Note: Descriptions are shown in the official language in which they were submitted.
~a~~~~~
HOECHST AKTIEN~ESELLSCHAFT HOE 92/F 063 Dr.WS/sch
Description
Antifoams fox solid crop protection agents
Ths invention relates to the use of specific perfluoro
alkylphosphinic acids and perfluoroalkylphosphonic acids
as antifoams in solid crop~protection agents.
Solid crop protection agents are currently usually
supplied in the farm of wettable powders and granules, in
particular in the form of water-dispersible granules.
It is known that herbicidal, fungicidal or insecticidal
active substances. are used alongside inert fillers, such
as chalk, kaolin or silica, in particular surface-active
substances, in the preparation of these formulations so
that the preparations axe well wetted and dispersed in
water when they are used. In the case of the water-
dispersible granules, rapid disintegration should addi-
tionally take place after introduction into water.
In addition, it is known that the surface-active sub-
stances, in particular wetting agents, frequently con-
tribute to intensification of the action, in particular
of foliaz-acting herbicides, and then are used in a
particularly high proportion in the formulations
(DE-A-2 926 800).
Wetting agents also lower the surface tension of the
spray slurry. As a result, uniform wetting of the leaf
surface and, associated with this, frequently a better
absorption of the active substances are ensured. However,
because of the low surface tension, these spray slurries
also tend to foam. This can lead to overflow of the spray
tank and to irregular spray coatings on the plants.
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The use of an antifoam as additive, which is added
separately to the spray slurry, can frequently provide a
remedy. However, the use as additives requires the use of
a further agent in addition to the crop protection agent
and, optionally, an additional wetting agent and in
practice is not readily used because of the requisite
additional metering and storage.
The obaect is, therefore, to find antifoams for solid
formulations, which antifoams are simple to handle and do
not lose their activity in the course of the formulation
process and the activity of which is retained during
storage of the preparations for 2 to 4 years.
A multiplicity of antifoams axe known and are reported,
for example, in "Ullmanns Enzyklopadie der technischen
Chemie" ("Ullmanns Encyclopedia of Industrial
Chemistry"), 4th edition, volume 20, pages 411-414 and by
W. Schonfeldt in "Grenzflachenaktive Alkylenoxid-Addukte"
("Surface-active alkylene oxide adducts°'),
Wissenschaftliche Verlagsgesellschaft MBM, Stuttgart
1973, pages 805-853.
However, the substances mentioned in these publications
axe not always suitable for the preparation of solid
formulations because they cannot be used in the prepara-
tion of wettable powders by grinding because of their
liquid or pasty nature or their low melting point, ox
because they lose their activity during the formulation
process. Thus, for example, highly active silicone
antifoam emulsions partly lose their antifoam properties
if they are exposed to high shear forces such as occur,
for example, in the preparation of water-dispersible
granules by spray drying or fluidized bed granulation of
aqueous suspensions. If the highly effective silicone
antifoams based on powders are used, they must be added
to the solid formulations by mixing after the latter have
been produced. The process requires the use of suitable
CA 02091746 2003-O1-07
28976-65
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mixing equipment and an additional operation. Built-up
granules sensitive to abrasion can be damaged by the mixing
operation.
Other solid antifoams, such as, for example,
E~ aluminum stearate, are not sufficiently effective,
especially when large amounts of wetting agent are used in
the formulation.
The use of antifoams from the group of chemicals
comprising the perfluoro(C6-C18)alkylphosphinic acids and/or
perfluoro(C6-C18)alkylphosphonic acids and/or their salts in
liquid, surfactant-containing systems has also been
disclosed (DE-A-22 33 941 and DE-A-21 336). The
incorporation of the antifoams in the liquid systems is as a
rule effected by addition with slow stirring.
Surprisingly, it has now been found that these
substances do not lose their antifoam action even under
severe mechanical stress - such as occurs, for example, when
grinding wettable powder formulations in hammer mills or
when wet-grinding active substances in bead mills to give
aqueous suspensions and during the subsequent granulation
thereof by spray drying by means of a single substance
nozzle or in a fluidized bed.
