CA1209363A - Pesticide granules - Google Patents

Abstract

PESTICIDE GRANULES
Abstract of The Disclosure This invention relates to a process of producing a granular pesticidal composition comprising mixing a pes-ticide or mixture of pesticides, with or without a solid carrier, with a polyvinylpyrrolidone, urea and a surfactant and pelletizing said mixture.

Description

PESTICIDE GRANULES
Background of the Invention 1. Field of the Invention The present invention relates to granular composi-tions comprising a pesticidal agent and process for the production of such compositions.

2. Description of the Prior Art Numerous synthetic, organic, biologically active materials are now commercially available and are useful for a wide variety of applications~ These materials include insecticides, insect repellents, herbicides, fungicides, acaricides, nematocides, molluscicides, rodenticides, and the like. All of these materials are referred to herein by the generic term pesticide. In use, it is generally desirable to spray these materials onto a substrate (plant, animal, etc.) or area to be treated. Because of its availability, minimal cost, and lack of adverse environ-mental effectsl it is preferred to apply these materials from an aqueous medium. However, many of these materials are insoluble in water and can be dissolved only in organic solvents. For this reason, such pesticides are conven-tionally, admixed with emulsifying agents and organic solvents to form concentrates which are subsequently added to water in small quantities to form emulsions. These concentrates are referred to herein as "emulsifiable ~i"`.

concentrates." Some of these pesticides are not soluble either in water or in suitable organic solvents Concen-trated formulations of these pesticides are generally prepared either as "wettable powders" or as "flowable formulations." In preparing a wettable powder from solid pesticide, the pesticide is finely ground and combined with an inert solid diluent such as kaolin, attapulgite clays, diatomaceous earth, etc., and a surfactant. When added to water in the desired quantity, the wettable powder forms a stable suspension in the water. Wettable powders may also be prepared from a liquid pesticide by combining the liquid pesticide with a finely ground adsorbent carrier such as diatomaceous earth or a hydrated calcium silicate. Surfac-tants are added to these liquid pesticide/carrier blends so that the wettable powder will form a stable suspension when added to water.
Wettable powders are normally prepared by first mixing all the ingredients of the formulation and then milling with further mixing as necessary to obtain homo-geneity as far as possible. Such powders have drawbacks;for example, they are often dusty, and this is highly undesirable if the active ingredient is toxic or irritating to human beings.
Additionally, wettable powders frequently must be pre-creamed, that is to say, they must be mixed with a small 93~;~

amount of liquid dispersant to form a homogeneous paste free from lumps before they can be diluted to the desired final concentration for use.
A pesticide composition designed for dispersion in a liquid carrier should ideally have a high content of active material, should be readily dispersible in the carrier and should then form a dispersion which is as stable as possible, requiring the minimum of subsequent agitation for homogeneity. The liquid carrier will, of course, for convenience normally be water. One way of solving these problems to make such insoluble powdered active ingredients into granules which readily break down when they are stirred into a liquid carrier to give a stable dispersion of the active ingredient.
By l'granular form" is meant granules at least substantially all of which have a mean particle size of at least 0.1 mm, i.e., a particle size much larger than the mean particle size of a powder, the mean particle size of whi h is measured in microns.
While granules produced according to the prior art techniques have been an improvement over the wettable powders and other means of dispersing pesticides, it has been found that in many cases granules do not break down and disperse in a liquid carrier as well as could be desired.

~3 Accordingly, it is a purpose of the instant invention to provide granules and a process for preparing them which is characterized by substantially improved dispersibility of said granules in a liquid carrier.
A particularly difficult problem is presented by low-melting pesticides. They are generally too soft under conventional granulating conditions and, therefore, do not form satisfactory pellets.
Patents of Interest 0 U. S. Patent No. Issued Inventorts) Assignee 4 r 102 r 673 7/25/78 Buntin Hercules

