CS208694B2 - Pesticidal compositions - Google Patents

Abstract

1433882 Water-dispersible grains containing pesticide IMPERIAL CHEMICAL INDUSTRIES Ltd 31 Dec 1973 [29 Jan 1973] 4388/73 Heading A5E Water-dispersible grains having a size within the range 0.5 to 5mm., comprising at least 15% by weight of a solid pesticide having a solubility in water of not more than 1% by weight and being in the form of particles less than 200 microns in diameter, comprising a disintegrating agent, at least 4% by weight of dispersing agent, having a water content of not more than 5%, and the grains dispersing at 1% dilution in hard water at 30‹C to give no sediment; may be obtained by forming an extrudable aqueous mix from the pesticide, the dispersing agent and the disintegrating agent, the free moisture content being such that on extruding the mix, moist coherent granules are obtained. Optional ingredients are water-soluble herbicides, wetting agents and fillers.

Description

The invention relates to a pesticide preparation, more particularly to pesticides formulated in a form particularly suitable for rapid dispersion in water. In particular, the invention relates to water-insoluble pesticides formulated in dispersible granules and to a process for preparing a pesticidal preparation in the form of dispersible granules.

One of the major problems of the pesticide industry is to adapt water insoluble pesticide formulations to suitable formulations that would rapidly form dispersions in water. Preparations in the form of dispersible powders are known, but are not very suitable for use, and in some cases may be dangerous in both manufacture and use. Powder formulations are bulky and are not always easy and safe to pack. Currently, pesticide research is focused on granular products which to some extent eliminate the disadvantages of powders. Granular preparations are particularly suitable when the grinding required for the preparation of the powdered preparations is carried out with a material or substance which is hazardous to grinding.

A variety of processes are used to prepare the granules and use known techniques such as suspension drying or spray drying of a wet blend containing pesticide and other ingredients. However, these processes often require grinding and / or pelletizing technologies.

The present invention provides water dispersible granules for use as a pesticide, having a particle size in the range of 0.5 to 5 mm, comprising a solid water-insoluble pesticide in the form of particles of less than 200 microns in diameter, characterized in that they contain from up to 80% by weight of pesticide, from 5 to 60% by weight of a water-deficient salt disintegrant which absorbs water in the form of water of crystallisation in contact with water, from 4 to 25% by weight of dispersant and not more than 5% by weight of water, measured by Dean-Stark method.

The invention also relates to a process for the preparation of water-dispersible granules, characterized in that the peeticide, the disintegrating agent and the dispersing agent, or water, are mixed together to form a displaceable aqueous mixture having such. free moisture content by forming a wet coherent granule upon extrusion, the mixture is extruded into these granules, dried to a free moisture content of not more than 5% by weight, as measured by the Di-Starke method, and the granules are sieved. Also, undesirable granules are removed.

The process allows the preparation of water-dispersible granules which are solid, non-encapsulating liquid components, such as dust, are good flavor when water is added and rapidly. The dispersion of the peeUcide (Octive Component) may be as high as needed, and the product has a high weight per weight.

Water insoluble means solubility in water at 20 ° C not greater than 1% by weight.

Peesicides which can be processed according to the process of the invention are often available in the form of a numbered paste or as a fit-cake, which partially yields water. It is advantageous to add a wetting agent to the mixture in addition to the dispersing agent. Any filler as well as any other component, for example a water-soluble pessicide, for example a herbicide, may also be added to the mixture. bip; y idylic salts.

The aqueous mixture is preferably mixed in a screw mixer or similar type, and the extruder is preferably extruded by mixing the mixture further in the alignment head.

The content is higher. is adjusted so that the mixture extruded from the machine is friable in the film.

This treatment or moisture content is important for the outcome of the process. If the mixture is too wet, the set mixture leaves the machine in a continuous column form (like Spinets) and does not disintegrate into granules of the desired range! velikossi. If the mixture is poured dry, the extruded mixture does not form a coherent granule and disintegrates during dusting. Although the mixture is poured dry, it can be treated by adding water or an aqueous solution. If it is too humid, it can be partially dried in a conventional manner, for example by gentle heating or in vacuum, or preferably by mixing the salt with water and water. After drying, screening is necessary or appropriate to remove the fine material formed during the process.

In accordance with these conditions, a dispersing agent, i.e. a surfactant, may be added to the liquid, for example water, to facilitate dispersion of the solvent. Preferably, a water-soluble dispersing agent is used. For example, a salt of lithium sulfooate such as Polyphon H; condensation products of fumaldehyde with a sulfonated unsulfonated or tubular phenol, umine or naphthenene or their derivatives, preferably molar, examples of such condensation products are Dispersol. T and tyapol PT.

