JPS645561B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a liquid pesticide with improved flowability and stability, the purpose of which is to create a new dosage form that can be applied neat or at low dilution ratios, i.e. at high concentrations of active ingredient, and is stable over a long period of time. It is located in a place that provides pesticides. Conventional pesticide formulations can be broadly divided into four types: powders, powders, granules, wettable powders, and emulsions. Powders contain about 2 to 5% of active pesticide ingredients and are mixed with, adhered to, and adsorbed with inorganic carriers such as talc, clay, kaolin, diatomaceous earth, bentonite, calcium carbonate, and white carbon, and are usually sprayed as they are. Powder is made by granulating a powder using a binder such as polyvinyl alcohol, carboxymethyl cellulose, starch, or sodium lignin sulfonate, and has a particle size of about 50 to 200 microns. Wettable powders contain about 20 to 50% of agricultural chemical active ingredients, and are composed of an inorganic carrier and a dispersant used in powders, and are dispersed and diluted in water before being sprayed. The emulsion contains about 20-50% of the active ingredient of pesticides, xylene,
It consists of organic solvents such as hexane and mineral oil, and emulsifiers, etc., and is emulsified and diluted in water before being sprayed. The biggest drawback of such formulations of pesticides is that they produce dust during handling and spraying, and drift is noticeable not only during normal spraying but also during aerial spraying by aircraft, and their use has been drastically reduced in recent years. Fine granules were developed to prevent this drift, and although they are in practical use, they are expensive and have low concentrations of active ingredients, making aerial spraying less efficient. The volume has been stagnant in recent years. Since the wettable powder contains a large amount of inorganic carrier, the diluted dispersion is unstable and may cause sedimentation, which may clog the nozzle of the sprayer and the atomizer. Furthermore, if the dilution ratio is low, the resulting slurry becomes highly viscous or paste-like, which often causes problems when spraying small amounts of liquid by aircraft. Emulsions are excellent in terms of workability, but the biggest problem is contamination and damage to coatings caused by the organic solvents they contain. In addition, carbamate drugs, which are major insecticides, are poorly soluble or insoluble in many organic solvents, making it difficult to emulsify them, and currently commercially available carbamate emulsions contain only active ingredients.
It is about 15%. Aerial spraying of pesticides has changed from the era of solid pesticide spraying, mainly consisting of powder, to the era of liquid pesticide spraying.
And there is a sudden shift to spraying small amounts of liquid. In view of this current situation, the present inventors have developed an inorganic carrier,
Contains active ingredients at high concentrations without containing organic solvents,
In addition, we investigated a dosage form that exhibits low viscosity and excellent fluidity, and can be applied as is or diluted at a low magnification, and suitably applied to spraying a small amount or a small amount of liquid. As a result of this study, we found that dispersing and stabilizing agricultural chemical active ingredients using an aqueous dispersion of copolymer particles with a particle size of 0.1μ or less has a low viscosity and excellent fluidity, and also contains the active ingredient at a high concentration and dilutes it. It was discovered that a new formulation of agricultural chemicals that is easy to prepare can be obtained. This new form of pesticide has the above-mentioned characteristics and is an excellent pesticide. However, when stored for a long period of time, the active ingredients of the pesticide may sometimes accumulate or form a layer of supernatant water called "floating water" in the upper layer. This may result in a loss of product value. As a result of further studies to improve this storage stability, we found that dispersing the agricultural chemical active ingredient in an aqueous dispersion containing polypropylene polyol using copolymer particles with a particle size of 0.1 μ or less improves storage stability. The present invention was completed by discovering that an excellent liquid agricultural chemical can be obtained. That is, the gist of the present invention is to provide a liquid agrochemical in which an agrochemical active ingredient is dispersed in an aqueous dispersion containing a polypropylene polyol and a dispersion of copolymer particles having a particle size of 0.1 μm or less. The agrochemical active ingredient that can be used in the present invention described above may be in either powder or liquid form. The particle size of the powder is preferably 200μ or less; if the particle size is too large, the dispersion stability will be poor and sedimentation and deposition will easily occur, which is not preferred. There are a wide variety of pesticide active ingredients, but examples include:
It is as follows. The symbol or name in front of ( ) or [ ] is the common name of the agricultural chemical substance, and the symbol or name in parentheses ( ) or [ ] represents its chemical name. That is, CYAP (0-p-cyanophenyl thiophosphate = 0,0-dimethyl) as an organophosphorus insecticide;
MEP (0,0-dimethyl thiophosphate = 0-4-nitro-m-tolyl), ECP (0-2,
4-dichlorophenyl=0,0-diethyl), diazinon (0,0-diethyl thiophosphate=0-
2-isopropyl-4-methyl-6-pyrimidinyl), pyridafenethione (thiophosphoric acid 0-2,
3-dihydro-3-oxo-2-phenyl-6-
pyridazinyl = 0,0-diethyl), Marathon [S-1,2-bis(ethoxycarbonyl)ethyl dithiophosphate = 0,0-dimethyl], Dimethoate [0,0-dimethyl dithiophosphate = S-(N
-methylcarbamoylmethyl), isothioate [S-2-(isopropylthio)ethyl dithiophosphate = 0,0-dimethyl], DMTP (S-2-methoxy-5-oxo-1,3,4-thiadiazolin-4 dithiophosphate) -ylmethyl=0,0-dimethyl), DDVP(2,2-dichlorovinyl phosphate=
dimethyl), EPN (phenylphosphonothionic acid 0
Carbamate insecticides such as NAC (1-naphthyl methylcarbamate), MTMC (m-methylcarbamate
tolyl), BPMC (methylcarbamic acid 0-sec-
natural insecticides such as pyrethrin, rotenone, etc. As a tick agent,
CPCBS (p-chlorophenyl p-chlorobenzenesulfonate), chlorpropylate (p,p'-isopropyl dichlorobenzilate), fenisopromolate (p,p'-isopropyl dibromobenzilate), BPPS [2-(p-sulfite)] EDB as a nematocide
(1,2-dibromoethane), EDC (1,2-dichloroethane), DCIP [bis(2-chloro-1-methylethyl) ether], etc. Maneb [ethylene bis(dithiocarbamic acid) manganese] as a sulfur disinfectant , polycarbamate [bis(dimethyldithiocarbamic acid) ethylene bis(dithiocarbamic acid) dizinc], thiram [bis(dimethylthiocarbamoyl) disulfide], etc., TPN (tetrachloroisophthalonitrile), fusaride ( 4,5,6,7-tetrachlorophthalide), IBP (S-benzyl thiophosphate = 0,0-diisopropyl), EDDP (0-ethyl dithiophosphate = S,S-
Diphenyl), PCNB as other fungicides
(pentachloronitrobenzene), eclomesol (5-ethoxy-3-trichloromethyl-1,2,
4-thiazole), captan [N-(trichloromethylthio)-4-cyclohexene-1,2-dicarboximide], phenazine oxide (phenazine 5-oxide), CNA (2,6-dichloro-
4-nitroaniline), anilazine [2,4-dichloro-6-(0-chloroanilino)-1,3,5
-triazine], thiophanate methyl [4,
4'-0-phenylenebis(3-thioallophanic acid) dimethyl], isoprothiolane (1,3-dithiolane-2-ylidenemalonate diisopropyl), fluorimide [N-(p-fluorophenyl)-dichloromaleimide], etc. as herbicides. ,
MCP (4-chloro-0-tolyloxyacetic acid ethyl ester), DNBP (2-sec-butyl-4,6-
dinitrophenol), NIP (2,4-dichlorophenyl p-nitrophenyl ether), MCC
(methyl 3,4-dichlorocarbanilide), vernalate (S-propyl dipropylthiocarbamate), molinate (S-ethyl hexahydro-1H-azepine-1-carbothioate), DCPA (3',
4'-dichloropropionanilide), putachlor [2-chloro-2',6'-diethyl-N-(butoxymethyl)acetanilide, DCMU [3-(3,
4-dichlorophenyl)-1,1-dimethylurea], simazine [2-chloro-4,6-bis(ethylamino)-1,3,5-triazine], terbacil (3-tert-butyl-5- chloro-6-methyluracil), DBN (2,6-dichlorobenzonitrile), MDBA (3,6-dichloro-2-methoxybenzoic acid dimethylamine salt), ACN (2-amino-3-chloro-1,4 -naphthoquinone), acephenone (4'-tert-butyl-2',6'-dimethyl-3',5'-dinitroacetophenone), etc.; Indolebutyric acid [4-(3-indolyl)butyric acid]-α-naphthylacetamide (1-naphthaleneacetamide), 6
-(N-benzylamino)purine, etc., β-naphthol, cycloheximide, as a repellent and attractant,
Tetrahydrothiophene, diallyl sulfide,
Eugenol (4-allyl-2-methoxyphenol), etc., and can be widely applied to carbide-based materials, which have been difficult to emulsify. These agricultural chemical active ingredients can be used alone or in combination of two or more. The liquid agricultural chemical of the present invention contains an aqueous dispersion of polypropylene polyol containing copolymer particles with a particle size of 0.1μ or less and is dispersed in this liquid. As the aqueous dispersion of copolymer particles used for this purpose, a colloidal dispersion of a copolymer with a particle size of 0.1 μm or less, called a so-called hydrosol, is suitable. Hydrosols and emulsions can be clearly distinguished by particle size, with the former being 0.1μ or less and the latter approximately 0.15 to 0.4μ. Furthermore, there are differences in the stabilization mechanisms of the dispersion systems. That is, emulsions usually contain a large amount of surfactant, whereas hydrosols contain only a small amount or no surfactant, and the stabilization is mainly due to the dissociation of carboxyl groups. Aqueous dispersion of the above copolymer particles forming part of the present invention (hereinafter referred to as colloidal dispersion)
