Note: Descriptions are shown in the official language in which they were submitted.
20721~
HOECHST AKTIENGESELLSCHAFT Dr.WE/gm HOE 89/F 352
Description
Selective herbicidal agents
The invention xelates to novel liquid ~elective herbi-
cidal agents which contain active compound6 from the
group comprising phenoxy herbicide~ and optionally
substituted 1-aryl-3-alkoxycarbonyl-5-alkyl-1,2,4-tri-
azoles in the form of emulsion concentrates which are
stable chemically and during use.
It is known that compounds from the group comprising
phenoxy-phenoxy herbicides and benzoxazolyloxy-phenoxy
herbicides can be combined with other compounds having a
selective herbicidal action or with agents which protect
crop plants (safeners) for the purpose of optimizing the
action spectrum to give finished formulations which are
stable chemically and during use.
It is known, inter alia, from European Patent A-0,174,562
(US Patent A-4,639,266) that benzoxazolyloxy-phenoxy
herbicides, such as, for example, ethyl 2-(4-(6-chloro-
2-benzoxazolylox~)-phenoxy-propionate (sic) (fenoxaprop-
ethyl) can be combined with safeners from the group
comprising optionally substituted 1-aryl-3-alkoxy
carbonyl-5-alkyl-1,2,4-triazole compounds by adding
corresponding amounts of a formulation of the 1,2,4-
triazole mentioned to the spray liquor shortly beforeapplication of the fenoxapropethyl, 80 that the advantag-
eous biological properties of the combin~tion of the two
active compounds can be utilized in this manner. However,
this process is cumbersome and time-consuming, and can
easily lead to incorrect dosages in practice.
There was thus the ob~ect of avoiding the~e difficulties
and of preparing ~iologically active homogeneous formula-
tions of these two active compounds which are stable
chemically and during use and which meet the requirements
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imposed in practice.
It was to be remembered in particular that the two
classes of active compound can have an adverse influence
on each other in the presence of customary formulation
S auxiliaries and stabilizers at elevated storage tempera-
tures and then undergo noticeable chemical changes,
especially over prolonged storage times, and lead to
components which are biologically less active or even
inactive. These disadvantages are overcome by the present
invention.
The present invention relates to liquid selective
herbicidal agents based on emulsion concentrate~, which
contain
a) one or more herbicidal phenoxyphenoxy- or heteroaryl-
oxy-phenoxy-carboxylic acid esters~
b) one or more compounds from the group comprising
optionally substituted l-aryl-3-alkoxycarbonyl-5-
alkyl-1,2,4-triazoles,
c) one or more carboxylic acid esters or phosphoric acid
esters of aliphatic mono- di- or polyalcohols as a
stabilizing agent,
d) one or more organic solvents, in particular with a
predominant content of aromatic solvent~, and
e) one or more emulsifiers and if appropriate wetting
agents and customary additive~.
The herbicidal phenoxy- or heteroaryloxy-phenoxy-
carboxylic acid esters which can be employed (component
a) are, for example, the known optionally substituted
phenoxyphenoxy-, quinoxalyloxyphenoxy-, pyridyloxy-
phenoxy-, benzoxazolyloxyphenoxy- or benzothiazolyloxy-
phenoxy-carboxylic acid esters, in the form of the pure
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optical isomers or as isomer mixtures (for example
racemates). The compounds are described, for example, in
DE-A 2,136,828 (US-A 4,238,626); DE-A 2,223,894 (US-A
3,954,442); British Patent 2,0432,539 ( 8iC ); British
Patent 1,599,121; and DE-A 2,640,730 (US-A 4,130,413).
The (C1-C4)alkyl, (C2-C~)alkenyl or ( C3-C4 )alkynyl ester~
are particularly suitable.
