U.S. patent application number 09/784536 was filed with the patent office on 2001-12-13 for copolymers and their use as drift control agents.
Invention is credited to Kupfer, Rainer, Zerrer, Ralf.
Application Number | 20010051145 09/784536 |
Document ID | / |
Family ID | 7631185 |
Filed Date | 2001-12-13 |
United States Patent
Application |
20010051145 |
Kind Code |
A1 |
Zerrer, Ralf ; et
al. |
December 13, 2001 |
Copolymers and their use as drift control agents
Abstract
What is claimed are copolymers consisting essentially of from 1
to 90% by weight of the repetitive structural unit of the formula
(1) 1 in which R.sup.1 is hydrogen or methyl, Z is a
C.sub.1-C.sub.4-alkylene group and X is hydrogen, an alkali metal
or ammonium, from 10 to 99% by weight of a repetitive structural
unit which is derived from olefinically unsaturated comonomers
containing at least one oxygen, nitrogen, sulfur or phosphorus atom
and from 0 to 20% by weight of crosslinking structures originating
from monomers having at least two olefinic double bonds. These
copolymers are suitable for use as drift control agents for crop
protection compositions.
Inventors: |
Zerrer, Ralf; (Karlstein,
DE) ; Kupfer, Rainer; (Hattersheim, DE) |
Correspondence
Address: |
CLARIANT CORPORATION
4331 CHESAPEAKE DR
ATTN: INDUSTRIAL PROPERTY DEPT
CHARLOTTE
NC
28216
US
|
Family ID: |
7631185 |
Appl. No.: |
09/784536 |
Filed: |
February 15, 2001 |
Current U.S.
Class: |
424/78.27 ;
525/344 |
Current CPC
Class: |
A01N 25/10 20130101;
C08F 220/585 20200201 |
Class at
Publication: |
424/78.27 ;
525/344 |
International
Class: |
A61K 031/795; C08F
008/34 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 16, 2000 |
DE |
10007044.2 |
Claims
1. A copolymer, consisting essentially of from 1 to 90% by weight
of the repetitive structural unit of the formula (1) 5in which
R.sup.1 is hydrogen or methyl, Z is a C.sub.1-C.sub.4-alkylene
group and X is hydrogen, an alkali metal or ammonium, from 10 to
99% by weight of a repetitive structural unit which is derived from
olefinically unsaturated comonomers containing at least one oxygen,
nitrogen, sulfur or phosphorus atom and from 0 to 20% by weight of
crosslinking structures originating from monomers having at least
two olefinic double bonds, except for those copolymers consisting
of 1-99% by weight of structural units of the formula (2) 6where
R.sup.2=hydrogen or methyl, R.sup.3=C.sub.1-C.sub.22-- alkylene,
R.sup.4=C.sub.1-C.sub.22-alkyl or hydrogen and X=ammonium, lithium,
sodium, potassium, an amine or a mixture of these substances and
99-1% by weight of structural units of the formula (3) 7where
R.sup.5=hydrogen or methyl, R.sup.6 and R.sup.7 independently of
one another are hydrogen or C.sub.2-C.sub.22-alkyl.
2. A pesticide preparation, comprising copolymers consisting
essentially of from 1 to 90% by weight of the repetitive structural
unit of the formula (1) 8in which R.sup.1 is hydrogen or methyl, Z
is a C.sub.1-C.sub.4-alkylene group and X is hydrogen, an alkali
metal or ammonium, from 10 to 99% by weight of a repetitive
structural unit which is derived from olefinically unsaturated
comonomers containing at least one oxygen, nitrogen, sulfur or
phosphorus atom and from 0 to 20% by weight of crosslinking
structures originating from monomers having at least two olefinic
double bonds.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the use of water-soluble or
water-swellable copolymers based on acrylamidoalkylsulfonic acid
salts as drift control agents in crop protection compositions.
[0002] Pesticides are applied in a highly efficient manner to
agricultural production fields using spray tanks in airplanes,
tractors and other devices. To achieve an application of the active
substances which is as accurate as possible, it is necessary to
obtain a spray cone which is as narrow as possible, and to avoid a
drift of the spray mist from the target area.
