LV10147B

LV10147B - Process for preparing of granulated herbicides

Info

Publication number: LV10147B
Application number: LVP-92-491A
Authority: LV
Inventors: Harju-Jeanty Pontus; Juppo Ari
Original assignee: Kemira Oy
Priority date: 1991-09-27
Filing date: 1992-12-24
Publication date: 1995-08-20
Also published as: WO1993005652A1; HU213638B; HU9400866D0; EE9400054A; LT3420B; LV10147A; CA2119753A1; NO178681C; NO941121D0; BG98679A; FI914545A0; PL172504B1; FI914545A; CZ69394A3; SK35594A3; JPH06510767A; HUT70887A; NO178681B; NO941121L; FI93416B

Description

LV10147 A method of producing herbicidal granular products

The present invention relates to a method of producing herbicidal granular products which contain carbamoyloxyphenyl-carbamates and/or substituted benzofuranes, known per se, as active ingredients, surfactants, suspending aģents, inert car-riers, and possibly other auxiliary aģents, such as stabi-lizers, defoamers, coloring aģents, and preservatives. The said active ingredients are insoluble in water and in the main foliage-acting, and they are thus sprayed, as water dilutions, onto the plant stand. For this reason the granules are made water dispersible so that a homogenous suspension which will not clog the sprayer will be obtained when the product is di-luted with water.

Carbamoyloxyphenylcarbamate and benzofurane herbicides have conventionally been formulated as emulsion concentrates in which the active ingredient is dissolved in organic solvents and can, with the help of solution emulsifiers, be caused to mix with water to form an emulsion. These formulations have, however, the drawbacks of toxicity of the products, due to the organic solvents, inflammability of the products, as well as difficulty of obtaining a stable uncrystallizing emulsion of the product together with water. Crystallization is typical specifically of methyl-3-tolylcarbamoyloxyphenylcarbamate.

Product forms in which the active ingredients are not in a dissolved form are as such advantageous, since then the problems of toxicity, inflammability, packaging material, and storage are usually avoided, since especially in the case of foliage-acting herbicides, penetration and translocation abilities are required in order to achieve sufficient biologic efficacy. Hydrolytic decomposition is often also a disadvantage. An active ingredient in molecular form is, in a true liquid, capable of penetrating through the wax and cuticle layers much more effectively than is a solid particle. For this reason, in- 2 soluble pārticies of the active ingredient must be-as finely ground as possible, ānd.;their penetration and translocation abilities must be improved with oils, organic solvent addi-tions, and surfactants. In the case of carbamoyloxyphenylcarba-matēs in particular, it is indispensable to' add exceptionally large amounts of these auxiliary aģents in order to achieve a sufficient biologic efficacy. Air-jet and suspension mills are used for the grinding to producē a maximally finely divided active ingredient, preferably in the order of magnitude of 1 -5 microns, in order to achieve biologic efficacy and as stable a suspension as possible when the granule is dispersed into water.

In solid form, the active ingredient may be present in a water dilutable formulation either as a liguid suspension concentrate or as a granular product dispersible in water. The disadvan-tages of a liguid product form often include storage difficul-ties, handling problems due to high viscosity, and the residues remaining in incompletely emptying containers. The last-mentioned disadvantage is becoming a significant environmental problem when the used containers are being disposed of. These problems are avoided with solid granules dispersible in a liguid. ~In addition, a granular product can be packaged in materiāls, such as carton, which load the environment less, and thus the empty packages are easier to dispose of.

The basie properties of water-dispersible granules include, in addition to the Chemical stability of the active ingredients, also a good' ability to be dispersed into water, sufficient granule strength so that detrimental dust is not detached in connection with storage or handling, free flow of the granules, and an ability to remain uncaked during storage. In order to achieve these properties, the granule may contain, in addition to a water-insoluble carrier, also dispersing, suspending, wetting, preserving, defoaming, and anti-caking aģents. 3 LV 10147

It is known that carbamoyloxyphenylcarbamates, the most notable of which are methyl-3-in-tolylcarbamoyloxyphenylcarbamate, ģenerāli^ named phenmedipham, and ethyl-3-phenylcarbamoyloxy-phenylcarbamate, generally named desmedipham (BP 679,283),

where R1 and R2 = CH3 or R1 = H and R2 = CH2CH, are selective and good by their herbicidal properties. These active ingredi-ents can be used separately or as mixtures together with each other and/or with other control aģents, especially for weed control in sugar beet cultivation.

Conventionally the above active ingredients have been formu-lated as emulsion concentrates. But since the aim is to avoid organic solvents, and since phenmedipham tends to crystallize when these formulation forms are diluted with water, the object has now been to producē water-dispersible granules of these active ingredients. It is previously known to prepare water-dispersible granules from herbicides (US 3.920".442)", as also dispersible triazine herbicidal granules, which contain a sur-factant which improves the crystallization properties (US 4,197,112), or granules the physical properties of which are improved by surfactants (EP 201,417). The obstacle to the com-mercialization of' dispersible carbamoyloxyphenylcarbamates has been the difficulty of incorporating sufficient biologic ef-ficacy into the product, since the amount of liguid oil and/or surfactants is very high in ratio to the amounts of the active ingredients (approx. 1:1) and uneconomical to implement techni-cally. '

It is known that a good biologic efficacy can be achieved with water dispersible granules made of certain active ingredients 4 of herbicides. However, with carbamoyloxyphenylcarbamates, sufficient efficacy cannot be reached by these methods.