3,954,440 5/4/76 Markley Dow U. S. 4,102,673 discloses l-phenyl-hexyl ureas mixed with carriers in the form of granules as herbicides.
rhis patent discloses the preparation of a granular composi-tion by admixing the phytotoxic material, i.e., pesticide, with an inert finely divided solid such a5 clay and with water. This material is placed in a granulating pan and granules are formed therein with subsequent removal of water or solvent. The composition preferably contains emulsifying material which may be one or more surfactants stated to be at a concentration sufficient to enable a suspension of the desired degree of stability when the composition is admixed~
with a suitable quantity of water. ~

~LZ~193163 U.S. 3,954,440 cliscloses employing 2-hydroxy-2-phenylbutylsulfonate compounds in herbicide compositions.
This patent discloses that the active ingredient, i.e., the herbicide, can be applied with solid adjuvants or carriers such as clay and silica and states that it is frequently desirable to incorporate a surface active agent in the compo-sition.
Summary of the Invention The present invention provides a granular p~sticidal composition comprising a pesticide or mixture of pesticides with or without a solid carrier, a polyvinyl-pyrrolidone, urea and a surfactant.
The present invention also provides a process of producing a granular pesticidal composition comprising mixing a pesticide or mixture of pesticides with or without a solid carrier with a polyvinylpyrrolidone, preferably cross-linked polyvinylpyrrolidone and polyvinylpolypyrrolidone, urea and a surfactant and pelletizing said mixture.
In accordance with the invention the surfactant may be a surfactant having a hydrophilic-lipophilic balance of about 5 to 30. The surfactant may be a nonionic surfactant.
The surfactant may be a cogeneric mixture of conjugated poly-oxyalkylene compounds containing in their structure at least one hydrophobic oxypropylene chain in which the oxygen/carbon atom ratio does not exceed 0.4 and at least one hydrophilic oxyethylene chain in which the oxygen/carbon atom ratio is greater than 0.4 and the percent of said hydrophilic oxyethylene chain in said surfactant may be about 20 to 80 and the molecular weight of the hydrophobic oxypropylene chains may be about 1200 to 4000.

~" f ~, ~2~3~3 In accor~ce witk the invention the pell~tized material may be dried at a temperature of fxom about 30 to 100C for a period of about 2 to 8 hours.
The term polyvinylpyrrolidone as used herein includes all polyvinylpyrrolidone compounds and compounds which are closely relates thereto. Where the pesticide is a low-melting pesticide, the pesticide and the surfactant are co-adsorbed onto a solid carrier material generally by simply mixing the pesticide and surfactant with the solid carrier.
Description of the Preferred Em~odiments According to this invention, there is provided a composition in granular form which may comprise by weight about 0.5 to 5 percent of a polyvinylpyrrolidone, about 5 to 15 percent urea, about 5 to 15 percent surfactant, bala /
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~'",A - 5a -~2~ 3~i3 pesticide and other additives. Polyvinylpyrrolidone is obtained by polymerization of N-vinylpyrrolidone as follows:

H ~ - CH2 - H C CH
H2C ~C=O ~ ~
N N

CH=CH2 CH-CH2 - n The other additives would include possibly other dispersants in amount rom about 1 to 5 percent and suspending agents in amount of about 1 to 5 percent by w~ight. ~urther additives in amount of about 1 to 10 percent by weight may also be included. Such other addi~ives include lignin sulfonates, naphthylene sulfonate, alkyarylsulfonate,-and sodium sulfosuccinate. Where the pesticide is an herbicide, additional materials may include one or more other major components such as plant growth regulators, insecticides, fungicides, plant nutrients and the like.
The granular pesticide compositions of the present invention may be prepared with any high-melting pesticide generally utilized in granular form. Emulsifiable concen-trates of the present invention are not limited to a particular pesticide or mixture of pesticides. Suitable pesticides which may be utilized include, for example, the following:

Atrazine: 2-chloro-4-ethylamino-6-isopropylamino 1,3,5-triazine Metribuzin: Amino-6-(1,1-dimthylethyl)-3-(methyl-thio)-1,2,4-triazin-5(4H)-one Carbaryl: l-naphthyl N-methylcarbamate Caparol: 2,4-bis(isopropylamino~-6-methylthio-s-triazine Carbofuran: 2~3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate Surfactants which may be employed in the instant invention are preferably those having an HLB (hydrophilic lipophilic balance) in the broad range of 5 to 30 and preferably 13 to 17. Nonionic surfactants are particularly preferred. Such nonionic surfactants include:polyoxy-alkylene-polyether polyols such as the polymerization product of an alkylene oxide sr of an alkylene oxide with a polyhydric alcohol. Any suitable polyhydric alcohol may be employed including both aliphatic and aromatic such as ethylene glycol, 1,3-propanediol, 1,2-propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butylene glycol, 1,5~
pentanediol, 1,4-pentanediol, 1,3-pentanediol, 1,6-hexane-diol, 1,7-heptanediol, 2-butene-1,4-diol, glycerol, 1,1,1-trimethylolpropane, l,l,l-trimethylolethane, hexane-1,2,6-triol, ~-ethylglucoside, pentaerythritol and sorbitol. Also 3~3 included with the term polyhydric alcohol are compounds derived from phenolic compounds such as 2~2-bis(4-hydroxy-phenyl)propane, commonly known as Bisphenol A, and hydroxy-alkyl ethers of such phenolic compounds such as bis-2-hydroxyethylether of hydroxyquinone.
Any suitable alkylene oxide may be used such as ethylene oxide, propylene oxide, butylene oxide, amylene oxide and heteric or block copolymers of these oxides. The polyoxyalkylene polyether surfactan~ may be prepared from other starting materials such as tetrahydrofuran and alkylene oxide-tetrahydrofuran copolymers; epihalohydrins such as epichlorohydrin; as well as aralkylene oxides such as s~yrene oxide. The polyoxyalkylene polyether surfactant may have either primary or secondary hydroxyl groups and, preferably are polyethers prepared from alkylene oxides having from 2 to 6 carbon atoms such as polyethylene ether glycols, polypropylene ether glycols, and polybutylene ether glycol. However, the resulting product must contain at least 20 percent by weight polyoxyethylene groups and preferably 20 to 80 percent polyoxyethylene groups.
Among the polyoxyalkylene polyether polyols which can be used in the compositions of the invention are those which correspond to the formula:

I Y[(c3H6o)mtc2H4o)n ~x ~.

~L2~93~3 wherein Y i5 the residue of an organic compound having from about 1 to 6 carbon atoms and containing x reactive hydrogen atoms in which x has a value o at 1east one, n has a value such that the oxyethylene content of the molecule is from about 20 to 80 weight percent.
Compositions of this type are more particularly described in U. S. Patent Nos. 2,674,619 and 2,677,700.
Other suitable polyether surfactants correspond to the formula:

y [ (c2H4o)n(c3H6Q)mH] x wherein Y, n, m and x have values as set ~crth above.
Compositions of this type are more particularly described in U. SO Patent 3,036,118. In either of the above formulas, compounds falling within the scope of the definition for Y
include, for example, propylene glycol, ethylene glycol~
dipropylene glycol, diethylene glycol, glycerin, penta-erythriol, trimethylolpropane, ethylenediamine and the like. Also, the oxypropylene chains optionially, but advantageously, contain small amounts of ethylene oxide and the oxyethylene chains, also optionally but advantageously, contain small amounts of propylene oxide. Among the ~

_ g _ ~Z~363 preferred compounds of the above type are those wherein Y is the residue of propylene glycol or ethylene glycol and x is 2. Such compounds have the general formulae:

II Ho~c2H4o)n~c3H6o)m~c2H4 )n wherein the total molecular weight of the polyoxypropylene groups is about 1200 to 4000 and III ( 3 6)m(C2H4)n(c3H6O) H

wherein the total molecular weight of the polyoxypropylene grups is about 1000 to 3100.
Additional preferred compounds of the above type are those wherein Y is the residue of ethylenediamine and x ls 4. Such compounds have the general formulae:

H(OC2H4)n(Oc3H6)m / (C3H6O)m(c2H4O)nH
IV ~ N-CH2CH2-N \
H(OC2H~)n(oc3H6)m (C3~6O)m(c2H4o)n wherein the total molecular weight of the polyoxypropylene groups is about 2000 to 7000 and ~2~36;~

