DK154960B - FLUID HERBICID AGENT IN THE FORM OF Aqueous Suspension Concentrate and Procedures for Combating Weeds - Google Patents

Abstract

1. Liquid, herbicidal agents in the form of aqueous suspension concentrates containing, as the active compound, isoproturon or mixtures of isoproturon with ioxynil, bromoxynil, mecoprop or salts of the last three active compounds and also formulating auxiliaries, which contain, as the formulating auxiliary, an alkali metal salt, preferably the sodium salt, of a condensation product containing sulfo groups and formed from a phenol and formaldehyde, and also alkali metal salts, ammonium salts or amine salts, preferably sodium salts, of alkyl polyglykol etherphosphate partial esters, in particular mono-(alkyl polyglycol ether)-phosphates or di-(alkyl polyglycol ether)-phosphates, the alkyl polyglykol ether radical of which consist of optionally substituted alkyl groups which can also contain double bonds and have preferably 6 to 24 and in particular 12 to 18 C atoms, and polyglycol ether groups having preferably up to 20 and in particular 4 to 12 ethylene oxide units (= EO units) per radical, the suspension concentrates having a temperature/viscosity coefficient of about 0.6 to 0.95, calculated on temperature increases in 20 degrees C intervals, within the temperature range from 10 to 70 degrees C, in particular 20 to 60 degrees C.

Description

1 DK 154960 B

ISLAND

The present invention relates to liquid herbicidal agents in the form of aqueous, storage stable suspension concentrates which also remain readily recoverable at higher temperatures and contain as isoproturon or mixtures of isoproturon with ioxynil, bromoxynil, mecoprop or salts of these three. the latter and as a formulation aid contain an alkali metal salt of a condensation product of a sulfo group-containing phenol and formaldehyde or of a phenol, an alkali metal sulfite and formaldehyde, and alkali metal salts of alkyl polyglycol ether phosphate partial esters.

The latter give the suspension concentrates in the temperature range 10-70 ° C a temperature / viscosity coefficient of between approx. 0.6 and 0.95, calculated on temperature increases in intervals of 20 ° C, so that the viscosity of the suspension concentrates 15 decreases reversibly with increasing temperature.

Isoproturon (3- (4-isopropylphenyl) -1,1-dimethylurine substance) is a known herbicide used to control small-seeded undesirable grasses (arable tail), as well as bird grass and chamomile species in the young developmental stage. To obtain a wider spectrum of herbicidal activity, it has been found advantageous to mix the also known active substances ioxynil (4-hydroxy-3,5-diiodobenzonitrile), bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) and mecoprop (2- (4-chloro-2-methylphenoxy) -propionic acid), thereby being able to control several types of weeds simultaneously with introduction. Thus, by the addition of ioxynil and bromoxynil to isoproturon, further drowsiness, honorary honors and stepmothers can be further combated, and blend preparations of isoproturon and mecoprop can also be used against climbers. The herbicidal effect of such effective combinations is known e.g. from DE Publication No. 23 43 985, as well as Cole and Horsnail, Proceedings 1976, Volume 1, British Crop Protection Conference-Weeds, pages 111-113.

Generally, pesticide-active substances are used e.g. in the form of emulsifiable concentrates, as well as spray powders

ISLAND

2

DK 154960 B

and suspension concentrates. Active substances which are difficult to solubilize in technical solvents, e.g. isoproturon, commonly used e.g. in the form of spray powders, but for the manufacture of spray powders, expensive grinding and filtration systems and often expensive synthetic silicic acids as carriers are required, and spray powders also have the disadvantage of being poorly metered or dosed and dusted during handling, thereby users can easily become contaminated and damaged. In addition, active substances contained in spray powder mixtures in the form of soluble alkali metal or ammonium salts often act strongly corrosive. In addition, spray powders of spray powders are only slightly stable as to the homogeneity of the dilute aqueous suspension, and the suspended particles of active substance and other solids settle relatively rapidly, so that after half an hour, only half of the stirred active substance is often found. substance in suspension, which mostly leads to a disparate distribution of the active substances on the plants.