Now it has been observed surprisingly that, with water dispers-ible granular Products which contain carbamoyloxyphenylcarba-mate, it is possible not only to achieve the above properties of a granular product but also to enhance them significantly by preparing a granular or tablet-form product in which an acti-vator is impregnated into a carrier, which for its part is added, evenly distributed or as a layer on the surface of the granule or the tablet or as a core inside the granule or the tablet. On the other hand, a separate grartule or tablet can be made of a liguid activator and the carrier. The granules, mixed together with granules containing the active ingredient, can be packaged in one Container, in one space within it, as a sufficiently evenly distributed granular mix to form one product, or can be used as a separately dispensed aģent in a tank mixture. A separate tablet can be dispensed together with a granular or tablet-form active ingredient to form a combined mixture for use.

By using an activator impregnated into a carrier, the enhancing of the biologic efficacy of solid carbamoyloxyphenylcarbamate has even been increased as compared with unimpregnated activator; this has been observed in both greenhouse and field tests.

As the carrier for the activator it is possible to use inorgan-ic substances which adsorb large amounts of oily substances and are of natūrai origin, such as silica-based substances, alumi-num oxide based substances, attapulgite, montmorillonite, mica-based substances, diatomite, bentonite, talcum, kaolin, lime, gypsum, and water-insoluble or water-soluble salts.

On the other hand, it is possible to use as the carrier porous organic substances of natūrai origin, such as ground wood or 5 LV10147 corn cobs, ground coconut or almond shells, ground olive skins, ground grain husks, ceļlulose, starch and alginates, or porous structures which are based on polymeric initial substances of natūrai origin which have been modified, such as lignin derivatives, ceļlulose derivatives, starch derivatives, and cyclodex-trins, or synthetic polymers such as polyacrylates, polyacryl-amides, polyvinyl derivatives, polymers of maleic acid, poly-urethanes, polylactides, and polyiners of glycolic acid.

The activator may be enclosed in the carrier material by coat-ing the impregnated pārticies with a polymer, such as polyvinyl alcohol, or with sugar based or sugar alcohol based substances, such as lactose, CMC and sorbitol. In this case the speed of release of the activator can also be regulated. A liguid activator can also be enclosed in capsules, which can further be used in a granular product. Encapsulation methods are commonly known. The strength of the granules and their resistance to abrasion can also be affected by means of coating materiāls. On the other hand, the flow of the product can be improved by them.

Ari activator which contains surfactants and/or oil is not im-portant for the actual granulation; its main purpose is to enhance the biologic action of the product.

The proportion of activator may be in general 1 - 80 % of the weight of the granular product, preferably 0.5-5 times the amount of carbamoyloxyphenylcarbamate in the product.

The activator may be in a solid or a liguid State (at 20 °C), in which case it can be impregnated into a carrier or be mixed with the mix to be granulated. Alternatively it may also be impregnated into or be attached to the product in some other manner after the granulation. 6

The activator may contain anionic, cationic, non-ionic or ara-pholytic surfactants, or these together with a mineral oil, vegetable oil or animal oil. The proportion of surfactants in the activator may be 2 - 100 %, preferably 50 - 100 %. The proportion of oil may respectively be 0 - 98 %, preferably 0 -50 %.

The anionic surfactants raay be alkyl sulfonates, alkylaryl sulfonates, sulfate ethers, fatty alcohol sulfates, sulfate ester sulfocarboxylic acids and their derivatives, alkyl-glycerolether sulfonates, sulfoesters, sulfonamides and phos-phoric acid mono- and diesters, bile acids“and their salts.

The cationic surfactants may be alkylamines or alkylarylamines, alkyl or alkylaryl imidazolines, and alkylaminoaraides.

The. non-ionic surfactants may be fatty alcohol ethoxylates, fatty acid ethoxylates, alkylaryl ethoxylates, alkyl sugar ethoxylates or alkyl sugar alcohol ethoxylates, alkylamine or alkylarylamine polyglycol ethers, fatty acid amide derivatives, diethanolamides or polydiethanolamides of fatty acids, derivatives of mono-, di-, and triglycerides, acetylene diols, and silicon-based surfactants.

The ampholytic surfactants may be alkyl and alkylaryl betaine derivatives, alkyl and alkylaryl (poly)glycine derivatives, alkylamide and alkylarylamide carboxylates, and alkylamine and alkylarylamine sulfonates. Surfactants which contain fluorine may also be used.

The oily substance may be a mineral oil, preferably having a low viscosity so that it can easily become impregnated into the carrier. On the other hand, the oil musinot significantly impede the crop plant. It is most advantageous to use low-aromatic paraffin oil, e.g. Neutral solvent 150, Εχχοη. The oily substance may be a vegetable oil or its hydrolysis prod- 7 LV10147 uct, such as soy oil or a fatty acid rnixture of soy oil. The oil may also contain phospholipids and sterols.

