalide and basic copper chloride are insoluble in water and insoluble in organic solvents, so even if there is a solvent that can dissolve these pesticides, practical emulsions can be produced. Because it did not dissolve as much as possible, it could not be obtained from emulsions with a low active ingredient content.

Therefore, for drug substances having such properties, powders containing fine mineral powder as a carrier and wettable powders containing surfactants have been used as formulations.

However, in the case of aerial dispersion of powder agents, scattering drift of the agent becomes a problem, and the use of fine powder agents F with less drift is being gradually implemented.

In aerial spraying, the spraying chemical solution is 8001r per 10are.
A small amount of less than Ll is used, but in diluted suspensions of wettable powders, the suspension stability of the sprayed liquid is poor, and when mixed with other agricultural chemicals or the hard water used, suspended particles may aggregate, resulting in separation and sedimentation. It has been impossible to prepare a spray solution for small-volume spraying at a high concentration, as this can clog the strainer of a helicopter or cause phytotoxicity due to aggregates adhering to crops.

As a formulation that does not have these drawbacks, suspensions in which fine particles of water-insoluble solid agricultural chemicals are uniformly dispersed in a liquid are being tested for practical use because they can be used in the same way as emulsions.

However, pesticide suspensions are not physically separated and require long-term stability.

Three methods are currently used for dispersing suspension agents.

That is, (1) aerial microspraying (UL), in which the undiluted solution is sprayed as is;
V scattering) '(2 + 8 times diluted and 8 per 10 are
00rrLl small amount spraying (LV spraying) (3) Normal ground spraying (usually 500 to 1000 times diluted spraying).

Therefore, in the case of micro-spraying in which the suspension agent is sprayed as a undiluted solution, the suspension agent flows out smoothly from the packaging container and passes through the wire mesh (150 mesh) of the helicopter's preparation tank.
A suspending agent of an appropriate viscosity is required so that it can be sprayed in a fixed amount from a spraying device at a specified time without clogging the strainer in the helicopter pump.

A possible solution would be to significantly increase the viscosity of the suspending agent in order to prevent liquid separation and maintain long-term physical stability, thereby preventing sedimentation of suspended particles. In this case, it becomes extremely difficult to handle as a normal liquid agent, it is difficult to pass through a strainer, and the discharge volume per hour is considerably reduced, making it impossible to spray a small amount.

In addition, in the case of aerial spraying at 8 times dilution, if the suspension agent is extremely viscous, it will not disperse immediately when poured into water and will remain in the form of oil droplets or discs, and will not be dispersed in the dilution container. It settles to the bottom and is dispersed in the water by vigorous stirring of the liquid, which takes an excessive amount of time to create a spray solution.

On the other hand, when the suspension agent has a low viscosity, it lacks long-term physical stability, and the settled solid particles form a hard sedimentary layer at the bottom of the packaging container, forming a so-called hard caking layer.

In such cases, even if the container is shaken violently, the fine solid particles do not easily redisperse as single particles, but instead exist as hard aggregates with a diameter of 1 to 2 mm, which can clog the strainer of the spraying device during spraying and destroy the purpose of spraying. cannot be reached.

The present inventors have demonstrated that agricultural chemical suspensions maintain physical long-term stability, can be passed through aerial spraying equipment without any separation, and can be used as a micro-spraying agent that is sprayed with a undiluted solution as a suspending agent. The property of the suspension agent is that it can be easily dispersed in water when diluted with water even when sprayed in a small amount at 8 times dilution. In order to satisfy the above-mentioned properties, the liquid viscosity of the suspension agent should be 200 to 200 at 20°C in order to satisfy the above-mentioned properties in the case of a suspension formulation containing both a solid agricultural chemical or a solid agricultural chemical that is sparingly soluble in water and a water-soluble solid agricultural chemical.
We have found that 500 cp is optimal.

The viscosity here is measured using a Brookfield synchronous electric rotational viscometer (B-type viscometer).

