CS224617B2 - Herbicide - Google Patents

Abstract

1. A liquid herbicidal composition, based on a pyridazone derivative and a biscarbamate, which contains a solution of the active ingredients in an acid amide of the general formula see diagramm : EP0044955,P10,F3 where R**1 ist alkyl of up to 8 carbon atoms or optionally methyl- or ethyl-substituted phenyl, and R**2 and R**3 are each alkyl which together have up to 8 carbon atoms, the acid amide having a total of 8 to 15 carbon atoms.

Description

The present invention relates to a herbicidal composition based on a pyridazone derivative and a biscarbetate which are soluble in an acid amide.

It is known to use 1-phenyl-4-amino-5-chloro-6-pyridazone (Chloridazone) as a herbicide (German patent 1 105 232, British patent 871 674). It is further known to use 3-methoxycarbonylaminophenyl-N- (3'-methylphenyl) carbemate (Phenmedipham) as a herbicide (cf. German Patent 1,567,151, British Patent 1,173,753). It is further known to use a mixture of Choridazone and Phenmedipham as a herbicide (cf. German Patent 1,642,216). Further, it is known to dissolve Chloridazone in N-methylpyrrolidone (cf. German Patent Specification 1,216,010). Further, the solvent is a mixture of Chloridezone and Phenmedipham in a mixture of N-methylpyrrolidone and morpholine (cf. German Patent 1,642,216).

To broaden the spectrum of herbicidal active ingredients, a mixture of two or more of the two or more individual active ingredients (tankmix) can be mixed in a dv8 container or a mixture of active ingredients can be used in a single directly usable formulation.

A mixture prepared in a storage tank is an aqueous diluted preparation adjusted to an applicable concentration from a mixture of both formulations of both active substances, which may be in the form of an emulsion concentrate (in liquid form), a suspension concentrate (Flowable) (as a solid) in a liquid) or in the form of a wettable powder (in solid form). In such compositions prepared in a storage container, often the mutual compatibility of the compositions used in the composition causes difficulties. Since the nature of the composition is determined by the chemico-physical properties of the active substance, these properties determine the choice of solvents and excipients, for example emulsifiers, dispersants and wetting agents. Thus, two different, even even the same types of compositions may be incompatible with the mixture prepared in the storage tank. This results in inter alia settling, coagulation, aggregation, precipitation, which makes it impossible to apply the mixture (by spraying).

In the case of a ready-to-use mixture preparation, on the other hand, formulations comprising at least two active substances which may co-exist in the form of an emulsion concentrate are used. suspension concentrate (Flodable) or in powder form (Wttable Powdee). These compositions can be converted directly into spray suspensions with the desired applied concentration by dilution with water. It is in principle possible to use any combination of different kinds of active substances. However, the formulations of two or more active substances according to the type of composition are considerably influenced or differences can be prevented e.g.

solubilities, melting points, specific as well as stability. A further difficulty lies in finding a suitable uniform system of excipients, such as excipients, wetting agents or dispersants, for the active substances which are mixed with one another.

It has proven particularly difficult to formulate a composition in the form of a liquid (emulsion surfactant) of two or more solid active substances which have extremely different solubilities in different solvents, and furthermore, because of the stability of one of the active substances, the choice of solvents can already be very limited. A further difficulty lies in the stability of the erythema, such mixtures, since there may be a disturbance here, for example, of the tendency to crystallize the various active substances in the spray suspensions due to their different solubilities during application (shouting). The tendency to crystallize the active substances is higher the better the water-soluble solvents, since the dilution of these solvents with water does not form an emulsion, but an aqueous solution in which the active substances are no longer soluble and therefore tend to crystallize. These difficulties are particularly evident in the known herbicidally well active mixtures of Chltridazone with Phenmediphan (cf. German Patent 1,642,216)

Subject. Accordingly, the present invention is a herbicidal composition based on a pyridezone derivative of the general formula

in which

R is chloro or bromo, and the biscarbamate of formula

wherein R 'is ^plated mettylovou or ethyl ^

R is chlorine, fluorine or methyl, ^R3 znmmená ^lu oor or hydrogen and ^R4 is hydrogen or ^Iu OOR bore, ^ čujcí in that it comprises a solution of active ingredients in a ratio of 80 to 150 parts hmmtnottních pyridazone derivative thereof to 50 to 100 parts by weight of biscarbamate in an acid amide of the formula > R2 < ² >

Table 2

Stability of active substance 2 (biscarbamate)

