DE2036671A1 - Agent for the control of undesired plant growth in water - Google Patents

Description

The invention relates to herbicides against aquatic weeds, which, when used together to combat undesirable vegetation in bodies of water, have a synergistic effect Have an effect The agents according to the invention can be used with a synergistic effect in such a way that that they release a certain amount of herbicidal substances when placed in water.

Aquatic herbicides are usually added to the water either in soluble or emulsified form or as dense granules are added, the latter sinking directly to the bottom of the water, where it is different Catfish decomposes, releasing copious amounts of herbicide into the water. The entire body of water is contaminated with herbicide, up to a concentration which is equal to or greater than the lowest lethal concentration

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centering (LLG), which is necessary to avoid the undesirable Kill plant species. Due to the solubility of the mit- ■ tel, natural diffusion, and currents present in lakes and ponds, there must usually be a large excess can be used to maintain this concentration. An example of such herbicides is copper sulfate, which is commonly used to treat water algae. The connection is very easily soluble, what to do with it leads to the fact that not only the "affected" areas are poisoned .will. For the rest must}! the herbicides currently in use and algicides also relatively high dosed in the desired limited areas to be treated "become what has a detrimental influence on the desired living beings in these areas"

It is therefore particularly advantageous to only use the surface in the immediate vicinity of the undesirable To treat aquatic plant species so that the best of the water body is essentially unspoiled for the preferred aquatic life remain. It is also useful to localize the application to a given target area, see above that the adjacent areas are not seriously contaminated by drift and diffusion »is most expedient a local control of undesirable aquatic plants with a very small amount of herbicide, so that both in the treated area as well as the likelihood of poisoning the desired aquatic flora and fauna is reduced »

In addition, the existing products do not control the common, undesirable aquatic plants, especially algae, to a sufficient extent. If you want to achieve control on a relatively broad front, you have to use both herbicides and algicides in such high doses that the water is highly contaminated and poisonous for everything you want

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Life in the water becomes «, is the vegetation accordingly diverse, so one usually has to apply a multiple treatment with different herbicides and even, then the weeds usually grow back quickly. Some of the well-known herbicides, such as copper sulfate, cause corrosion of pumping and spraying equipment and are also toxic and dangerous to handle. A herbicide for aquatic plants with a broad spectrum of activity and low toxicity, that is slowly developing its effect is apparently not currently known.

Processes are known with which one can use pesticides such as insecticides or herbicides can be treated in such a way that the active ingredient is only slowly applied is delivered. Such sustained release agents have been made by encapsulating the active ingredient in slowly soluble substances, by dilution with an inert substance, e.g. by adsorption on sand or clay, by mixing with a water-insoluble resin, etc. Such agents work mainly by having the Diffusion is controlled in a mechanical way. With these agents, the particles sink due to the density of the carrier quickly to the bottom and do not adhere to the leaves of the plants, which are distributed over the entire body of water.

It has now been shown that the effectiveness of water-soluble herbicides can be significantly improved, if the herbicide is reversibly pre-adsorbed in ionized form on an ion exchanger, the latter itself is finely divided or on an inert, finely divided material whose density is slightly higher or lower than water is applied as a coating or as a deposit. In certain cases the ion exchanger can be used together with the herbicide can be applied as a coating to the inert carrier particles. If the particles are only used, e.g. for

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control of unwanted vegetation, introduced into water they sink through the aqueous medium without significant loss of adsorbed herbicide and come to rest on the plant surfaces that are randomly distributed throughout the water. The herbicide is then slowly released through ion exchange freely, and at a rate roughly equivalent to that at which the plant releases the herbicide can absorb until it dies. The loading of the particles with herbicide is limited, so that the latter soon after the aquatic plants die, is used up. The rate of desorption of herbicide from the in Contact with the plant can be due to its ::. Able to be reinforced. The plant exhales COp, that with Water gives an HCO ^ ion, which in turn by anion exchange Herbicid sets free and thus helps to maintain the lethal surface conditions. In distilled In water, the rate of desorption is slower than in water from lakes, which contains dissolved anions.

It has also been shown that with essentially insoluble copper compounds, used in very small amounts, many undesirable aquatic plants can be effectively controlled. Soluble copper compounds have already been used for this purpose, but because of the solubility of these agents, large amounts were necessary for effective control of aquatic vegetation in a certain area. Therefore the whole water contained copper in an amount of desirable plants, fish and other creatures harmful was "contrast enter the insoluble copper-containing compounds are not in the entire water but are only active ₉ where plants grow at the sites. After application, the particles sink in the water until they reach a plant surface. They are then held by the plants or

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adhere to them, as in the case of foliage plants. Find here then a very slow solution of copper ions takes place, which in the previously copper-free area on the plant surface penetration. To the extent that a small amount of Rupfer ions is released, they are absorbed by the plant, which leads to the fact that further copper ions are slowly released.