[0003] The drift of the spray cone is determined substantially by
the droplet size. The smaller the droplets, the longer the
residence time in the air and the higher the tendency to evaporate
and/or to drift horizontally and to miss the target location. The
drift effect can be reduced considerably by adding suitable drift
control agents to pesticide formulations, which drift control
agents increase the size of the droplets in the spray mist. The
formulations modified by drift control agents additionally have to
be insensitive to shear forces to which they are exposed in the
spray pumps and nozzles. Drift control agents are furthermore
required to have good biological degradability, compatibility with
the other components of the crop protection composition and high
storage and temperature stability. It is well known in the prior
art that the rheological properties of aqueous compositions can be
modified by adding water-soluble polymers, for example
polyacrylamides, acrylamide/acrylic acid polymers, sodium
polyacrylate, carboxymethylcellulose, hydroxyethylcellulose,
methylcellulose, polysaccharides and natural and synthetic guar
gum
[0004] (U.S. Pat. No. 4,413,087, US 4,505,827, US 5,874,096).
[0005] Unsatisfactory is the viscoelastic behavior of the additives
when shear and pressure forces are applied.
[0006] Under mechanical stress in the spraying device, the
viscosity is lowered and the droplet size in the spray mist is
reduced.
[0007] It is a further disadvantage that the polymers used for
modifying the viscosity of the aqueous preparations lose some of
their thickening action in the presence of electrolytes, for
example sodium chloride, calcium chloride and magnesium sulfate.
Cellulose derivatives are highly electrolyte-tolerant but not
temperature-stable enough. Biopolymers, such as xanthan gum, are
electrolyte- and thermostable, but expensive and poorly
storage-stable.
[0008] Both for economical and ecological reasons, there are
attempts to find suitable drift control agents which effectively
increase the droplet volumes of the aqueous compositions, even
under the influence of shear forces, in the presence of
electrolytes and under thermal stress, and which reduce the drift
of the spray cone.
[0009] Polymers of acrylamido-2-methyl-propanesulfonic acid and
acrylamide and their use as additives in cement slurries for
cementing deep underground drillings are known from DE 197 52
093.
SUMMARY OF THE INVENTION
[0010] Surprisingly, it has been found that water-soluble and
water-swellable copolymers based on acrylamidoalkylsulfonates and
olefinically unsaturated monomers containing at least one oxygen,
nitrogen, sulfur or phosphorus atom and from 0 to 20% by weight of
a suitable crosslinker are very good thickeners for aqueous
preparations and, when these compositions are sprayed, effect an
increase in the particle size and a reduction of the spray cone. In
addition, the polymers used according to the invention have good
viscosity properties. Under the action of shear forces, the
particle volumes are reduced only slightly. In addition, the
compositions according to the invention have high electrolyte,
temperature and storage stability.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] The invention provides copolymers consisting essentially of
from 1 to 90% by weight of the repetitive structural unit of the
formula (1) 2
[0012] in which R.sup.1 is hydrogen or methyl, Z is a
C.sub.1-C.sub.4-alkylene group and X is hydrogen, an alkali metal
or ammonium, from 10 to 99% by weight of a repetitive structural
unit which is derived from olefinically unsaturated comonomers
containing at least one oxygen, nitrogen, sulfur or phosphorus atom
and from 0 to 20% by weight of crosslinking structures originating
from monomers having at least two olefinic double bonds.
[0013] The exceptions are those copolymers consisting of 1-99% by
weight of structural units of the formula (2) 3
[0014] where R.sup.2=hydrogen or methyl,
R.sup.3=C.sub.1-C.sub.22-alkylene- , R.sup.4=C.sub.1-C.sub.22-alkyl
or hydrogen and X=ammonium, lithium, sodium, potassium, an amine or
a mixture of these substances and 99-1% by weight of structural
units of the formula (3) 4
[0015] where R.sup.5=hydrogen or methyl, R.sup.6 and R.sup.7
independently of one another are hydrogen or
C.sub.2-C.sub.22-alkyl.
[0016] The preferred monomer of the formula (1) is
2-acrylamido-2-methylpr- opanesulfonic acid and its salts,
preferably the ammonium salt. Suitable olefinically unsaturated
monomers containing at least one oxygen, nitrogen, sulfur or
phosphorus atom are, for example, styrenesulfonic acid,
acrylamidopropylmethylenesulfonic acid (AMPS), vinylsulfonic acid,
vinylphosphonic acid, allylsulfonic acid, methallylsulfonic acid,
acrylic acid, methacrylic acid and maleic acid (and its anhydride)
and the salts of the acids mentioned above with mono- and divalent
counterions. Preferred counterions are lithium, sodium, potassium,
magnesium, calcium, ammonium, monoalkylammonium, dialkylammonium,
trialkylammonium or tetraalkylammonium, where the alkyl
substituents of the amines independently of one another are
C.sub.1-C.sub.22-alkyl radicals which may be substituted by 0 to 3
hydroxyalkyl groups, the alkyl chain length of which may vary in a
range from C.sub.2-C.sub.10. Additionally, it is also possible to
use mono- to triethoxylated ammonium compounds with a different
degree of ethoxylation. Particularly preferred counterions are
sodium and ammonium. The degree of neutralization of the mole
fraction of the acids described above may also differ from 100%.