The oily substance may be of aniraal origin, in which case it is preferable if the oil contains a large amount of unsaturated fatty acids and their glycerides.

It is a prereguisite for the granulation of the active ingredient, or of the active ingredient and its carrier which contains an activator, or for the granulation of the carrier or the active ingredient or the activator, that the material to be granulated is finely divided.

The material can be comminuted, for example, while dry in an air jet mill or as a suspension in a pearl mill. It is essen-tial that the particle size of the solid is on average approx. 10 um and that of the active ingredient preferably in the order of 5 p (measured by a Coulter apparatus), in order for the biologic efficacy to be achieved.

In the granulation, auxiliary aģents can be used which promote granule formation, re-wetting of the· granules, and rapid decom-position and dispersion of the granules at the time the solu-tion for use is being prepared, as well as aģents which inhibit the foaming of the solution for use. Since the active ingredient may decompose in a basie solution for use, inorganic or organic pH control aģents may be used in the mixture, such as phosphoric acid or its acid salts and citric acid, so that the pH of the solution for use will be below 7, preferably 3.5 - 5.5.

Auxiliary granulation aģents may be used in granules in which the active ingredient and the activator are in the same granule or in separate active-ingredient granules and activator granules. δ Aģents promoting the decomposition of the granule, which may be polymers such as polyviņyl pyrrolidone and starch and its modi-fied forms, or salts such as airanonium sulfate, or organic water-soluble compounds such as urea, or substances capable of liberating gas, such as carbonates.

As aģents improving the suspension of the granules it is pos-sible to use, as is commonly khown, dispersants such as phenyl sulfonates, alkylnaphthalene sulfonates and polymerized naph-thalene sulfonates, polyacrylic acids and their salts, poly-acrylamides, polyalkoxydiamine derivatives, polyethylene oxides, polypropylene oxide, polybutylene oxide, taurine derivatives and their mixtures, and sulfonated lignin derivatives. Dispersants can be used at 0.1 - 50 %, preferably 5 - 20 % of the granular product.

Similar products may also be used as aģents promoting granula-tion, such as polyethylene glycol, in which case it is advan-tageous to add the activator-containing component at a propor-tion of 1 - 20 % to the completed granule which contains the active ingredient.

The foaming of a mixture to be prepared for spraying can be' · controlled with defoamers such as silica-based aģents. It is preferable to use such aģents at 0 - 0.5 % of the amount of the granular product.

Prior-known methods can be used for the granulation, such as disc granulation, spray drving (e.g. Niro), fluid-bed granulation (e.g. Glatt and Schugi), stir granulation using a vertical mixer (e.g. Fielder) or a blade mixer (e.g. Forberg), extruder granulation (e.g. Nica) or compacting granulation (e.g. Bepex apparatus) or centrifūgai granulation (e.g. CF-granulator, Freund Industrial Co), or spray-bed granulation.

The activator may be compressed into a water-dispersible tab- 9 LV10147

Iet, in which case its size may vary depending on the matrix. Conventional tablet presses include rotation (Mansty) and ec-centric tablet presses (Diaf).

It is also possible to use for the granulation and tabletting two or nore of the above methods in series. The granule sur-face can be hardened mechanically by rounding the granule, for exainple, by using a Spheronizer apparatus (Nica) or by coating the granules with materiāls suitable for the purpose, as mentioned above.

It is important that the granular product is dried. The pro-duct may be dried either in the apparatus- used for the granu-lation or in a separate apparatus intended for drying (e.g. a fluid-bed drier). It is advantageous if the moisture content of the granular product is below 5 %, preferably below 1 %.

The granule size of the final product may vary, depending on the granulation method, on average up to 3 mm or considerably higher, in the case of tablets dispersible in water.

It is self-evident that also other control aģents can be mixed together with carbamoyloxyphenylcarbamates (such as phenmedipham and desmedipham) to form a granular product. The control aģents may be herbicides, aģents for plant-disease control, and insecticides, as well as growth control aģents.

It is advantageous to use herbicides used particularly in the cultivation of sugar beet, such as ethofumesate, methamitron, chlorodazone, lenasil, pyridate, metholachlorine, trichloro-acetic acid, EPTC, quinmerac, cycloate, chlopyralide, flur-oxipyr, isocarbimide, propham, trifluraline, alloxydime so-dium, cetoxydime, diallate, fluazifop-butyl, triallate, dala-pon or propagizafob.

The products of the invention can be used after the emergence 10 of seedlings of the crop plant, preferably in several rounds of application during the growing season. A suitable amount of active ingredient per one spraying is 0.1 - 1 kg per hectare, depending on the number of rounds of application.

The invention is described below in greater detail with the help of examples.

Example 1 A separate granular phenmedipham product can be prepared frora a raw-material mixture which contains: phenmedipham 80 % lignin sulfonates 7.4 % phenyl sulfonates 7.0 % diatomite 2.0 % kaolin 3.6 %

The raw materiāls used for the preparation are pre-ground with an air-jet mill (Alpine) for granulation. The granulation can be carried out by extrusion (Nica), in which case water is mixed with the dry mix at 10 % of the mix. The diameter of the openings in the matrix is 1 mm. The extruded mix is cut into granules of approx.'2 mm in leiigth, which can be further round-ed in a Spheronizer apparatus. The product is dried in a fluid-bed drier. The product obtained by the method disperses excel-lently into water.