Rozppoutědlo Temperature depending on time N-methyl ^p- yr- 30 Noc: 2 ° C obseh effective 100 ALIGN! 96.7 76.3 r ^ don (pure substances 0.05% H2O) (% of the breakdown time (min) 5 30 210 50 Noc: 2 ° C active substance content (%) degradation time 92.3 76.5 52.8 (min) 5 20 May 60 ^ methy ^ o? - 50 Noc: 2 ° C content effective 99.5 98.1 95.5 mid (technical) % (%) degradation time (min) 5 20 May 60 70 Noc: 2 ° C active substance content (%) degradation time 98.5 87.2 57.4 (min) 7 30 63 80 Noc: 2 ° C active substance content (%) 85.4 54.7 32.9 lstftrtn 80 Noc: 2 ° C active substance content (%) degradation time 93.0 (h) 24

Vezrnm Where applicable, the means maai be largely stable in storage for ^a F 2 years ^ρ ^ 1 te ^p lot ^and CH from 30 to 40 ° C, ^»p and previously listed ^d Measured ^d ata illustrate the difficulty ^{of p at} pH Ravy a directly prepared preparation of pyridazones and biscarbamates. Another serious problem is the selection of a suitable system of auxiliaries such as emulsifiers and wetting agents, which in addition must not adversely affect the stability of the biscarbamates.

Thus, the directly usable formulation disclosed in German Patent No. 1,642,216 under example 6/1, which contains the poorly suitable N- (611-111) in addition to morpholine, shows poor storage behavior (poor stability during storage). storage),

Table 3 gives an example of the results of two preparations with the active substances Chloriaaonn (substance 1) and Phenmedipham.

The degradation of Phenmedipham at various temperatures was monitored.

^{r 1} represents an alkyl group having up to Θ carbon atoms or optionally a methyl or ethyl group substituted by a phenyl group, and

3

R ^fc and R ^j represent an alkyl group having up to 8 carbon atoms in total, and the acid amide encrypts a total of 8 to 15 carbon atoms.

The pyridazone derivatives can be dissolved to a sufficient extent only in extremely polar solvents, which are poorly suited for emulsion co-ethers, such as dimethylphenolpyrrolidone and methylsulfones, while the biscarbamates are very they are well soluble but extremely unstable in said solvents and are sufficiently stable to be formulated only in isophorone or cyclohexanone, but these solvents do not dissolve or dissolve the pyridazone derivatives completely and are therefore unsuitable for these compounds. Although, in principle, mixtures of both types of solvents are possible, the proportion of the polar component must be chosen so high that insufficient stability of the biscarbamates or poor solubility of the pyridazone derivatives has to be taken into account.

T a b u 1 k a 1

Examples of chloridazsau and biscarbamates

Substance 1: Chloridezone

About Ct

Compound 2: biscarbamate

^ огрот ^^^ Solubility in% (g of substance in 100 g of solution at room temperature (20 ° C) Solubility of the solvent in water (%)% by weight of solvent in water (%) substance 1 substance 2 isoforča 6.0 33.7 i .έ cyclo ^^ an ^ 7.0 35.0 3-4 N-meeihlpy r ro fol he 22.5 30.8 100 ALIGN! dime tty xs ulfoxi í 29.3 55.3 100 ALIGN! dime thyioomamide 22.1 47.2 100 ALIGN!

In Table 2, the stability of the active compound of the above compound 2 in various solvents is exemplified. Compound 1 does not show any problems in these solvents in terms of stability. The concentration of the active compound in these experiments was 0.002. The analysis was carried out by high-pressure liquid chromatography.

Table 3: Degradation of the active substance in preparations

Recipe (g / liter) Temperature Phenmedipham degradation time content of active substance 50 Phenmedipham temperature room (20 ° C) 4 weeks 79.5% 15 ° Chloridazone 200 wetting agents' 2) 50 emulsifier ’ Deň: 32 ° C 4 weeks 4.8% to 1000 g of dimethylformamide Explanation: ethoxylated isooctylphenol 2) ethoxylovany Castor oil

Recipe (g / liter) Temperature Phenmedipham degradation time content of active substance 167 Chloridazone Deň: 32 ° C 1 hour 30.8% 83 Phenmedipham 300 N-methylpyrrolldone 2 hours 16.4% 24 morpholine 3 hours 12.8% 100 emulsifier 326 of the distillation residue 70 ° C 1 hour 3.21% after distillation cyclohexanone 2 hours totally degrades:

(cf. German patent

642 216, example 6/1)

2)

Explanation: ¹ ethoxylated castor oil

The use of a mixture of dimethylformamide and isophorone instead of dimethylformamide alone results in a noticeable improvement in the stability of Phenmedipham (about 60% after 4 weeks at 50 ° C), but this result is by no means sufficient for practical purposes.