H(OC3H6)m(Oc2H4)n ~ (C2H4O~c3H6O)mH
V \ ~ CH2CH2 N
H(OC3H~)m(oc2H4)n (C2H4O)n(c3~6o)m wherein the total molecular weight of the polyoxypropylene groups is about 3000 to 600G.
Compositions of this type are more particularly described in U. S. 2,979,528~
Other suitable polyether surfactants correspond to the formulae:

VI Y[(C4H8O)m(C2H4O) H] and VII Y[(c2H4o~n(c4H8o)mH]x .0 wherein Y, n, m and x have values as set forth above.
Compositions of this type are described more particularly in U. S. Patent 2,828,345 and U. S. Patent

4,326,977.

In either formula, VI or VII, compounds falling within the scope of the definition for Y include, for example, butylene glycol, ethylene glycol, dibutylene glycol, diethylene glycol, glycerin, pentaerythritol, trimethylolpropane, ethylenediamine and the like. Also, the 3~3 oxybutylene chains optionally, but advantageously, contain small amounts of oxypropylene groups and oxyethylene groups and the oxyethylene chains also optionally, but advanta-geously, contain small amounts of oxybutylene and oxy-propylene groups.
Preferred compounds of the above type are those wherein Y is the residue of butylene glycol or ethylene glycol and x is 2. Such compounds have the general formulae:

VIII ( 2 4O)n(c4H8o)m(c2H4o)nH and IX HO(C4H8O)m(c2H4o)n(c4H8 )m wherein the total molecular weight of the polyoxybutylene groups is about 1500 to 10,000~
Other suitable polyether surfactants are the polyoxyalkylene compounds consisting of the nucleus of an organic reactive hydrogen compound having from 1 to 6 reactive hydrogen atoms, at least one heteric hydrophobic polyoxyalkylene chain having an average oxygen/carbon atom ratio of less than 0.5, said hydrophobic polyoxyalkylene chain consisting of polymers of oxyalkylene groups selected-~2~363 from the group consisting of oxypropylene, oxybutylene, oxyamylene, oxystyrene, mixtures of said oxyalkylene groups with each other and mixtures of said oxyalkylene groups with oxyethylene groups, and at least one heteric hydrophilic polyoxyethylene chain consisting essentially of about 20 to 50 weight percent of oxyethylene groups and about 80 to 50 weight percent of higher molecular weight oxyalkylene groups selected from the group consistin~ of oxypropylene, oxy-butylene, oxystyrene, and mixtures thereof, said heteric hydrophilic polyoxyethylene chain having an average oxygen/carbon atom ratio of greater than 0.4, and wherein the average molecular weight of said mixture of polyoxy-alkylene compounds ranges from about 3000 to 7500.
Suitable organic reactive hydrogen compounds having from 1 to 6 reactive hydrogen atoms include mono- and polyhydric alkanols having up to 6 carbon atoms per molecular; alkyl ethers of alkanols having up to 6 carbon atoms per molecule, primary alkylamine~ having up to 6 carbon atoms per molecule, secondary dialkylamines having up to 6 carbon atoms per molecule, alkylene polyamines having up to 6 carbon atoms per molecule~ piperazine, carbon-substituted methylpiperazines, alkane amides having up ~o 6 carbon atoms per molecule, N-alkyl alkane amides having up to 6 carbon atoms per molecule, benzenesulfonamide, N-ethylbenzenesulfonamide, N-propylethanesulfonamide, and -~

