JPS62242601A - Oil-in-water type agrochemical suspension composition excellent in storage stability - Google Patents

Abstract

PURPOSE:The title composition that is composed of a liquid or paste hydropho bic agrochemical, a surface active agent, another surface active agent of polyoxyethylene nonyl phenyl ether and a de-icer such as glycerol, thus showing good storage stability. CONSTITUTION:The title composition is composed of 40-70wt% of a liquid or paste hydrophobic agrochemical, 1-15wt% of a surfactant of formula I [R is residue of 2-6C diol; A is formula II (m is 17-50; n is 2-35)], 0.1-5.0wt% of another surfactant of polyoxyethylene nonyl phenyl ether of 10-18 HLB, 5wt% or less of a de-icer such as glycerol or ethylene glycol and the rest amount of water. The composition can be used almost in the same way as an emulsifier is handled and shows very high chemical and physical storage stability for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides hydrophobic pesticides in liquid or paste form that can be used in the same way as emulsions without using organic solvents, and that have good long-term storage stability. The present invention relates to a method for producing an oil-type suspension agricultural chemical composition.

Conventionally, powders, emulsions, wettable powders, granules, liquids, flow agents, aqueous solvents, etc. have been used as agrochemical formulations, but among these, hydrophobic M drugs that are liquid or paste-like at around 0°C The dosage forms of 1 include emulsions, powders, and wettable powders. The emulsion contains pesticides such as xylene, naphtha, cyclohexanone, and DM.
F, is manufactured by dissolving it in an organic solvent such as methylnaphthalene and adding an emulsifier, but because it contains an organic solvent, it may have flammability, unpleasant odor, toxicity, irritation, increased chemical damage, etc. In many cases, it was also a drawback. On the other hand, there are powders, wettable powders, and granules as formulations that do not use organic solvents, but among these, powders and granules have a small pesticide content of 1 to 15%, making the manufacturing cost of the formulation relatively high. There is a tendency to
Wettable powders have a relatively small pesticide content of 30 to 40%, and require the use of a large amount of white carbon, which has a large oil-absorbing capacity. However, there are problems such as difficulty in spraying in small amounts at high concentrations.

In order to improve the drawbacks of such liquid or paste hydrophobic pesticide formulations, liquid or paste hydrophobic pesticides are suspended as fine particles using water as a base material instead of using organic solvents or finely powdered inorganic carriers. Several turbidly dispersed dosage forms have been developed.

Aqueous emulsions (microemulsions) have a relatively low content of liquid or paste hydrophobic pesticides, about 1 to 15%, and use a large amount of emulsifier (20% or less) to
It is a preparation that has a solubilized state of 1 micron or less. Kaisho 49-54547,
JP-A-51-41437, JP-A-52-122626
No., JP-A-52-122628, JP-A-54-231
No. 23, JP-A-55-31056, JP-A-60-13
No. 2907).

On the other hand, a technique for stabilizing liquid or paste hydrophobic pesticides by dispersing and suspending them in water as relatively large particles of about 1 to 100 microns is to use a high-speed dispersion machine in the presence of a water-soluble polymer. Techniques have been developed for dispersing particles and imparting storage stability by preventing agglomeration and coalescence of dispersed particles through its thickening action (Japanese Patent Application Laid-Open No. 53-99302, JP-A No. 55-17301, JP-A No. 55-17301, No. 55-124707,
JP-A-55-124708, JP-A-55-12920
No. 1, JP-A-55-130901, JP-A-56-49
No. 303, JP-A-56-49307, JP-A-56-1
No. 20608, JP-A-58-118501, JP-A-Sho 5
8-128301, JP 58-162503, JP 58-192810, JP 59-39810, JP 61-37707).

The key points of these technologies are PVA, gum arabic, CMC
, HEC, MC, guar gum, sodium alginate, carrageenan, gelatin, carboxy starch, cellulose sulfate derivatives, polyacrylate, polymethyl methacrylate, PEG, albumin and other water-soluble polymers are used as thickeners in an amount of 1 to 10%, Furthermore, if necessary, general nonionic surfactants, anionic surfactants, inorganic salts,
It contains urea etc. Among these water-soluble polymers, PVA and gum arabic are particularly useful. However, since this type of oil-in-water suspension composition uses a water-soluble polymer as a thickener, the content of hydrophobic pesticides is as low as 10-40%, and its viscosity is 700-200%.
It is as high as 0 cps and is not only inconvenient to manufacture and handle, but also remains in the spray solution because it remains attached to the container, is difficult to disperse in water when preparing the spray solution, and the dispersed particles are as large as 1 to 100 microns. It has several problems that need to be improved, such as insufficient suspension stability and a tendency for its agrochemical action to be weaker than that of emulsion-type emulsions.