Suitable herbicides of component a) are, for example, the
active compounds
methyl 2-(4-(2,4-dichlorophenoxy)-phenoxy)-propionate
(diclofop-methyl),
methyl 2-(4-(4-bromo-2-chlorophenoxy)-phenoxy)-
propionate,
methyl 2-(4-(4-trifluoromethylphenoxy)-phenoxy)-
propionate,
methyl 2-(4-(2-chloro-4-trifluoromethylphenoxy)-phenoxy)-
propionate,
ethyl 4-(4-(4-trifluoromethylphenoxy)-phenoxy)-pent-2-
enoate,
ethyl 2-(4-(3,5-dichloropyridyl-2-oxy)-phenoxy)-
propionate,
methyl or 2-ethoxyethyl2-(4-(3-chloro-5-trifluoromethyl-
pyridyl-2-oxy)-phenoxypropionate (haloxyfop-methyl or
haloxyfop-2-ethoxy-ethyl),
propargyl 2-(4-(3,5-dichloropyridyl-2-oxy)-phenoxy)-
propionate,
ethyl 2-(4-(6-chlorobenzoxazol-2-yl-oxy)-phenoxy)-
propionate (fenoxaprop-ethyl),
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ethyl 2-(4-(6-chlorobenzothiazol-2-yl-oxy)-pheno~y)-
propionate (fenthiaprop-ethyl~,
methyl 2-(4-(3-chloro-5-trifluoromethyl-2-pyridyloxy)-
phenoxy)-propionate,
butyl 2-(4-(5-trifluoromethyl-2-pyridyloxy)-phenoxy-
propionate (sic) (fluazifop-butyl),
ethyl 2-(4-(6-chloro-2-quinoxalyloxy)-phenoxy-propionate
(sic) (quizalofop-ethyl) and
ethyl 2-(4-(6-fluoro-2-quinoxalyloxy)-phenoxy)-
propionate.
The active compounds mentioned in the D,L- or in particu-
lar the enxiched or pure D-form are preferred.
Agents according to the invention containing the herbi-
cidal active compound diclofop-methyl or fenoxaprop-ethyl
are particularly preferred. Most of the abovementioned
active compounds are also described in "The Pesticide
Manual", 8th edition 1987, British Crop. Protection
Council.
Suitable compounds for component b) of the agents accord-
ing to the invention are the compounds mentioned in
European Patent A-0,174,562, preferably the 1-(2,4-
dichlorophenyl)-3-(C,-C4-alkoxy)carbonyl-5-halogenoalkyl-
1,2,4~triazole compounds, in particular the 1-(2,4-
dichlorophenyl)-3-ethoxycarbonyl-5-halogenoalkyl-1,2,4-
triazoles, in which the halogenoalkyl radical is prefer-
ably CCl3, CHCl2 or CHF2CF2.
Low molecular weight esters of carboxylic acids or
phosphoric acid~ with alcohols, diols or polyols, for
example e6ters of aliphatic C2-C5-carboxylic acids or
phosphoric acid and linear or branched aliphatic C2-C12-
alcohols, -diols or polyols, are of particular interest
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as component c) having a stabilizing action. Preferred
compounds here are esters of carboxylic acid~, such as
acetic acid, propionic acid, butanoic acid or pentanoic
acid, in particular acetic acid, or of orthophosphoric
S acid with alcohols, such as methanol, ethanol, propanol,
isopropanol, n~ , t- and 2-butanol, n-, i- or 2-
pentanol, n-, i- or 2-hexanol, heptanol, octanol, non-
anol, decanol, undecanol and dodecanol, or diols, such as
glycol, propanediol, butanediol and hexanediol, or
polyols, such as glycerol, pentaerythritol and hexitol.
Particularly preferred compounds are phosphoric acid
esters, such as tri-n-butyl phosphate, or esters of
acetic acid with C2-C5-alcohols or with diols, such as
l,4-butanediol, or with triols, such as glycerol, in
particular the esters butyl acetate, pentyl acetate,
hexyl acetate, heptyl acetate, nonyl acetate, 1,4-bis-
(acetoxy)-butane and glycerol triacetate.
Organic solvents, such as aliphatic or aromatic hydro-
carbons, aliphatic cyclic and acyclic ketones, N-methyl-
pyrrolidone, dimethylformamide and alkylene glycol mono~and diesters or corresponding ethers, especially solvents
having a high content of aromatics, are suitable, for
example, as component d).
Examples of suitable aromatic solvents are toluene,
xylenes, higher-boiling aromatic fractions and methyl-
naphthalenes, and a particularly suitable ketone is
cyclohexanone.
Customary emulsifiers, preferably one or more from the
group comprising alkylbenzenesulfonates, such as calcium
dodecylsulfonate, and fatty acid polyglycol esters, such
as ethoxylated castor oil, are suitable as component e).
Any wetting agents contained in the agents are preferably
tho~e from the group comprising alkylphenol polyglycol
ethers and alkanol polyglycol ethers.