The invention therefor relates to solid formulations
of active substances, which are used in crop protection, and
which.contain surface-active substances (wetting agents), in
combination with a surfactant (antifoam) from the group of
chemicals comprising the perfluoroalkylphosphinic acids and/or
perfluoroalkylphosphonic acids and/or their salts.
In one aspect, the invention provides a solid
formulation, comprising: 1 to 80% by weight of a solid
active substance for use in crop protection; and 2 to 60% by
CA 02091746 2003-O1-07
28976-65
- 3a -
weight of one or more wetting agents in combination with 0.1
to 10 percent by weight of a surfactant {antifoam) selected
from the group consisting of perfluoro- (C6-C18) -
alkylphosphinic acids, perfluoro-(C6-Cl8)-alkylphosphonic
acids, salts of the acids and mixtures thereof; wherein the
solid formulation is prepared from a mixture of formulation
constituents under exposure of high shear forces in the
presence of one or more of the antifoams.
In a further aspect, the invention provides a
wettable granular formulation for the use in crop
protection, comprising: 1 to 80% by weight of a solid
active substance for use in crop protection; and 2 to 60% by
weight of one or more wetting agents in combination with 0.1
to 10 percent by weight of a surfactant (antifoam) selected
from the group consisting of perfluoro- (C6-C1$) -
alkylphosphinic acids, perfluoro-(C6-C18)-alkylphosphonic
acids, salts of the acids and mixtures thereof; wherein the
wettable granular formulation is prepared from a mixture of
formulation constituents under exposure of high shear farces
in the presence of one or more of the antifoams.
The invention also provides processes for
preparing the solid formulations of the invention,
comprising: grinding together the active substances with
any further components and optionally preparing an aqueous
suspension from the solid formulation, which is subsequently
granulated; or mixing the solid formulation constituents
under exposure of high shear forces in the presence of one
or more of the antifoams.
The proportion of antifoam in the formulation can
be up to 10% by weight, but in general 0.1 to 5% by weight,
preferably 0.1 to 5% by weight and in particular 0.2 to 2%
by weight are used.
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The formulation also contains 2 to 60~ by weight, prefer-
ably 5 to 50~ by weight, of one or more wetting agents,
preferably from the group comprising the alkanesulfon-
ates,alkylnaphthalenesulfonates,alkylbenzenesulfonates,
alkylpolyglycol ether-sulfonates, alkylsulfosuccinic acid
half-esters, fatty acid N-methyltaurides or mixtures of
the above wetting agents.
The active substances, which can be supplied in the form
of solid formulations, include all suitable biologically
active organic compounds, preferably herbicides and
safeners, insecticides, fungicides, acaricides,
nematicides, pheromones and repellents, in particular
herbicidal active substances, such as glufosinate-
ammonium, glyphosate, bialaphos, active substances from
the phenoxy series, such as CMPP, MCPA, 2,4-D, active
substances from the phenoxyphenoxy series, such as
diclofopmethyl, or the heteroaryloxyphenoxy series, such
as phenoxapropethyl, phenoxaprop-P-ethyl, active
substances from the urea series, such as isoproturon,
diuron, linuron, monolinuron and chlortoluron, active
substances from the series comprising the sulfonylureas,
such as amidosulfuron, tribenuron (DPX-L5300),
thiameturon-methyl (DPX-M6316), metsulfuron-methyl
(DPX-T6376), primisulfuron-methyl and nicosulfuron,
active substances from the series comprising the
triazines, such as atrazine or simazine, active
substances from the series comprising the imidazolinones,
such as imazapyr, imazac,~uin, imazethapyr and
imazamethabenz, and diphenyl ether derivatives, for
example acifluorfen, fluoroglycofen, lactofen and
bifenox, dicotylene herbicides, for example ioxynil,
bromoxynil, dicamba, diflufenican, fluroxypyr, phen-
medipham, desmedipham, bentazone, metamitron, metribuzin,
chloridazon, ethofumesate or the active substance
trifluralin, and safeners, such as, for example, the
compounds described in EP-A-86750, EP-A-94349,
EP-A-191736, EP-A-346620, EP-A-333131, EP-A-269806,
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EP-A-159290, DE-A-2546845, PCT/EP-90/02020 and
PCT/EP-90/01966;
fungicidal active substances, such as, for example,
active substances from the series comprising the azoles,
for example triadimefon, cyproconazole, myclobutanil and
dichlobutrazol, active substances from the series
comprising the dithiocarbamates, such as maneb, zineb and
mancozeb, the benzimidazoles, for example carbendazime,
or active substances such as, for example, procymidone,
iprodione, vinchlozoline, thiophanate-methyl, cymoxanil,
folpet, copper oxychloride, sulfur or TPTH; insecticidal
active substances, such as, for example, active
substances from the series comprising the pyrethroids,
such as deltamethrin, acrinathrin, tralomethrin,
permethrin and cypermethrin, active substances from the
benzoylurea series, such as diflubenzuron, or active
substances such as, for example, endosulfan, pirimicarb
or silafluofen.