12~931~3 mono- and polycarboxylic alkanoic acids having up to 6 carbon atoms per molecule.
In general, each of said hyrophobic chains is attached at one end thereof to one end of one of said hydrophilic chains and the so-formed hydrophobic-hydrophilic chains are attached at one end thereof to the nucleus of said reactive hydrogen compound at the site of each of its reactive hydrogen atoms~ Such a mixture of conjugated polyoxyalkylene compounds is described in U. S. Patent Nos.
3,101,374 to John T. Patton, Jr It is preferred that the hydrogen compound having from 1 to 6 reactive hydrogen groups be a compound having 3 reactive hydrogen groups.
Where the pesticide material is a low-melting material, it has been found that such low-melting materials present problems in that they do not form granules properly under the granulating conditions. Accordingly, in accor-dance with this invention, the pesticide material is co-adsorbed along with the above-described surfactant onto a solid carrier which is usually a dispersible inert solid.
This is accomplished by admixing the pesticide material and the surfactant with an inert finely divided solid such as, for example, clay, carbon, plaster of Paris, attapulgite clay, bentonite, diatomaceous earth, inorganic phosphates, gelatin, sodium lactate, polyvinyl alcohol, precipitated silica, silica gel, urea, anhydrous sodium sulfate, sodium chloride, and starch. If the pesticide material is liquid, it is co-adsorbed onto a carrier as described. If the material neat is solid, then it is melted and then co-adsorbed. The composition of this co-adsorbed material is by weight about 25 to 60 percent pesticide, 1 to 8 percent surfactant, and 75 to 30 percent solid carrier material.
Suitable low-melting pesticides include-Fluchloralin: N-(2-chloroethyl) a,~,~-trifluro 2,6-dinitro-N-propyl-p-toluidine Trifluralin: a, ~ -trifluoro-2,6-dinitro,N,N-dipropyl-p toluidine Pendimethalin: N-~l-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzeneamide Alachlor: 2-chloro-2'-6'diethyl-N-(methoxymethyl)-acetanilide Metolachlor: 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-l-methylethyl)acetamide In a conventional commerical preparation of low-melting pesticides, they are generally produced dissolved in a suitable solvent. Accordingly, prior to co-adsorbing on the carrier, the solvent is removed by conventional means such as distillation.

;;a.f~ ~93~3 The carrier having co-adsorbed thereon the pesticide and surfactant i5 then crushed and screened in conventional crushing and screening apparatus to a particle size of 10 to 1000 microns. In some instances, the particle size is already within this range and such crushing and screening is not necessary.
In a preferred embodiment of the instant inven-tion~ the low-melting pesticide and surfactant are sprayed onto a moving bed of the carrier material in an apparatus such as a tilted pan of the type similar to the pelletizer to be subsequently described or in a rotating barrel or on a moving belt. The surfactant and pesticide may be each sprayed separately or they may be mixed together first and then sprayed onto the carrier. Most low melting pesticides generally melt at 40 to 50C and, accordingly, they are melted at this temperature and then sprayed onto the carrier at such temperature.
After the co-adsorption and crushing, and screening step where required, the co-adsorbed pesticide and surfactant on carrier is then mixed with the polyvinyl~
pyrrolidone and urea and any other possible additives as described above.
The mixture of pesticide, polyvinylpyrrolidone, surfactant, urea and any possible additives with or without -the carrier are then agglomerated into granules by sub- ~

~9363 jecting a mass of the finely divided particles produced as described above to a tumbling action by a continuously moving surface such as the inner surface of a rotating cylinder or drum or a rotating pan or disc tilted at an angle. In general, the material to be granulated or agglomerated is mixed with a conventional plasticizer, generally water. The granulated particles produced by the method of this invention range from about 0.1 mm diameter to about 5 mm diameter. The time required to pelletize the material will vary depending on the shape and size and design of the pelletizing apparatus. Subsequent to pellet-izing, the granules are dried immediately at a temperature of from about 30 to 50C for a low-melting pesticide. For a high-melting pesticide, the drying temperatures are in the range of about 40 to 100C and even higher temperatures may be used for high~speed drying. Drying time would depend on the amount of material to be dried and the design of the drying apparatus or drying means. Other means for pelleti-zing besides the tilted pan or rotating cylinder include the plough-type mixer and a vertical fluidized bed. The process of the instant invention may be performed batch-wise or continuously. The latter may use a conventional bin, feeder, rotary type mixer and drier having, for example, helical blades turning within a container or surface whereby the material to be mixed is fed at one end and exits from -~

~2~3~3 the other end and pelletizers such as pan pelletizers of the overflo~ type which may be operated continuously along with fluid bed type driers and suitable conveyors.
In order to apply the granulated products of this invention, generally the granules are dispersed in a solvent such as water whereupon the granules break up and disperse easily. This dispersion is then applied by spraying uniformly onto the plants.
The following examples further illustrate the invention. In the examples as well as in the specification, all temperatures are in degrees centigrade and all parts and percentages are by weight unless otherwise stated.