As the measurement conditions, for example, the viscosity of the liquid is measured at 20° C. using a rotor AI with a BL type viscometer manufactured by Tokyo Keiki Seisakusho and the rotor rotation speed is 12 rpm.

The upper limit of measurement in this measurement is 500 cp, and the liquid viscosity can be measured with high accuracy.

The solid agricultural chemicals that are sparingly soluble in water used in the present invention are solid at room temperature and can be pulverized by mechanical operation.
It is desirable to have a chemically stable material that has low solubility in water and is not hydrolyzed by water.

For example, 1-naphthyl N-methylcarbamate, 4.5.
6,7-titrachlorphthalide, 3,5-xylyl N-
Examples include, but are not limited to, methyl carbamate, methalyl N-methyl carbamate, N-tetrachloroethylthiotetrahydrophthalimide, basic copper chloride, methyl 2-benzimidazole carbamate, 2-(4-thiazolyl)-6-benzimidazole, etc. It is not something that will be done.

These solid agricultural chemicals that are poorly soluble in water are usually ground to 10 μm or less using an ultrafine grinder such as a jet o-mizer, but the average is 5 μm or less.
Finely ground to less than µm (and gives a good suspending agent).

As water-soluble solid agricultural chemicals, kasugamycin hydrochloride, streptomycin sulfate, polyoxin complex, validamycin A, 0.S-dimethyl N-acetyl phosphoroamide thioate, etc. have high solubility in water and high chemical stability in water. Examples include, but are not limited to.

As for the combination of a solid agricultural chemical that is poorly soluble in water and a solid agricultural chemical that is water-soluble, the above-mentioned combinations of both groups are possible.

Namely, kasugamycin hydrochloride and 4,5,6,7-titrachlorphthalide, kasugamycin hydrochloride and 1-naphthyl N-methylcarbamate, validamycin A and 4,5
- 6,7-titrachlorphthalide, and further kasugamycin-hydrochloride, validamycin A, and 4,5?6,7-titrachlorphthalide are also possible.

Combinations of solid pesticides that are sparingly soluble in water, such as 1-naphthyl N-methylcarbamate and 4,5,6,7-titrachlorphthalide, 1-naphthyl N-methylcarbamate and 3
- Examples include, but are not limited to, 5-xylyl N-methyl carbamate, 3,5-xylyl N-methyl carbamate, and 4,5,6,7-titrachlorophthalide.

It is generally desirable that the suspension contains 40% or more of these agricultural chemical ingredients.

It goes without saying that the amount of water used must be greater than that capable of dissolving the water-soluble drug substance, but normally 30% or more is required in the suspension, and if less than that, the viscosity of the suspension will increase. increases too much, reducing practicality.

The surfactant used can be an anionic surfactant or a combination of a nonionic surfactant and an amphoteric surfactant to make the fine bulk of the hydrophobic solid pesticide that is poorly soluble in water compatible with water and dispersed therein.

Namely, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate, naphthalenesulfonate formalin condensate, polyoxyethylene alkylphenyl sulfate soda, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene Octylphenol ether, phosphoryoxyethylene nonylphenol ether, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyoxyethylene acyl esters, oxyethylene oxypropylene block polymers, etc. can be used.

In general, a nonionic activator gives wetness to a hydrophobic solid pesticide, while an anionic activator gives dispersion power in the system, so it is desirable to use them in combination.

In addition, the nonionic surfactant also functions as a spreading agent in the suspending agent.

Unlike emulsion formulations, only a very small amount of surfactant is needed, and usually 0.1 to 5% is sufficient to achieve the purpose.

However, when selecting an activator, it is necessary to select one that is compatible with the properties of the agricultural chemical substance to be used.

The water-soluble polymer used may be semi-synthetic or synthetic, with methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, and polyethylene oxide being particularly effective.

These may be used alone or in combination of two or three.

These water-soluble polymers act as so-called protective colloids in the dispersion system of the suspending agent to improve the stability of the system.

This is due to the enveloping and protective action of the hydrophilic colloid, which is a fine colloidal particle of the hydrophobic drug substance, and the other is the stabilization of the dispersion system due to the thickening of the water-soluble polymer.