The said active substances can also be supplied in com-
bination with one another in the form of solid formula-
tions. The active substance content is as a rule 1 to
80~ by weight, preferably 5 to 60~ by weight.
Suitable perfluoroalkyl group-containing surfactants are,
in particular, perfluoro(C6-Clz)alkylphosphinic acids and
perfluoro(C6-Clz)alkylphosphonic acids and their alkali
metal salts, such as sodium or potassium salts, their
ammonium salts, (Cz-Cle)-alkylammonium salts and also
salts with (Clo-Clay-alkylamineethoxylates and ethylene-
diamineethoxylates or mixtures thereof. The perfluoro-
alkyl group-containing surfactants are commercially
available, for example ~Fluowot PP (mixture of (C6-Clz)-
perfluoroalkylphosphinic acids and (Cs-Clz)-Perfluoro-
alkylphosphonic acids, Hoechst) or can be prepared by
known methods (DE-A 21 11 167).
~~9~.'~4~
- 6 -
In addition to the said active substances, the effective
antifoams found and wetting agents, the solid
formulations can also contain further conventional
formulating auxiliaries, such as, for example, dispers-
ants, agglomeration auxiliaries, stabilizers, inert
fillers and water-soluble substances, for example
ammonium sulfate, urea or sodium sulfate, the content of
these substances as a rule being 0 to 70~ by weight,
preferably 5 to 50~ by weight.
The said active substances are also known and are
described in "Pesticide Manual'° (by the British Crop
Protection Council) or in "Farm Chemicals Handbook 91"
(Meister Publishing Company, Willoughby, Ohio).
The said perfluoroalkyl group-containing antifoams can
also be used in combination with antifoams belonging to
other substance categories, in particular in combination
with silicone-based antifoams.
By means of the perfluoroalkyl group-containing surfact-
ants used according to the invention it is possible to
provide wettable powder formulations and granule formula-
tions, and in particular also water-emulsifiable
granules, with antifoams which do not lose their activity
either during the preparation or during storage of the
products for 2 to 4 years.
In addition to the said active substances, the perfluoro-
alkoxy graup-containing surfactants and wetting agents
and also, optionally, further conventional formulating
auxiliaries, the said water-emulsifiable granules can
contain a high-boiling solvent or solvent mixture. They
also contain an at least partially water-soluble casing-
and structure-forming material, which preferably essen-
tially comprises at least one substance from the group
comprising gelatin, gum arabic, cellulose derivatives,
starch derivatives, sodium alginates, polyvinyl alcohols
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and polyvinylpyrrolidones. Its content is 10 to 80~ by
weight, prefer«bly 25 to 60~ by weight. A casing- and
structure-forming material which essentially comprises a
polyvinyl alcohol obtained by partial hydrolysis of
polyvinyl acetate or a mixture of such polyvinyl alcohols
is preferred. Polyvinyl alcohols, or mixtures thereof,
with a degree of hydrolysis of preferably 72 to 99 mold
and a viscosity of preferably 2 to l8cP, determined in a
4~ strength aqueous solution at 20°C (for example ~Mowiol
grades), are obtained by hydrolysis, preferably partial
hydrolysis, of polyvinyl acetate. The polyvinyl alcohols
preferred for the present invention have a molar mass of
preferablX 10,000 to 20,000. They are prepared by
partial, preferably 72 to 99 mold, alkaline hydrolysis
of corresponding polyvinyl acetates.