If the practically insoluble copper compounds and the compounds bound to ion exchangers are used together,

bicide emerged, now a synergistic effect in the fight against undesirable creatures in the water, the expression Synergism is used here in the normal sense as the simultaneous effect of different means, their overall effect is greater than the sum of their individual effects. Due to the resulting synergistic effect, joint Use with small amounts of the two compounds effectively combating a wide range of undesirable aquatic plants, thereby reducing water pollution. and toxic effects to desired living beings are minimal, because both herbicides slowly hit the plant surface become free occurs only in the immediate vicinity of the plant surface that is in contact with the particles a concentration that is higher than the Lowest Lethal Concentration (LLC) of the herbicide in question. That all the rest of the water remains harmless to fish and people. This way of planting without wasteful and killing off dangerous over-treatment is decidedly both an economic and a biological benefit. In addition, the particles are distributed when they sink, ν that only the plants within the treated area be attacked by the slow release of the toxin. The drift is very low and plants in adjacent Areas continue to thrive undisturbed

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Ion exchangers which can be used according to the invention are • inter alia »a wide variety of inorganic substances» aluminum hydroxide is particularly suitable because of its amphoteric character and relatively low cost «, other metal hydroxides such as magnesium hydroxide, zinc hydroxide _t iron hydroxide, copper hydroxide j» the basic salts of calcium and barium as well as insoluble ones are polymeric organic ₉ quaternary amines, such as cross-linked polymeric quaternized polyvinylpyridine and Polyvinylaminestyrole, may also be used on the respective finely divided carrier _a to provide a surface layer or "coating sur adsorption to offer the toxic agent"

The inorganic materials are preferably _p because they are cheaper and because this reduces the amount of organic impurities which consume dissolved oxygen by biodegradation and disrupt ^ the human and animal life form, if appropriate soluble decomposition products or even damage ,,

Siliceous materials such as clays ₈ Mica vermiculite ;, and most soils are cationic surface ^ what their use was "controlled release of cationic Herb suffering ,. as lgi-dimethyl - ^^ '- Mpypidiniumdibromid (referred to below as "compound lX ^sa ") suggested. Unfortunately, however, these substances have too great an affinity for cations and release is practically impossible before normal decomposition occurs To avoid carriers, they would have to have a much larger amount of herbicide sorted than that which is necessary ₉ to saturate the surface capacity for cations ₀ This would, however, be wasted ₉ since a large part of the herbicide is never released again for the control of aquatic plants

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can be. Suspensions of these siliceous substances in water even make a normal treatment with soluble, cationic HerMciden ineffective because of the speed with which these suspensoids the cationic Herbicide from the. Remove solution.

However, it has been shown that the affinity of these silicic acid-containing substances for cations is significantly reduced if their surface is treated beforehand with Al- (OHK. An Al (OHK or with Al (OH)., coated Cationic herbicides sorbed to surfaces by clays, mica, vermiculite, etc. are retained firmly enough to to avoid substantial decomposition during the sinking, but on the other hand are released quickly enough, to make these substances useful for the purposes of the invention.

Will this finely divided carrier material with a Coated ion exchanger, which is then treated with the herbicides, so the preparation drops within reasonable Time without significant loss of herbicide through the aqueous medium to the target area where it is at the to surface to be treated remains. The shape and size of the particles are chosen so that the adhesive force is stronger than gravity or the forces caused by water currents.

Numerous granular substances can be modified so that their surface takes on anion exchange properties. Some of these substances are hydrobiotite, vermiculite, sand, talc, kaolin, titanium dioxide, clay, bentonite, mica, aerosil (extremely light SiO ₂ ), microspheres made of glass and perlite. Practically any water-insoluble material can be used as long as it can be coated with the ion exchanger and hold it in place against the influence of the water.

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Hydrobiotite is a mica-like material that is produced by replacing potassium in biotite with water, e.g. as in "The American Mineralogist", V.26, No. 8, pp. 478-484 (194D described.

The choice of substrate or carrier depends on the intended use. For example, if the herbicide is to be released slowly at the bottom of a body of water, a material "with a high bulk density" that settles quickly, such as sand, clay, mica or fine-particle, pelletized hydrobiotite or vermiculite, is chosen. such as expanded vermiculite, perlite or hollow microspheres made of glass. A medium-density material, such as finely ground, expanded hydrobiotic or vermiculite, is more suitable for treating aquatic vegetation that is distributed throughout the water one can also use the anion exchange material as such as a carrier without an inert substrate ₀

The rate of sedimentation and the ability to adhere to the surface of aquatic plants can through the use of additives such as polyvinyl alcohol or hydroxyethyl cellulose (e.g. the one under the trade name "Vistik" available) can be modified as desired. Desired If necessary, the particles can be coated with the organic polymers in order to reduce the rate of release of the herbicide to decrease even further.

