JPS6115841B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to an agrochemical powder that suppresses electrostatic charging to the spout tube of a sprayer during spraying. Generally, when spraying pesticide powder with a power spreader,
Static electricity is generated in the jet tube made of vinyl chloride or nylon, but this charged potential is ±
If the voltage exceeds 30KV, spark discharge will occur between the jet pipe and the sprayer, and the sprayer will receive a strong electric shock. Although this electric shock is not a direct threat to human life because the voltage is high but the current is low, it poses a serious safety problem for spraying work, as it can frighten sprayers and cause them to lose their feet. Some research has been conducted in the past regarding electrostatic charges during pesticide spraying. For example, compared to calcium carbonate and clays, the charging of the spout tube by pesticide carriers is
It contains less talc, bentonite, etc., and the white carbon used as an adjuvant has an antistatic effect (Pesticide Production Technology, No. 25, p. 9,
1971), or when the jet tube is coated with an antistatic agent (Denkyl/TS) containing a special cationic surfactant, an antistatic effect is observed (Agrochemical Mechanization Research Institute report, March 1971, multi-mouthed hose jet). The results of research such as research on antistatic agents for antistatic agents have been disclosed. On the other hand, calcium carbonate is extremely useful as a carrier for pesticide powders. It has good stability against organic phosphorus and carbamate pesticide base agents, which are generally said to be unstable, and Japan has abundant reserves of calcium carbonate minerals, so its supply is stable and inexpensive. Moreover, it has many advantages as a carrier for agricultural chemicals, such as high purity and few impurities. However, pesticide powders containing calcium carbonate powder as a main carrier are strongly electrostatically charged in the jet tube and other areas during spraying.
It has the disadvantage of often giving the sprayer a strong electric shock. As mentioned above, there is a method of coating the spray head with an antistatic agent, but the antistatic effect is not always sufficient and the effect is not long lasting. It is not put into practical use, perhaps because the process of treating the parts with an antistatic agent is complicated. The inventors have developed a method for suppressing electrostatic charging during spraying of pesticide powders containing calcium carbonate as a main carrier.
As a result of repeated research into ways to solve the problem in the formulation of pesticide powders, we unexpectedly discovered that this electrostatic charge could be specifically suppressed by incorporating a small amount of talc into the formulation, and the present invention was developed. completed. The charging phenomenon that occurs when spraying pesticide powder is not fully understood, but it is thought to be caused by static electricity generated when the powder discharged from the sprayer collides with the inner wall of the spray tube, rubs, or peels off. When powder is discharged at a slow flow rate, such as in a manual spreader, the amount of static electricity generated is small, but when powder is discharged at high speed, as in a power spreader, the amount generated is large. Furthermore, if the material of the spout tube is conductive, the generated static electricity will leak out and the charged potential will be maintained low, but when using a spout tube made of highly insulating material such as vinyl chloride, the charge There is less leakage and the charged potential becomes higher. It is also known that the generation of static electricity is greatly affected by the type of discharged powder and the humidity in the atmosphere, but the detailed generation mechanism is not clear.
This is one of the technical areas in which preventive measures are extremely difficult. Pesticide powders generally consist of about 1 to 5% of active ingredients and a small amount of stabilizers for the main ingredient or auxiliary agents and carriers for the purpose of improving physical properties such as fluidity, adhesion, and cohesion of the powder. has been done.
Although the influence of the main agent and auxiliary agents on the generation of static electricity cannot be ignored, it is natural that the influence of the carrier, which constitutes the majority of the pesticide powder, appears most strongly. The present inventors also investigated clay as a carrier,
Electrostatic charges generally tended to be stronger in pesticide powders using calcium carbonate than when using talc, bentonite, zeolite, ziecrite, kaolin, silica powder, or mixtures thereof. This tendency was especially obvious when using calcium carbonate that had been classified into fine particles of 10 microns or less. Calcium carbonate, which has been cut into fine particles of 10 microns or less, is an extremely useful pesticide carrier that suppresses drift during spraying of pesticide powders and prevents environmental pollution. The particle size of the carrier used in pesticide powders is such that at least 95% of the particles pass through a 46 micron sieve, and as much as possible, fine particles of 10 microns or less, which strongly affect the occurrence of drift, are removed by means such as classification. Preferably. However, cutting to a size of 10 microns or less requires advanced manufacturing technology and leads to a decrease in production efficiency, so cutting completely is not preferable as it increases the price of the carrier. usually