3i2~9363 Examples 1 and 2 Water-dispersible granules were prepared from a low-melting pesticide chemical known under the common name fluchloralin and having a chemical name N-(2-chloroethyl)-~,~,-trifluoro-2,6-dinitro-N-propyl-p-toluidine. This product is an herbicide and is generally produced as a solution in a conventional solvent. Two granular composi-tions were prepared by removing th~ solvent by vacuum distillation and spraying the fluchloralin onto a carrier absorbate along with a nonionic surfactant referred to herein as surfactant #1. In Example 1 the solid carrier was an attapulgite type clay having low viscosity when dispersed in water sold under the trademark Attasorb LVM. In Example 2 the the carrier was hydroxylated silicon dioxide, amorphous, sold under the trademark Hi-Sil T-600. In both cases the surfactant was surfactant #l which is the polyoxy-ethylene adduct of a polyoxypropylene hydrophobic base having a molecular weight of about 1750 wherein the oxy-ethylene content is about 50 weight percent of the molecule. The fluchloralin was first mixed with the surfactant and the molten mixture then sprayed onto the solid carrier in a tilted rotating pan. In the first example the fluchloralin-surfactant-carrier ratio was 43.5/2.3/54.2 by weight. In Example 2 the weight ratio was~
50.2/2.6/47.2. rhe fluchloralin and surfactant adsorbed on~

~Z~ i3 the carrier was then mixed with the xemaining components as shown in Table I below.

TABLE I
Example Component 1 2 Parts by Weight Fluchloralin/surfactant/carrier 78.8 Fluchloralin/surfactant/carrier - 78.8 Urea 9.65 9.65 KOLLIDON~ C.L. polyvinylpyrrolidone* 2.15 2 r 15 MARASPERSE C-21 2.0 2.0 MOREWET EFW 0.5 0.5 MOREWET D-425 2.0 2.0 NINATE 401 (10% aqueous solution~ 2.5 2.5 Residual water (3) 2.4 2.4 Total 100.0 100.0 *A commonly available polyvinylpyrrolidone that has been polymerized to produce a gel-like product having exceptionally high water dispersibility, The residual water in the above table is the residue after drying the yranules at 120F for 8 hours.
Both of the above formulations were pelletized into granules using a Ferro-Tech~ Model 16 laboratory pan pelletizer sold by Ferro-Tech, Wyandotte, Michigan 48192. -~

~2~93~3 The granules produced were then dried at 120~F for 8 hcurs and screened to the U. S. standard sieve siæe ranges indicated in Table II below. The granules produced in Examples 1 and 2 as well as granules from the only granu-lated low-melting commercial pesticide that appeared to be available were tested for dispersibility. The rate of dispersibility is the time in seconds required for the granules to disperse to the point where discreet granules disappear. These times in seconds are set forth below in Table II.

TABLE II
Rates of Dispersibility, seconds U. S. Standard Example No. Commercial Sieve Size Range 1 2 Product -14 +20 225 195 315 -20 +40 210 180 270 -40 +60 140 135 210 -60 +80 15 15 120 The commercial product is believed to be the product having the common name pendimethalin which is N-(l-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzeneamine. This product has a melting point o 54C.
From Table II above it can be seen that the granules from the compositions prepared according to this 93~i3 invention had greatly superior dispersibility to the commercial product.
Example 3 The high-melting pesticide having the common name atrazine, which is chemically defined as 2-chloro-4-ethyl-amino-6-isopropylamino-1,3,5-triazine, was mixed with urea, polyvinylpyrrolidone and several surfactants in a conven-t.ional mixing apparatus to form the composition set forth inTable III bel~w.
TABLE I~I
Componen~s Parts by Weight Atrazine technical powder 79.5 Surfactant #2 1.5 Urea 6.6 KOLLIDONX CL polyvinylpyrrolidone 2.2 PETRO*ll 4cO
MARASPERS~ C-21 1.5 NINATE*401, 10% aqueous solution 4.7 Total 100.0 This mixture was pelletized and dried as described above.
The product was then screened to the various sieve sizes shown in Table IV below. These granules were then tested for dispersibility along with granules of atrazine prepared commercially by another process. The products after drying * Trademark - 22 -3~

