HU183071B - Process for producing solide or sprayable compositions containing herbicides as active agents - Google Patents

Abstract

The present invention relates to a process for the preparation of sprayable compositions wherein the 15-95% herbicidal active ingredient or mixture of active ingredients is admixed with a known excipient in an amount of 3 to 55% which provides the necessary wetting and dispersing effect alone. The compositions thus produced have a better buoyancy and wettability, and a lower foaming capacity than the compositions containing the separate dispersant and wetting agent. The sprayable herbicidal compositions of the present invention comprise a liquid wetting dispersant obtained by condensation of β-naphthalene sulfonic acid and aqueous sulphite alkali earth by formaldehyde. For solid sprayable agents, a solid wetting agent, dispersing agent is used in the preparation of the agent. -1-

Description

The present invention relates to a process for the preparation of spray formulations containing one or more herbicidal active ingredients.

It is known that in agriculture (especially in plant protection) the active compounds, in their original concentrated form, cannot be used directly but must be formulated with suitable formulation aids and processes which can be sprayed directly at the application site (diluted with water to the prescribed concentration). Formulations of this type include wetting powders (WP formulations), aqueous suspensions (FW formulations), aqueous solutions and emulsifiable concentrates (WSC and EC formulations).

Wettable powder formulations contain, in addition to the active ingredient, wetting agents, dispersing agents and, optionally, other additives, such as carriers (such as aluminum or magnesium silicate, synthetic silicic acid, etc.), viscosifying agents, preservatives and the like. The amount of active ingredient in wettable powders varies within wide limits; these preparations usually contain from 20 to 80% of the active ingredient. The total amount of dispersants and wetting agents in wettable powder formulations is usually 0.5 to 15%.

Aqueous suspensions generally contain up to 50% of a solid, particulate, poorly water-soluble or water-insoluble active ingredient, as well as dispersants and wetting agents. The total amount of dispersants and wetting agents used in these products usually ranges from 0.5% to 15%. Aqueous suspensions may also optionally contain further additives such as antifreeze agents (such as ethylene glycol), antifoam agents (such as silicone oil), preservatives, corrosion inhibitors, and the like.

Aqueous solutions and emulsifiable concentrates generally contain from 20% to 60% active ingredient, 2% to 10% wetting and emulsifying agents.

Wettable powder formulations are usually prepared by dry grinding a suitable mixture of the components, and aqueous suspensions are generally prepared by wet milling a suitable mixture of the components. The aqueous solutions and emulsifiable concentrates are obtained by simple mixing.

The wetting agents and dispersants used in the formulation of the herbicidal active ingredients in WP are as follows:

- they allow the preparation to form a suspension in water, - stabilize the resulting suspension, - promote the wetting effect of the sprayed suspension, e.g. moistening foliage or soil particles.

In EC formulations, emulsifiers and wetting agents ensure that the concentrate, when poured into water, forms a spontaneous emulsion, the emulsion is stable and well wetted. The WSC formulation does not always contain a wetting agent.

A further essential requirement for dispersants, wetting agents and emulsifiers for use in WP formulations of herbicides is that these agents are not toxic in themselves and do not adversely affect the biological activity of the active ingredient. Foaming of aqueous solutions of wetting, emulsifying or dispersing agents is also a requirement for the applicability of the finished product.

Since excipients with good dispersing properties usually have little or no wetting effect, in practice a mixture of dispersants and wetting agents is used to achieve the desired effect.

The wettable powder formulations and aqueous suspensions containing the herbicidal active ingredient are most often dispersants such as lignin sulphonic acid salts, methylcellulose or other celluloses, and as the wetting agent usually soaps, sulphated fatty alcohols, sulphonic acid aryls, , and ethylene oxide adducts of fatty alcohols and alkyl phenols. Compositions of this type, including dispersants and wetting agents, are disclosed, for example, in U.S. Patent Nos. 165,806, 166,087, 167,463, 168,897, 168,910, 169,434, 169,480, and 170,426. Hungarian Patent Specification No. 1,542,978,

642,273, 1,807,567, 2,135,768, 2,400,217, and

No. 602,537 German Patent Publication No. 1 152 185, 1 168 029, 1 168 932, 1 205 085, 1 206 155 and 1 434 697 British Patent Specification.