The suspension can be verified with an experiment in which 1 g of product is dispensed into a 100 ml narrow-tipped graduated tēst tube containing 100 ml of distilled water (+25 eC). After the wetting of the granules has been noted, the tube is turned 30 times through 180 degrees. Sediment formation is observed for 1 min, 5 min, and 10 min.

In the case of the above-mentioned granules, the amount of sediment separated at 1 min after mixing is 0.05 ml, at 5 min 11 LV10147 after mixing 0.05 ml, and at 10 min after mixing 0.05 ml.

The average particle size in the suspension, determined using a Coulter LS 130 apparatus, was approx. 2 p.

For comparison purposes, a determination of the suspension pro-perties was performed on a commercial product called Goltix.

The values obtained were: 1 min) 0.01 ml; 5 min) 0.1 ml; and 10 min) 0.18 ml.

Example 2 A separate granular phenmedipham product can be prepared from a pre-ground raw material mixture which contains: phenmedipham 89 % lignin sulfonate derivatives 7.2 % phenyl sulfonates 3.6%

The mixture can be granulated by spray drying from a 50 % agueous suspension of the mixture (Niro). The average size of the granules depends on the size of the apparatus. The granules are round in shape. Determined by the method described above, the suspension results are: 1 min) 0.15 ml; 5 min) 0.9 ml; 10 min) 1.2 ml. The average particle size in the'suspension is 3 um.

Example 3 A separate granular phenmedipham product can be prepared from the raw materiāls mentioned in Example 1 by using disc granul-ation, in which case the mix to be granulated is wetted using water at 10 % by weight, calculated from the dry matter. The suspension results are: 1 min) 0.02 ml; 5 min) 0.15 ml; 10 min) 0.25 ml. The average particle size in the suspension is approx. 3 μτη.

Example 4

Separate granules containing an activator can be prepared by 12 making from a pre-ground carrier mixture by disc granulation granules which contain: silicic acid (precipitated, e.g. Zeolthix 265) 85 % ammonium sulfate 2 % sodium chloride 6 % lignin sulfonates 2 % phenyl sulfonates 5 % and by impregnating into it an activator solution (mixture A) which contains: alkyl-sorbitol ethoxylate 42 % fatty alcohol ethoxylate - 21 % ethoxylated fatty acid esters 8 % ethoxylated fatty acid phosphate esters 5 % alkylaryl sulfonic acid 5 % alkylamine ethoxylate 4 % paraffin oil 15 % at the ratio 1 : 1.5

Separate granules containing an activator may also be mixed to form a single granulē mixture with the above-mentioned granule formulations which contain active ingredients, or it can be dispensed separately to form a tank mixture with them. The granules disperse moderately into water.

Example 5 A granular product containing phenmedipham and an activator can be prepared from a raw-material mixture which contains: 16.0 % 2.6 % 5.5 % 7.0 %, 5.5 % 5.0 % phenmedipham lignin sulfonates phenyl sulfonates urea kaolin diatomite

mixture B 13 LV 10147 polyethylene glycol 8.0 % ♦

Mixture B contains: silicic acid (precipitated) 37.5 % bentonite 2.5 % fatty alcohol ethoxylates 16.0 % polyoxyethylene sorbitols 33.8 % paraffin oil 5.1 % alkylamine ethoxylates 5.1 %

The mixture is granulated in a disc in which the mix is heated to +70 °C, and the formed granular product is cooled back to room temperature. The suspension properties of the· product are moderate.

Example 6 A layered granular product containing phenmedipham and an acti-vator can be prepared from a mixture which contains: phenmedipham 16.0 % lignin sulfonates 2.7 % phenyl sulfonates 5.3 % 15.5 % 5.0 % 5.0 % 50.4 % (as in Example 5) kaolin diatomite

polyethylene glycol mixture B

Mixture B is applied as a coating with the help of polyethylene glycol to a granule prepared from the other raw materiāls, at +70 °C in a disc granulator. The suspension properties of the granular product are moderate.

Example 7 A granular product containing phenmedipham and an activator can be prepared by the extrusion technigue from a raw-material mixture which contains: phenmedipham 32.0 % 14 lignin sulfonates 7.4 % phenyl sulfonates 2.0 % kaolin 1.1 % diatomite 2.0 % naphthene sulfonates 2.0 % mixture C 50.0 % Mixture C contains: silicic acid (precipitated) 34.0 % phenyl sulfonates 0.8 % ammonium sulfate 0.8 % sodium chloride 1.6 % lignin sulfonates 0.8 % naphthene sulfonates 2.0 % mixture A 60.0 %

The suspension properties are: 1 min) 0.15 ml; 5 min) 0.3 ml; 10 min) 0.4 ml.