For pesticide suspensions, as mentioned earlier (due to various constraints on dispersion of the formulation, ``moderate dispersion'' is required to ensure long-term stability of the suspension and facilitate redispersion before use. By utilizing the thickening properties and structural viscosity properties of these water-soluble polymers, the liquid viscosity of the preparation is raised to 200 to 500 cp at 20°C.

The amount of water-soluble polymer added is 6% or less in the system based on the viscosity obtained, which almost achieves the purpose.

When directly formulating a water-soluble polymer powder into a drug product, there is a problem with how to dissolve it in water, and it forms a "mamako". It is necessary to incorporate it into the formulation system.

Even if the composition of the present invention contains some adjuvants as described below, this does not impede the present invention.

That is, it may contain an agent for preventing decomposition of agricultural chemical active ingredients, a pH adjusting buffer, an antifreeze agent, an antifungal agent, a fragrance, a pigment, an antifoaming agent, and the like.

EXAMPLES Below, the present invention will be described in detail with reference to Examples, and then the test results of the compositions of the invention will be shown in detail.

Example 1 1 g of sodium alkylnaphthalene sulfonate and 0.21 w of nonionic surfactant polyoxyethylene nonyl phenyl ether were added to 31.5 P of water and dissolved by stirring.

Next, add kasugamycin hydrochloride 1.31 and dissolve it, then add the dry ultrafinely pulverized bactericide 4,5,6,7-titrachlorphthalide 161 and stir thoroughly using a homogenizer to disperse. let

Next, 50 g of a 2% aqueous solution of hecarboxymethyl cellulose was added little by little to this solution, and thoroughly stirred with a Chemister stirrer to obtain a uniform suspension composition.

The carboxymethyl cellulose used was a 1% solution with a concentration of 20
Those exhibiting a viscosity of 0 to 300 cp were used.

The viscosity of the obtained suspension composition was measured using a BL type viscometer using rotor A1 at 12 rpm at a liquid temperature of 20°C.
It was 25 cp.

Example 2 11 parts of sodium alkylnaphthalene sulfonate and 0.2 parts of nonionic surfactant polyoxyethylene nonylphenyl ether are placed in 31.5 parts of water and stirred to dissolve.

Next, kasugamycin-hydrochloride 1.31 was added and dissolved, and then ultra-finely powdered using a jet-o-mizer.
- Add 16 g of 6,7-tetrachlorophthalide and stir thoroughly using a homogenizer to disperse.

Next, in this liquid henomite heptooxyglobil cellulose 3
% aqueous solution was added little by little and thoroughly stirred with a Chemister stirrer to obtain a uniform suspension composition.

The hydroxypropyl cellulose used was a 2% aqueous solution with a viscosity of 150 to 400 cp.

The viscosity of the suspension composition obtained was 350 cp at a liquid temperature of 20° C. as measured by the above-mentioned measuring method.

Example 3 1 g of a naphthalene sulfonic acid formalin condensate and 0.4 P of a nonionic surfactant polyoxyethylene lauryl ether are placed in 31.3 P of water and dissolved by stirring.

Next, kasugamycin-hydrochloride 1.31 was added and dissolved, and then ultra-finely powdered using a jet-o-mizer.
- Add 16 g of 6,7-tetrachlorophthalide and stir thoroughly using a homogenizer to disperse.

Next, in this liquid, hydroxyethyl cellulose 2.3
% aqueous solution was added little by little and thoroughly stirred with a Chemister stirrer to obtain a uniform suspension composition.

The hydroxyethyl cellulose used was a 2% aqueous solution with a viscosity of 800 to 1500 cp.

The viscosity of the suspension composition obtained was 220 cp at a liquid temperature of 20° C. as measured by the above-mentioned measuring method.

Example 4 Naphthalene sulfonic acid soda formalin condensate 11 and polyoxyethylene octylphenyl ether 0.5 S' are placed in 31.7 f of water and dissolved by stirring.

