Title of Invention	A PROCESS FOR THE PREPARATION OF MANCOZEB SUSPENSION CONCENTRATE AND PESTICIDE FORMULATION MADE BY THE PROCESS
Abstract	A process for the preparation of Mancozeb supension concentrate having low particla size, low viscosity and high suspensibility by employing Mancozeb in a powder form comprising the steps of; a) Mixing of water and additives in a high shear mixer along Mancozeb powder to get homogenous premix; b) Wet milling of the premix to get the intermediate slurry; c) Blending of the slurry with suspending and antitacking agents to get the formulation

Title of Invention

A PROCESS FOR THE PREPARATION OF MANCOZEB SUSPENSION CONCENTRATE AND PESTICIDE FORMULATION MADE BY THE PROCESS

Abstract

A process for the preparation of Mancozeb supension concentrate having low particla size, low viscosity and high suspensibility by employing Mancozeb in a powder form comprising the steps of; a) Mixing of water and additives in a high shear mixer along Mancozeb powder to get homogenous premix; b) Wet milling of the premix to get the intermediate slurry; c) Blending of the slurry with suspending and antitacking agents to get the formulation

Full Text	FORM - 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE Specification (See section 10 and rule 13) AQUEOUS FUNGICIDAL FORMULATION INDOFIL CHEMICALS CO. (a division of MODIPON LTD.) an Indian Company of Nirlon House, Dr. Annie Besant Road, Mumbai 400 025, Maharashtra, India THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED. This invention relates to an improved process of preparation of an aqueous fungicidal formulation with excellent suspension properties and more particularly, fo the preparation of aqueous formulation of Mancozeb having an extremely low Ethyelene Thiourea content. BACK GROUND Mancozeb is a well - known fungicide and its method of preparation is described in US 1000137 . Mancozeb, or zinc salt of Maneb, is a result of various experiments carried out by different people to stabilize Maneb. Several references are cited which describe methods to stabilize Maneb such as US 3856836, US 2974156, US 3173832, which quote the use of formaldehyde, soluble zinc salts and Hexamethylene tetra amine to stabilize the formulation . Mancozeb, technically is a Zinc Manganese salt of Ethylene bisdithiocarbamate (IUPAC Manganese ethylene bis (dithiocarbamate) (polymeric) complex). Compositions containing Mancozeb have been used for a long time in agriculture and horticulture for combating and / controlling injury to plants from fungal diseases. Generally the compositions are diluted in water prior to application and are sprayed on plants / fruit trees. Various formulations types of Mancozeb include wet table powders, aqueous suspension concentrate and water dispersible granules. It is very important that the pesticide formulated have good suspension characteristics. The practices of Indian farming where mixing of agricultural chemical into the tank mix is still at a rudimentary stage, and the use of sophisticated technologies of mixing and spraying are not affordable by the farmer, it becomes doubly important that the pesticide remains in uniform suspension until the period farmer sprays the chemical onto his fields. 2 This invention creates a formulation of Mancozeb with very high suspensibility features, low viscosity and caking issues. Mancozeb has a higher stability when compared with individual salts that is Manganese or Zinc salt of ethylene bisdithiocarbamate. According to that process, Mancozeb can be prepared by reaction of a manganese soluble salt with disodium salt or dipotassium salt of ethylene bisdithiocarbamate, which is further treated with a soluble zinc salt , formaldehyde. Alternatively, mancozeb can be prepared by precipitating ammonium ethylene bisdithiocarbamate (Amobam) with manganese salt and further treating it with soluble zinc salt. Nab am is the preferred salt because it yields maneb of lowest ETU content. Usually, soluble ethylene bisdithiocarbamate is prepared by reacting together carbon disulfide, ethylene diamine and sodium hydroxide. The exact order of mixing of these products is not critical although some orders may be more convenient than others and lead to a higher concentrations of aqueous solutions of ethylene bisdithiocarbamate, these solutions being preferred for shipping and handling and also more stable than diluted solutions . DETAILS OF PRIOR ART In patent no GB 929210 claims made for a composition comprising a manganese salt of bisdithiocarbamic acid mixed with hexamethylene tetramine to reduce the tendency of the manganese salt to decompose. The composition is manganese salt of Bis dithiocarbamic acid and is in dry state. The process and the percentages of the raw materials have been claimed. GB 996264 encompasses a method of preparation of manganese bisdithiocarbamate which is further complexed with either one of the following metal ions: Zinc, Copper, Iron, and carrying out the process of complex formation in various proportions. Formulations 3 forming aqueous fungicidal composition comprising of finely divided metal complexed manganese bis dithiocarbamate (and/ or complexed with polyvalent metal ions as claimed in 1-4 ) according to claim 1 together with a wetting agent, a dispersing agent or stabilizer for the bisdithiocarbamate or mix mixture of two such additives using slurry as raw material. ES 51587 claims about preparing a stabilized aqueous compositions of maneb treated with aqueous formaldehyde and aqueous solution of soluble zinc salt combined or in either order, and if necessary mixing the result with further water to obtain an aqueous compositions comprising maneb and 0.05 to 5% by weight of the total composition of formaldehyde and 0.05 to 5% by weight total composition, calculated as Zinc salt. The stabilized maneb composition has been worked out to be 10 - 50%. The process for preparation of this composition has been claimed where examples demonstrated are descriptive of complete process. US 4185113 Claim for the composition comprising a metal salt of ethylene bisdithiocarbamate and selected from a group consisting of Zinc and Manganese, and 0.1 to 10% by weight based on the metal salt of cinnamic aldehyde to stabilize the formulation, both wettable powder and suspension concentrate have been described. The claims also are for the process of incorporation of cinnamaldehyde into the formulation. EP 0257533 The claims are for the fungicidal formulation of Mancozeb, maneb, or Zineb using Ethylene propylene oxide block co-polymers with ehtoxylated and phosphatized alkanol or arylphenol salts . The details of the surfactants have been claimed. Further, other ingredients used for the formulation that is naphthalene sulfonate, formaldehyde, and mixture of lignosulfonate with monmorillionite is claimed . 