were screened to the sieve size~ shown in Table IV below and the various sizes tested for dispersibility ~s described above. The results are shown in Table IV below. As can be seen, the atrazine granulated in accordance with the instant process was greatly superior in rate of dispersibility to that of th~ commercial atrazine product.
In the above compositions, both Table I and Table III, with the exception of the surfactant~ the following names are trademarks for the materials indicated.

Marasperse*C~21 is liqnosulfonate, calcium salt.

Morewet*EFW is sulfated alkyl carboxylate and sulfonated alkyl naphthalene, sodium salt Morewet*D-425 is sodium naphthalene formaldehyde condensate.

Ninate*401 is alkylarylaryl su~fonate, calcium salt.

Surfactant #2 is a formulated surfactant based on a block copolymer of ethylene oxide and propylene oxide which are condensed into * Trademark ~931~;3 ethylene gLycol and has the average molecular weight of 3400.

Petro*ll is an alkyl naphthalene sulfonate, sodium salt~

TABLE IV
Rates of Di spers i bi 1 i ty, seconds U. S. Standard Sieve Size RangeExample 3Commercial Product -14 ~20 20 60 -20 +40 15 45 -40 +60 10 30 -60 +80 5 20 It is to be understood that various changes and modifications may be made in the foregoing invention without departing from the spirit of the invention and scope of the appended claims.

* Trademark

Claims (12)

What is claimed is:

1. A process of producing a granular pesticidal composition comprising mixing a pesticide or mixture of pesticides, with or without a solid carrier, with a poly-vinylpyrrolidone, urea and a surfactant and pelletizing said mixture.

2. The process of claim 1 wherein said pel-letizing is performed in the presence of a plasticizer.

3. The process of claim 2 wherein said plas-ticizer is water.

4. The process of claim 3 wherein said pelletized material is dried at a temperature of from about 30 to 100°C
for a period of about 2 to 8 hours.

5. The proces of claim 1 wherein said surfactant has a hydrophilic-lipophilic balance of about 5 to 30.

6. The process of claim 5 wherein said surfactant is a nonionic surfactant.

7. The process of claim 6 wherein said surfactant is a cogeneric mixture of conjugated polyoxyalkylene compounds containing in their structure at least one hydrophobic oxypropylene chain in which the oxygen/carbon atom ratio does not exceed 0.4 and at least one hydrophilic oxyethylene chain in which the oxygen/carbon atom ratio is greater than 0.4 and the percent of said hydrophilic oxyethylene chain in said surfactant is about 20 to 80 and the molecular weight of the hydrophobic oxypropylene chains is about 1200 to 4000.

8. The process of claim 7 wherein said pesticide is selected from the group consisting of .alpha.,.alpha.,.alpha.-trifluoro-2,6-dinitro,N,N dipropyl-p-toluidine and 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine.

9. The process of claim 5 wherein the amount of said polyvinylpyrrolidone is about 0.5 to 5 percent by weight, the amount of urea is from about 5 to 15 percent by weight, the amount of said surfactant is about 5 to 15 percent by weight, the balance pesticide and conven-tional additives in normal amounts.

10. The process of claim 5 wherein said pesti-cide is a low-melting pesticide and is co-adsorbed with said surfactant onto a solid carrier material prior to said pelletizing step.

11. The process of claim 10 wherein the product of said co-adsorption step contains by weight about 25 to 60 percent pesticide, about 1 to 8 percent surfactant, and about 75 to 30 percent solid carrier.

12. A granular pesticidal composition comprising a pesticide or mixture of pesticides with or without a solid carrier, a polyvinylpyrrolidone, urea and a sur-factant.