is a hydrosol with a particle size of 0.1μ or less, at least
It is necessary to contain 50% or more, particularly preferably 70% or more, and preferably a hydrosol containing 0.05μ or less is suitable. Emulsions with a particle size of 0.15μ or more may disperse pesticide active ingredients in the very early stages, but their retention stability is poor, and powdered active ingredients in particular tend to settle, accumulate, or float in a short period of time. Resulting in.
Furthermore, when using a so-called water-soluble polymer solution in which the polymer is completely dissolved in water at the molecular level (generally with a particle size of 0.005μ or less), the dispersibility is extremely poor and the polymer becomes paste or pudding-like, making it difficult to maintain desirable fluidity. Pesticides that have been used cannot be obtained. The copolymer in the above colloidal dispersion may be one that forms an aqueous colloidal dispersion depending on the balance between the dissociation of hydrophobic groups and carboxyl groups, and in particular, the copolymer composition, polymerization method, manufacturing method, etc. There is no limit to A preferred method for introducing the carboxyl group is easy and copolymerization of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, and crotonic acid. Examples of the hydrophobic monomer include acrylic acid alkyl ester, methacrylic acid alkyl ester,
Examples include vinyl acetate, styrene, acrylonitrile, vinyl chloride, vinylidene chloride, and olefins such as ethylene, propylene, butadiene, and isobutylene. Furthermore, hydroxyl group, sulfonate group,
A suitable amount of a monomer having an amide group or an alkylammonium group may be copolymerized. The polymerization method is preferably emulsion polymerization or solution polymerization because it is simple. For example, Special Publications No. 49-36942, No. 52-5341,
It can also be produced by the method disclosed in No. 52-47489. In the case of emulsion polymerization, an unsaturated carboxylic acid and a comonomer are polymerized in the presence of a small amount of an emulsifier, followed by heating and adding a solvent as necessary under mechanical shearing. A colloidal dispersion is prepared by partially or completely neutralizing with an alkali such as ammonium oxide or organic amine. When a solvent is added, it is removed by distillation as necessary. The amount of unsaturated carboxylic acid suitable for making a colloidal dispersion varies depending on the unsaturated carboxylic acid, the type of neutralizing alkali, the composition of the comonomer, etc., but is generally 5 to 30% by weight ( (total amount of monomer)
In the case of a copolymer mainly composed of acrylic acid alkyl ester, the amount of acrylic acid or methacrylic acid is about 5 to 15% by weight. The degree of neutralization is preferably the minimum amount required to form a colloidal dispersion, and a pH of 6 to 8 is appropriate, and a pH of 7.5 or less within this range is particularly desirable. This is because many of the active ingredients of agricultural chemicals are decomposed by acids and alkalis, especially alkalis. The alkali is preferably sodium hydroxide or an organic amine with a relatively high boiling point, such as mono-, di-, or triethanolamine, morpholine, or the like. This is to make it easier to wash away pesticides from hands, protective clothing, sprayers, and painted surfaces that have drifted and adhered to them when spraying pesticides. The copolymer used in the present invention can be similarly produced by solution polymerization, or by polymerizing an unsaturated carboxylic acid and a comonomer in a hydrophilic or hydrophobic organic solvent, and after neutralization, the solvent is removed with water. A colloidal dispersion is obtained by substitution. As another production method, an unsaturated carboxylic acid such as maleic acid is added to rosin or petroleum resin at high temperature, and a colloidal dispersion is obtained by neutralization with alkali. Furthermore, lower alkyl esters such as methyl acrylate and ethyl acrylate can be saponified with a strong alkali such as sodium hydroxide and potassium hydroxide to form a colloidal dispersion. These aqueous colloidal dispersions have dissociation of hydrophobic groups and carboxyl groups [-COOMM is Na,
K, Li, _NH4 ,