The present inventors have improved the above-mentioned drawbacks of oil-in-water type suspension pesticide compositions based on the conventional technology of liquid or paste hydrophobic pesticides, and can be used almost in the same manner as emulsions, and As a result of extensive research into a technique for manufacturing a novel oil-in-water suspension pesticide composition that has excellent chemical and physical storage stability over a long period of time, we have found that the general formula ( The present invention was completed by discovering the use of the surfactant shown in 1).

That is, the agricultural chemicals to which the present invention is applied are mainly hydrophobic agricultural chemicals that are sparingly soluble or insoluble in liquid or paste form at around 0°C and have a solubility in water (at 20°C) of about 2000 ppm or less, and their oil-in-water suspension. The composition provides a chemically and physically stable dosage form without oil layer separation even during long-term storage. The gist of the present invention is as follows.

(1) Hydrophobic pesticide in liquid or paste form 40-70
% (same below weight %), 1 to 15% of a surfactant represented by general formula (1), and the remainder water.

A-R-A... (1) (In the formula, R represents a diol residue consisting of 2 to 6 carbon atoms, and A is represented by the following formula.

CH.

[H(OCH,CH,)n(OCHCH,)mo]m represents an integer of 17 to 5o, and n represents an integer of 2 to 35. ) (2) Polyoxyethylene nonyl (or octyl or decyl) phenyl ether, polyoxyethylene styryl (or benzyl) phenyl (
or cresyl or phenyl phenyl) ether in an amount of 0.1 to 5% of the nonionic surfactant. Composition.

(3) A product containing glycerin, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, diglycerin, methyl cellosolve, methyl carbitol, cellosolve, carbitol, etc. at a rate of 5% or less as an anti-icing agent. The oil-in-water suspension agricultural chemical composition according to item 1.

The compound represented by the above general formula (1) is a polyoxyethylene polyoxypropylene block polymer type nonionic surfactant, in which propylene oxide is first added to a diol compound under an alkali catalyst at 1oO to 150°C.
, 2 to 10 kg/d (7) It can be easily synthesized by carrying out an addition reaction under pressure and further adding ethylene oxide under the same conditions. Preferred diol compounds as starting materials include those having 2 to 6 carbon atoms, ie, ethylene glycol, propylene glycol, butanediol, hexylene glycol, diethylene glycol, dipropylene glycol, and the like.

The addition rate of ethylene oxide to the polyoxypropylene polymer is preferably in the range of 10 to 50% (weight ratio), but generally HL
Oil-in-water type suspension pesticide compositions with good stability can often be obtained by combining one or more types of compounds with a wide range of B ranging from 1 to 15. , physicochemical properties of the target pesticide,
It is necessary to select and mix the most suitable one based on the content rate, storage conditions, etc.

The second surfactant constituting the present invention has an HLB of 10 to 1.
8 selected from polyoxyethylene nonyl (or octyl or dodecyl) phenyl ether, polyoxyethylene styryl (or benzyl) phenyl (or cresyl or phenyl ale) ether, and the oil-in-water suspension according to item 1. It promotes storage stability of agrochemical compositions.

A content of 0.1 to 5.0% in the composition is sufficient.

The third substance constituting the present invention is an anti-icing agent, such as ethylene glycol, propylene glycol,
dipropylene glycol, glycerin, diglycerin,
Methyl cellosolve, methyl carbitol, cellosolve,
Carbitol etc.

The use of this substance prevents freezing of the aqueous layer and separation of suspended pesticide particles when the oil-in-water type suspension pesticide composition according to the present invention is stored at -5°C to -10°C. Therefore, a content of 5% or less is usually sufficient.

In connection with the present invention, inorganic salts such as sodium chloride, potassium chloride, calcium chloride, ammonium sulfate, chloride, Addition of ammonium, a low specific gravity organic solvent, etc. is not only acceptable but may also be useful in some cases.