Example 8 A granular product containing phenmedipham and desmedipham can be prepared from a mixture which contains: phenmedipham '60.0 % desmedipham 20.0 % lignin sulfonates 5.9 % phenyl sulfonates 5.6 % kaolin 4.0 % diatomite 2.0 %

The suspension properties of the granular product are: 1 min) 0.01 ml; 5 min) 0.02 ml; 10 min) 0.03 ml.

Example 9 A granular product containing phenmedipham and ethofumesate can be prepared by the disc granulation technigue from a mixture which contains: 15 LV10147 5.6 % 2.0 % 16.8 % The suspension properties were: 1 min) 0.15 ml; 5 min) 0.5 ml; 10 min) 0.8 ml. phenraediphara ethofumesate lignin sulfonates phenyl sulfonates naphthene sulfonates bentonite urea

The suspension properties of the 0.01 ml; 5 min) 0.03 ml; 10 min)

Example 9 b

Granules containing phenmedipham pared by disc granulation from a phenmedipham ethofumesate lignin sulfonates phenyl sulfonates diatomite kaolin 32.0 % 40.0 % 6.0 % 5.0 % 9.0 % 0.2 % 7.8 % granular product are: 1 min) 0.04 ml. and ethofumesate can be pre-mixture which contains: 35.0 % 34.7 % 5.9 %

Example 10 A'granular product containing phenmedipham and methamitron can be prepared by disc granulation from a mixture which contains: phenmedipham 16.0 % methamitron 64.0 % lignin sulfonates 5.9 % phenyl sulfonates 5.6 % diatomite 2.0 % kaolin 6.5 O. Ό

The suspension properties of the granular product are: 1 min) 0.01 ml; 5 min) 0.02 ml; 10 min) 0.03 ml. 16

Example 11 A granular product containing phenmedipham and chlorodazone can be prepared by disc granulation frora a mixture which contains: I· phenmedipham 25.0 % chlorodazone 50.0 % lignin sulfonates 5.9 % phenyl sulfonates 5.6 % diatomite 1.1 % kaolin 12.4 %

The suspension capacity of the granules is·: 1 min) 0.03 ml; 5 min) 0.10 ml; 10 min) 0.15 ml.

Example 11 b A granular product containing phenmedipham and chlorodazone can be prepared by disc granulation from a mixture which contains; phenmedipham 20.0 % chlorodazone 60.0 % lignin sulfonates 5.9 % phenyl sulfonates 5.6 % diatomite 1.1 % kaolin 7.4 %

The suspension properties of the product are; 1 min) 0.03 ml; 5 min) 0.10 ml; 10 min) 0.15 ml.

Example 12 A granular product containing phenmedipham, desmedipham and chlorodazone can be prepared by disc granulation from a mixture which contains; phenmedipham 12.0 % desmedipham 3.0 % chlorodazone ' 45.0 % lignin sulfonates 5.9 % phenyl sulfonates 7.0 % 17 LV 10147 fluorinated surfactant 2.0 % alkylaryl betaine 5.0 % diatomite 1.0 % kaolin 19.1 %

The suspension capacity of the granules is: 1 min) 0.1 ml; 5 min) 0.35 ml; 10 min) 0.45 ml.

Example 13 A tablet containing phenmedipham and an activator can be pre- o pared by compression using a pressure of 300 kg/cm from a mixture which contains: phenmedipham 24.0 % lignin sulfonates 5.9 % phenyl sulfonates 3.0 % naphthene sulfonates 4.5 % potassium hydrogenphosphate 6.0 % sodium carbonate 5.0 % magnesium stearate 1.0 % mixture C 50.0 % kaolin 0.6 %

The tablet can be made in a mold having a diameter of 50 mm, in which case 30 g of mixture is used.

The suspension properties of the tablet are moderate when the dispersion of the tablet in a 500 ml decanter containing 300 ml of water is observed visually.

Biologic experiments:

The activities of the formulations produced were tested in action against weeds commonly encountered in sugar beet cul-tivation, such as amaranth (Amaranthus retroflexus), rape (Brassica napus), goosefoot (Chenopodium album), and common chickweed (Stellaria media). Four pots per weed species per tēst specimen were used in the experiments. The efficacies were 18 evaluated in accordance with typical evaluation principles on a scale of 0 - 10, the complete destruction of the plant being described by 10. The mean of four pots was reported.

The sensitivity to injury of the sugar beet (Beta vulgaris) was determined on the same scale.

Experiment 1 '

The biologic efficacy of a mixture of granular phenmedipham (as in Example 1) and a granular activator (as in Example 4) was compared with a phenmedipham-containing emulsion concentrate preparation (Kemifam) available on the marķēt. The amounts of active ingredient in the tēst specimens were the same, 640 g of active ingredient per hectare. The efficacies were inspected 7 days after the spraying.

Active ingredient Efficacy product/ hectare ama ranth Kemifam 4 1 5.7 Example 1 0.8 kg 0.7 Example 1 + Example 4 0.8 kg 1.5 kg 4.0 Example 1 + Example 4 0.8 kg 3.0 kg 7.3 rape goose- foot chick- weed sugar beet 7.8 9.8 7.0 1.0 0.0 0.0 3.0 0.0 8.0 8.3. 7.7 0.3 8.2 8.7 7.2 1.0

The result shows that a granular phenmedipham product without an activator is not biologically effective. On the other hand, by means of the granular activator the granular phenmedipham product can be activated so that with the same amount of the product (3.8 kg as compared with 4 1) its action on amaranth, rape and common chickweed is better than that of the reference, and injury to the sugar beet is very little.