Suitable are all degrees of neutralization between 0 and 100%, the
range between 70 and 100% being particularly preferred.
[0017] Furthermore suitable are esters of acrylic or methacrylic
acid with aliphatic, aromatic or cycloaliphatic alcohols having a
carbon number of C.sub.1-C.sub.22, open-chain or cyclic.
[0018] N-vinylamides (vinyllactams) of a ring size of from 3 to 9,
for example N-vinylformamide (VIFA), N-vinylmethylformamide,
N-vinylmethylacetamide (VIMA), N-vinylacetamide, N-vinylpyrrolidone
(NVP) and N-vinylcaprolactam. Amides of acrylic or methacrylic acid
can also be used as monomers. Examples which may be mentioned are,
inter alia, acrylamide, N,N-dimethylacrylamide,
N,N-diethylacrylamide, methacrylamide, alkoxylated acrylamides or
methacrylamides (for example MAPTAC, APTAC). Other suitable
monomers are 2- and 4-vinylpyridine, vinyl acetate, glycidyl
methacrylate, acrylonitrile, vinylphosphonic acid and esters or
alkali metal, alkaline earth metal or ammonium salts thereof,
DADMAC and vinylsulphonic acid or its corresponding Na.sup.+,
K.sup.+, Li.sup.+, Mg.sup.2+ or Ca.sup.2+ salts. It is, of course,
also possible for combinations of the monomers listed to be
present. As already mentioned, the sum of the comonomers used can
be from 9.99 to 98.99% of the total mass of the polymer. The
polymers used according to the invention as drift control agents in
crop protection compositions can be crosslinked, i.e. they contain
compounds having at least two double bonds which are polymerized
into the polymer. Suitable crosslinkers are, in particular,
methylenebisacrylamide or methylenebismethacrylamide, esters of
unsaturated mono- or polycarboxylic acids of polyols, such as
diacrylate or triacrylate or methacrylates, for example butanediol
or ethylene glycol diacrylate or methacrylate, and also
trimethylolpropane tri(meth)acrylate and allyl compounds, such as
allyl (meth)acrylate, triallyl cyanurate, diallyl maleate,
polyallyl esters, tetraallyloxyethane, triallylamine,
tetraallylethylenediamine, allyl esters of phosphoric acid and
derivatives of vinylphosphonic acid, furthermore, allyl or vinyl
ethers, for example dipropylene glycol diallyl ether, polyglycol
diallyl ether, triethylene glycol divinyl ether, hydroquinone
diallyl ether, multifunctional alcohols, tetraethylene glycol
diacrylate, trimethylolpropane diallyl ether,
methylene-bis-acrylamide or divinylbenzene.
[0019] The polymers according to the invention are prepared by
free-radical copolymerization in C.sub.1-C.sub.6-alcohols,
preferably in tert-butanol.
[0020] The polymerization can be carried out at in a temperature
range of from 0 to 150.degree. C., preferably between 10 and
100.degree. C., and at atmospheric pressure or else under elevated
or reduced pressure. As usual, the polymerization can also be
carried out in an atmosphere of protective gas, preferably under
nitrogen.
[0021] For initiating the polymerization, it is possible to use
high-energy fields or the customary chemical polymerization
initiators, for example organic or inorganic peroxides, such as
benzoyl peroxide, tert-butyl hydroperoxide, methylene ketone
peroxide, cumene hydroperoxide, azo compounds, such as, for
example, azodiisobutyronitrile, and also inorganic peroxy
compounds, such as (NH.sub.4).sub.2S.sub.2O.sub.8 or
K.sub.2S.sub.2O.sub.8 or H.sub.2O.sub.2, if appropriate in
combination with reducing agents, such as sodium hydrogen sulfite
and iron(II) sulfate or redox systems which, as reducing component,
comprise an aliphatic or aromatic sulfonic acid, such as
benzenesulfonic acid and toluenesulfonic acid, or derivatives of
these acids, such as, for example, Mannich adducts of sulfinic
acid, aldehydes and amino compounds.