The metal hydroxides used as ion exchange coatings are conveniently made by precipitating the hydroxide in an aqueous slurry of the particles applied to the surface of the selected inert, finely divided material. This can be done in a number of ways.

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as shown in the equations given below visible »

Ie neutralization of the soluble alkaline form.

NaAlO ₂ + HZ + HO ₂ > Al (HO) ₃ + NaZ,

wherein HZ any inorganic acid such as HCl, H-SO ^, HNO ~ or an organic acid with Is carboxyl, sulfonic or phosphoric acid groups.

2. Neutralization of the soluble acidic porm _e

AlX ₃ + 3NaA + 3HO ₂ ) Al (OH) ₃ + 3NaX +

wherein X is an anion of a strong acid such as Cl "", Br ~~, S0 ^ ~, NO «" "or a mixture of one such anion and OH, and where A is either OH or an anion of a weak acid such as acetic acid, Benzoic acid and the like.

The thickness of the hydroxide coating depends on the ratio of the amount of metal hydroxide produced to the available surface area of the inert, particulate substrate present in the mixture. The metal hydroxide coatings can still contain some of the anions used to carry out the neutralization without any significant loss of exchangeability. The composition of the coating thus corresponds in reality, for example, to Al (OH) -S _{- n} \ » where X represents various anions exchanged from the solution. The size of this sorption (s) is proportional to the final concentration, which is determined by the equilibrium constants at the pH value in question.

Optionally, one can NaAlO ₂ in accordance with Method 2 above with 'the acid neutralizing the relevant herbicides or can be used to ^Ne Vfiitftj 3f ^ ^ ^e nffft mineral acid

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ORIGINAL INSPECTED

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and then an anion exchange with the ge ~ ■ wanted herbicide either in the same solution or after filtering off the solid and adding in the second Solution slurried again, cause *

The ion exchange rafcion that is used to bring the herbicide into the ion exchange material, is the replacement of OH by inorganic or organic anions «, this reaction can be described in general terms represent by the following equation;

^{A1 (0H)} 3-A ^{+ ffiZ} ~ "^ ^Alim h-lm + n) ^Z m \ ^{+ m0H}

In addition to this reaction, adsorbed anions can also be replaced instead of OK groups:

+ mZ

The relative rates of these alternative reactions are determined by the relative affinity of the ions in question for the metal hydroxide substrate.

The general nature of this reaction can be made visible by sorption of a colored group, including anions such as ΜηθΓ, CrOJT _s or organic dyes with -OH, -GO ₉ H ₈ -SO ^ H or -P0 ~ H ₉ groups such as easing fluorescin "Methyl orange and the like used",

These colored unions are extracted with multiple times. slowly desorbed with distilled water. the The rate of desorption is increased by the presence of salts according to the well-known principles of lorlenaustau- v.

sches. *

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The use of color-bearing particles is useful as a visual aid in demarcating the treated areas. So little color was given off * if you put the particles in one with water from one The lake-filled tank of about 90 liters was allowed to settle. "Within a day, however, a 0.64-1.77 cm thick developed Layer at the bottom of the tank where the particles had settled. Became the container with growing plants charged and the sedimentation experiment repeated, so The colored layer was shown not only on the ground but also around the particles deposited on the plants and the intensity the color decreased sideways in the water to the outside and from the leaves downwards. Also particles that run off Water added in a field did not impart any noticeable color to the running water except in the area where the particles then collected in standing pools.

For combating vegetation in water particularly suitable anions are as follows: 7-0xabicyclo- ^ 2 ~, 2.1 / "- heptane-2» 3, dicarboxylate (I) 2, ⁱ KDichlorphenoxyacetat (II), 2- (2 , 4,5-trichlorophenoxy) prop _w ionate (III), triehloroacetate (IV), 2,2-dichloropropionate (V), 4-amino-3,5,6-trichloropyridine-2-carboxylate (VI), arsenite ( VII) and the like. They have the following structural formulas:

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• Cl- 2036671 12 - Cl ^ 1A-3Ö 263 1
OCH ₂ CO ₂ Cl
Γ ³ (-)
) —OCHCO ₂

II

III

IV

CH ₂ CCl ₂ CO ₂

VI

AsO

2 VII

The sodium or potassium salts of anions I, II, III, IV, V and VI are also available in the trade under trivial and trade slogans known, e.g. Endothall (Aquathol) or ,, 2,4-D-Silvex (Aqua-Vex), or, TCA, "or Dalapon (Radapön) and Picloram (Tordon). The common names relate to compounds of the acids in question.