It is stabilized by the balance of counter ions such as [formula], and is considered to be a type of polymeric surfactant. Pesticide active ingredients with hydrophobic and hydrophilic groups are attached and adsorbed to colloidal copolymer particles, and move smoothly through the system together with colloidal particles, resulting in excellent fluidity and low viscosity pesticides. It is presumed that On the other hand, the polypropylene polyol used in combination with the colloidal dispersion has an ether bond based on propylene oxide in the molecule, and a secondary
This refers to polyether polyols having primary OH groups or primary OH groups. A specific example of a chemical formula is as follows. (1) As a diol (2) As a triol (3) As a polyol Although this is the above, the structure is not particularly limited to this. Here, n is an integer that may be the same or different, and m is also an integer. Further, all of the ether constituent units need not be based on propylene oxide, and as long as at least 30% is propylene oxide, the rest may be based on ethylene oxide. That is, the colloidal dispersion as an aqueous dispersion may contain a polyalkylene polyol in which at least 30% of all alkylene groups are propylene groups.
These polypropylene polyols are generally rarely obtained in pure form, but in the form of mixtures of various molecular weights. The average value of these molecular weights is 200~
A number of about 10,000 can be preferably used in the present invention.
Further, mixtures of two or more of diols, triols, and polyols of higher types can also be preferably used. The amount of polypropylene polyol to be blended is 5 to 100 parts, preferably 5 to 100 parts per 100 parts (parts by weight of solid content) of the copolymer for forming the colloidal dispersion.
10 to 60 copies. If the amount of polypropylene polyol is small, the active ingredient of the pesticide will accumulate and “floating water” will occur.
The improvement effect is small, and adding more than necessary is not only economically disadvantageous but also undesirable because it increases the viscosity of the liquid agricultural chemical. By incorporating such a polypropylene polyol, the storage stability of liquid agricultural chemicals is further improved. The reason for this remarkable improvement in storage stability is not clear, but a nonionic polymer hydration layer is formed on the surface of the colloidal particles of the aqueous copolymer dispersion, and pesticides are adsorbed to this hydration layer. By being stabilized,
It is presumed that storage stability is imparted. The outline of the method for producing the agricultural chemical of the present invention will be described below. First, a colloidal dispersion, ie, an aqueous dispersion of copolymer particles with a particle size of 0.1 μm or less, is prepared to a concentration of 10 to 50% by weight. If restrictions on viscosity are acceptable during work, it may be 50% by weight or more. The viscosity at this time is preferably 10 to 10,000 cps, particularly about 10 to 1,000 cps from the viewpoint of workability. Polypropylene polyol is liquid at room temperature, and can be easily dispersed and mixed by adding it directly to a colloidal dispersion and stirring. The viscosity of the system increases slightly due to the addition of polypropylene polyol. The viscosity of the dispersion after blending is 20 to 2000 cps.
From the viewpoint of workability and stability of the pesticide, it is preferable to keep the amount of water at a certain level. Pesticide active ingredients can be applied in either solid or liquid form, but in the case of solids, it is preferable to crush them into powder.
The particle size should be 200μ or less. 100 parts of a mixed solution of polypropylene polyol and colloidal dispersion are efficiently stirred, and 20 to 300 parts, particularly preferably 20 to 150 parts, of the agricultural chemical active ingredient are gradually added and stirring is continued until uniform mixing is achieved. In this case, an antifoaming agent may be added to the mixed liquid in advance, if necessary. Agrochemicals with excellent fluidity of 50 to 10,000 cps can be obtained by stirring for about 30 minutes to 1 hour. If the viscosity is too high, adjust the concentration and amount of the liquid mixture and the amount of the agricultural chemical active ingredient to reduce the viscosity. Despite the high concentration of 15 to 60% by weight, the obtained pesticide shows excellent fluidity, has good storage stability over a long period of time, and can be easily diluted with water. Alternatively, the agrochemical active ingredient may be dispersed in a colloidal dispersion and then the polypropylene polyol may be added. Sodium polyacrylate, ammonium polyacrylate, carboxymethyl cellulose, hydroxyethyl cellulose, methyl callose, sodium lignin sulfonate, polyvinyl alcohol, polyethylene glycol, gelatin, starch, casein, sodium alginate, guar gum, locust bean gum, as required A small amount of water-soluble polymer such as xanthan gum may be added. If the amount added is too large, the stability of the system will be impaired, so care must be taken in this regard. In addition, surfactant if necessary,
It is also possible to mix a small amount of a polymer emulsion and an organic solvent. The present invention makes it possible to spray trace or small amounts of carbamate pesticides, which were conventionally difficult to emulsify, avoids problems caused by organic solvents in emulsions, and has excellent long-term storage stability. It is possible to obtain a new form of pesticide, and it can be said that its industrial value is extremely large. Next, examples and comparative examples will be shown to specifically explain the present invention. The colloidal dispersions used in each example (Examples 1 to 25) were A, B, C, D, and E shown in Table 1 below.
There are five types of polypropylene polyols, and six types of polypropylene polyols are A, B, C, D, E, and F shown in Table 2.