[0022] In general, the polymers have a number-average molecular
weight of from 1000 to 20 000 000 g/mol. Preference is given to a
molecular weight of from 20 000 to 5 000 000, in particular 100 000
to 1 500 000 g/mol.
[0023] The invention provides furthermore pesticide preparations
comprising a copolymer of repetitive structural units of the
formula (1), of structural units which are derived from
olefinically unsaturated compounds containing an oxygen, nitrogen,
sulfur or phosphorus atom and crosslinking structures as described
above. These pesticide preparations may also comprise copolymers of
the monomers of the formulae (2) and (3). In addition to these
copolymers serving as drift control agents, the pesticide
preparations comprise the customary active compounds, such as
herbicides, insecticides, fungicides, acaricides, bactericides,
molluscides, nematicides or rodenticides. Preference is given to
herbicidal preparations. Suitable herbicidally active compounds are
in particular glyphosate, but also acifluorfen, asulam, benazolin,
bentazone, bilanafos, bromacil, bromoxynil, chloramben, clopyralid,
2,4-D, 2,4-DB, dalapon, dicamba, dichlorprop, diclofop, endothall,
fenach, fenoxaprop, glamprop, fluazifop, flumiclorac,
fluoroglacofen, fomesafen, fosamine, glufosinate, haloxyfop,
imazapic, imazamethabenz, imazamox, imazapyr, imazaquin,
imazethapyr, ioxynil, MCPA, MCPB, mecoprop, methylarsonic
acid/MSMA, naptalam, picloram, quinclorac, quizalofop,
2,3,6-TBS-TCA.
[0024] The preparations according to the invention may comprise the
copolymers based on acrylamidoalkylsulfonic acid salts as drift
control agents in virtually any amount. Preference is given to the
following preparations:
[0025] Formulations as tank-mix and ready-to-use compositions
comprise from 0.01 to 10% by weight, preferably from 0.0025 to 2%
by weight, of pesticide and from 0.0001% by weight to 5% by weight,
preferably from 0.0025 to 2%, particularly preferably from 0.02 to
1%, of the copolymer according to the invention. The weight ratio
of copolymer to pesticide can in this case be from 1:10 to 500:1,
in particular from 1:4 to 4:1.
[0026] Concentrate formulations, which are diluted prior to use,
may comprise the pesticide in amounts of from 5 to 60% by weight,
preferably from 20 to 40%, and the copolymer based on
acrylamidoalkylsulfonic acid salts in amounts of from 3 to 50% by
weight. Here, the weight ratio of copolymer to pesticide can be
from 1:20 to 1:1, preferably from 1:10 to 1:2.
[0027] In addition to the copolymers based on
acrylamidoalkylsulfonic acid salts, the formulations according to
the invention may comprise further thickeners, antigelling agents,
antifreeze, solvents, dispersants, emulsifiers, preservatives,
adjuvants, binders, antifoams, thinners and wetting agents.
[0028] The thinner used can be xanthan gum and/or cellulose, for
example carboxy-, methyl-, ethyl- or propylcellulose, in amounts of
from 0.01 to 5% by weight, based on the finished composition.
Suitable solvents are monopropylene glycol and animal and mineral
oils. Suitable dispersants and emulsifiers are nonionic,
amphoteric, cationic and anionic surfactants.
[0029] Suitable for use as preservatives are organic acids and
esters thereof, for example ascorbic acid, ascorbic acid palmitate,
sorbate, benzoic acid, methyl- and propyl-4-hydroxybenzoate,
propionate, phenol, for example 2-phenylphenate,
[0030] 1,2-benzisothiazolin-3-one, formaldehyde, sulfurous acid and
salts thereof. Suitable antifoams are polysilicones. Adjuvants that
are available are polyglycerol esters, alcohol ethoxylates,
alkylpolysaccharides, fatty amine ethoxylates, sorbitan and
sorbitol ethoxylate derivatives and derivatives of
alk(en)ylsuccinic anhydride. Suitable diluents, absorbents or
carriers are carbon black, talc, kaolin, aluminum stearate, calcium
stearate or magnesium stearate, sodium tripolyphosphate, sodium
tetraborate, sodium sulfate, silicates and sodium benzoate.