Next, add 1.31 g of kasugamycin-hydrochloride, add 4.5 f of validamycin A, dissolve it, add 16 g of the fungicide 4,5,6,7-tetrachlorophthalide that has been ultra-finely powdered using a jet-o-mizer, and use a homogenizer. Stir thoroughly to disperse.

Next, a 2% aqueous solution of henotylcellulose 451 was added little by little to this liquid and thoroughly stirred with a Chemister stirrer to obtain a uniform suspension composition.

The methylcellulose used was a 2% aqueous solution with a viscosity of 1500.
I used the one from ep.

The viscosity of the suspension composition obtained was 300 cp at a liquid temperature of 20°C as determined by the above-mentioned measuring method.

Example 5 11 parts of sodium alkylnaphthalene sulfonate and 0.2 parts of polyoxyethylene nonylphenyl ether are placed in 31.5 parts of water and dissolved by stirring.

Next, kasugamycin-hydrochloride 1.31 was added and dissolved, and then ultra-finely pulverized with a jet miser 4, 5, 6, 7
- Add titrachlorphthalide 161 and stir thoroughly using a homogenizer to disperse it.

Next, in this liquid, a 5.2% aqueous solution of hepolyethylene oxide 5
Add 0g little by little, stir thoroughly with Chemister stirrer,
A homogeneous suspension composition was obtained.

The polyethylene oxide used was a 5% aqueous solution with a viscosity of 90.
0 to 3000 cp was used.

The viscosity of the suspension composition obtained was 480 cp at a liquid temperature of 20° C. according to the measurement method described above.

Example 6 Sodium dodecylbenzenesulfonate 0.5 and alkylnaphthalenesulfonic acid f0.5 in 40.3S' of water
? and polyoxyethylene nonylphenyl ether 0.
Add 41 and stir to dissolve.

Next, 1-naphthyl N- was ultrafinely pulverized using a jet miser.
Methyl carbamate 40? and stir thoroughly using a homogenizer to disperse.

Next, in this solution, add 3% hydroxypropyl cellulose.
Aqueous solution 18.31? was added little by little and thoroughly stirred with a Chemister stirrer to obtain a uniform suspension composition.

The hydroxypropyl cellulose used was a 2% aqueous solution with a viscosity of 150 to 400 cp.

The viscosity of the suspension composition obtained was 415 cp at a liquid temperature of 20° C. as measured by the above-mentioned measuring method.

Example 7 Water 46.8'? 0.5 P of sodium naphthalene sulfonate formalin condensate, 0.5 P of sodium alkylnaphthalene sulfonate, and 0.21 P of polyoxyethylene nonylphenyl ether are placed in the solution and stirred to dissolve.

Next, 1-naphthyl N- was ultrafinely pulverized using a jet miser.
Methyl carbamate 201.4.5.6.7-titrachlorphthalide 101 is added and thoroughly stirred using a homogenizer to disperse.

Next, 3% hydroxypropyl cellulose in the liquid.
22 g of the aqueous solution was added little by little and thoroughly stirred with a Chemister stirrer to obtain a uniform suspension composition.

The hydroxypropyl cellulose used was a 2% aqueous solution with a viscosity of 150 to 400 cp.

The viscosity of the suspension composition obtained was 260 cp at a liquid temperature of 20° C. as measured by the above-mentioned measuring method.

Example 8 1 g of sodium alkylnaphthalene sulfonate and 0 of polyoxyethylene nonylphenyl ether in 36.3 y of water
．． Add 22 and stir to dissolve.

Next, the 4, 5, 6, 7-
Add titrachlorphthalide 207 and stir thoroughly using a homogenizer to disperse it.

Next, in this solution, add 2% hydroxyprobyl cellulose.
42.5 P of an aqueous solution was added little by little and thoroughly stirred with a Chemister stirrer to obtain a uniform suspension composition.

The hydroxypropyl cellulose used was a 2% aqueous solution with a viscosity of 150 to 400 cp.

The viscosity of the suspension composition obtained was 290 cp at a liquid temperature of 20° C. as measured by the above-mentioned measuring method.