Pourable, storage-stable aqueous suspensions, e.g. may contain 20-50 weight solids in fine distribution, do not have the disadvantages described above for the spray powders as their preparation occurs by grinding coarse aqueous suspensions of active substance in ball or sand mills and since filter systems do not is necessary, the equipment cost is not very large.

In contrast, the development of truly storage-stable and practically usable suspension concentrates, unlike '30 *, is more difficult compared to spray powders and emulsifiers.

Emulsifiable concentrates and spray powders are in practice available as single-phase systems and can e.g. in the form of a solution or a powdered product is stored relatively problem-free. However, at the time of use after dilution with water, they must be able to form emulsions or suspensions in a short period of time, which after international testing.

3 DK 154960 B

o regulations, e.g. for spray powders, that is, after half an hour of spraying, 50% by weight of the particles of the active substance must still be suspended. In contrast, aqueous suspension concentrates of solid 5 constitute solid / liquid two-phase systems in which the solid particles exert uninterrupted forces such as the thermal molecular movement, the sedimentation force and the mutual attractive forces. However, when suspension concentrates are usable in practice, they must be storage stable over two years, which means that the atomization of the active substance particles must be maintained and guaranteed for at least this period. The dispersion must remain pourable, and thickening of the suspension and sediments which cannot be spontaneously agitated must be excluded. By nature, such two-phase systems are unstable and prone to separation in the constituents, which is enhanced with increasing storage time and temperature. In many cases, the dispersions solidify and form cool sediments that can no longer be dispersed in the above liquid. In addition, the dispersed particles of active substance will often fade abruptly when mixing the suspension concentrates with other pesticidal preparations, and this is especially true when the added agents contain salts or the active substances themselves have salt character, e.g. are present or used in the form of carboxylic acid salts or phenolates. Such 25 blanks may e.g. may occur by admixture of pesticidal agents in dilute ready-to-use spray liquids of pesticidal suspension concentrates, but may also, possibly more or less delay, already by the storage of suspension concentrates of solid active substances added to such salts or phenolates of active substances. This is especially true for the suspension concentrates described above containing combinations of isoproturon with mecoprop, bromoxynil and ioxy-nil, which are in practice a considerable need.

In suspension concentrates, time- and temperature-dependent processes can occur that affect the quality of the product. After theoretical conceptions, a suspension should be 4

ISLAND

DK 154960 B

car, when, in a variety of dispersing, wetting and viscosity modifiers, they can be incorporated into the appropriate concentration for the particular applications and these bond to the particles to be dispersed and charge them optimally electrostatically in one way , so that the resulting repulsive forces can overcome the extremely strong and increasing particle finesse Van der Waals's attractive forces. With increasing fineness of the particles, on the other hand, through their corresponding increasing thermal mobility, the sedimentation force can be counteracted. By increasing uniform electrostatic charge of the particle, an enhanced polarization of the surrounding water molecules is induced, which results in a growing thicker hydrate envelope of polarized water molecules, which causes the suspension of water to rise. decreases and the product becomes better pourable. If suitable surfactants provide that the hydrate envelope is also maintained at increasing storage temperatures, the attractive forces of the particles are further shielded, despite increasing thermal mobility. On the other hand, if the particles are not completely uniformly charged or already partially discharged through excess surfactants, a stable dispersion at higher storage temperatures over time can thicken or form cool, non-dispersible precipitates, since in these in case of the increasing mobility of the active substance particle with increasing storage temperature, the latter's energy is sufficient, 30 due to the less well-formed hydrate enclosures, to approach so much that their attracting forces can become effective, resulting in thixotropy. behavior and time-dependent rearrangements of the hydrate enclosures, making the dispersion more unstable. However, these are theoretical notions that would help explain such time-dependent processes, and in fact,

"DK 154960 B

D

o the rates odd more varied, and measurement methods such as for measuring the zeta potential for finding an optimal particle charge, for concentrated dispersions can provide no information. Something similar also applies to the development of very low viscous dispersion compositions, because, as it turns out in practice, it is difficult, first, for several composition constituents to first determine those which could be due to the heterogeneity of the criteria to be used. suitable to be included in further long-term stability tests.