On the basis of the above findings, it was therefore necessary to use a solvent for a ready-to-use preparation that fulfills the following conditions:

(a) low solubility in water (= low tendency of active substances to crystallize)

b) good stability of biscarbamate

c) a relatively good ability to dissolve the pyridazone derivative and biscarbamate.

It has now been found that a liquid herbicidal mixture based on pyridazone derivative and biscarbamate meets the above conditions when it contains a solution of the active compounds in an acid amide of the formula

in which д! represents an alkyl group of up to 8 carbon atoms or optionally a methyl group or an ethyl group substituted with a phenyl group, and

R ^J and R represent an alkyl radical with up to 8 carbon atoms, and amide EŽ contains 8 to 15 carbon atoms.

Examples of acid amides are summarized in Table 4. The solubilities of Compound 1 (Chloridezone) and Compound 2 (biscarbamate), as listed in Table 1, as well as the solubility of the solvent in water were determined.

The amides listed in Table 4 are prepared in a known manner by reacting the acid chlorides with the appropriate amines with the addition of auxiliary bases.

Table 4: Solubilities of compounds 1 and 2 in acid amides at room temperature

Number Formula

Solubility in% substance 1 substance 2 (Chloridazone) (biscarbamate)

Water solubility (%)

39.9

37,0 1,7

3 0 _{/ ¥ 9} .η CH, -CN ³ X ^X C ₄ H ₉ -n 12.2 43.8 4 C / H _Q -n II / ⁴⁹ G-H, -CN 7.8 45.4 5 ²⁵ x · C ₄ H ₉ -n ⁰ from ^C ? ^H5 I / nCjEj-CN 10.8 41, 6

0.3

1.1

Solubility in% substance 1 substance 2 (Chloridazone) (biscarbamate)

Water solubility (%) continued Table Number Formula

⁰ / ^C 2 ^H 5 II / ^{2 5} 6 1 C 1 -CN ₃ h ₅ 8.1 49.0 0 Ο, Η, -η II Z ³ ^ 7 n-C 1 -C-N Ζ ^ Ηγ-η 10.4 38.8

, 2, ¹ , 5

0 II z С3Н7-П 8 i-CH 2 -C-N 9.6

45.5

1.6 nC ₄ H ₉ -CH-CN ° 2 ^H 5

10.8

29.1

1.5

IT

S ^C L ^H * ^ c _from H 5>

10.8

39.5

3.7

11 ^ _Vs СН _Ь 12 .С.Η q - * (O) C ~ N ~ ^W> ₃ с н, -г>

8.6

29.4

2.2

3.3

33.3

0.5

Pyridazone derivatives are, for example, chloridazone, 5-amino-4-bromo-2-phenyl-3 (2H) -pyridazinone.

Bislcerbernate derivatives are, for example, Phenmediphem, (3-chloro-4-fluorophenyl) carbamic acid 3 - [(ethoxycarbonyl) emino] phenyl ester, (3,4,5-trifluorophenyl) carbamic acid 3-f (ethoxycarbonyl) amino] phenyl ester.

Since the solubility of solid active substances in emulsion concentrates should also be ensured at low temperatures, for example at temperatures as low as -5 ° C, it may be necessary to add polar co-solvents for some of the solvents listed in Table 4 for reasons of cold stability in an amount of up to 10 to 15% by weight. Dimethyl sulfoxide has proved to be a favorable solvent

Non-ionic or anionic products customary in plant protection are used as emulsifiers. Such emulsifiers are, for example, ethoxylated castor oil, dodecylbenzenesulfonic acid calcium salt, ethoxylated oleic acid monoethanolamide, ethoxylated isooctylphenol.

Wetting agents are, for example, ethoxylated octylphenol, nonylphenol, alkylphenol polyglycol ethers, tributylphenol polyglycol ethers.

The liquid herbicidal mixtures according to the invention contain, for example, 80 to 150 g of pyridazone derivative per liter of liquid, in particular 100 to 120 g per liter. The liquid herbicidal mixtures according to the invention further comprise, for example, 50 to 100 g of biscarbamate per liter of liquid, in particular 70 to 90 g per liter of liquid. These mixtures contain, for example, 30 to 100 g of emulsifier per liter of liquid, in particular 40 to 60 g per liter of liquid. Further, they contain, for example, 50 to 120 g of wetting agent per liter of liquid, in particular 90 to 110 g per liter of liquid.