Similarly, for the purpose of increasing the stability of the suspended state, a surfactant other than the surfactant of the general formula (1) of the above (1) and the above (2), such as the general formula (1) ) other than polyoxyethylene polyoxybrobylene block polymer type nonionic surfactants, polyoxyethylene castor oil, polyoxyethylene fatty acid ester, polyoxyethylene alkylphenyl ether formalin condensate, polyoxyethylene sorbitan alkylate, polyoxyethylene sorbitan alkylate, oxyethylene dialkylphenyl ether, etc.

In addition, anionic surfactants such as alkylbenzene sulfonates, alkylnaphthalene sulfonates, naphthalene sulfonate formalin condensates, dialkyl sulfosuccinates, alkyl sulfates, alkyl sulfonates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene alkylphenyl ether sulfonates, Oxyethylene styryl (or benzyl) phenyl (or phenylphenyl) ether sulfate, polyoxyethylene alkyl phenyl ether phosphate, polyoxyethylene styryl (or benzyl) phenyl (or phenylphenyl) ether phosphate, alkyl biphenyl sulfonate, N-methyl Since a small amount of fatty acid tauride or the like may be added, there is no problem in using these surfactants in combination in the present invention as necessary. In addition, by using antifoaming agents such as silicone or silicone emulsion, fatty acid amide, fatty acid, alkyl polyoxyethylene polyoxypropylene block polymer ether, foaming troubles in the production and use of the composition according to the present invention can be avoided. In many cases, it is preferable to prevent this.

In addition, for the purpose of increasing the chemical stability of hydrophobic pesticides in water and suppressing reactions such as hydrolysis.

In order to adjust the pH of the aqueous layer to the stabilization range of the target pesticide, various pH adjusters and buffer substances may be added, or epoxy compounds, lactone compounds, phosphate ester salts, etc. may be used. In some cases, it may be preferable to do so.

The agricultural chemicals targeted by the present invention are liquid or paste at around 0°C, and have a solubility in water of about 200°C at 20°C.
If it is about 0 ppm or less, it can generally be targeted, and the following agricultural chemicals can be exemplified.

In insecticides, 09O-dimethyl-3-methyl-4-nitrophenylphosphorothioate (fenitrothion);
0,0-Dimethyl-3-methyl-4-methylthiophenyl phosphorothioate (Fention), 0.0-diethyl-2-isopropyl-4-methyl-6-pyrimidinyl phosphorothioate (Diazinon), 0.0-dimethyl-3-[ α-(Ethoxycarbonyl)benzylcophosphorodithioate (Elsan), 0-seQ, butylphenylmethyl carbamate (BPMC), O-ethyl-5-propyl-2,4-dichlorophenylphosphorothiolothioate (Prothiophos), etc. In addition, 3-allyl-
2-Methylcyclopent-2-en-4-on-1-yl chrysansemate (allethrin), 5-(benzyl-
3-furylmethyl) chrysansemate (resmethrin)
, 5-propargyl-3-furylmethyl chrysansemate (phenothrin), 3-phenoxybenzyl chrysansemate (phenothrin), 3-phenoxybenzyl-
2,2-dimethyl-3-(β,β-dichloro) and nylcyclopropanecarboxylate (permethrin), α-
Cyano-3-phenoxybenzyl-cis, trans-3
Synthetic pyrethroid pesticides such as -(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropanecarboxylate (Cypermethrin) are used as fungicides, including methylarsenic bis(dodecyl sulfide) (Marus).

09O-diisopropyl-8-benzylphosphorothiolate (IBP), 5-methoxy-3-trichloromethyl-1,2,4-thiadiazole (ecromezole),
Herbicides include 5-p-chlorobenzyldiethylthiocarbamate (benthiocarb), 5-(2-chlorobenzyl)-N,N,-diethylthiocarbamate (orthobencarb), α-chloro-2°, 6° -diethyl-N
-(n-butoxymethyl)acetanilide (butachlor), α-chloro-2',6'-diethyl-N-(n-
propoxyethyl) acetanilide (pretilachlor), S-ethylhexahydro-IH-azepine-1-
Examples include carbothioate (molinate), S-ethyl-N-cyclohexyl-N-ethylthiocarbamate (cycloate), but the scope of the present invention should not necessarily be limited to these agricultural chemicals.