Furthermore, it is known that in the development of storage-resistant, pourable dispersion preparations using the technical qualities of active substances can in no way rely on the suspension conditions for a single production batch, since small changes in the content of bicomponents in the individual batches of substance can significantly affect the stability of dispersions produced therefrom. It is therefore also necessary to further test the final optimized composition after numerous formulation experiments with numerous different technical batches of active substance for reproducibility and, if necessary, modify or possibly fundamentally rework the formulation. In this regard, the composition of suspension concentrates of isoproturon is a notable example, with larger scale 25 isoproturon produced, e.g. depending on the method of preparation and the purification methods used, may contain 97% by weight of pure active substance in addition to approx. 2 wt.% Ortho · isomer and 1 wt.% Meta-isomer or 97 wt.% Of pure active substance in addition to 1.5-3 wt.% Of meta-isomer and up to 1 wt. 30 ortho isomers and the determination of storage stable. dispersion compositions are exceedingly hampered by such small changes in quality of the isoproturon.

These difficulties are further compounded by blending. the isoproturon having any technical qualities of 35 ioxynil, bromoxynil, mecoprop or its salts such as e.g. the alkali metal or amine salts.

ISLAND

6

DK 154960 B

It has been found that compositions of dispersions or processes for their preparation, as described in the literature, when used to formulate suspension concentrates of isoproturon or 5 of combinations of isoproturon with ioxynil, bromoxynil and mecoprop do not lead to storage stable products. Thus, e.g. the susceptibility of isoproturon is not improved by the use of partially hydrolyzed polyvinyl acetates, e.g. as in United States Patent No. 4,071,617, and 10 even in stored dispersions appear precipitates which cannot be redispersed. This also applies when non-ionic emulsifiers, plant gums and anionic surfactants are used for the formulation, as in e.g. United States Patent No. 3,948,636 and British Patent No. 1,480,110. Nonionic emulsifiers containing polyglycol ether groupings and e.g. used in amounts from approx. In addition, about 2% by weight may cause crystal growth for the relatively poorly soluble isoproturon. Use of block copolymer polyether glycols such as those e.g. is obtained by addition of ethylene oxide to a condensation product of propylene oxide and propylene glycol, next to dispersants and also under the addition of silicic acids such as e.g. according to German publication no. 25 47 968 or 26 51 046, leads to dispersions which, upon storage 25, solidify into shear-resistant products. Said block β-copolymer polyether glycols also cause certain recrystallizations of the suspended active substance particles to form coarser particles. Isoproturon-containing suspension concentrates containing polymers of polycarboxylated vinyls, e.g. polymethacrylates, will secrete cool precipitates, e.g. by mixing isoproturon according to United States Patent 3,060,084. Unusable, non-storage stable suspension concentrates that become thick during storage at higher temperatures, e.g. 50 ° C is also obtained by mixing isoproturon e.g. according to German Patent Publication No. 26 51 046, and also dispersions which e.g.

0 7

DK 154960 B

According to United States Patent No. 3,157,486 as a formulation aid, lignin sulfonate contains and in the examples therein no additional wetting agent, storage is stable.

The suspension concentrates referred to are often not sufficiently malleable in the spheres or sand mills required for their manufacture, and this may be especially the case for such formulations whose viscosity is so strongly temperature dependent that the suspension at temperatures between ca. 35 and approx. 55 ° C. thickening. However, such temperatures are easily reached in technical production grinding plants, although their cooling jacket is cooled with water, the heat released by decomposing the material, in such formulations, causing an increase in viscosity, which in turn leads to a deterioration of the heat release from the grinding process. The charge is poured into the cooling jacket, so that the temperature of the grinding charge rapidly rises again and can easily reach 90 ° C, whereby the dispersions can frequently become fully solid or even reach or exceed the melting point of low melting active substances.

For example, those with increasing temperature are thicker becoming isoproturon dispersions or those which, in stability storage experiments at 50 ° C, solidify after a few days or weeks and do not form redispersible precipitates when using conventional dispersants such as e.g. sodium salts of lignin sulfonic acids, sodium salts of formaldehyde condensation products with sodium sulfite and phenol or nonylphenol or naphthol or naphthalene sulfonic acids, and wetting agents such as sodium salts of alkylbenzenesulfonic acids or of alkyl sulfuric acids or of butylnaphthalenesulfonic acids, as well as fatty alcohol polyglycol ethers or block copolymer polyether glycols.