A carrier cut to 20%, preferably 15% or less can be advantageously used to suppress drift. Specifically, when spraying pesticide powder that uses calcium carbonate or calcium carbonate, which is a finely divided powder of 10 microns or less, as the main carrier, with a backpack-type power sprayer equipped with a direct injection tube, The potential of the electrostatic charge generated in the area could reach -50KV or more, often giving the sprayer a strong electric shock. It is said that when an object in the air is charged to a high potential of 30KV or more, the insulation of the air is broken and discharge occurs, so if the charged potential can be suppressed to at least ±30KV or less, preferably ±20KV or less, spraying is possible. Strong electric shock to workers can be avoided, and the purpose of preventing static electricity can be achieved in practice. For calcium carbonate, which exhibits such a strong electrostatic charge, as a result of various searches for compounds that exhibit a charge-suppressing effect by blending, it was surprisingly possible to discover an unexpected effect in talc. When 5% of talc is added, it is possible to lower the potential, but preferably when the amount of talc is 10% or more, a remarkable suppressing effect is observed, and it is sufficiently possible to reduce the potential to below ±20 KV.
However, depending on the type of agricultural chemical active ingredient and the composition of the adjuvant, it is possible to achieve sufficient practical effects if the amount is 5% or more. In other cases, the already known white carbon was effective, but the brand fluctuation was large and the effect was not as good as the talc of the present invention, and white carbon is a fairly expensive auxiliary agent, so it has no economic effect. Much inferior to talc. Other fine mineral powders, organic or inorganic powders, polymeric substances,
None of the liquid additives had any noticeable effect. The mechanism by which electrification can be suppressed to a preferable range by adding talc to an agrochemical powder using calcium carbonate is completely unknown. For example, when spraying calcium carbonate, the surface potential of a direct injection pipe becomes negatively charged, while in the case of talc, it becomes positively charged, so it is assumed that this is due to the neutralization of the charge, but this is more than the case with talc. This is denied because even if a strongly positively charged substance is added to the battery, the effect may be weak or hardly noticeable at all. It is quite surprising that only talc has an antistatic effect. The talc used in the present invention is not limited by its purity or brand, and any talc commonly used in agrochemical powders will exhibit sufficient effects. There is also no particular limitation on the type of base agent, and any base agents such as fungicides, insecticides, herbicides, and plant growth regulators can be used. The adjuvants are also of the type commonly used in agricultural powders, and as long as they are blended in amounts within the range, they do not impede the purpose of the present invention. In order to produce the agrochemical powder of the present invention, no special machinery or equipment is required; any equipment that generally produces agrochemical powder may be used, and even if the entire raw material is mixed and then pulverized, Even if a more concentrated product is pulverized and then diluted with a carrier, any method can be applied, and there are no particular restrictions on the timing of blending talc. Next, the present invention will be specifically explained with reference to test examples and examples. All percentages and parts in the description are based on weight. Test example 1 Charged potential of various carriers (1) Equipment Back-type power spreader (manufactured by Kyoritsu Noki, DM-9
Attach a direct injection pipe (made of vinyl chloride, total length 140cm, consisting of three 40cm straight pipes and one 20cm curved pipe) to the mold), place the sprayer on a steel pedestal, and attach the tip of the direct injection pipe to an iron stand. Each was fixed so that the direct injection pipe was approximately 1 m above the ground. The potential generated approximately in the center of the direct injection pipe was measured using a current collector potential measuring device (Kasuga Electric, Model KS-325) and a recorder (Kasuga Electric, Model KS-325).
KR-500 model) was installed so that it could be measured by a device connected to it. (2) Measurement Set the throttle lever for adjusting the engine rotation of the power spreader to 5/10 and the metering lever for adjusting the powder discharge amount to 5/10, and spread 1 kg of test powder onto the surface of the direct injection pipe. The generated charging potential was measured and recorded. The recorded potential value may show an abnormally high potential when the dilute powder remaining in the sprayer is discharged at the start and end of spraying, but these abnormal values were deleted and the potential was sprayed in a steady state. The average value of the upper and lower limits of the recorded values (which fluctuate up and down even in this steady state) within a period of time was taken as the charging potential. In addition, since the measured values are strongly influenced by atmospheric temperature and humidity and vary widely from day to day, a reference powder was set and data on measurement days where the measured values were abnormal were deleted. (3) Measurement results

