DD209953A5 - CHEMICALLY STABLE HERBICIDAL COMPOSITIONS - Google Patents

Abstract

The invention relates to novel herbicidal compositions for use in agriculture. The aim of the invention is to provide chemically stable herbicidal compositions whose active ingredient content remains constant over a long period of time. According to the invention, chemically stable m-bis-carbamate based herbicidal compositions are provided which additionally comprise a surface active agent of the class of phosphoric acids mono- or diesterified with polyoxyethylated alkylphenol of general formula II in which X represents a hydroxyl group or a group, m and n independently represent an integer from 1 to 80, such that the sum m + n is equal to or less than 80; p is an integer from 1 to 4, preferably 1; R is a linear or branched C deep 4 -12 alkyl group, a bis-alpha-phenylethyl group or a benzyl group.

Description

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Chemically stable herbicidal compositions Field of application of the invention

The present invention relates to stable herbicidal compositions, in particular to herbicidal compositions containing m * 3-ish carbamates, for agricultural use ♦

Characteristic of the known technical solutions

The herbicides designated as ra-bis-carbamates are compounds with good herbicidal activity which have been used for many years in the weed killing of important agricultural crops. The m <-8-carbamates may be replaced by the following; general. Formula to be represented * · -.

⁰ R *

I! ^ ^R

ο - c -

R ²

NH-C-O-RU 0

(1) 3

Representative examples of herbicides of this class are phenmediphara (Trivialna.me the compound of formula I, in

which R = H, R ^ = 3-tolyl, R ° = CHL,) and DesIndipham

° 1

(Trivial name of the compound of formula I in which R = H>

R ² = phenyl, R ³ = ethyl),

η η

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These herbicides are generally used in the form of liquid compositions _t to be diluted before use, and consist of the active substance, an organic solvent and a surfactant "

Examples of usable in the above compositions, organic solvents are aromatic hydrocarbons, alicyclic ketones (cyclohexanone, isophorone) t esters Dimethylformajnid Dimethyl sulfoxide, etc .; usable surfactants are ζ * Θ * polyethoxylated alkylphenols, alcohols, carboxylic acids and amines, and alkylbenzenesulfonic acid

3 salts or naphthalenesulfonic acid salts.

The disadvantage of these formulations formulated in the usual way is that during the. Storage tends to emerge / significant decomposition, therefore, the concentration of the herbicide decreases and the herbicidal activity of the compositions is reduced.

 Such compositions are often physically unstable because the active substance, especially at high and low temperatures, tends to crystallize, resulting in deposits and solid, discrete products.

In order to overcome such disadvantages, various solutions have been investigated which, however, include the use of complex mixtures (not less than four components) of solvents, stabilizers and surfactants in the compositions.

US Pat. No. 3,898,075 describes a process for stabilizing the herbicide in liquid compositions, which comprises adding to the compositions, in an amount of from 0.05 to 5% by weight, an organic acid selected from one of the following classes: aliphatic Dicarboxylic acids, aliphatic hydroxycarboxylic acids, nitroaromatic monocarboxylic acids, aromatic bicarboxylic acids, aliphatic or aromatic sulfonic acids _f is added.

The above patent also teaches that other acids, such as i.a. Phosphoric acid, are not suitable for stabilizing the herbicides of the formula I.

BE-PS 884 482 describes herbicidal compositions containing phenmedipham as the active substance. These compositions have been found to be physically stable at high and low temperatures for long periods of time.

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aim the invention

The aim of the invention is to provide new herbicidal compositions which are chemically stable,

Explanation of the essence of the invention

It is an object of the present invention to find suitable additives which provide chemical stability on the basis of m- biscarbamate herbicidal compositions »

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In monitoring investigations to those described in the above BE-PS compositions has been found that a particular, represented here composition consisting of 40 Gevi * ~% Phenmediphara, 30 wt ~% dimethylformamide, 20 Gevi _e ~% xylene and 10 wt - "Rolfen 10 D" ® (trademark for a mixture of mono- and diesters of phosphoric acid with nonylphenol polyoxyethylated with 10 moles of ethylene oxide per mole of substrate), which confers considerable chemical stability to the active substance by adding phenmedipham is subject to only negligible decomposition over time.