It has now been found that liquid herbicidal agents in the form of aqueous, storage stable suspension concentrates which also at higher temperatures remain well pourable and as

DK 154960 B

active substance contains isoproturon or mixtures of isoproturon with ioxynil, bromoxynil, mecoprop or salts of the latter three active substances together with formulation aids can be obtained by using as a formulation auxiliary 1-10 wt.% alkali metal salts of a condensation product of a sulfo group. phenol and formaldehyde or of a phenol, alkali metal sulfite and formaldehyde, and 0.5-8% by weight alkali metal salts of alkyl polyglycol ether phosphate - partial esters, especially mono- or di- (alkyl polyglycol ether) -10 phosphates, the alkyl polyglycol ether residues consisting of optionally substituted alkyl groups which may also contain double bonds, having 6-24, especially 12-18 carbon atoms and polyglycol ether groups having up to 20, especially 4-12 ethylene oxide moieties (= EO units).

The phosphoric acid partial ester salts give the suspension cones in the temperature range of 10-70 ° C, especially 20-60 ° C, a temperature viscosity coefficient of between approx. 0.6 and approx.

0.95, calculated on temperature increases in intervals of 20 ° C, whereby the viscosities of the suspension concentrates 20 decrease reversibly with increasing temperature.

Accordingly, the present invention relates to liquid herbicidal agents in the form of aqueous suspension concentrates containing as an active substance isoproturon or mixtures of isoproturon with ioxynil, bromoxynil.

25 mecoprop or salts of the latter three active substances together with formulation aids which are characterized in that they contain, as formulation aids, 1-10% by weight of alkali metal salts of a sulphog group-containing condensation product of a phenol and formaldehyde, as well as 0.5-8% by weight of alkali metal salts of such alkyl polyglycol ether phosphate partial esters, especially mono- or di- (alkyl polyglycol ether) phosphates, wherein the alkyl polyglycol ether residues consist of optionally substituted alkyl groups which may also contain double bonds, with 6-24, especially 9

DK 154960 B

12-18 carbon atoms, and polyglycol ether groups of up to 20, especially 4-12 ethylene oxide units (EO units).

Preferably, as the alkyl polyglycol ether phosphate partial ester salts, orthophosphoric acid mono or diester salts may be used, especially mixtures of both the partial ester salts and preferred are the sodium salts. The preparation of the alkyl polyglycol ether phosphate partial ester salts used according to the invention, which are known products, can be carried out according to known methods.

Preferably, the alkali metal salts, especially the sodium salts, are used by mono- or diesters of orthophosphoric acid with polyglycol ethers of higher alcohols or of fatty alcohols such as e.g. coconut fatty alcohol, wax alcohols or synthetic alcohols with polyglycol ether groups of up to 20, 15 preferably 2-20 and especially 4-12 EO units. Also, the use of phosphoric acid partial ester salts with alkyl polyglycol ether residues of unsaturated higher alcohols or unsaturated fatty alcohols can in many cases be advantageous. The alkyl groups may also be substituted, e.g. with alkoxy or halogen, but preferred are unsubstituted alkyl groups. Furthermore, mixtures of various phosphoric acid partial ester salts can also be used.

According to the invention, the amount of phosphoric acid partial salts used is between ca. 0.5 and approx. 8% by weight, calculated on the final suspension concentrate.

Commercial phosphoric acid partial salts of the kind described above are obtained e.g. under the designations "Forlanit® P" and "Forlanon" (Fa. Henkel KGaA).

Said phosphoric acid partial ester salts can give the 30 herbicidal and isoproturon-containing suspension concentrates in the temperature range 10-70 ° C, especially 20-60 ° C, a temperature viscosity coefficient of between about 0.6 and approx. 0.95, calculated on temperature increases in intervals of 20 ° C.

35 o 10

DK 154960 B

The term temperature viscosity coefficient refers to a factor which, in the specified temperature range, sets the viscosities measured for the suspension concentrate at intervals of 20 ° C relative to each other. This factor constitutes the quotient of the viscosity measured at the higher temperature and similarly measured at the 20 ° C lower temperature viscosity of the suspension concentrate. If the temperature-viscosity coefficient is less than 1, the viscosity of the particular suspension concentrate decreases with increasing temperature, and if it is greater than 1, the viscosity increases.