Experiment 2

In the experiment, the efficacies of granular products contain- 19 LV10147 ing phenmedipham and an activator were compared with that of an emulsion concentrate product (Kemifam) available on the marķēt and of a suspension concentrate product (Betaflow) available on the marķēt. The amount of active ingredient per hectare was 640 g/ha in ali the experiments. The evaluation was carried out 14 days after the spraying. Tēst product

Kemifam Betaflow Example 5 Example 6 chick- sugar weed beet 4 1 3 1 4» 4 1 3 1

Efficacy ama- ranth rape 4 4 4 4 3 3 4 3

The results show that the granular formulations of phenmedipham have biologic efficacies egual to those of both of the emulsion and suspension concentrate references. The injury to the crop plant is also the same.

Experiment 3

In the experiment, the efficacy of a mixture of a granular product (such as Example 8) containing phenmedipham (69 %) and desmedipham (20 %) and a granular product (such as Example 4) containing an activator was compared with a commercially available emulsion concentrate preparation containing phenmedipham (129 g/1) and desmedipham (34 g/1). The amounts of active ingredient per hectare were 652 g for Betanal Compact and 640 g for Example 8 + Example 4. The efficacies were determined 14 days after the spraying. Tēst product Efficacy product/ ama- rape goose- total sugar hectare ranth foot . beet Betanal 4 1 5.5 · 7.2 7.0 19.7 1.0

Compact 20

Example 8 0.8 kg 8.3 5.3 9.0 22.6 1.0 + Example 4 3.8 kg 1

The experiment also shows that a mixture of phenmedipham and desmedipham works even better than the corresponding emulsion concentrate product which served as a reference. The injury to sugar beet was the same with both products.

Experiment 4

In the experiment, the efficacy of granules (such as Example 9) containing phenmedipham and ethofumesate and of granules (such · as Example 4) containing an activator was compared with that of a commercially available emulsion concentrate product, Betaron, which contains phenmedipham 80 g/1 and ethofumesate 100 g/1.

The efficacies were determined 14 days after the spraying. The total amount of active ingredients per experiment was 640 g/ha. Tēst product Efficacy product/ ama- rape chick- sugar hectare ranth weed beet Betaron 3.6 1 5 6 9 1 Example 9b 0.81 kg 4 5' 8 1 Example 9b 0.81 kg + Example 4 0.67 kg 8 7 8 1

The experiment shows that a granular mixture of phenmedipham and ethofumesate also reguires the addition of an activator, whereby a biologically at least equally good result is achieved as with the reference. Injuries caused are identical.

Experiment 5

In the experiment, the efficacies of a granular product containing phenmedipham and methamitron (such as Example 10) and of that product and a granular activator (such as Example 4) were compared with the efficacy of a tank mixture which con-sisted of a phenmedipham suspension concentrate product which 21 LV10147 contained active ingredient 160 g/1 and of a granular methamitron product (Goltix) having a concentration of 700 g/kg. The amounts of active ingredients per hectare were the same for ali the tēst specimens. The efficacies were deterrained 14 days after the spraying. Tēst product Efficacy product/ ama- rape chick- sugar hectare ranth weed beet phenmedipham 1.5 1 SC Goltix 1.37 kg 9.5 9.5 10 ’· 0 Example 10 1.5 kg 7.0 7.0 -9.0 0 Example 10 1.5 kg + Example 4 1.1 kg 7.0 9.0 9.5 0

Methamitron, which works both soil-applied and foliage-applied, does not reguire activators in the same way as does phen-medipham; the relatively high efficacy of granular product 10 is an indication of this. However, even in this case a signif-icant improvement of action on rape is achieved with an addi-tion of activator. Overall, using a granular product of phen-medipham + methamitron + activator, an excellent selective biologic action is achieved without any symptoms of injury in' the sugar beet.

Experiment 6

In the experiment, a comparison was made among the efficacies of a granular product containing phenmedipham and chlorodazone, such as Example 11 b, in which the concentrations were 20 and 60 % respectively, and it and a granular activator, such as Ex-ample 4, and a suspension concentrate containing effective phenmedipham and chlorodazone, the concentrations being 100 and 300 g/1. On the other hand, the significance of the granular activator in a triple-mixture granular product which contained phenmedipham, desmedipham and chlorodazone was investigated.

The amounts of active ingredient per hectare are the same for 22 ali the tēst specimens. The efficacies were determined 14 days after the spraying Tēst product Efficacy product/ chick- ama- ' rape sugar hectare weed ranth beet phenmedipham 4.8 1 SC chloro-dazone 6.0 8.0 8.0 0 Example 11b 2.4 kg 5.0 4.0 3.0 0 Example 11b 2.4 kg + Example 4 2.3 kg 6.0 6.0 7.0 * 0 Example 12 3.2 kg 7.0 6.0 5.0 1.0 Example 12 3.2 kg + Example 4 2.3 kg 9.0 6.0 7.5 1.0 The experiment shows clearly how the increase in efficacy important also in the mixture formulation of foliage-acting phenmedipham and soil-acting chlorodazone. The same applies to the triple mixture which contains foliage-acting desmedipham in addition to the two former.