It has also been found that a number of known surface-active compounds derived from polyoxyethylated alkylphenols of mono- and di-substituted phosphoric acid, but having at least one free acid functionality, as described below, the m-8is-carbamate herbicides in compositions for agricultural .Use one to confer remarkable chemical stability *

The fact that these surfactants derived from phosphoric acid and having at least one free acid functionality capable of stabilizing m-bis-carbamate herbicides is particularly surprising, bearing in mind that U.S. Patent 3,898,075 teaches that U.S. Pat Phosphoric acid is not suitable for this purpose.

According to the invention, chemically stable herbicidal compositions based on barium carbamates are available

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which at a ratio of 90: 1 b-is 1:40 is a surface-active agent or a mixture of surfactants from the class of polyoxyethylated alkylphenol mono- and di-substituted phosphoric acid of the general formula

W ^ " 2.2m

HO-P

in which

X is a hydroxyl group or a group

- (0 - CH ₂ - CH ₂ ) _n - ° Λ O /;

in and η are each independently an integer from 1 to SO inclusive, such that the sum m + η is less than or equal to 80?

ρ is an integer from 1 to 4, preferably 1; R is a linear or branched C ^ ₂ alkyl group, a bis ~ p -hylyl group or a benzyl group is _r *

The use of the surfactants of formula II as stabilizers in the herbicidal compositions containing the m ~ 3is-carbafiiates makes it possible to avoid the use of other additives and offers the considerable advantage of stable compositions of ra-bis-carbamate.

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consisting only of the active substance, an organic solvent and a surfactant of the particular class mentioned *

In particular, according to the invention stable herbicidal compositions are provided, of m ~ to ~ carbamates of the composition:

a) herbicidal m-bis-carbamate of formula I 0.5 to 45 wt .- /;

b) Surfactant of the formula II 0.5 to 20% by weight

c) organic solvent selected from aromatic or alkylaromatic hydrocarbon * alicyclic ketones, esters of carboxylic acids, dimethylsulfoxide, dimethylformamide, honoester glycols or mixtures thereof to 100 G®N _m ~%

with the proviso that when the herbicide of formula I is phen'-medipham, the surfactant "Rolfen 10 D" ® and the solvent is a mixture of disethylformamide and xylene, these substances are in a weight ratio other than 40: 10: 30 : 20, since this composition has already been described in BE ^ -PS 884 482.

The compositions of the present invention are long stable because, as shown in the examples, the herbicide undergoes only negligible decomposition, while in the conventional compositions the degradation is significant.

The compositions of the present invention are generally self-emulsifying in water due to the presence of compound II, which acts both as a stabilizer and as a surface active agent.

However, if the chosen solvent is sparingly soluble in water and if the compound of formula II is used in amounts near the lower limit (eg less than 4% by weight), it may be convenient to use a conventional surfactant of another chemical To add class, only to improve the emulsifiability of the composition according to the invention in water.

Organic solvents useful in the compositions of this invention are e.g. Benzene, toluene, xylene, also in the form of commercially available isomeric mixtures, alkylbenzenes having 9 to 12 carbon atoms, also in the form of commercial mixtures, cyclohexanone, isophorone, ethyl acetate, butyl or

2-octyl phthalate, methyl cellosolve, cellosolve acetate, etc.

The amount of the herbicidal formula I in the composition depends on its solubility in the chosen organic solvent.

The compounds of formula II are known as surfactants, also for use in agriculture; however, their use in stabilizing herbicides of the m-bis-carbamate class has hitherto never been described, as far as is known.