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The ethoxylated castor oil or ethoxylated ricinic acid
which can be employed according to the invention con-
tains, in particular, 20 to 60 EO units (EO = ethylenoxy
units). The products Emulsogen EL 400 or ~Emulsogen EL
360 (Hoechst AG), for example, can be employed. The fatty
acid polyglycol esters contain, in paxticular, 12-18
carbon atoms in the fa~ty acid part. The ethoxylated
alkylphenols are, in particular, nonylphenols and prefer-
ably contain 20-200 EO. These include, for example,
~Arkopal N 100 (Hoechst AG). Ethoxylated (c~-c2o~alkanols
having an EO content of 3 to 20 EO, for example ~Genapol
X 060 ~Hoechst AG) may be mentioned as preferred alkanol
polyglycol ethers. Of the emulsifiers and wetting agents
mentioned, ethoxylated castor oil and the alkanol poly-
glycol ethers are particularly suitable according to theinvention.
The herbicidal agents according to the invention can
contain further customary additives for emulsion concen-
trates, for example stabilizers against moisture, such
as, for example, acid anhydrides, substituted amines and
epoxide compounds, such as epoxidized linseed oil or soya
oil.
The herbicidal agents according to the invention as a
rule contain 5-50% by weight, preferably 20-35% by
weight, of components a) and b), 2-20% by weight, in
particular 5-15% by weight, of component c) and further-
more 5-40~ by weight, preferably 10-25% by weight, of
solvent and 10-30% by weight, pre~erably 15-25~ by
weight, of emul~ifiers and wetting agents.
The ratio of the active compound components a) and b) to
one another in the formulations is preferably 5:1 to 1:3.
The optimum amount of component c) depends on the amount
of active compounds a) and b) and can easily be deter-
mined in preliminaxy experiments.
The invention furthermore relates to a proce~s for the
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- 7 -
preparation of the agents according to the invention. For
this, the abovementioned components are mixed with one
another in the required amounts at temperatures of
preferably 10 to 60C, advantageously at room tempera-
ture or slightly above, until a homogeneous solution ofthe individual component~ has formed.
For carrying out the process in practice, the solvent or
solvent mixture is first initially introduced into a tank
with a stirrer; the two active compound componentQ a) and
b) are then added and the mixture is stirred until a
clear solution is obtained. The compounds of component c)
to be employed according to the invention are allowed to
run slowly into this solution and the emulsifiers and if
appropriate wetting agents and further additives are then
added. The mixture is subsequently stirred until a clear
solution is formed. The entire operation is advantage-
ously carried out at room temperature or slightly above.
The sequence of addition of the components can also be
different.
The emulsion concentrate prepared, which corresponds to
a practically anhydrous solution of components a)l b), c)
and e) in the organic solvent, is outstandingly stable
towards chemical degradation of the active compounds and
towards phase separations, such as, for example, the
precipitation of components, even at comparatively high
active compound contents. They therefore have a very good
storage stability and are suitable for storage under
climatically adverse conditions, in particular al80 at
high temperatures o$ 30 to 50-C.
Before biological use of the emulsion concentrates, these
are mixed with water to give emulsions which present no
problems when used and which are not inferior in their
activity to the combination~ of the active compounds a)
and b), formulated if appropriate, prepared in the spray
tank.
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The following Examples are intended to illustrate the
invention in more detail:
~xample 1
9.5% by weight of fenoxaprop-P-ethyl (I) (D-isomer of
fenoxaprop-ethyl) are dissolved in 42% by weight of
xylene at 25-30C, while stirring. 4.7~ by weight of 1-
(2,4-dichlorophenyl)-3-ethoxycarbonyl-5-trichloromethyl-
1,2,4-triazole (II) and then 12% by weight of a C12-Cl8-
fatty alcohol polyglycol ether (containing 6 E0) and 6.8%
by weight of a Cl2-C18-fatty acid polyglycol ester (con-
taining 40 E0) are added to the clear solution and the
mixture is stirred until a clear solution is obtained.
5.0% by weight of epoxidized 80ya oil, 10.0% by weiqht of
a xylene solution of the Ca salt of dodecylbenzene-
sulfonic acid and 10% by weight of glycerol triacetateare added to this solution and the mixture is subse-
quently stirred for 20 minutes.
A portion of the sample is stored at 50C for 3 month~
and then analyzed:
Content, Content after
starting value 3 month~/50C
Compound I 9.2% by weight 9.1% by weight
Compound II 4.6% by weight 4.6% by weight
Comparison Example 1
25 The experiment from Example 1 is repeated, the same
amount of xylene being added instead of 10% by weight of
glycerol triacetate. The sample is likewise stored at
50C for 3 months and then analyzed.