Among these agricultural chemicals, a technique similar to the present invention regarding butachlor is described in JP-A-58-162504; Since this method uses an activator, it is understood that the technical content is different from the present invention. That is, JP-A-58-162504 discloses the formula % (where R is alkyl, aryl or alkylaryl, n is approximately equal to 1250 and m is approximately 2200 for an approximate molecular weight of 3500). equal). As used herein, the term "alkyl" refers to straight or branched chain alkyl having 1 to 5 carbon atoms. The term "aryl" refers to an aromatic group containing 6 to 12 carbon atoms, such as phenyl or naphthyl. The term "alkylaryl" refers to an alkyl-substituted phenyl group (
An alkyl group here refers to a radical which may be straight-chain or branched and may have from 1 to 20 carbon atoms. 〕(
[The quotation in brackets] is used as an emulsifier. Furthermore, JP-A-57-80306 and JP-A-58-
No. 162505 describes a technique using a surfactant as a method for producing a [11 emulsion of phenoxyalkane carboxylic acid ester. Among these, nonionic surfactants, especially fatty acid polyethylene glycol esters, aliphatic alcohol glycerides, or alkylphenol polyethylene glycol ethers and polyoxyethylene polyoxypropylene block polymers, unsaturated fatty acid taurides and fatty acid alkyl taurides, A technique is described in which the alkali metal salt of the compound is used in combination with a polyoxyethylene alkylaryl ether phosphate or a polyoxyethylene fatty amine, and is understood to be different from the present invention.

The hydrophobic pesticides exemplified here are in liquid or paste form at 0 to 5 degrees Celsius, taking into account the normal storage conditions for pesticide formulations in Japan, but in cases where there is no need to store them at low temperatures such as 0 to -5 degrees Celsius. The agricultural chemicals may be liquid or paste-like at around the relevant storage temperature, and the gist of the present invention should not be limited to hydrophobic agricultural chemicals that are liquid or paste-like at around 0 to -5°C.

Thus, the general components of the oil-in-water suspension agricultural chemical composition according to the present invention are as follows.

・Liquid or paste hydrophobic pesticide: 40 to 70% (weight% and below are the same) ・Nonionic surfactant represented by general formula (1) in item (1) above = 1 to 15% ・(2) above Nonionic surfactant whose HLB is 10 to 18: 0 to 5% ・20 to 5% of the anti-icing agent in item (3) above ・Other additives (density balancer, nonionic surfactant) , anionic surfactant, antifoaming agent, pH adjuster, etc.): Small amount (as necessary) Water: Residue When producing an oil-in-water type suspension agricultural chemical composition having the above composition, usually High-speed emulsifiers such as homomixers, homoblenders, homogenizers, colloid mills, and turbine-type emulsifiers and gallin-type porosifiers are sufficient.Usually, the operating conditions of these emulsifiers are such that all components of the composition in question are Preparation, 4000-2000 rpm (preferably 500
It is sufficient to perform high-speed stirring for 5 to 10 minutes at a speed of 0 to 15°00 rpm, and no special method is required.

The oil-in-water type suspension agricultural chemical composition according to the present invention produced by such a method generally has a particle size of 1 micron or less, and does not have a cream layer or an oil layer even when stored for a long period of time at -5 to 40°C. It is stable without any separation (a small amount of aqueous layer separation may occur, but it becomes a homogeneous suspension with simple stirring), and the viscosity is about 800 cp.
Shows physical properties below sJQ. This composition can not only be used as it is for spraying in small amounts, but also easily diluted with water to any desired concentration and exhibits a stable emulsified state, so it can be sprayed in the same manner as conventional emulsions.

Hereinafter, the technical contents of the present invention will be explained using examples.

Example (i) Emulsifier composition (a) Emulsifier 1 Surfactant of general formula (1) in which R is propylene, n is 11, and m is 32: 40% (same below weight%), general formula (1) Mixture of 60% interfacial viscosity agent (2) in which R is hexylene, n is 26, and m is 19 (b) Emulsifier 2 In general formula (1), R is propylene, n is 11. A mixture of 0% surfactant where m is 32, general formula (1) R is propylene, surfactant where n is 25 and m is 32 = 30% (c) Emulsifier 3 of general formula (1) A surfactant in which R is butylene, n is 11, and m is 32 = 40%, R in the general formula (I) is propylene, and n is 80. Mixture of surfactant where m is 15: 40%, polyoxyethylene (10 mol) nonylphenyl ether 20% (d) Emulsifier 4 In general formula (1), R is propylene, n is 15, m is 45, A mixture of a certain surfactant: 45%, a surfactant of general formula (1) in which R is hexylene, n is 26, and m is 19, and polyoxyethylene (15 mol) dodecylphenyl ether = 10%. (e) Emulsifier 5 Surfactant in which R in general formula (1) is propylene, n is 111, m is 32: 20%, surfactant in which R in general formula (1) is propylene, n is 30, and m is 15 Emulsifier 6 A surfactant in which R is propylene, n is 11, and m is 32 in the general formula (f) = Suspension of a mixture (if) of 35%, a surfactant of general formula (1) in which R is propylene, n is 26, and m is 19: 40%, polyoxyethylene (30 mol) styryl phenyl ether = 25% Example of composition (a) Example 1 Benthiocarb: 83 gr, emulsifier 1 nia gr.