[0031] The wetting agents used can be alcohol
ethoxylates/propoxylates.
[0032] To assess the effect of the copolymers used according to the
invention, from the sodium salt of 2-acrylicamido-2-methylsulfonate
and acrylamide, on the drift potential of an aqueous formulation,
the mean droplet volumes of the spray mist and the distribution of
the droplet size were determined both under normal conditions and
under the action of shear forces and compared with the values
determined for pure water.
1TABLE 1 Mean diameter (.mu.m) of the droplets Diameter (.mu.m)
Without shear With shear Substance forces forces Water 262 260
Emigen DPR 476.1 296.3 Polymer 1 510 420
[0033] At a temperature of 20.degree. C., an aqueous solution of
0.12 g/l of polymer 2000 or 12.00 g/l of Emigen DPR/I was sprayed
using a Teejet XR8003 VS spray nozzle (tip@ 40 psi) from a distance
of 30 cm on to an Aerometrics PDPA laser measuring system (325
volts), and the particle diameter of 10 000 droplets was
determined. In each case, the measurement was carried out in three
repetitions. Using a rotary pump at a rotation speed of 4.0 gal/min
and a total of 12 rotations, the aqueous solutions were, at a
temperature of 20.degree. C., subjected to shear forces, and the
droplet diameters were determined.
2TABLE 2 Percentage of droplets < 150 .mu.m, in % by volume % by
volume Without shear With shear Substance forces forces Water 19.0
19.0 Emigen DPR 6.6 16.6 Polymer 1 7.0 9.5 Chemical designation of
Emigen .RTM. DPR from Tables 1 and 2: Partially hydrolyzed
polyacrylamide
[0034] Polymer 1 was prepared as follows:
[0035] Copolymer of 70% by weight of AMPS and 30% by weight of AM,
ammonium salt
[0036] 1700 g of rectified tert-butanol were initially charged in a
3 liter Quickfit flask fitted with anchor stirrer, reflux condenser
with waste-gas washer, combined thermometer/pH-meter and gas inlet
tube, and admixed with 50 ml of distilled water. The reaction
vessel was located in a thermostatted heating bath.
[0037] This reaction vessel was flashed with nitrogen gas, and in a
gentle countercurrent of nitrogen, 245 g of
acrylamido-2-methylpropanesulfonic acid AMPS 2404.RTM. (registered
trade mark of Lubrizol) were introduced. The AMPS did not dissolve
completely in the tert-butanol, and some of it was present as a
solid-in-liquid dispersion. The pH of this mixture was below pH 1.
Using the gas inlet tube, gaseous ammonia was introduced above the
liquid phase until the pH of the dispersion was between pH 7 and 8.
After the desired pH range had been reached, stirring was continued
for 1 hour, and the pH was monitored continuously. The reaction
vessel was once more flashed with nitrogen, and 105 g of acrylamide
were introduced. After the acrylamide had been introduced, the pH
was checked once more and, if required, adjusted to a range of pH
7-8. A constant stream of nitrogen was passed through the solution
for at least 1 hour. After this inertization time, the residual
oxygen content was checked using an oxygen electrode. If the
measured residual oxygen content in the liquid phase is above the
value of 1 ppm, the liquid phase has to be inertized again, until
this value is reached. Subsequently 1.5 g of AIBN were added in a
gentle stream of nitrogen, and the reaction vessel was heated to
60.degree. C. Shortly after an internal temperature of 60.degree.
C. had been reached, introduction of nitrogen gas was terminated,
the polymerization reaction typically starting after a few minutes,
which could be detected by an increase in temperature of
10-15.degree. C. Approximately 30 minutes after the polymerization
reaction had started, the temperature maximum had been passed, and
the temperature in the reaction vessel was increased to the boiling
point of tert-butanol, using the heating bath.
[0038] Under gentle reflux, the material, which was now viscous,
was stirred for another two hours.
[0039] The reaction product, present as a viscous suspension of
polymers in tert-butanol, was separated off by filtering off the
tert-butanol, followed by dying in a vacuum drying cabinet.
[0040] Yield: 365 g of polymer 1
[0041] Ammonium salt of poly (acrylamido-2-methylpropanesulfonic
acid-co-acrylamide)
[0042] Dry matter: 96% by weight (2.5% by weight of tert-butanol,
1.5% by weight of water)
[0043] k-value of a 0.5% by weight strength solution: 212
* * * * *