Cations that have proven to be particularly useful for controlling aquatic plants include 1,1'-ethylene-2,2 ' -bipyridinium (VIII), 1,1'-dimethyl - * »·, 4'-bipyridinium (IX): ^

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N-CHc

IX

and Cupriion.

The bromides and chlorides of cations VIII and IX are commercially available under the protected names Diquat "or Paraquat known.

Each compound is added to control a limited number of living plants that are relevant to it Compound are specifically sensitive to. The choice of the one to be sorbed on the ion exchange surface Herbicides is determined by the species to be eradicated. Therefore, if there are several undesirable plants in one area, which respond to different herbicides, two or more sorbed ionic herbicides must be used come. Such combinations can include anionics and cationics. If necessary, neutral herbicides, such as 2,6-dichlorophenyl cyanide (Casoron) or the esters of E ^ -dichlorophenoxyacetic acid can also be used by the neutral compound is allowed to sorb in the porous supports. One can get three or more types of herbicides in this way on the same particle or one then has a mixture of three or more species on separate particles. Since the agents according to the invention offer the possibility of killing the plants or animals concerned without having to do more than affects the environment in direct contact with the plant or animal, treatment with more

x
fold herbicides are practically possible from the viewpoints of cost, herbicl charge capacity and synergistic activity. · Χ or with several herbicides at the same time ^ _

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Among the many substantially insoluble copper-containing compounds found to be useful the following are preferred: basic copper (II) carbonate, copper (II) bicarbonate, copper (I) oxide, copper (II) benzoate, Copper (II! Hydroxide, copper (II) oxide, Copper (I) thiocyanate, copper (I) azide and copper (II) azide " Copper azide is considered explosive but is readily used in an aqueous slurry. Basic copper (II) carbonate (hereinafter referred to simply as copper carbonate) is generally preferred because it is readily available, cheap and extremely effective. It is essentially 100 # CuCO-.Cu (OH) with traces of others Metals known as malachite. The compound 2CuCOo * Cu (OH), which is called azurite, can can also be used »

Although the insolubility of the invention copper compounds to be used made one expect that they would be poorly suited as herbicides for aquatic weeds, it has It has been shown that these insoluble copper compounds, together with the herbicides described above, are effectively undesirable Combat plant growth in the water without any undesirable effects on fish and other living things in the water exercise.

It has been shown that the effectiveness of the practically insoluble copper compounds against undesirable Vegetation in the water without harmful side effects is mainly due to the mechanism with which the agents according to the invention develop their effect.

The copper compounds, such as malachite, are used in the form of finely divided, wettable powders. Are the Connections cannot be networked from the start; so can a

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Wetting agents such as sodium dioctyl sulfone succinate can be added. The new agents can also be mixed with other customary inert substances. This is the case with certain, for example Compounds advantageous to add agents for preventing dust, such as glycerin.

After mixing with water, the slurry is only sprayed onto the surface of the water within the infected area, unlike soluble algicides, which are introduced into the water and after dissolving penetrate the entire water area. When the compound according to the invention sinks in the water, it settles on the plants or attaches itself firmly to them. At this point there is a very slow release of copper ions into the previously copper-free area on the plant surface. As soon as a small amount of copper ions is released, these are taken up by the plant, which causes more copper ions to be slowly released. This type of reaction can best be described as an equilibrium reaction based on the principle of Le Ghatelier. According to this principle, the uptake of the copper by the plant creates a pressure on one side of the equilibrium reaction, which disturbs the equilibrium of the solution. Because the copper ions are withdrawn from the solution by the plant, further copper ions are released again, which in turn are absorbed, which leads to the release of further copper ions. Because of this controlled release, only a small amount of the sparingly soluble copper compound needs to be used, from which it can be seen how important it is that the copper compound is practically insoluble. High concentrations of copper ions are not necessary and are also not present in other places, except on the top of the plant.

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area where the copper is absorbed. As a result, find no toxic effects on the desired organisms present in the environment take place.

The sparingly soluble copper compounds to be used according to the invention have a solubility in pure water of up to about 50 mg / l, calculated on the dissolved copper ion. The preferred solubility range for these compounds is between about 0.001 and V.0 mg / 1 copper ion, and this range does not pose a threat to desirable aquatic life. Copper compounds with a solubility of more than 50 mg / l usually dissolve before they reach the plant to be killed. Too early dissolution of these compounds leads to effects like those observed with copper sulphate, so that the advantages described for practically insoluble copper compounds - localized action on the plant surface, low toxicity for fish, low water pollution and use of small amounts - are not achieved. The agents are used in finely divided form so that they come into closest contact with the undesired plants, thereby increasing the effectiveness of the copper uptake by the plant. For the purposes of the invention, the copper compounds are crushed to about 0.0025-2.5 cm, preferably 0.025-0.25 cm, in diameter. Coarse-grained material would sink to the bottom and is therefore unsuitable for the purposes of the invention.