Various tests related to the composition of the present invention Long-term stability of the suspended state of the composition of the present invention, presence or absence of hard caking layer formation, dispersibility in water when diluted 8 times and 1000 times, redispersibility of the suspending agent, use for micro-spraying Table 1 shows the results of testing the ejection time and other factors in relation to viscosity using a testing device, along with the comparative test results.

The display of an example in the "Formulation" column in the table indicates that the formulation of components other than the water-soluble polymer used in the formulation of the test composition is the same as that of the indicated example.

To test the long-term stability of the suspended state, 15rrLl of the suspension is placed in a 307711 test tube (16 mm diameter) and left for a predetermined number of days.

The initial volume of 151117 (rnl!) is Ho, and the volume of the settling surface after a predetermined number of days (mQ is H, H/HoX
100 is the stability.

Therefore, the higher the numerical value, the higher the stability, and a stability of 100 indicates that the suspending agent is not separated.

The presence or absence of a hard caking layer is determined after one month of standing, with a diameter of 11rL.
A stainless steel wire of 1.5 m was allowed to fall naturally into the suspending agent, and the sedimentary layer at the bottom of the vessel was examined.

Resuspendability is determined by shaking the test tube subjected to the stability test after one month of standing to see if it can be resuspended 10 times, and at the same time checking to see if the suspended particles have become coarse.

A discharge test using a test device for micro-spraying (Nosuishield LEK-02-2 model) was carried out in the following manner.

Using a LEK-02-2 test rotary atomizer, the time required for discharging 100 ml of suspension agent was determined.

In the test, a pressure of 1.0 kg/crA was used, and an orifice diameter of 2.5 mm was used.

In normal spraying, when spraying is 18 m and the spraying speed is 35 mph, assuming that 100 ml per 10 are is sprayed from 4 nozzles, the required discharge amount from one nozzle is 7 r.
ul/sec is required.

Similarly, 7.8 Trll/sec is required at 20 m during spraying, and 8.6 ml/sec at 22 m during spraying.

In our country, it is normal to spray 22771 while spraying, so in this test, to spray 100ml of suspension agent, it is necessary to spray it in 11.6 seconds or less.

If it takes more time to spray, the efficiency of spraying will decrease.

As shown in the results in Table 4, the long-term stability of the suspending agent is
Above 0.00 cp, it is excellent, while below it, long-term stability is compromised.

If the stability is 90 or higher for a long period of 3 months, there will be no practical problem.

Further, a suspension agent having a stability of 90 or higher is easily dispersed when resuspended before use.

If the viscosity is less than 200 cp, a hard caking layer will be formed at the bottom of the container due to decreased stability, and the precipitated particles will not be dispersed even if resuspended.

On the other hand, when a suspending agent is poured into water for 8-fold or 1000-fold dilution, those with a viscosity of 500 cp or more will not be directly dispersed in water, but will fall in the form of oil droplets, making the dilution process difficult.

In addition, in a discharge test using a test device for micro-spraying, the discharge rate was 7 to 9 ml per second, which is normally required for spraying! These conditions are fully satisfied if the suspension has a viscosity of 200 to 500 cp.
A formulation of 500 cp or more requires an excessively long ejection time, which is unfavorable in terms of spray efficiency.

As the viscosity of the suspension increases above 500 cp, it is good for storage stability, but when diluted in water, the high viscosity makes it difficult to self-disperse, making it difficult to use in LV sprays or ground sprays. It becomes difficult to prepare a spraying agent for use.

In addition, it becomes difficult to discharge from the small amount spraying device for helicopters normally used in Japan, making it impossible to spray.

Claims (1)

[Claims] 1. In a system that simultaneously contains a solid pesticide that is sparingly soluble in water or a solid pesticide that is sparingly soluble in water and a water-soluble solid pesticide, a system that uses water as a dispersion medium, consists of a surfactant and a water-soluble polymer, and contains a water-soluble polymer The liquid viscosity of the suspension agent is 200 to 200 at 20°C.
500 cp.