On comparable compositions it can be shown that e.g. a replacement of the alkyl polyglycol ether phosphate partial ester salts by similar amounts of the corresponding alkyl phosphate partial ester salts, the alkyl groups of which show no polyglycol ether groups (see Comparative Example 1} or with the corresponding tris - (alkyl polyglycol ether) phosphates no longer present in salt formation (see Comparative Example 2), results in complete loss of the surprising and advantageous properties of the suspension concentrates of the invention, such as storage stability, pourability and a temperature viscosity coefficient of <1.

The alkali metal salts of the sulfo group-containing condensation products of phenols and formaldehyde used according to the invention are also known products, e.g. are described in German Publication No. 19 45 100 together with their manufacture. The preparation can be carried out e.g. both by reaction of phenolic components with formaldehyde and alkali metal sulfite or bisulfite in the alkaline region as well as by corresponding reaction of core sulfonated phenolic components with formaldehyde. The highly alkaline condensation products thus obtained can advantageously be neutralized with an acid, e.g. sulfuric acid, which may be important due to the alkali sensitivity of many biocidal active substances. The mole ratio of phenolic component to formaldehyde

DK 154960B

11

ISLAND

hyd in the condensation products is preferably between about 1: 1.3 and approx. 1: 2.5. For the condensation reaction used as phenolic components e.g. sulfo group-containing single-core phenols, especially lower alkyl groups of substituted phenols, or sulfo group-containing two-core, non-condensed mono- or bifunctional phenols or mixtures thereof and formaldehyde or the corresponding sulfo group-free phenols, formaldehyde and alkali metal sulfite or 'bisulfite. Preferred alkali metal salts are the sodium salts, and preferred phenolic components are e.g. nucleosulfonated and lower alkyl groups, nucleosubstituted phenols, especially nucleosulfonated cresols or the corresponding sulfo group-free alkyl phenols or cresols, and mixtures of phenolic components may also be used.

The amount of alkali metal salts used by the sulfo group-containing phenol-formaldehyde condensation products according to the invention is between about 1 and approx. 10% by weight, based on the finished suspension concentrate.

In a particularly preferred aspect, the present invention relates to liquid herbicidal agents in the form of aqueous suspension concentrates containing asoproturon as active ingredient or mixtures of isoproturon with ioxynil, bromoxynil, meco-prop or salts of these last three active substances, and formulation aids which herbicidal agents according to the invention are characterized in that they contain 15-60% by weight of isoproturon, 0-42% by weight of oxynil, bromoxynil, mecoprop or salts thereof, the total content of active substances being a maximum of 60% by weight, 30- 10% by weight alkali metal salts of sulfo group-containing condensation products of a phenol and formaldehyde, 0.5-8% by weight alkali metal salts of (C6-C24) alkyl polyglycol ester (2-20 EO) phosphate partial esters, 0-0.4% by weight alumosilicate with leaf structure, 0.2-2% by weight foam remover, 0-10% by weight antifreeze and up to 100% by weight water.

ISLAND

12

DK 154960 B

As alumosilicates with leaf structure may be used the products commonly used as suspending aids, e.g. montmorillonite or concreteite.

As antifoam agents, conventional products are preferred on the basis of tributyl phosphate or on a silicon basis, the latter being preferred.

As antifreeze agents, conventional agents for lowering the freezing point of water, e.g. ethylene glycol, propylene glycol and glycerol, of which ethylene glycol is preferred.

As the aqueous component for the preparation of the suspension concentrates, e.g. ordinary drinking water or tap water, preferably one having a hardness of 20 dH (German hardness). but salt water can also be used.

The suspension concentrates of the invention are thin-liquid and easily pourable, especially when containing up to 50% by weight of active substance or mixture of active substances.