Ethylene glycol: 4gr and tap water 56gr in an emulsifying container of a homogenizer (universal type manufactured by Nippon Seiki) (
200 mm) and at room temperature, the number of rotations was 10. OO
Emulsify by stirring for 5 minutes and add Benthiocarb 55.
A suspension composition was obtained containing %. (Suspension compositions were obtained using the same homogenizer and under the same conditions in the following Examples) (B) Example 2 IBP: 85 gr, emulsifier 2: 7 gr, propylene glycol: 3 gr, and tap water 55 gr. , I.B.
A suspension composition containing 57% P was obtained.

(c) Example 3 Fenitrothion: 83 gr, emulsifier 3: 8 gr, ethylene glycol: 4 gr, and tap water 55 gr,
A suspension composition containing 55% of fenitrothion was obtained.

(d) Example 4 BPMC: 83gr, emulsifier 3: 8gr, methyl cellosolve: 8gr, and tap water 53gr were prepared, B
A suspension composition containing 55% PMC was obtained.

(e) Example 5 Fenthion: 90gr, emulsifier 4gr, ethylene glycol: 3gr, and tap water 50gr were charged to obtain a suspension composition containing 60% fenthione.

(F) Example 6 Fenitrothion: 60gr, BPMC: 36gr, Emulsifier 5: 8gr, ethylene glycol: 2gr, and tap water 44gr, fenitrothion: 40%, B
A suspension composition containing 24% PMC was obtained.

(G) Example 7 Pretilachlor: 95 gr, emulsifier: 4:6 gr, ethylene glycol: 3 gr, and tap water: 48 gr were charged to obtain a suspension composition containing 63% of pretilachlor.

(H) Example 8 Elsan: 83 gr, emulsifier 6.6 gr, propylene glycol: 4 gr, and tap water 57 gr were charged to obtain a suspension composition containing 55% Elsan.

(iii) Test method (a) Viscosity measurement method Using a 2gr oil-in-water suspension composition, an E-type viscometer (
1 by VISCONICED type manufactured by Tokyo Keiki Co., Ltd.
The viscosity was measured at 0 rpm and 25°C.

(b) Particle size measurement method: 100mf of 5 microliters of oil-in-water suspension composition
The average The particle size was calculated.

c) Long-term storage test 1oomQ of the oil-in-water suspension composition was placed in a cylindrical white storage bottle with a screw stopper (bottom diameter 3.6cm x height 10cm,
After putting it in a container (with a 0 scale) and sealing it, store it at -5℃ and room temperature (20℃).
~25°C) and 40°C for 30 and 60 days, and the presence or absence of separation of the oil layer, cream layer, and water layer was observed.

The test results are shown in Table 1. According to the present invention, an oil-in-water type suspension agricultural chemical composition having excellent storage stability can be obtained.

Claims (3)

[Claims] (1) Hydrophobic pesticide in liquid or paste form 40-70
% (same below as weight %), 1 to 15% of a surfactant represented by general formula (I), and the remainder water. A-R-A...(1) (In the formula, R represents a diol residue consisting of 2 to 6 carbon atoms, and A is represented by the following formula, ▲ Numerical formula, chemical formula, table, etc. ▼ m is an integer from 17 to 50, n is an integer from 2 to 35.) (2) Polyoxyethylene nonyl (or octyl or decyl) phenyl ether, polyoxyethylene styryl (or benzyl) phenyl (
or cresyl or phenylphenyl) ether at 0.
The oil-in-water type suspension agricultural chemical composition according to claim 1, characterized in that the composition is contained in a range of 1 to 5%. (3) As an anti-icing agent, glycerin, ethylene glycol, diethylene glycol, propylene glycol,
The oil-in-water suspension agricultural chemical composition according to claim 1, which contains 5% or less of dipropylene glycol, diglycerin, methyl cellosolve, methyl carbitol, cellosolve, carbitol, etc.