The density of the copper compounds, which are practically insoluble in accordance with the invention, in the crystalline state is far above the density of water, so that the substances therein quickly sink. The sedimentation behavior of the compounds was determined as follows: 5 g of the compound were dispersed in 45 g of water and the slurry was poured into a pipe 9.5 cm in diameter with a water column of 166 k cm from the surface to the test cross-section. To count the particles as they pass through the test cross

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Cut became a light source and a photomultiplier used. The sedimentation was strongest in about 8 minutes and 20 minutes after the introduction the material for the most part sold. The result shows that most of the particles disappear within 8 to 20 minutes settle on the plant surface, and not over a wide area Area to be distributed. This is important in that only the amount of copper necessary to combat the algae in a given area needs to be supplied, and that is not the whole lake or pond must be saturated with the agent. The toxicity to desired species is minimal and the The costs are significantly lower than with the previous methods.

The water solubility of the preferred according to the invention Copper compounds were determined by introducing the compound in question into 3 »8 liters of water, the Amount was chosen so that the copper concentration, if complete solution would have been 5 mg / l. For example, when testing malachite, the watery Slurry stirred for 4 hours then analyzed for copper. In the distilled water alone the copper content was 0.007 mg / l, while in the distilled water it was also slurried Malachite a copper content of 0.020 mg / 1 was detected. In the same way with ordinary lake water the copper content was 0.030 ppm, while the same water with malachite had a copper content of 0.090 ppm. These results show that malachite or basic copper carbonate is practically insoluble in distilled water or in water from inland lakes, so that the addition of this agent poses no threat to others contained in the water Living being means.

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The compounds provided according to the invention with synergistic effect can be used in different amounts, the ratio of the ingredients each other depends on the respective purpose. Agent for controlling aquatic weeds according to the invention with synergistic Effect contain 0.5 to 250 parts of active organic herbicide per part of active copper-containing compound. Ion exchange herbicide can be used in an amount of 1-282.5 kg / ha, preferably 4.5-68 kg / ha to combat undesirable Aquatic plants are used. To control plants such as Hydrilla verticillata, amounts of up to 125 kg / ha were used used without any damage to the desired vegetation. The above numbers relate to the proportion of funds received Ion exchange herbicide.

The copper compound can be used in an amount ranging from 0.28 to 450 kg / ha with the preferred range is slightly less than 11.25 kg / ha. To control algae, 0.025-5, preferably 0.05 1.0, are used Parts of copper per million parts of water, For vascular plants such as Ceratophyllum demersum, about 0.05 to 20.0 is used ppm. The specified amounts relate to the total copper content, but due to the poor solubility of the ' bonds, the amount of dissolved copper is always much less than the total amount. Appropriately, one turns as little as possible of the copper-containing compound, in order to avoid any risk of poisoning, although the toxicity of the compounds according to the invention is very low. A targeted treatment allows the control of a wide spectrum of undesirable aquatic plants with very few Concentrations of the two components »

• -

The agents according to the invention are largely independent of the nature of the water »They have an inner

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half of a wide temperature range. Your effectiveness is also independent of the various water conditions, such as clarity, hardness or total alkalinity or pH value and .other parameters. They are practically at every stage of growth of Chara leaf algae, Hydrilla verticillata, Elodea canadensis, etc. ", effective. Opposite the pumping equipment and the Mixing vessels, the agents are non-corrosive and they are safer to use than soluble copper compounds.

The following examples, in which the parts as parts by weight are to be understood, serve to explain the invention in more detail.

example 1

313 g (1 * 3 moles) of hydrated aluminum chloride, AlCl ,,. 6H _? O, were dissolved in 1 l of water and the solution was brought to a pH of 5 »5 with solid sodium hydroxide. The product which precipitated out was filtered off, dried and then comminuted to a fine, white powder. The material was repeatedly extracted with 500 ml of distilled water each time, the amount of Cl ~ removed with each extraction being determined by volumetric titration. The extraction was continued until less than 0.1 g / l Cl ~~ was detectable in the filtrate. The elemental analysis of the residue after 12 extractions gave the following values:

₂₃ Cl;
$ 0.01 Na; $ 0.01 Si; according to the empirical formula

^A1Na O, OOO4 ^iSiO 2 ⁾ O, OOO3 ^iA1 2 ° 3 ⁾ O, O3 ^(OH) 2.78 ^C1 O, 22 or, if the minor impurities are neglected:

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The relative affinity of organic acids for Al (OH) ο J ^ X _n is graded as follows: dicarboxylic acid)> monocarboxylic acid; Disulfonic acids y monosulfonic acids; strongly acidic phenols ^ weakly acidic phenols »

Samples of the material obtained in this way were ion-exchanged with the herbicide anions I to VII from aqueous Subjected to standard solutions of herbicide salt. The amount of ion adsorbed was determined by elemental analysis.