Not only do they retain their thin fluidity by heating, but they are surprisingly reversibly more thinly fluid at elevation of temperature, without loss of the suspending and dilution properties, e.g. can be of importance especially when stored and used in warm climatic zones. Products made according to the invention are easily formalized, surprisingly, despite their relatively low viscosities, excellent storage stability, possess very good moisture properties and dilution properties when adjusted to spray liquid concentrations upon dilution with water, and exhibits excellent compatibility with combination preparations, which, in order to broaden the biological spectrum of action, are often added to the ready-to-use diluted spray liquid suspensions.

The active ingredient content of the suspension concentrates according to the invention is preferably 15-60% by weight, especially 20-50% by weight, at least 18% by weight of isoproturon, when further in the product is ioxynil, bromoxynil, mecoprop 35 or salts thereof. As salts of the latter three active substances, their water-soluble salts are preferably used, especially alkali metal salts.

13 DK 154960 B

ISLAND

The preparation of the suspension concentrates takes place e.g. in that isoproturon together with the additional active ingredients added according to the invention are stirred in an aqueous solution or optionally suspension of the formulation aids, whereupon this coarse suspension is optionally decomposed e.g. by grinding in a corundum or toothed mill for fines of approx. 200 microns and then finitial in a ball mill or sand mill, whereby the isoproturon and the other particles in the suspension are imparted with a particle size of 0.1-15 microns, substantially below 5 microns. The fineness measurements are performed using a disk centrifuge or with a Coulter-Counter counting apparatus.

The use of the agent e.g. in agriculture or in the open field is done simply by adding the dilution water to the isoproturon-15-containing suspension concentrates according to the prescribed application rates and stirring for a short time, after which they are applied to the plants in effective quantities. The dilute aqueous syringe suspensions are distinguished by the comparison of spray powders or emulsifiable concentrates, especially in that, even after 24 hours of standing, they still contain the active substances almost uniformly distributed. In contrast, syringe powder suspensions separate very quickly, so that after a 1/2 hour delay, they have very often already precipitated 25 half of the active substance. Likewise, after 1-4 hours of emulsions, the emulsified concentrates are again secreted as an oil or a cream.

In addition, the isoproturon-containing suspension concentrates of the invention exhibit surprisingly excellent physical compatibility with known insecticidal and fungicidal compositions in the ready-to-use spray liquids 30, which can be admixed in the ready-to-use spray tea liquids in the form of spray powders or emulsifiable concentrates.

The invention further relates to a method of controlling weeds which comprises applying a herbicidal surface to a herbicidal effective amount of a herbicidal agent according to the invention.

DK 154960 B

14

ISLAND

The following examples are intended to further illustrate the invention.

Example 1 By grinding the components in a 2 mm diameter glass ball mill, a liquid aqueous suspension concentrate of the following composition is prepared: 50.0% by weight isoproturon, 6.0% by weight sodium salt of a cresol-formaldehyde sodium sulfate. condensate, prepared from 1 mole of m-cresol, 1.36 mole of formaldehyde and 0.57 mole of sodium sulfite. The product is a multiple times crosslinked polymer, the structure of which is unknown, 3.0% by weight sodium salt of (C ^-C ^) alkyl polyglycol ether phosphate mono - / - diester ("Forlanit® P"), 0.2% by weight alumosilicate powder (montmorillonite), 1.0 wt% silicone foam antifouling ("SE 2", Wacker GmbHl, 4.0 wt% ethylene glycol, 35.8 wt% water.

The dispersion is ground to such a degree that 90% by weight of the suspended particles have a diameter of less than 5 microns as measured by a Coulter-Counter apparatus.

By pouring 2 ml of this suspension concentrate into 99 ml of water, a spontaneously formed suspension dilution is obtained which has a surface tension of 36-42 dynes / cm-1 at 20 ° C and which, even after 12 hours of standing, shows only traces of precipitated particles . Unlike comparable spray powders, the susceptibility here is almost 100%, measured by the CIPAC test methods.

The dispersion is easily pourable and remains stable even during 3 months storage at 0 and 50 ° C. In the storage test, only a 0.3% by volume dispersion can be detected, which after spontaneous shaking is spontaneously redispersible. A crystal growth of the isoproturon particles cannot be detected. By increasing the storage temperature by each time 20 ° C from 20 to 60 ° C, the dispersion becomes reversibly more and more thin-flowing without compromising stability.