The disadvantages of using a separate dispersant and a separate wetting agent for the preparation of wettable powder formulations and aqueous suspensions containing the herbicidal active ingredient are the following: first, the dispersant must be selected for the active ingredient to provide sufficient buoyancy. The selection of an effective dispersant requires many attempts. At the same time, perfect wetting of the solid particles in the system must be achieved, which requires separate attempts to select or apply the appropriate wetting agent.

The use of two types of substances also raises the problem of the proportion at which they are best used and whether they are chemically and biologically compatible. Particular difficulties arise from the potential toxicity of wetting and dispersing agents and from the potential for increased toxicity in mixtures. Finding these also requires arduous experimental work.

In addition to the complexity and complexity of the experimental work, the use of a separate dispersant and a separate wetting agent also has technological disadvantages. The possible differences in consistency between the two materials, the fluctuations in their quality, the harmonization of the frequently changing qualities, and the possible different treatment of the two materials give rise to technical difficulties.

Most of the above-mentioned known and widely used wetting agents have a high foaming effect in aqueous solution, which significantly complicates the spraying of the formulated pesticidal formulations.

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Technically, there would be a need for an agent that combines the advantageous properties of known dispersants and wetting agents without their drawbacks, thereby providing a technological advantage in their use.

FIELD OF THE INVENTION The present invention relates to a process for the preparation of a sprayable herbicidal composition containing a dispersant having a wetting effect.

In our experiments, the unexpected result was that no additional wetting agent was required for WP formation if the dispersant was followed by condensation of formaldehyde with β-naphthalenesulfonic acid and aqueous sulfite solution, neutralization of the resulting mixture, . The material is preferably used in powder form (ND) for WP formulation, for liquid serum forms, 40-60% is preferably 50% active ingredient concentrate (ND-F). Sprayable herbicidal formulations containing this type of wetting agent do not foam during wet milling or spraying, remain stable in hard water, spread well on the surface to be treated, and possibly through interaction between the dispersant and the agent. is absorbed faster.

The process according to the invention is technologically much simpler to prepare than compositions containing conventional ornamental dispersants and wetting agents because of the need for a single formulation which is easy to formulate, rather than two separate components. The compositions of the present invention exhibit an optimal wetting and dispersing effect in terms of both preparation (grinding) and storage stability and use (dilution with water and subsequent spraying). The dispersant, which also has a wetting effect, is resistant to acids and alkalis, so it can be safely used in aqueous compositions with a pH other than neutral.

Further experiments have shown that the application of the substance in the liquid form of the herbicides results in an increase in the efficacy of the active ingredient. Studies in plants have shown that the composition with a 50% wetting agent dispersant has an increased herbicidal effect, which means that using 3 kg / ha of the compound according to the invention, herbicide is more effective than using the right amount of active ingredient. we would have applied it alone. This enhanced herbicidal effect can be detected, for example, in Zea mays, Avena sativa, Beta vulgaris, Trifolium pratense, Sinapis alba, Panicum capillare, Setartia viridis and Echinochloa crus-galli. In this way, the mixture prepared by the process we have developed also results in a saving in active ingredient, which is not insignificant.

To prove this fact, the results of experiments with maize crop are shown below in Figures 1-3. Table.

Table 1

Enhancement of herbicidal action with a wetting agent dispersant

Test plant: maize

herbicide Dose 1 / ha Disp. wetting Dose 1 / ha HER the herbicide effect %-the Plus effect %-the Dinoseb- acetate (standard) 1.5 30 0 Dinoseb- acetate 1.5 the invention of material 3 50 20 Dmoseb- acetate 1.5 the invention of material 6 60 40 glyphosate (standard) 1 - 70 0 glyphosate 1 the invention of material 3 90 20 glyphosate 2 the 6 100 30

material of the invention

Table 2

Enhancement of herbicidal action with a wetting agent dispersant

Test plant: maize herbicide formulation Dose 1 / ha Disp. wetting Dose 1 / ha HER the herbicide effect %-the Herbicide plus effect "- _the" o " Arets 50 * 3 - - 20 0 (standard) Arets 50 * 3 invention of wetting effect dispersing ammunition 3 50 30 Arets 50 * 3 invention of wetting effect dispersing ammunition 6 60 40 Glialka 20 ** 5 - - 70 0 (standard) Glialka 20 ** 5 invention of wetting effect dispersing ammunition 3 90 20 Glialka 20 ** 5 invention of wetting effect dispersing ammunition 6 100 30

* = 50% Dinosebacetate ** = 20% Glyphosate

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Table 4

Table 3

Enhancement of herbicidal action with a wetting agent dispersant

Test plant: maize

Herbicidal formulation Application rate 1 ha Herbi- cid effect %-the % Of plus effect 40% glyphosate 10 10% alkyl polyethylene glycol ether 50% water 20% glyphosate 2.5 70 0 15 50% dispersant according to the invention 30% water 2.5 90 20 20% glyphosate 50% dispersant according to the invention 30% water 5 100 30 20

It is clear from these data that when moisturizing dispersant by the present process was proven in practice and ⁵ used herbicidal agents, so their effect significantly increases.