【table】

【table】

[Table] Example 1 The colloidal dispersion A700 shown in Table-1 was
It was transferred to a beaker, and 90 g of polypropylene polyol A shown in Table 2 and water were added to make a total of 1 kg.
The concentration of the prepared aqueous solution will be 30%. 7cm long 4
Stirring was performed using a stirrer equipped with blades at a rotation speed of 300 rpm. While stirring, 750 g of NAC (1-naphthyl methylcarbamate) powder was gradually added over 3 minutes.
NAC powder spreads and mixes smoothly after addition.
After 10 minutes, the mixture became almost homogeneous. Stirring was further continued for 30 minutes after the addition was completed to obtain a white homogeneous liquid pesticide. Although this pesticide contained a high NAC concentration of 42.9%, it had a low viscosity of 2450 cps and had good workability. The storage stability (see note in Table 3) was also good, making it suitable as an agricultural chemical for aerial spraying. Examples 2-25 Agrochemicals were produced according to Example 1 with the compositions shown in Table-3. When an antifoaming agent was added, the foam disappeared and the mixture could be mixed more smoothly. Agrochemicals with low viscosity and excellent fluidity were obtained, which can be applied to various types of agrochemical active ingredients in liquid and powder form. All had good storage stability and were suitable as agricultural chemicals for aerial spraying.

【table】

[Table] Comparative Examples 1 to 6 Table - as a liquid for dissolving or mixing pesticide active ingredients
A test according to Example 1 was conducted using the material shown in Example 4. The results are shown in Table 4.

[Table] From this Table-4, the following can be said. (1) Even when the agrochemical active ingredient is dispersed and mixed using a completely dissolved aqueous polymer solution (Comparative Examples 1 to 4), the viscosity increases during preparation, loses fluidity, and solidifies into a paste or pudding. And then the next day,
It was found that solidification progressed and it was unsuitable as an agricultural chemical formulation. (2) In Comparative Example 5, in which the pesticide active ingredient was added to the emulsion, the dispersion had low viscosity and good miscibility, and became a uniform white dispersion immediately after stirring, but the retention was poor and the NAC was reduced the next day. It is difficult to say that it is ideal because it has settled and accumulated. (3) When a nonionic surfactant is used (Comparative Example 6), it solidifies the next day, similarly to Comparative Examples 1 to 4, and is inappropriate. Comparative Examples 7 to 11 Table 1 without blending polypropylene polyol
A pesticide active ingredient was added only to the colloidal dispersion shown in Example 1 according to Example 1, and the test was conducted. The results are shown in Table 5. In both cases, the dispersibility of the active pesticide ingredients is good, but in an accelerated storage stability test at 50°C for 30 days, sedimentation or "floating water" occurred, indicating poor long-term storage stability. .

【table】

Claims (1)

[Claims] 1. A liquid agrochemical in which an agrochemical active ingredient is dispersed in an aqueous dispersion containing copolymer particles with a particle size of 0.1μ or less and a polypropylene polyol.