The surfactants of formula II are available as a single compound or mixture, both in terms of the number of moles of ethylene oxide per mole of phosphoric acid derivative and with respect to the sub-

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Stituents on the phenolic ring, readily available commercially. Also commercially available are mixtures of mono- and diesters of phosphoric acid of formula II with a different degree of ethoxylation *

If a particular, not readily available commercially available compound of formula II is desired * then this can be easily prepared by known methods. "Thus, z * B, a mono- or Oihalogenid of phosphoric acid with 1 or 2 Hol of an alkali salt (phenates) implement a polyoxyethylated alkylphenol by known methods *

As is known, ethoxylation is controllable over a wide range, but by nature the reaction provides mixtures of products with a number of ethylene oxide per mole of substrate in a fairly narrow range, hence the term "degree of ethylation" means the statistical average of the number of moles of ethylene oxide per mole of substrate »

The preparation of the compositions according to the invention is carried out by mixing the components in the predetermined amounts. The practical purposes and the results obtained are quite analogous to those obtained with known compositions containing the same herbicides,

Execution example

The following examples illustrate the present invention using the following abbreviations:

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Surface active agents of the formula II

l! tl $ -llz ~ ~ ^with -nonylphenol which has been polyoxyethylated with 10 ETO (10 moles of ethylene oxide per mole of substrate). monoesterified phosphoric acid; the product available as "Rolfen 10" ® from ROL Co was used. 1® £ 3 £ _ίίζ5 ⁼ Mixture of one with nonylphenol polyethoxylated with 10 ETO Xst ₁ dibbled phosphoric acid and Tens II Aj was the product of ROL Co "Rolfen 10 D" ®,

- Jt -

Tens IIiC = with bis - ^ - phenylethylphenol which has been polyoxyethylated with 10 ETO, monoesterester phosphoric acid; verwen-j det was the product of the ROL Co. as "Rolfen 40" commercially available.

Tens_II-D - = with nonylphenol polyoxyethylated with 80 ETO, monoesterified phosphoric acid; was used as the "Rolfen 80" ^ commercially available material of the ROL Co.

Surface active agents of the comparative compositions OR-25 ETO = polyoxyethylated castor oil with 25 ETO DBS-Ca = calcium dodecylbenzenesulfonate solvent

DMF = dimethylformamide; DMSO = dimethyl sulfoxide, xylene = commercial mixture of xylene isomers.

15 Example 1

A composition according to the invention (composition 1.1) was prepared by dissolving 5 g of phenmedipham in 90 g of cyclohexanone and adding 5 g of surfactant HA to the solution. The mixture was stirred to homogeneity at room temperature Composition 1.1 was placed in a thermostat at 54 ° C and allowed to sit for 14 days. At the end of the heating time, phenmedipham was quantitated directly by high performance liquid chromatography (HPLC) on Sample ¹ '. A decomposition below 0.5% was noted.

25 Example 2

The compositions according to the invention prepared according to Example 1 are listed in Table 1, while comparison compositions containing no surface-active agents or those of different classes are shown in Table 2.

30 are guided.

ω oil ω ο ia * ι, 2 Ν. U O Table 1 Oil 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 O Ι.13 Oil Component; Wt .-% 5 15 Compositions according to the invention Composition no. 30 30 30 45 15 15 15 15 30 1.12 30 1.14 Herbicide of the formula I 90 80 60 60 60 45 80 65 5 5 20 .55 20 55 30 15 15 30 15 15 Phenmedipham Desmedipham of formula II 30 30 Solvents Cyclohexanone Isophorone DMF DMSO Xylene Dioctyl phthalate Methyleellosolve 5 5 10 5 10 10 10 10 10 10 10 30 15 15 10 1 ³⁰ · Vh I 15 15 surfactant .1 is in example 1 described. Tens H-A Tens H-B Tens H-C Tens H-D ΙΟ 10 * = the composition 1