The herbicidal agents thus prepared were used in amounts each corresponding to 0.00025 g of the herbicide adsorbed distributed on test vessels each containing 4.5 1 of water, in which there were aquatic weeds that were representative of the group of weeds that were considered sensitive to it was known to the herbicide in question. The herbicide particles deposited on the leaves of the plants. ■

For comparison, an equivalent amount of the plant in question was placed in other vessels containing the same plants Herbicids introduced in its solvated salt form.

In all cases, the plants whose leaves according to the invention were coated with the herbicide became fine divided material were in contact, killed within one week, while the plants of the comparison experiment were killed indefinitely continued to grow ο

Example 2

100 g of sodium aluminate were dissolved in 3 l of water and the clear solution ./ (pH 12.5) slowly with 20 ^ aqueous Nitric acid neutralized. The amount of precipitation increased linearly with every further addition of acid.

sam back to about 10, corresponding to a $ 85-90 »- igen N.eu-

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tralization. In further addition, the pH value changed relatively quickly and the mixture was brought to a pH value of 5.5 »The precipitate was filtered off and dried overnight at 120 G ^0. The product was then crushed to a fine powder and extracted three times with 2 liters of distilled water each time. Elemental analysis (66.3 % Al ₉ OoJ 10.3 % NO «; 0.04 % Na) showed that the product consisted essentially of Al (OH) _{0 ft} (NO ^) _no .

The material, which may be referred to as nitrate aluminum hydroxide, absorbed anions rapidly, as evidenced by the ease with which it was colored by anionic dyes but not neutral dyes. Its ion exchange properties corresponded essentially to those of the material _{β prepared in Example 1}

Other mineral acids such as hydrochloric acid, sulfuric acid, carbonic acid and phosphoric acid were used instead of nitric acid to precipitate the alurainium hydroxide. The amount e of anion "X" contained in the product Al (QH) ,, X _n depended on the relative affinity and the concentration of the acid anion at the time of deposition or precipitation.

Instead of mineral acids and organic acids were used with comparable results, Z _0, stearic acid, benzoic acid, cinnamic acid, succinic acid anions corresponding acids I to V, picric acid or phenol; Here too, the aluminum hydroxide was precipitated by simple neutralization. As long as the final pH was higher than that at which the acid form becomes insoluble, the content of anion in the product was about the same as when using mineral

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acids. The composition of the products can be shown by the general formula

where X is the anion used for neutralization and η is a value between about 0.1 to 2 or more.

The anions X and OH can be successively replaced by other organic anions (T), for example the above-mentioned anions I to VII, and a product is then obtained which is expressed by the equation Al (OH) ^ _ / _{n + m} λ ^x _m ^T _n can be represented.

The produced particles with herbicide coating were equally effective against aquatic weeds, regardless of whether they 1) by direct neutralization of sodium aluminate with the herbicide in acid form or 2) by subsequent exchange of the anion of the active ingredient for X or OH in ^A1 (° ^H _{) 3_ n} ^x _n had been made. The effectiveness of the herbicide corresponded approximately to that of the products of Example 1, the test plants being used in k _t 5 1 containers; In the present case, too, the amounts of herbicide were significantly lower than when the herbicide was used in soluble form.

Example 3

10 parts of sodium aluminate were dissolved in 500 parts of water. O parts of finely powdered hydrobiotite were stirred with the solution for 20 minutes. The mixture was neutralized by addition of acetic acid (pH 7), and evaporated at 7O ⁰ C under reduced pressure to dryness. The residue was washed with water and dried again. The analysis showed an organic ion content of 1 * f, 8 % ₉ , the ratio of Al: RCO ₂ in the coating being 2.5: 1.

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The ion exchange properties of the adsorbed anion corresponded to the properties manifested in the absence of an inert carrier. Observation of the eosin exchanged material with a microscope of 60X magnification revealed a uniform coloration with eosin and indicated that the coating was firmly bonded to the support. Of eosin dye was prepared as described above by extraction with dilute salt solutions of the relevant anions replaced by these anions. As above, the coated hydrobiotite particles absorbed other herbicides by ion exchange

Example 4

9.36 parts of sodium aluminate (70%) were dissolved in 420 parts of demineralized water and 24.3 parts of 35% strength hydrochloric acid were slowly added. The mixture was stirred further until the precipitate which had initially appeared had redissolved. 92.8 parts of powdered hydrobiotite were suspended in the solution and the slurry was heated to 80.degree. 234 parts of 20% sodium 2- (2,4,5-trichlorophenoxy) propionate were added to the slurry so that the basic aluminum salt of 2- (2,4,5-TrIChIOrPhenoxy) propionic acid was deposited on the hydrobiotite carrier taking leave. The aqueous slurry was spray-dried in a known manner and gave a free-flowing powder which contained the active ingredient 24.3 $ salt of 2- (2,4,5-trichlorophenoxy) propionic acid (trade name "Silvex").