ISLAND

"DK 154960 B

ID

The temperature viscosity coefficient is determined by measuring the viscosities of the suspension concentrate using a Brookfield viscometer at 20, 40 and 60 ° C. The suspension is first frozen for enclosed air bladders, shaking on a vibration apparatus for 30 minutes in a round-bottom flask under a reduced pressure of 20 mm water column, after which the dispersion is brought into the measuring vessel on the Brookfield viscometer and heated to a thermostat. 20, 40 and 60 ° C. Viscosity measurements are carried out using spindle # 2 at 2.5, 10 and 10 rpm. The result is given below:

Temperature viscosity coefficient in 15

Viscosity increasing intervals

Island Island

Brookfield (mPa * s) Pa 20 C

Viscosimeter Measurement conditions_ (measured) _ (calculated) _ spindle # 2 2.5 rpm. at 20 C 6320 ^ 0.675 20 ..... 40 ° C 4272) 0.640 11 »" 60 ° C 2736 ________ spindle # 2 10 rpm. at 20 C 1924 0.748 ...... 40 ° C 1440) 0.638 11 ° 60 ° C

The viscosities of the suspension concentrate decrease with increasing temperature and the temperature viscosity coefficients resemble some water. Thus, the measured coefficient indicates that the hydrate envelope surrounding the individual particles is surprisingly stable even at increasing temperatures, otherwise the viscosity would increase due to the increasing effective forces of attraction between the suspended particles.

35

ISLAND

16

DK 154960 B

Example 2 In the same way as in Example 1, a ball mill with glass balls of 2 mm diameter is prepared in the milling of the components to a particle size of approx.

5 microns a suspension concentrate of the following composition.

20.00% by weight isoproturon, 40.00% by weight mecoprop sodium salt ("U 46 KV" powder, BASF AG), 2.00% by weight sodium salt of a cresol-formaldehyde sodium sulfite condensate, cf. Example 1, 10.00% by weight sodium salt of (C 12 C18) alkyl polyglycol ether - phosphate mono - / - diester ("Forlanit P", Henkel KgaA), 1.00 wt% silicone foam remover ("SE 2", Wacker GmbH), 0.05 weight alumosilicate powder (bentonite), 35.95 weight water.

This suspension concentrate has excellent storage stability, even at long term storage at 50 ° C, it is easily pourable and its viscosity decreases with increasing temperature. The result of the viscosity determinations in intervals of 20 ° C, carried out as described in Example 1, is given below.

20

Temperature-viscosity coefficient in 22 Viscosity increasing intervals

Brookfield (mPa-s) of 20 ° C

viscosimeter_ Measurement conditions (measured) _ (calculated) _ spindle # 2 2.5 rpm. at 20 ° C 4224 ^ 0.90 "" "40 ° C 3805 0 gi 30 -_" "" 60 ° C 3492_ Spindle No. 2 10 rpm. at 20 ° C 1326 Q gg ...... 40 ° C 1Π8} Q'fQ7 _11 "* '60 ° C 1020__ 35

17 DK 154960 B

ISLAND

Example 3 In the same way as in Example 1, a ball mill with glass balls of 2 mm diameter is prepared by grinding the components to a particle fineness of approx.

5 microns a suspension concentrate having the following composition: 30.00% by weight isoproturon 10.00% by weight ioxynil 3.00% by weight sodium salt of a sulfo group-containing phenol-formaldehyde condensation product, cf. ) -phosphate, 1.00 wt% silicone foam remover ("SE 2", Wacker GmbH} 0.05 wt% alumosilicate powder (montmorillonite) 49.95 wt% water.

15 This suspension concentrate is low viscous and easily pourable, and after storage for 3 months at 50 ° C shows virtually no precipitate.

The temperature viscosity coefficients, measured at intervals of 20 ° C as in Example 1, are between 0.8 and 0.92, 20.