By wetting agent is meant a surfactant which facilitates the wetting of dispersible grams in water. Wetting agents which can be used in the process and which can be formulated are, for example, salts of alkyl phosphonates such as Arylan S, and Arylan SX; ethylene oxide condensates with alcohols, alcohols, amines, or acids or alkenylphenols, e.g. ЛОуХпА ^ сУо e1ULphtoates such as Perainaa BX.

All surfactant. however, most of the surfactants are far more effective in one effect than the other. The old man can thus select the surfactant which is the lowest for the purpose.

By disintegrating agent is meant in the invention a solid, water-soluble substance, for example a salt or a simple organic substance, which aids the disintegration of dispersible granules in water to form a dispersion. Compounds which may be used as disintegrating agents are sodium acetate, sodium sulfate, sodium bicarbonate, and citric acid. Preferably, mixtures of disintegrants are commonly used.

By a salt with insufficient water content is meant a salt capable of scrubbing water as crystal water and thus reducing the amount of moisture in the mixture to a level which is suitable for the correct extrusion of simas. Suitable salts are, for example, sodium acetate, sodium sulfate and magnesium sulfate. If desired, the same salt can be added to the extrusion mixture and can simultaneously serve as a disintegrant, i.e., it can perform both functions.

The peeide particle size used in the present invention is less than 200 microns. Generally, size is preferred!,! particles from 5 to 50 microns, but larger or smaller particle sizes are ^ я ^ а ^^ с !. Often the pressed paste paste often contains between 10 and 50% by weight. water.

In the description, puticides include chemical crop protection agents that include insecticides, aceaicides, moluusccides, herbicides, plant growth-inhibiting agents, plant fungicides, antifungal agents, and anti-viral agents. The specific pesticides that can be made into the dispersible granular surfactants of the invention are as follows.

However, the invention is not limited in any way by the enumeration of these specific pesticides, these examples are for the purpose of illustration only.

Labeling Chemical name

Captan N- (trCchltmltyltho Cekklhlex-4-eo-1,2-dkcarboximide Caapífol N- (1,1,2,2-metolachlor butyl thio) etLOLolex ^{4lon-b-1,2ddkaaí} oxmid Drazo ^ clm 4 · (2-Chlorobenzoyl) -3-methyl-5-oxoxazole Ме ^ гохоНш  4- (3-Chloro-phenoxy) -3-ethyl-5-isoquinazoline Ethirmol . 2-Ethyl-amino-4-yl-5-n-butyl-6-hydroxy-xi; Р-гО ^ юЬ , ^ ^ Ιο ΙιοΙοο ^> ^6-d iлetylpeτiiid0n 4eyl-dileeykarílmát Simazin 2-chloro-4,6-bis (ethylmethyl) -1,3,5-triazine

Dosetu! water-insoluble peesicides that can be processed to the prepaate of the invention are disclosed in H. Mattin: Peanicide Meanua, 3rd edition, published by British Crop Pro tecit on Coound.

^O ^ donkeys b8ah yl no ^b of degree m ^ ktoH vytlačitelé a n ^{d s} "is dependent on něěi cel ^E, CDE factors including type specific peeticidu used and its ratio in Sooss, particles peesicidu and general theological alli1UllitlCh siiěi. Generally, however, the free moisture content of the displaceable aqueous mixture is between 5 and 25% by weight.

The aperture used in the formation of the Oss may be, for example, a screw stirrer or a spiral Oxio with protrusions, such as those known under the names Winkololth and Grnrdener. Alternatively, a planetary mixer may be used, such as a mixer known as

Nauta.

In general, any extruder can be used for extrusion, particularly extruders known under the name Elanco. Especially preferred is the small-scale extruder, model Elanco XDC 100. Preferably, the extruder throat ^, i.e. the orifice through which the mixture is pressed and extruded, is provided with sieves having mesh sizes of 0.55 mm and 1.2 mm. although it is also possible to use larger branches of the eye. In an embodiment, the machine is filled such that the rotating filling screw fills the chamber of the extruder, the walls of which are provided with mesh of the size described. The extrusion rate may be within a wide range; in general, the Elanco XDC 100 has a sufficient speed, for example from 35 kg to 120 kg of extruded compound per hour ·

The drying of the friable extruded material can be carried out in any type of drying device. Optionally, the drying can be carried out simply in the open air, but accelerated drying is preferable. Preferably, a fluidized bed drying is used, a suitable fluidized bed dryer being an ^L Mánesty-Petrie dryer type MP 100S. This drying is preferably conducted so that the temperatures are ^to EN ^é it mater ^ial with the nail, ^{and characterized} hundredth ^pit e.g. at ⁶⁰ ° C for 30 mine ^{tonne (price} may use higher temperatures and shorter times and vice versa) .