When the said water-soluble materials are used, in
particular when specific polyvinyl alcohol grades or
mixtures thereof are used, water-emulsifiable granules
which have an average particle diameter of 0.3 to 5 mm,
preferably 0.5 to 2 mm, and which do not produce dust,
are free-flowing, can readily be metered volumetrically
and are readily emulsifiable in water are formed, for
example by the fluidized bed process using the counter-
current principle.
Suitable high-boiling organic solvents are mainly high-
boiling aromatic compounds, such as, for example, 1- or
2-methylnaphthalene, dimethylnaphthalenes and other
polynuclear aromatic compounds. However, other water-
immiscible solvents axe also suitable, for example
aromatic compounds, such as alkylbenzenes and xylenes,
aliphatic compounds, such as paraffin oils, vegetable
oils, alicyclic compounds, alkanols, such as cyclohexanol
and isooctyl alcohol, ethers, ketones, such as cyclo-
hexanone, 4-methylcyclohexanone and isophorone, and
esters, such as ethyl benzoate and tri-n-butyl phosphate.
Liquid pesticide active substances can also be used
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without organic solvents. The high-boiling solvent or
solvent mixture content is 0 to 80~, preferably 20 to
60~.
The antifoams are also effective if they are added to the
aqueous sprax slurries of the formulations before these
are applied.
The invention therefore also relates to the dilute
formulations (spray slurries) which contain the
constituents of the solid formulations described in
approximately 50- to 500-fold dilution.
The following examples illustrate the invention without
restricting the invention thereto. The percentages are by
weight.
Example 1
Glufosinate-ammonium 20 WG
20$ glufosinate-ammonium
40~ ~Hostapur OS
39~ ammonium sulfate
1 ~ ~Fluowet PP
The granules are prepared in accordance with
DE-A-39 26 800 by spraying an aqueous solution of
glufosinate-ammonium onto the pulverulent mixture of the
remaining constituents of the formulation in a fluidized
bed.
Example 2
Glufosinate-ammonium + diuron (12 + 18) WG
12.0 glufosinate-ammonium
18.2$ diuron, 99~ strength
16.0 ~Hostapur OS
12.0$ ~Genapol LRO
~~91~4f~
_ g
5.0$ ~Vanisperx GB
1.8$ ~Fluowet PP
35.0 kaolin
The granules are prepared in accordance with
IDE-A-39 26 800 from an aqueous suspension having a solids
content of 40~ by granulation in a fluidized bed. The
suspension is prepared by grinding all of the formulation
constituents extremely finely in water with the aid of a
bead mill.
Example 3
Isoproturon + amidosulfuron (60 + 1.5) WP
60.61$ IPU, technical grade, 99~ strength
1.56$ amidosulfuron, technical grade, 96~ strength
10.00 ~Geropon SC 213
6.00 ~Texapon K12
21.OO~k kaolin 1777
0.83 ~'Fluowet PP
The wettable powder is prepared by grinding all of the
formulation constituents in a hammer mill.
Example 4
Isoproturon -~ amidosulfuron (75 + 1.5) WG
75.76 IPU, technical grade, 99$ strength
1.56 amidosulfuron, technical grade, 96~ strength
10.00 ~Geropon SC213
6.00 ~Texapon K12
0.30 ~Forlanit P
5.20$ kaolin 1777
0.50 silicone antifoam SE2
0.68 ~'Fluowet PP-potassium
The granules are prepared by spraying an aqueous suspen-
sion having a solids content of 50$ by means of a single
- 10 -
substance nozzle and drying in a conventional spraying
tower using the co-current principle.
The aqueous suspension is prepared by grinding all of the
formulation constituents in a bead mill.
Example 5
Amidosulfuron + bromoxynil + diflufenican (2.2 + 37.5 +
7.5) WG
40.32 bromoxynil, technical grade, 93~ strength
2.37 amidosulfuron, technical grade, 93~ strength
7.73 diflufenican, technical grade, 97~ strength
8.00 ~Geropon SC 213
4.00 ~Texapon K 12
2.00$ ~Luviskol K 30
34.58 kaolin 1777
0.50$ silicone antifoam SE 2
0.2.5 antifoam 416
0.25 ~Fluowet PP
The granules are prepared from an aqueous suspension
having a solids content of 50~ in a fluidized bed. For
preparation of the aqueous suspension, the formulation
constituents with the exception of antifoam 416 are
ground in a bead mill and antifoam 416 is then added with
slow stirring.