[Table] As shown in the table above, most carriers were positively charged, but calcium carbonate was negatively charged and its potential was high. Test Example 2 Effects of Various Additives Calcium carbonate (cut products) was blended with the various additives shown in the table below, ground and mixed, and then the charging potential was measured using the method shown in Test Example 1 to determine the charging suppression effect. saw.

【table】

[Table] As mentioned above, talc was found to have a remarkable antistatic effect. However, although some effects of white carbon were recognized, mixing a large amount of white carbon is not preferable because it promotes drift of the pesticide powder and leads to environmental pollution. Example 1 Using the formulations shown in the table below, the pesticide base Rabside (Kureha Chemical Co., Ltd., trade name), the anti-drift agent Drireless A (Sankyo Co., Ltd., trade name), and the absorbent carrier Carplex #80 (Shionogi & Co., Ltd., trade name) were used. ) and talc (butterfly) were mixed and ground with an atomizer to obtain a concentrate. 20 parts of this concentrate and 80 parts of calcium carbonate (cut product) were mixed with a ribbon mixer to obtain a rubside powder of the present invention. Loveside 2.5 parts Drillless A 0.5〃 Carplex #80 0.5〃 Talc (butterfly mark) 16.5〃 Calcium carbonate (cut product) 80.0〃 This pesticide powder has little drift during spraying, and electrostatic charge is suppressed to a favorable potential. Ta. Example 2 Using the formulation shown in the table below, the pesticide main ingredient Diazinon, the same Meoval (Sumitomo Chemical, trade name), and the Drileless A absorbent carrier Sorex CM (Tokuyama Soda, trade name) were used.
20 parts of a concentrate obtained by mixing and talc (Taihei) and pulverizing with an atomizer and 80 parts of calcium carbonate (cut product) were mixed with a ribbon mixer to obtain a mixed powder of diazinon and meoval of the present invention. Diazinon 1.0 parts Meoval 1.5〃 Driles A 1.0〃 Sorex CM 3.0〃 Talc (Taihei) 13.5〃 Calcium carbonate (cut product) 80.0〃 This pesticide powder has little drift during spraying,
Moreover, electrostatic charging was also suppressed to a desirable degree. Example 3 Concentrate 30 obtained by mixing and pulverizing Loveside, Diazinon, Meobal, Driles A, the absorbent carrier Carplex #1120 (Shionogi & Co., Ltd., trade name) and talc (Saitama) according to the formulation shown in the following table. and 70 parts of calcium carbonate (cut product) to obtain a mixed powder of rubcide, diazinon, and meovar of the present invention. Loveside 2.5 parts Diazinon 1.0〃 Meoval 1.5〃 Driles A 1.5〃 Carplex #1120 1.5〃 Talc (Saitama) 22.0〃 Calcium carbonate (cut product) 70.0〃 This pesticide powder has less drift during spraying,
Electrostatic charging was also suppressed. Example 4 40 parts of a concentrate obtained by mixing and pulverizing Loveside, Sumithion (trade name, Oyu Kagaku), pesticide base Batsa, Dorileth A, Carplex #80, and talc (butterfly stamp) according to the formulation shown in the following table. and 60 parts of calcium carbonate (cut product) were mixed to obtain a mixed powder of the present invention. Loveside 2.5 parts Sumithion 2.0 Patsa 2.0 Drillless A 1.5 Carplex #80 3.0 Talc (butterfly) 29.0 Calcium carbonate (cut product) 60.0 This agricultural chemical powder suppresses both drift and electrostatic charge during spraying. was. Reference Example 1-1 Agrochemical powder as in Example 1 except that talc (butterfly) is calcium carbonate (heavy). Reference example 1-2 Example 1 except that the talc (butterfly stamp) is clay
The same pesticide powder. Reference Example 2-1 The same pesticide powder as in Example 2 except that talc (Taihei) is calcium carbonate (heavy). Reference example 2-2 Example 2 except that talc (Taihei) is clay
The same pesticide powder. Reference Example 3-1 The same pesticide powder as in Example 3 except that talc (Saitama) is calcium carbonate (heavy). Reference example 3-2 Example 3 except that talc (Saitama) is clay
The same pesticide powder. Reference Example 4-1 The same pesticide powder as in Example 4 except that talc (butterfly) is calcium carbonate (heavy). Reference example 4-2 Example 4 except that the talc (butterfly stamp) is clay
The same pesticide powder. Test Example 3 The charged potential during spraying of the pesticide powders prepared in Examples and Reference Examples was measured in the same manner as in Test Example 1.

[Table] As shown in the table above, all of the agrochemical powders of the present invention suppressed charging to within the preferred potential (±20 KV). Test Example 4 A direct injection tube was attached to the backpack-type power sprayer used in Test Example 1, and 3 kg of six types of agricultural chemical powders prepared in Examples and Reference Examples were actually sprayed, and the sprayer The degree of electric shock caused by discharge was investigated. The sprayer wore rubber sports shoes and work gloves, carried the sprayer on his back, and held the direct injection pipe. Also, the temperature at this time was 12°C and the relative humidity was 38%, which was a low and dry weather condition.

【table】

[Table] Although the weather conditions were such that static electricity was easily generated,
The agrochemical powder of the present invention was able to significantly suppress electrification.

Claims (1)

[Scope of Claims] 1. A pesticide powder comprising calcium carbonate powder as a main carrier and 5% or more of talc. 2. The agrochemical powder according to claim 1, wherein the calcium carbonate powder is substantially 46 microns or less, and the content of powder of 10 microns or less in the total powder is 20% or less.