Table 3 shows that the molded material produced by us herbicide effect _3Q 20% better than a gyomirtószeré containing double amount of the active material. If the amount of active ingredient is doubled in the experiment, the herbicidal effect reaches 100%. Thus a 30% increase over the ₃₅ impact against the agent containing the same amount of glyphosate.

The effect of the dispersant used in the compositions of the present invention, which also has a wetting effect, on plant organisms alone was investigated under greenhouse conditions following post-emergence treatment. Under these conditions, plants are most sensitive to chemicals. The powdery dispersant (ND) and an aqueous solution of the dispersing agent 50% (ND-D) were tested on the resulting plants követ- _45:

Zea mays (corn), Avena sativa (oats), Trifolium pratense (red testis), Sinapis alba (mustard), Panicum capillare (millet), Beta vulgaris (sugar beet), Setaria viridis (muhar), Echinochloa grus-galli 59 (Cocksfoot) ).

The results of the tests are shown in Table 4.

plant species kg / 2 Pusztu ND if 1000 liters ND-F water 2 using 20 % of views 200 20 200 Zea mays 0 0 0 0 0 0 Avena sativa 0 0 0 0 0 0 Beta vulgar 0 0 1 0 0 1 Trifo'ium pratense 0 0 2 0 0 3 Sinapis alba 0 0 10 0 0 10 Panicum capillare 0 0 0 0 0 0 Setara viridis 0 0 0 0 0 0 Echirochloa crus-galli 0 0 0 0 0 0

The data in Table 4 confirm that the phytotoxic dose range of the dispersant with wetting effect starts at a dose of about 200 kg / ha. Considering that up to 2 kg to 5 kg of dispersant per sprayed area of these pesticide formulations, no adverse biological effects are to be feared when using this new type of dispersant.

In the WP formulation process of the present invention, 0.5 to 20% by weight of the wetting dispersant and 3 to 55% by weight of the liquid serum formulation are preferred.

The following examples illustrate the composition of the herbicidal compositions of the present invention without limiting the scope thereof.

Example I

Process for the preparation of a wetting agent dispersant

100 parts by weight of crude naphthalene were melted at 130 ° C and sulfonated with 96-98% sulfuric acid at 130-160 ° C for 4 hours. The resulting melt, predominantly of β-naphthalene sulfonic acid, was poured into an autoclave previously filled with 40 parts by weight of an ash-free, 50% by weight dry matter sulfite base. The sulphite lye concentrate is obtained by evaporating the sulphite waste liquor from the pine tree sulphite digestion. The composition of the sulphite alkali concentrate used (on a dry basis) is as follows: lignin sulphonic acid: 50-55% by weight, reducing sugars: 25-30% by weight, sugars: 4-8% by weight, resins: 2-4% by weight, total sulfur content: 2 - 4% by weight, ash content: 0.5 - 5% by weight. Subsequently, 35 parts by weight of water are added to the autoclave, the temperature of the mixture is adjusted to 65 to 70 ° C, and 30 parts by weight of a 40% aqueous solution of formaldehyde are added slowly, keeping the temperature at 80 ° C. below. After the addition of the formaldehyde solution, the mixture was stirred for 3 hours at 80-85 ° C, and the pH of the mixture was adjusted to 6.5 to 7.5 with concentrated aqueous ammonia (about 75-80 parts by weight of concentrated aqueous solution). need ammonia solution). The neutralized mixture contains 380 parts by weight of the same grade of sulphite alkali concentrate

183,071 was added, the mixture was stirred at 70-75 ° C for half an hour, and the pH of the mixture was adjusted to 6.5 to 7.5 with concentrated aqueous ammonia. The resulting mixture was concentrated to a dry solids content of 50-60% by weight and optionally dehydrated.