Field experiments

Field experiment 1

The purpose of the experiment was to compare the biologic ac-tion of granular products containing phenmedipham to the action of emulsion and suspension concentrate products already avail-able commercially.

The experiments were conducted in accordance with conventional field experiment practices. There were three rounds of applica-» tion, ali performed after the emergence of seedlings of sugar beet. The efficacy was examined visually and evaluated in rela-tion to an untreated plant stand, the value for which was 0. Value 100 describes complete control capacity. The amount of 23 LV 10147 phenmedipham used in each round of spraying was 480 g/ha. Tēst product product/ha efficacy % 1 Kemifam 3 * 3 1 75 (phenmedipham 160 g/1, EC) 2 Batanal Plus 3 * 3 1 83 (phenmedipham 160g/l, SC) 3 Example 1 3 * 0.6 kg 83 Example 4 3 * 1.15 kg 4 Example 1 3 * 0.6 kg 93 Example 4 3 * 2.3 kg 5 Example 1 3 * 0.6 kg 83 Example 4 mixture A 3 * 1.4 kg 6 Example 7 3 * 1.5 kg 55 7 Example 7 3 * 1.5 kg 81 Example 4 3 * 1.15 kg

The efficacy of the granular product containing an active in-gredient, used together with a granular activator, the total amount of the material used being 1.75 kg/ha, is as good as the efficacy of the suspension product when used at 3 1/ha. When a granular product containing more activator was used, in which case the total amount of material used is 2.75 kg/ha, a sig-nificantly better efficacy is obtained with the granular product than with the suspension product. In the experiment, the granules containing activator were dispensed separately for reasons of test-performing technigues, but it is clear that a granular mix containing an active ingredient and an activator can be mixed in advance to form a single homogenous mix to be dispensed as one.

Together with a granular product vhich contains active ingredient it is possible to use a liguid activator in the con-ventional manner as a tank mixture, as in tēst specimen 5. The activator granules of Example 4 contain mixture A 60 %, in which case tēst specimens 4 and 5 contain egual amounts of the 24 liquid ingredient. However, itcan be observed surprisingly that the solid carrier raaterial of the granular product in-creases the effect of the activator granules on the efficacy of the active ingredient by up to 10 %. It is also noteworthy that this granular product is more than 10 % more effective than the commercial suspension concentrate product and up to 20 % more effective than the commercial emulsion concentrate product.

Field experiment 2

In the experiment, the biologic efficacy of a granular product containing phenmedipham and ethofumesate (Example 9 a) and an activator (Example 4) was compared with the efficacy of an emulsion concentrate product (Betaron) available on the marķēt. The overall tēst arrangements were as in field experiment 1.

The amount of active ingredient used was 540 g per ha per spraying round. Tēst product product/ha efficacy % 1 Betaron 3*31 95 phenmedipham 80 g/1 ethofumesate 100 g/1 2 Example 9 a 3 * 0.75 kg 91 Example 4 3 * 0.58 kg 3 Example 9a" 3 * 0.75 kg 93 Example 4 3 * 1.15 kg

With a total amount of 1.33 kg of the granular product, almost the same efficacy was obtained as with 3 1 of the emulsion concentrate. The handling of the product containing an active ingredient and an activator in connection with the spraying did not cause difficulties.

Field experiment 3

In the experiment, the efficacies of a conventional spraying prograra used in the cultivation of sugar beet and a spraying program based on granules were compared. In practice, phenmedipham, methamitron or ethofumesate is not generally used 25 LV10147 alone, but tank mixtures of these are used, in which the mixing ratios may vary, depending on the weeds.

Kemiron is an emulsion concentrate containiņg ethofumesate 200 g per liter, and granular ethofumesate (EFU granule) is a water dispersible granular product containing effective in-gredient 65 %. The amounts of active ingredient per hectare were the same with both the tēst specimens.

Conventional program: lst spraying 1.5 1 Kemifam + 1 kg Goltix + 0.5 1 Kemiron 2nd spraying 1.5 1 Kemifam + 1 kg Goltix +.1.0 1 Kemiron 3rd spraying 1.5 1 Kemifam + 0.5 kg Goltix + 1.0 1 Kemiron I.