If it is necessary to use a sieving to remove fine material, can be used ^live jakýtali type ^network and suitable veHkos ^ o ^k. Sieves are preferably in podroM ^ib crawfish. For example, British Standard mesh screens of between 8 and 30 have a suitable screen size.

Suitably, the vibration sieving of the extruded mixture is performed by sieving the mixture through a BS 8 mesh screen, removing the granules remaining on the screen, then passing the passed screen through a 30 mesh screen, removing the granules and fines through the screen and as the final product. the granules remaining on the BS 30 mesh are used.

The removed granules and fine material are recirculated and added to the next batch of the mixture.

The invention is illustrated by the following examples.

EXAMPLE ^T en ^t o ^{d comm} la illustrates execution ^ d ^ pergova lných granuK contained ^ UJ ^I C ^and the CB. Dog c ^ ^id Cornrnon British Standard Name: drazoxolon. This compound of the chemical formula

Cl '

it has the chemical name 4- (2-chlorophenylhydrazono) -3-methyl-5-isoxazolone. The ingredients used in the preparation are listed below, their name or trade name being given for each ingredient together with an indication of their effect and the amount used. The preparation is given for 10 kg of dispersible granules containing 60% drazoxolone. Drazoxolone has a particle size in the range of 2.5 to 20 microns and is produced in the form of an aqueous pressed paste (filter cake).

5 208694 Used yolk (g) Drazoxolone aqueous pressed paste (71.8% active ingredient, 75.5% solids) Polyphon H (dispersing agent) 8 360 1 500 Ary lan SB (wetting agent) 100 ALIGN! sodium sodium citrate 400 Anhydrous sodium acetate 372

OTY powder

318

The ingredients were mixed together in a Nauta mixer for 10 minutes. The pressed paste is added first, then sodium acetate is added, followed by the other ingredients. The resulting wet powder mixture is extruded at a rate of about 90 kg per hour using an Elanco extruder (Moddl XDCS 100) using a 0.55 mm sieve. The extruded mass disintegrates into coherent grandies upon leaving the screen. The product was collected and dried in a 60 ° C swirl dryer so that the remaining water content was 3.5% as determined by the Deai-Stark method. The product is then sieved and the fraction passing through 10 mesh B.S. sieves (British Standard) and collected on 30 mesh B.S. sieves is collected (finer and larger fractions are then recirculated and processed together with the next batch).

The product has the following characteristics:

Disintegration and suspensibility:

g of the product is added to 100 ml of standard hard water Woold Health Authhoity Speeification for Pesticides 2nd ed. 1961 (WHO, Geneva) in a Crowe flask. The flask was inverted and placed in a water bath at 30 ° C. After 2 minutes the sedimentation should be no more than traces.

After 5 minutes, the amount of sediment should not exceed 0.1 ml.

After 30 minutes the amount of sediment should not exceed 0.3 ml.

After 30 minutes, the suspension is sieved through 120 mesh B.S. s. (8.5 cm diameter) and no mmttrial is left on the sieves when clear of water.

VzlhLed:

Loose granules! product

Moisture content: Between 2.0 and 5.0% water according to Dean and Stark

Sialial Aialysis: Passes 10 mesh B. S. S. It remains on 30 mesh B. S. S.

Example 2

This example illustrates the preparation of a 50 kg dispersed granular preparation containing paraquate ions and simazine.

Paraquat (36.1% cation) 10.4 1 Si-mezin (technical) 15,0 kg C Ethyl methyltyl Ionate bromide 2,0 kg magnesium sulphate (anhydrous) 26,0 kg

Magnesium sulphate is introduced into the mixer and paraquate ions are added as a concentrated paraquate dichloride solution. Simazine and surfactant are then added and mixed.

б

The resulting mixture was extruded, dried and sieved as described in Example 1.

The product complies with the requirements of example 1 ·

Example 3

This example describes the preparation of a dispersible granular preparation containing a pesticide known under the trade name Pirimicarb.

kg of batch contains the following components:

Pirimicarb (aqueous pressed paste, 78% solids) 2.56 kg Dyapol Ρ. T. 0.6 kg sodium acetate (anhydrous) 0.4 kg Blue Lake dye 0,04 kg talc S2 0,96 kg

The ingredients are mixed together (first the active ingredient, then sodium vinegar and then the remaining ingredients) in a Nauta mixer and the final extrusion mixture contains 9.5% free water.

The mixture is then extruded as described in Example 1 at a rate of about 40 kg per hour. The product is dried in a fluid bed dryer at an inlet temperature of 60 ° C until the residual moisture content is between 0.5 and 1%. The granules are then sieved and the product is collected between 8 and 30 mesh B sieves.

The product complies with the claims at the end of Example 1, except:

(a) 0.2 g of product is used for the disintegration and suspensibility test and the limit after 5 and 30 minutes was 0.05 ml and 0.1 ml;

(b) the moisture content of the product is between 0.5 and 1%.