Example 4 In the same manner as in Example 1, a ball mill with glass balls of 2 mm diameter is prepared by grinding the components to a particle size of approx. 5 ml-25 cron a suspension concentrate of the following composition: 35.00 weight isoproturon, 10.00 weight bromoxynil sodium salt, 2.00 weight sodium salt of a cresol-formaldehyde sodium sulfite condensate, cf. Example 1, 3.00 weight sodium immunoassay. / di 2 (C 2 -C 2 g) alkyl polyglycol ether (4-12 EO) phosphate, 1.00 weight silicone foam remover ("SE 2", Wacker GmbH}, 0.05 weight alumosilicate powder (bentonite) , 48.95 weight water, 35 This suspension concentrate is easily pourable and after showing for 3 months at 50 ° C shows practically no 18

DK 154960 B

o precipitation. The temperature viscosity coefficients, measured at intervals of 20 ° C as described in Example 1, are between 0.78 and 0.93.

Comparative Example 1

A mixture of a composition as described in Example 1 wherein, however, instead of the sodium salt of (c12 "c18" alkyl polyglycol ether phosphate mono - / - diester ("Forlanit P"), 3.0 wt% sodium monor. di-1C-C1-C6 gialkylphosphate 10 ("Forlanit.F 452", Henkel KGaA), is milled as described in Example 1 by means of a 2 mm diameter glass ball mill to a particle suspension concentrate. fineness of the constituents of about 5 microns During grinding, the mixture becomes more and more viscous due to the heat developed under 15, which causes a temperature increase to about 50 ° C and cannot be dissipated by cooling with 15 ° C water. After grinding is complete, the mixture is cooled to room temperature, the glass beads are sieved and the suspension concentrate is examined as described in Example 1.

The temperature viscosity coefficient is 1.1-1.2, and in storage experiments at 50 ° C the product already shows, after one month, a separation in the above aqueous layer and a cool precipitate containing the active substances and can no longer be dispersed.

25

Comparative Example 2

A mixture such as that described in Comparative Example 1, but in place of the sodium mono / di- (C --C C.) alkyl phosphate ("Forlanit F 452") containing 3.0% by weight of tris (dodecyl tetra-glycol ether) phosphate, milled and worked up as described in Comparative Example 1. The temperature rises during milling also to approx. 50 ° C and the heat cannot be removed by cooling with water of 15 ° C as the viscosity of the mixture increases greatly. The temperature-viscosity coefficient for this suspension concentrate is 1.2-1.4, and in storage experiments at 50 ° C, the product has already solidified after one month to a tough, gel-like mass that can no longer be diluted with water.

Claims (4)

1. Liquid herbicidal agents in the form of aqueous suspension concentrates containing as an active substance iso-proturon or mixtures of isoproturon with ioxynil, bromoxynil, mecoprop or salts of the latter three active substances, together with formulation aids, characterized in that: those containing formulation aids contain 1-10% by weight of alkali metal salt of a sulfogroup-containing condensation product of a phenol and formaldehyde, as well as 0.5-8% by weight of alkali metal salts of such alkyl polyglycol ether phosphate partial esters, especially mono or di (alkyl polyglycol ether) ) phosphates wherein the alkyl polyglycol ether residues consist of optionally substituted alkyl groups which may also contain double bonds, having 6-24, especially 12-15 18 c ar bon atoms, and polyglycol ether groups having up to 20, especially 4-12 ethylene oxide units (EO units). Liquid herbicidal agents according to claim 1, characterized in that they contain: 15-60% by weight isoproturon, 20-42% by weight ioxynil, bromoxynil, mecoprop or salts thereof, the total content of active substances not exceeding 60% by weight , 2-10 wt.% Alkali metal salts of sulfo group-containing condensation products of a phenol and formaldehyde, 0.5-8 wt.% Alkali metal salts of (Cg - ° 24> alkyl polyglycol ether (2-20-EO) phosphate partial esters, 0-0.4 wt. % alumosilicate with leaf structure, 0.2-2 wt% foam remover, 0-10 wt% antifreeze, the rest to 100 wt% water. Liquid herbicidal agents according to claims 1-2, characterized in that they contain the sodium salt of a sulphogroup-containing condensation product of cresol and formaldehyde, as well as the sodium salts of mono- or di-C1-C6-alkyl alkyl polyglycol ether (4-12 EO) phosphates. DK 154960 B Method for controlling weeds, characterized in that a herbicidal effective amount of an aqueous dilution of a herbicidal agent according to claims 5 to 1-3 is applied to the weed-infested surfaces or substrates.