03 fO K> O Ul O Table 2 cn - 2.7 2.8 2.9 2.10 Ui I Component; Wt .-% Comparative Compositions Composition No. I 2.1 2.2 2.3 2.4 2.5 2.6 30 30 15 15 Herbicide of the formula I 30 40 45 15 65 5 5 65 5 5 Phenmedipham Desmedipham 5 15 30 15 15 15 Solvent Cyclohexanone Isophorone DMF DMSO xylene 95 80 77 70 20 85 5 65 10 10 10 surfactant 0R-2t ETO DBS-CA 3

AV ·

Example 3_

Determination of Chemical Stability "of the herbicide in the composition

An amount of 100 g each of the compositions of Table 1 (vgl- Example 2) according to the present invention and the Verg.leichszusammensetzungen of Table 2 (see. Example 2) were placed in a glass container in a thermostat of 54 "C ⁰ After 14 days, the amount of active substance (herbicide) directly in the sample was determined by high performance liquid chromatography (HPLC).

The results obtained, expressed as percent decomposition of the herbicide, are shown in Table 3. From the data in Table 3 it can be seen that in the compositions of the invention the herbicide compound turns out to be chemically stable at high temperatures over a long period of time.

Table 3 of m-bis-carbamate herbicides I Herbicide degradation *; % has been. chemical stability different composition after 14 days at 1 54 ° C 1 < 0.5 Composition no. <0.5 5 (see Tables 1 and 2) < 0.5 , 1.1 <0.5 1 .2 , <0.5 1.3 <0.5 1 .4 < 0.5 10 1.5 <0.5 1.6 <0.5 1 . 7 <0.5 1 . 8th <0.5 1.9 <0.5 1.10 <0.5 15 1 .11 < 0.5 - 1.12 8.3 1.13 7.8 1.14 69.0 2.1 38.0 2.2 12.3 2. 3 49.0 20 2.4 53.1 2.5 27, 2 2.6 9.5 2 .7 7.8 2.8 and "^ 0.5" indicates that 2.9. within the sensitivity range of the analytical method 25 2. 10 no decomposition found * "4" means "less than"; 30 35

Claims (3)

Claim 1, chemically stable herbicidal compositions based on N-bis-carbamates, characterized in that it is in a weight ratio between 90 ": 1 to 1: 40, a surfactant or a mixture of surfactants from the class of phosphoric acids, with polyoxyethylated alkyl phenol mono- or di-esterified, the general formula II (O-CH ₂ -CH ₂ ) _ra ~ G HO - P ^ in which X represents a hydroxyl group or a group - (O-CH ₂ -CH ₂ ) _n - 0 ra and η are independently an integer of inclusive "1 to 80 such that the sum m + η is equal to or less than 80; ρ is an integer of 1 to 4, preferably 1, * R is a linear or branched C, ^ ₂ alkyl group, one BiSf-o ^ -phenyl et hy! Group or a benzyl group is included * 2 _# Herbicidal compositions according to item 1, characterized in that the tn-bis-carbamate herbicide is the compound Phenmedipham or Dismediphätn. 25.11,1983 AP A 01 N / 253 62 722/12 3 »Chemically stable herbicidal compositions characterized by the fact that they consist of a) m-bis-carbamate herbicide 0.5 to b) surfactant of Formula II 0.5 to c) an organic solvent selected from aromatic or alkylaromatic hydrocarbons, alicyclic ketones, esters of carboxylic acids, dimethylsulfoxide, dimetylfonnainide, glycol monoether or mixtures thereof. on with the proviso that when the herbicide phenmediphanr, the surfactant, is a mono- or di-esterified phosphoric acid with nonylphenol polyoxyethylated with 10 moles of ethylene oxide per mole of substrate, and the solvent is a mixture of dimethylformamide and xylene Substances in a weight ratio other than 40: 10: 30; present *