Example 4

This example illustrates the preparation of a dispersible granular preparation containing the pesticide Metazoxolone. A 25 kg batch contains the following ingredients:

Metazoxolone '(aqueous pressed paste, 94% solids) 2,67 kg Polyfon H 3,75 kg Arylan SX sodium acetate (anhydrous) GTY Dust (Kaolin Thinner) 0,25 kg 2,5 kg 15.83 kg

Metazoxolone (with an average particle size of 8 microns) is mixed with sodium acetate, and the other ingredients are then added to the mixture. The water content of the mixture is then adjusted to 20 wt.

Using the procedure described in Example 1, the mixture is extruded and dried in a fluidized bed dryer at an inlet temperature of 60 ° C so that the residual moisture is between 2 and 4% by weight.

The dried product is sieved and the fraction between 10 mesh B.S. and 30 mesh B.S.

The product complies with the requirements of Example 1 and has a limit in the disintegration and suspendability test after 5 minutes of 0.2 ml and after 30 minutes. 0.5 ml and the moisture content is between 2.0 and 4.0%.

Example 5

This example illustrates the preparation of dispersible grams containing Captan as a pesticide (active ingredient). The preparation has the following composition:

Captan (technical dust average particle size 5 microns) 2,500 g Polyfon H.. . 375 g sodium bicarbonate 875 g Alylan SB 50 g sodium acetate (anhydrous) - 205 g Speston. . 1200 g water 1000 g

Mixing of the above components is carried out for 3 minutes at room temperature. screw mixer. 1 liter of water is then added and stirring is continued for a further 5 minutes.

A mixture containing 13.0% of free water is extruded, dried, and sieved as described above

in Example 1 . The content of Captan in the preparation is 45.0% and the preparation does not contain water. When adding

rapid disintegration into water results in an aqueous pesticide suspension.

The details of some of the ingredients used in the foregoing examples are given below.

Dyepol PT (D ' D ' York York ™ Dfewaree, Sulfanilic Acid Condensate, Film Aldehyde and Urea), and also contains sodium sulfate. Telek S2 is coarse talc; Polyfon H (Bead !, Weetvaco, USA), sodium.

Arylan SB (addi ^ and ^ l ^ Ώ Lankro ιηΐοάΐβ) are dodecylblnzen8ulf acid with branching ^and A ^ -yl ^ ^SX Nym chain (SX has Menne number of branches than SB)

Spasten is a fine earth kaolin.

The herbicidal granules containing mixtures of insoluble herbicides with herbicidal bipyridyl salts (e.g. halides) are preferably prepared according to the invention. Granules containing paraquate and simazine mixtures are shown in Example 2. Similarly, mixtures of diquate salts with insoluble herbicide diuron and granules comprising mixtures of 1,1'-bis (N, N-diltytadinocarbonyl) -4,4'-bipydylium may be prepared. salts with an insoluble atrazine herbicide.

As explained in the foregoing examples, the invention relates to water dispersible grams having a size of 0.5 to 5 mm, characterized in that they contain. at least 15%, and generally no more than 80%, of an ammoniacal solid of water insoluble pesticide in the form of particles less than 200 microns in diameter, a disintegrant, generally at a level of from 5 to% by weight, and at least 4% but preferably no more than 25% %, a dispersant having a water content (measured by the Dean and Starke method) of not more than 5% and which, when dispersed to 1% dilution in standard hard water at 30 ° C, gave almost no sediment after two minutes.

Claims (4)

OBJECT OF THE INVENTION A water-dispersible granule for a pesticide having a particle size in the range of 0.5 to 5 mm comprising: a solid, water-insoluble pesticide in the form of particles of less than 200 microns in average, characterized in that they encase from 15 to 80% of hour-to-day pesticides, from 5 to 60% by weight of disintegrant containing a water-inefficient salt which, in contact with water, absorbs water in the form of water of crystallization, from 4 to 25% by weight of dispersant and not more than 5% by weight of water, measured by the Deirn-Starke method. 2. A process for the preparation of water-dispersible grandi according to claim 1, characterized in that the pesticide, disintegrating agent and dispersing agent, if desired, are mixed together to form a displaceable aqueous mixture having a free moisture content such that a wet coherent grande is formed. , the mixture is extruded onto these. The granules are dried to a free moisture content of not more than 5% by weight, as measured by the Demn-Starke method, and the granules are sieved to remove undesirable granules. 3. A process according to claim 2, characterized in that the content of the free moisture-displaceable aqueous mixture is treated with salt additive by a lack of water which, in contact with water, absorbs water in the form of fryytalizing water. 4. A method according to claim 2 or 3, characterized in that a water-soluble pesticide is added to the displaceable aqueous mixture.