Example 5

In a lake overgrown with Elodea canadensis, 3 separate areas were marked out, each along the shore ' Il was 4.3 m at a width of $ 30 m. The plants were in the last stages of vigorous growth. The marked out areas were now with the aluminum hydroxide salt of the 3 »6-Endoxo-

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hexahydrophthalic acid (Endothal, prepared according to example 1) treated on the support described in Example 3 and with a practically water-insoluble copper compound, wherein the treatment was carried out once with the individual substances and then with both substances together in order to achieve the synergistic effect Effect. To be determined in the control of vegetation. The substances were mixed in the amount shown in the table below in a fiberglass tank with a mechanical stirrer and the slurry was spread evenly over what was to be treated Area sprayed. The results are shown in the following overview:

Try means
No.

1 Endothal hydroxyaluminum salt on a mica carrier (active ingredient $ 13.4)

2 basic copper carbonate

3 Endothal hydroxyaluminum salt on a mica carrier (active ingredient $ 13.4) and basic copper carbonate

The percent suppression of vegetation found 12 days after treatment showed that copper carbonate alone had no effect, and that the hydroxyaluminum salt of Endothal had a suppression of only $ 20 "In contrast, when the two substances were used together in the same dose, a $ 100 Achieve suppression, which indicates the synergistic effect of the combination. The adjacent areas showed during healthy plant growth during the trial period.

Example 6

In a large swamp covered with thick vegetation

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dosage
kg / ha Under
depression
% 81.5 20th 13.5 O 81.5 13.5 100

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was covered by fully grown Hydrilla verticillata, four areas of 0.1 ha each were defined, each separated by a buffer zone. The water temperature was 26 ^° C. The areas were treated as described in Example 5, for which the herbicidal agents listed below were used in the dosage indicated.

Area means

dosage oppression
in % η. 15 days 1.5 15th 1.5 0 1.5 1.5 35

Hydroxyaluminum salt of
Endothal on mica carrier (active ingredient $ 13.4)

basic copper benzoate

Hydroxyaluminum salt of
Endothal on mica carrier (13.4 # active ingredient)
and
basic copper benzoate

The area treated with both compounds showed a much stronger herbicidal effect than the sum of the effects of both substances would have been expected. The adjacent areas remained essentially unchanged.

Example 7

In one with a mixed vegetation of Elodes canadensis and Myriophyllum exalbescens covered lake, three areas of 0.4 ha each were defined. The water temperature was 21 ° C. The staked out areas were treated as in Example 4, the following agents and dosages were used.

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Dosage suppression area mean kg / ha jn $ η, 28 Tg.

1 hydroxy aluminum salt of
2- (2,4,5-trichlorophenoxy) - _Q propionic acid on mica- " ^x carrier (24,3 # active ingredient)

2 basic copper carbonate 0.85 0

3 hydroxyaluminum salt of
2- (2,4,5-Trichlorophenoxy) - _Q1 propionic acid on a mica carrier (24.3 # active ingredient) +

¹ basic copper carbonate 0.85 50

Here, too, a synergistic effect in the control of undesired vegetation could be observed if both compounds were used together. The indicated suppression of 50% relates to both types of plants. The vegetation around the treated areas remained unchanged,

Example 8

In a lake with strong growth of Ceratophyllum demersum, 3 areas of 0.4 ha each with buffer zones in between were marked out. The water temperature was 24 ^° C. The areas were treated according to Example 4, for which the following substances were used in the specified dosage:

Area means

1 Endothal hydroxyaluminum salt on a mica carrier (13.4 # active ingredient)

2 basic copper oxide

3 hydroxyaluminum salt of

Endothal on a mica carrier (active ingredient $ 13.4) +

basic copper oxide

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dosage
ppm oppression
in % after 20 days 1.0 50 0.5 0 1.0 '' •
0.5 90

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Twenty days after the treatment, it was found that the basic copper oxide alone (area No. ₀₂ ) had no noticeable effect on the vegetation, while the hydroxyaluminum salt of Endothal produced only a 50% suppression. However, the combination of both substances resulted in a 90% suppression, indicating a synergistic effect. The vegetation in the adjacent areas was not influenced during the duration of the experiment.