Example 6
Amidosulfuron 50 WP
52.08 amidosulfuron, technical grade, 96$ strength
10.00 ~Tamol NNO
6.00 ~Texapon K 12
20.00$ kaolin 1777
11.40$ ~Wessalon S
0.52 ~Fluowet PP
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The wettable powder is prepared by grinding all of the
formulation constituents in a hammer mill.
Example 7
Carbendazim 80 WG
80.88 carbendazim, technical grade, 99~ strength
5.62 ~Tamol NNO
2.90 ~Mowiol 3/83
5.60$ starch
0 . 2 ~ ~'Bronidox L
0,2$ silicone antifoam SE 2
3.60$ ~Forlanit P
The granules are prepared by spray drying an aqueous
suspension having a solids content of 55~ in a conven-
tional spray drier and the aqueous suspension is prepared
by grinding all of the formulation constituents in a bead
mill.
Example 8
Fluoxaprop-P-ethyl -E fenchlorazole-ethyl (12 + 6) WEG
12.50 fluoxaprop-P-ethyl, technical grade, 96~ strength
6.15 fenchlorazole-ethyl, technical grade, 97.6$
strength
43.50 ~'Solvesso 200 (Exxon Chemical)
20.00 ~'Mowiol 3/83
11.35 ~'Mowiol 4/88
5.00 ~'I~Tostapur OSB
0.50$ ~Fluowet PP
1.00 residuvl moisture
101 g of a polyvinyl alcohol prepared by partial saponi-
fication of polyvinyl acetate and having a viscosity of
3 cP (determined in 4~ strength aqueous solution at 20°C)
and a degree of hydrolysis of 83 mold are dissolved in
600 g of water and 57.3 g of a polyvinyl alcohol prepared
- 12 -
in the same way and having a viscosity of 4 cP and a
degree of hydrolysis of 88 mold are added slowly, with
vigorous stirring. The aqueous phase is then homogenized.
A solution of 63 g of fenoxaprop-P-ethyl and 31 g of
fenchlorazole-ethyl in 220 g of ~Solvesso 200 is then
allowed to run into the aqueous phase while continuing to
stir and the speed of rotation of the stirrer is then
increased so that the oily droplets formed in the aqueous
phase have an average diameter of 5 to 10 Vim.
The resulting suspension is then metered into a
laboratory fluidized bed drier. The water-dispersible
granules thus obtained have a particle diameter of 0.5 to
2 mm. A stable suspoemulsion forms in water.
The surfactants and auxiliaries listed in Examples 1 to
8 are known and can be obtained from
Hoechst AG (~Hostapur OS, ~Genapol LRO, ~Mowiol)
Henkel KG (~Texapon K12, ~Forlanit P,
~Bromidox L)
BASF (~Taniol NNO, ~'Zuxiskol K 30 )
blacker Chemie GmbH (Silicone antifoam SE 2)
Rhone-Poulenc (~Geropon SC 213, Antifoam 416)
Borregaard A.S. (~Vanisperse CB)
Exxon Chemical (~Solvesso)
Foam test
A 1 1 measuring cylinder (diameter: 5 cm) closeable with
a glass stopper is filled with 500 ml of standard water
D (342 ppm CaC03 hardness according to CIPAC Handbook 1,
p. 878). After adding 5 g of product, the closed cylinder
is turned 10 times through 180° and back again. Immedi-
ately thereafter the time taken for the foam formed to
collapse is measured.
Result:
~(f~1'~4
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When formulations which contain the antifoams according
to the invention are used, 90~ of the foam disappears
within 2 to 3 min and frequently the entire foam also
collapses within 1 min.
When formulations are used which are prepared by the
processes indicated in the examples and which do not
contain the antifoams according to the invention or
silicone-based antifoams, the foam frequently remains
stable for more than 30 min.