Example 1

In preparing a liquid composition, the wetting agent is first dissolved in water and then the active ingredient is dissolved. The wetting dispersant is used in a 50% solution.

Quantity of the ingredients of the mixture:

20% glyphosate (N-phosphonomethylglycine)

50% wetting liquid dispersant (ND-F) (prepared according to Example I; dry matter content: 50%)

30% water.

Example 2

A slurry was prepared by wet milling in a pearl mill.

Materials used:

50% atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine)

15% ethylene glycol

Solid dispersant (ND) with 8% wetting effect (Example I)

27% water.

Example 6

By grinding, a solid spray was prepared from the following materials:

55% Cl-Br-uron (N- (4-bromo-3-chlorophenyl) -N'methoxy-N'-methylurea)

18% synthetic silica 20% kaolin

7% ND

Example 7

By grinding, a solid spray was prepared from the following materials:

40% propachlor (N-isopropyl-2-chloroacetanilide)

14% Cl-Br-uron

11% atrazine

20% Silica 7% Calcium Silicate 8% ND

In Example 1, the use of ND-F has the advantage of enhancing the action of glyphosate. In this way, less active ingredients should be used to achieve the same herbicide effect.

A-2-7. The results of the tests for the quality of the formulations exemplified in Examples 1 to 4 and the results of the tests are set forth below. The following formulations were used as comparators for the quality tests:

Example 3

By grinding, a solid product was prepared from the following materials:

95% atrazine 5% dispersant.

Preparation A:

55% linuron

17% synthetic silica 20% kaolin

4% alkylphenol polyethylene glycol ether 4% lignin sulfonic acid salt

Example 4

By grinding we made a solid spray from the following materials. '

55% monolinuron (N- (4-chlorophenyl) -N'-methoxyN'-methylurea)

20% synthetic silica 20% kaolin

5% ND

Example 5

By grinding, a solid spray was prepared from the following materials:

55% linuron (N- (3,4-dichlorophenyl) -N'-methoxy-N'-methylurea)

17% synthetic silica 20% kaolin

8% ND

Preparation B:

55% Cl-Br-uron

18% synthetic silica 20% kaolin

4% alkylphenol polyethylene glycol ether 3% lignin sulfonic acid salt

Preparation C:

65% propachlor

27% silica 4% fatty alcohol sulfate 4% lignin sulfonic acid salt.

Floatability, wettability and foaming ability were determined for formulations.

The floating capacity is described in U.S. Patent No. 21,922-65. measured according to the method described in Hungarian standard.

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The wettability was determined as follows:

A 500 ml beaker, 8 cm in diameter, was filled with tap water at 20 ° C and 12 NK 'hardness. The time required to moisten the powder was then measured.

The foaming capacity was determined under the same conditions as the buoyancy measurement, except that only 150 ml of the 0.5% aqueous suspension of the powder composition was measured in a 250 ml graduated stoppered graduated cylinder.

The foam volume was read immediately after thirty shaking and after 5 minutes of standing. The results of the assays are shown in Table 5.

Table 5

Preparation (example number) Air- ability, ° / / 0 wetting time s Foam volume, ml immediately After 5 minutes Second 99 - 5 1 Third 99 8 6 1 4th 93 12 6 1 5th 85 10 5 1 6th 86 10 4 1 7th 89 13 5 1 THE. 75 20 115 90 B 74 15 110 95 C. 70 20 130 120

The data in Table 5 show that the herbicidal WP formulations prepared by the process of the present invention have a better buoyancy and wettability and a much lower foamability than the samples containing separate dispersants and separate wetting agents.

Claims (2)

CLAIMS 1. A process for the preparation of solid or spray formulations containing one or more herbicidal active ingredients comprising 15 to 95% active ingredient or mixture of active ingredients, 12 to 40% additive (s), wherein said mixture is present in an amount of 3 to 55% at room temperature. powder or a 40 to 60% dry solids, wettable dispersant prepared by condensation and neutralization of β-naphthalenesulfonic acid ⁰ and aqueous sulfite solution in formaldehyde. (Priority: November 12, 1982) 2. A process for preparing a solid or sprayable formulation (5 for the preparation of wafers containing 15 to 95% of your active ingredient), 2 to 40% of your additive) containing one or more herbicidal active ingredients, characterized in that the dispersant is stirred at room temperature and It was prepared by condensation and neutralization of 10 β-naphthalenesulfonic acid and aqueous sulfite alkaline solution. (Priority: January 18, 1980)