Example 9

In a large shallow bay of a lake of about

60 hectares became three separate areas of each

61 m χ 6l m staked out. The bay was infested with Myriophyllum exalbescens (I), Elodea canadensis (II), Utricularia vulgaris (III) and Ceratophyllum demersum (IV). All Plants were in the active growth stage. The water depth in the treated areas was uniformly between 1.06 and 1.22 m. The water temperature during the treatment was 23 C, and the weather was sunny and calm The fabrics listed below were weighing about 10 times their weight mixed with water and sprayed evenly over the surface of the areas.

Area means

Hydroxyaluminum salt of 2- (2, ^, 5-trichlorophenoxy) - propionic acid (2 ^, 3% active ingredient)

basic copper oxide

Hydroxyaluminum salt of 2- (2,4,5-trichlorophenoxy) propionic acid (24.2 % active ingredient) +

basic copper oxide 11.2

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Dosing
ung in
kg / ha Oppressive
kung in %
n.25 Tgo Plant
Zen 22.5 50
60
70
60 I.
II
III
IV 11.2 oooo I.
II
III "
IV 22.5 100
90
'95
100 I.
II
III
IV

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The table shows that the two compounds a synergistic effect when administered together unfold, which led to a $ 100 suppression of plant growth, while the copper compound at all no suppression resulted in »The adjacent areas remained unchanged.

Early in the growing season in a, Buaiii 3iit very gently flowing brackish water _? which was infested by Myriophyllum spicatum, 6 separate areas of 0 _t k ha each marked out. The water temperature was 16 ⁰ C ₀ The herbicides listed in the Table were mixed with the IC times its weight of water and uniformly sprayed over the surfaces. The water was 1.5 m deep everywhere.

Dosage suppression area mean kg / ha a ...... 2 ^ daysjg

Hydroxyaluminum salt of

2- (2,4,5-trichlorophenoxy) - Jk

propionic acid on mica carrier (23 _S 1 ^ active ingredient) - hydroxyaluminum salt of ■ 2- (2j4,5-trichlorophenoxy) - 3 ^ "30 propionic acid on mica carrier (23 * 1 $ active ingredient)

basic copper carbonate Ik k basic copper carbonate lA

Hydroxyaluminum as of

2- (2,4,5-trichlorophenoxy) - Jk propionic acid on mica carrier (23.1 $ active ingredient) +

basic copper carbonate ik

Hydroxyaluminum salt of

2- (2,4, -5-trichlorophenoxy) -3k

propionic acid on mica • carrier (23 * 1% active ingredient) + basic copper carbonate

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The evaluation of the tests showed that the

2- (2, ⁱ K, 5-trichlorophenoxy) propionate as an anionic herbicide alone gave a 25-30% suppression, while the basic copper carbonate alone was practically ineffective. In contrast, the two substances together resulted in a suppression of almost $ 100 at the same dose. The infestation in the adjacent areas increased significantly during the tests.

867231 claims;

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Claims (8)

Patent claims 1. Means for combating undesirable flora in waters with delayed release of active ingredients, characterized by an active ingredient content in the form of a synergistically effective Geaiisches from (1.) one through. reversible ion exchange ars the surface of a water-insoluble » fine-grained inert carrier bound ionic herbicide and / 2.) a practically water-insoluble! Copper connection 2. Means according to claim 1, characterized marked e t that, as a practically water-insoluble Eupfer compound, Eupfer- <El) carbonate, copper (I) oxide, copper (II) oxide, Copper (II) benzene, copper (II) bicarbonate, copper (II) ~ contains hydroxide, Eupfer (l) azide or copper (II) azide. 3. Means according to claim 1 or 2. » characterized in that the bihydroxyaluminum salt is used as the ionic herbicide which contains 3,6-sndoxohexahydrophthalic acid. 4. Agent according to one of claims 1 Ms 3, characterized in that it is the ionic herbicide Contains dihydroxyalurainium salt of 2 »4" dichlorophenoxyacetic acid. - 31 - 0093Θ7 / 206-0 ' Ά-38 263 5. Agent according to one of claims 1 to 3 _f, characterized in that it contains as the ionic herbicide aas dihydroxyaluminum salt of 2- (2,4,5-Trichlorphencx; y ^ propionic acid. 6. Agent according to one of claims 1 "to 5, characterized in that it is a fine-grain carrier for the herbicide contains aluminum hydroxide. 7. ₍ Agent according to one of claims 1 to 5 «. Characterized in that it contains as a water-insoluble, fine-grained inert carrier for the herbicide hydrobiotite. 8. Agent according to one of claims 1 to 7, characterized in that it contains 0.5 to 250 Sew.-ropes active organic herbicide per part by weight of active Zupferverbindungen available. 867232 ' 009887 / 206Q