Program based on granules: lst spraying 0.2 kg Example 1 + 1 kg Goltix + 1.15 kg EFU-granules 2nd spraying 0.2 kg Example 1 + 1 kg Goltix + 0.3 kg EFU-granules 3rd spraying 0.2 kg Example 1 + 0.5 kg Goltix + 0.3 kg EFU-granulēs each spraying containing 1.15 kg Example 4

Efficacies: conventional program 90 % granule-based program 89 %

The results show that the program based on granular products has worked as well as has the program in which phenmedipham and ethofumesate are in liguid form as emulsion-emulsion concen-trates. 26 LV10147

Claims 1. A method for enhaņcing the efficacy of granular or tablet-form herbicidal products, such as methyl-3-m-tolyl-carbamoyloxyphenylcarbamate, ethyl-3-phenylrcarbamoyloxyphenyl-carbamate, 2-ethoxy-2,3-dihydro-3,3-dimethylbenzofurane-5-yl-methane sulfonate, 5-amino-4-chloro-2-phenylpyridazine-3(24)-one and 4-amino-4,5-dihydro-3-methyl-6-phenyl-l,2,4-triazine-5-one, by using activators known per se. characterized in that the activator substances and activator constituents are impreg-nated into and/or mixed with a solid carrier material which possibly contains auxiliary aģents known per se, whereby a solid activator coraposition is obtained, and the obtained solid activator composition is contacted with the herbicidal product either a) by forming a layer it on the granule or tablet surface or b) by incorporating it as a core inside the granule or tablet or c) by mixing the solid components together. 2. A method according to Claim 1, characterized in that the carrier is inorganic or organic by structure or is a mixture of such substances. 3. A method according to Claim 2, characterized in that the carrier is of natūrai origin. 4. A method according to Claim 2, characterized in that the carrier is of synthetic origin. 5. A method according to any of the above claims, characterized in that the activator ingredient is made up of prior-known surfactants and/or oils. 6. A method according to Claim 5, characterized in that the surfactants are anionic, cationic, amphoteric or non-ionic surfactants or their mixtures. 27 7. A method according to-Claim 5, characterized in that the oils are mineral oils, vēgetable oils, animal oils, their hy-drolysis products, or their mixtures. 8. A method according to Claim 5 or 6, characterized in that the proportion of surfactants is approx. 50 - 100 % of the activator ingredient. 9. A method according to Claim 5 or 7, characterized in that the proportion of oil is at maximum approx. 50 % of the activator ingredient. 10. A method according to Claim 1, characterized in that the proportion of the activator ingredient is approx. 10 - 70 %, preferably 30 - 90 %, of the solid activator composition. 11. A method according to Claim 1, characterized in that the auxiliary aģents are aģents reguired for the dispersing, wet-ting, granulating, stabilizing, pH control, or defoaming of the activator. 12. A method according to Claim 1, characterized in that the herbicidal products and the solid activator composition are granulated or tabletted together or separately. 13. A method according to Claim 1, characterized in that other plant protection aģents, preferably chlorodazone and methamitron, are used in the same granule or as a separate granulē together with carbamoyloxyphenylcarbamate, pireferably phenmedipham, desmedipham and/or ethofumesate. LV10147 28

Abstract

The invention relates .to a method of producing granular mix-tures which contain herbicides known per se, the activator used being a solid composition in which the activator ingredients are either impregnated into and/or raixed with a carrier raaterial.

Claims

EN 10147 t Formulation 1. Method for enhancing the efficacy of granular or tablet form herbicide preparations such as methyl 3-m-tolylcarbamoyloxyphenylcarbamate, ethyl 3-phenylcarbamoyloxyphenylcarbamate, 2-ethoxy-2,3-dihydro-3,3-dimethylbenzofuran -5-ylmethanesulfonate, 5-amino-4-chloro-2-phenylpyrazin-3 (2H) -one and 4-amino-4,5-dihydro-3-methyl-6-phenyl-1,2, 4-Triazin-5-one, using known activators, characterized in that the activator and activator components impregnate the solid carrier material and / or mix with a carrier that may contain known auxiliary agents and thereby form a solid activator composition which is contacted with a herbicide preparation either: a) forming a herbicide layer on the surface of an activator granule or tablet;

A method according to claim 1, wherein the carrier is inorganic or organic by its structure or a mixture of such substances.

3. A method according to claim 2, wherein the carrier is of natural origin.

4. A method according to claim 2, wherein the carrier is a synthetic product. - 2 -

Method according to any one of the preceding claims, characterized in that the activator consists of a known surfactant and / or oil.

6. A process according to claim 5, wherein the surfactants are anionic, cationic, amphoteric or non-ionic substances. mixtures.

7. A process according to claim 5, wherein the oils are mineral oils, vegetable oils, animal oils, hydrolysed by products, or mixtures thereof.

8. A method according to claim 5 or 6, wherein the surfactant is present in an amount of about 50-100% of the amount of the activator.

9. A method according to claim 5 or 7, wherein the oil ratio is at most 50% of the amount of activator.

Method according to claim 1, characterized in that the proportion of the active ingredient in the activator is about 10-70%, preferably 30-90% of the amount of the solid activator composition.

A method according to claim 1, wherein the auxiliary agent is the substances required for dispersing, wetting, granulating, stabilizing, controlling the pH or preventing foaming of the activator.

12. A method according to claim 1, wherein the herbicidal preparations and the solid activator composition in granules or tablets are combined or separately.

13. A method according to claim 1, characterized in that other plant protection agents, preferably chloridazone and metamitron, are used in the same granule or separate granule together with carbamoyloxyphenyl-carbamate, preferably phenmedipham, desmedipham and / or ethofumesate.