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Content, Content after
starting value 3 months/50C
Compound I 9.2% by weight 8.6% by weight
Compound II 4.6% by weight 3.3% by weight
~xa~ple 2
12.5% by weight of fenoxaprop-P-ethyl (I) (= D-isomer of
fenoxaprop-ethyl) are dissolved in 35% by weight of
xylene at 25-30C, while stirring. 8.8% by weight of 1-
(2,4-dichlorophenyl)-3-ethoxycarbonyl-5-trichloromethyl-
1,2,4-triazole (II) and then 10% by weight of a C12-Cl8-
fatty acid polyglycol ether (containing 8 E0) and 8.7% hy
weight of a C12-C1B-fatty acid polyglycol ester (containing
40 E0) are added to the clear solution and the mixture is
stirred until a clear solution is obtained. 5% by weight
of epoxidized linseed oil, 10.0% by weight of a xylene
solution of the Ca salt of dodecylbenzenesulfonic acid
and 10% by weight of tri-n-butyl phosphate are added to
this solution and the mixture is subsequently stirred for
about 20 minutes.
A portion of the sample is stored at 50C for 3 months
and then analyzed:
Content, Content after
starting value 3 months/50C
Compound I 11.8% by weight 11.7% by weight
Compound II 8.2% by weight 8.2% by weight
Compari~on Example 2
The experiment from Example 2 is repeated, but instead of
the 10% by weight of tri-n-butyl phosphate the same
amount of xylene is added. The sample i8 likewi~e stored
at 50C for 3 months and then analyzed.
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Content, Content aftsr
starting value 3 months/50C
Compound I 11.6~ by weight 9.9% by weight
Compound II 8.1~ by weight 6.5% by weight
Example 3
16.5% by weight of fenthiaprop-ethyl (III) are dissolved
in 42% by weight of xylene at 25-30C, while stirring.
8.2~ by weight of 1-(2,4-dichloro-phenyl)-3-ethoxy-
carbonyl-5-trichloromethyl-1,2,4-triazole (II) and then
5% by weight of a Cl2-Cl8-fatty alcohol polyglycol ether
(containing 10 E0) and 6.3% by weight of a C12-C1a-fatty
acid polyglycol ester (containing 36 E0) are added to
this clear solution and the mixture is stirred until a
clear solution is obtained. 5% by weight of epoxidized
linseed oil, 5% by weight of calcium dodecylbenzene-
sulfonate and 12% by weight of hexyl acetate are added to
this solution and the mixture is subsequently 3tirred for
about 20 minutes.
A portion of the sample is stored at 50C for 3 months
and then analyzed:
Content, Content after
starting value 3 months/50C
Compound III 15.6% by weLght 15.4% by weight
Compound II 7.7% by weight 7.6% by weight
Comparison ~ample 3
The experiment from Example 3 is repeated, but in~tead of
the 12% by weight of hexyl acetate the same amount of
xylene is added. The sample is likewise 3tored at 50C
for 3 months and then analyzed.
2~721~4
11
Content, Content after
starting value 3 months/50C
Compound I 15.5~ by weight 13.9% by weight
Compound II 7.6~ by weight 6.0% by weight
~xample 4
The procedure is analogous to Example 1, but 1-(2,4-
dichlorophenyl)-3-ethoxycarbonyl-5-dichloromethy~ 2~4-
triazole is employed as the triazole compound. A compar-
ably stable emulsion concentrate is obtained.
~xample 5
The procedure is analogous to Example 2, but 1-(2,4-
dichlorophenyl)-3-ethoxycarbonyl-5-(1,1,2,2-tetrafluoro-
ethyl)-1,2,4-triazole is employed as the triazole com-
pound. The resulting emulsion concentrate is stable at
50C for 3 months and in particular exhibits no notice-
able degradation of the active compound content.
Biological ~xamples
The emulsion concentrates obtained according to the
preparation examples are diluted to the use concentration
with water and used against monocotyledon or dicotyledon
or mono- and dicotyledon weeds in field experiments.
The biological studies show that there are no noticeable
differences between the fini~hed formulations and the
combinations of the individual active compounds prepared
in the spray tank (tank mixture) either in plant toler-
ance or in herbicidal action.