Example 1

The following table summarizes the results of the Phenmedipham stability determination at various temperatures and at constant time. 500 mg of the technical active substance are dissolved in 25 ml of solvent, the solution is stored at the chosen temperature for 24 hours and then the content of the active substance is analyzed analytically using high pressure liquid chromatography.

Table 5:

Solvent Phenmedipham active substance temperature temperature time active substance content

isophorone Deň: 32 ° C 70 ° C 24 hours 24 hours * 99.3% 96.3% dimethylformamide Deň: 32 ° C 24 hours 9.3% 70 ° C 24 hours active substance unprovable 2-ethylhexanecarboxylic amide Deň: 32 ° C 24 hours 98.1% Acid (Compound 9) 70 ° C 24 hours 98.0% from table 4) Butyric acid N, Ν-dipropylamide Deň: 32 ° C 24 hours 100.0% (Compound No. 7 of Table 4) 70 ° C 24 hours 97.6% 3-Methylbenzene-, Ν-diethylamide- Deň: 32 ° C 24 hours 95.5% carboxylic acids (compound 70 ° C 24 hours 60.0%

No liz Table 4)

Fig. 1 s d 2

Production of emulsion concentrate of the following composition:

j 120 g / liter Chloridazone g / liter Phenmediphem

100 g / liter of dimethylsulfoxide

100 g / liter of wetting agent (isooctylphenol x 5.7 EO ethylene oxide) g / liter of emulsifier (isooctylphenol x 25 PO propylene oxide x 40 EO) into 1000 ml of 2-ethylhexanecarboxylic acid Ν, dimethyl-dimethylemide

Storage of this emulsion concentrate at 50 ° C for 4 weeks resulted in only a slight overwhelming of Phenmadipham.

By testing 0.5 or 2.0% of the aqueous emulsion, which was prepared by diluting the emulsion concentrate with water, for emulsion stability for 6 hours at room temperature, 0.4-0.0 ml of the bottom sediment was found.

He did

An emulsion concentrate was prepared in an analogous manner to that of Example 2, to which 3 g / liter of N-isopropylsulfamic acid was added. Storage at 50 ° C for 4 weeks showed no degradation of Phenmadipham (biscarbamate).

Ex. к lad 4

Preparation of emulsion concentrate of the following composition:

1CC g / liter Chloridazone g / liter rlienmedipham

100 g / liter of wetting agent / isooctylphenol x 5.7 EO ethylene oxide / g / liter of emulsifier (isooctylphenol x 25 PO propylene oxide x 40 EO) g / liter of bromoacetic acid to 1000 ml of 3-methylbenzenecarboxylic acid Ν, diet-diethylamide

By testing stability i ^; henmedipham showed no degradation when stored at 50 ° C for half a year.

Example 5

Preparation of emulsion concentrate of the following composition:

120 g / liter of Chloridezone g / liter of 3- (ethoxycarbonyl) aminophenyl ester (3-chloro-4-fluorophenyl) cyanoboronic acid (substance 2 of Table 1)

CO g / liter of dimethylsulfoxide • 100 g / liter of wetting agent (isooctylphenol x 5.7 EO (ethylene oxide) g / liter of emulsifier (1-octylphenol x 25 PO (propylene oxide) x 40 EO) g / liter of N-isopropylamine ¹¹ to 1000 ml N) 2-ethylhexanecarboxylic acid-dimethylamide.

After 4 weeks storage at 50 ° C, no degradation of biscarbamate was found.

By testing 0.5 or 2.0% of the aqueous emulsion for emulsion stability after 6 hours at room temperature, a slight sediment was formed on the bottom.

Example 6

An emulsion concentrate was prepared analogously to Example 4 from Chloridazone in Phenmediphan, but dimethyl formanide was used in place of the N, N-diethylemide of 3-methylbenzenecarboxylic acid. After half-year storage at 50 ° C, 36 C degradation of the active substance Phénmediphan was found.

Claims (2)

SUBJECT OF THE INVENTION A herbicidal composition based on a pyridazone derivative of the general formula wherein chlorine or bromine and a biscarbamate of the general formula wherein methyl or ethyl is chlorine, fluorine or methyl, fluorine or hydrogen and fluorine or hydrogen, characterized in that: contains a solution of the active ingredients in a ratio of 80 to 150 parts by weight of pyridazone derivatives to 50 to 100 parts by weight of biscarbamate in the acid acid emide formulas П d2 U / P, </ R -CN ^ R ³ wherein the alkyl group having up to 8 carbon atoms or the optionally methyl or ethyl group is a substituted phenyl group; and 2 3 R and R are alkyl having up to 8 carbon atoms in total, and the acid amide contains 8 to 15 carbon atoms in total.