4 US 1000137 The patent claims a water insoluble co reacted manganese-metal ethylene bisdithiocarbamate consisting of at 1 least one of the following metal namely: cobalt, copper, iron, lead ,mercury, nickel and zinc and where in the mole ratio of manganese to other met al is from 40: 60 to 90: 10 with specific physical properties . Claim for the process for the active ingredient synthesis has been made claim for dispersions of bisdithiocarbamate in water together with wetting agent, or wetting with a dispersing agent. US 4344890 Claimed is a process of preparation of stabilized aqueous compositions of salt of ethylene bisdithiocarbamate with water soluble manganese salt to obtain maneb and further mixing with maneb with formaldehyde and zinc and the improvements in the process to obtain the stabilized formulation is described. US 6004570 Claims a dithiocarbamate composition where in the dithiocarbamate is mancozeb, maneb, Zineb, Propineb, Metiram, thiram, Ferbam, Metham or Dazomet and the composition is in form of a suspension concentrate or dust, Wettable powder or dispersible granules along with polyvinyl alcohol with a molecular range of 10,000 to 50,000 with a hydrolysis level of 50%. FR 2610171 Claims a dithiocarbamate composition which contain manganese and / or zinc in percentages of 20 to 70%, 0.2 to 8 parts of at least one water soluble copolymer dispersing and stabilizer derived from an ethylenically unsaturated carboxylic acid or ethylenically unsaturated sulphonic acid salt, 0.2 - 3 parts of at least a protective agent from 0.5 to 3 parts of antifoamer, 0.03 to 2 parts of thickening agent and 0.2 to 5 parts of at least one surface active agent, the rest is made up of water . 5 DRAW BACKS The formulations prepared above have drawbacks such as caking, high viscosity and low suspensiblity. Mancozeb being a molecule displaying a thixotropy in aqueous conditions under varying degrees of temperature and humidity increases in viscosity parameter makes the formulation difficult to pour from application point of view. Further caking problem is encountered and the formulation cannot be shaken back into a suspension SUMMARY OF INVENTION The present invention describes a process of preparation of mancozeb suspension concentrate formulation having high suspension characteristics. Unlike all the other processes where the product of interest is prepared from maneb slurry, this process employs mancozeb in a powder form. The route for synthesis of Mancozeb, is in accordance to our patented process FN 186435. The trick of formulating the product with the above properties lies in thixotropy and viscosity issues not settling in during the process of formulation . Further, the addition of suspending agent takes place at two stages, one the dry stage, to ensure complete coverage of the particles with the suspending agent to reduce the electro kinetic effect, and two, at the wet end , to give the formulation increased suspension characteristics . A homogenization stage followed by Wet milling of the formulation using wetting, dispersing, anticaking and suspensibility enhancing agents is carried out to get the formulation into its final form. The dithiocarbamates in aqueous formulation have various salts of dithiocarbamic acids in different concentrations ranging form 10 to 65%. Preferably, the dithiocarbamates are one or more components selected from ethylene bisdithiocarbamic acid, its alkali salt or 6 transition metal salt and its complexes. In accordance with a preferred embodiment of this invention, the ethylene bisdithiocarbamate has Manganese and Zinc as metal ions. Typically, the particulate composition has a particle range of 1 to 5 microns. The reduction in particle size is affected by subjecting the homogenized mixture to grinding media. In addition to the active ingredient component the ingredients will normally include a surfactant component and optionally other components such as filler component to provide the desired active ingredient content and / or a suspending agent / wetting agent. The term surfactant is used in the broad sense to include materials which may be referred to as emulsifying agents, dispersing agents and wetting agents and the surfactant component may comprise one or more surfactant selected from the anionic, nonionic type. Examples of surfactants of the anionic type include sodium dodecyl benzene sulphoante, sodium, calcium or ammonium lignosulphoante, sodium formaldehyde condensates polymer salt, (Lomar D), Naphthalene formaldehyde condensate sodium salt (Morwet D 425 [tm]) Suitable non ionic type include for example condensation products of ethylene oxide with alkyl phenols such as octyl phenol, nonyl phenol. Preferably the surfactant component will comprise at least one wetting agent such as those selected from alkyl naphthalene sulfonates, phosphate esters , and / or at least one dispersing agent such as those selected from the group of naphthalene condensates, ligno sulfonates. Typically the total surfactant component will comprise from 2 to 20% and preferably from 3 to 10% by weight of the dry weight of the composition. The dispersions or solutions can also contain adhesives, such as for example starch syrup, dextrose, sucrose, dextrin, poly vinyl acetate, Xanthan gum. 7 In addition the Suspension concentrates can contain antifreeze agents such as glycerin, glycols, silica. It also contains antifoaming agents such as silicone antifoaming agent. DETAILS OF LAB PROCESS The unit operations involved in the manufacture of Mancozeb suspension concentrate is as follows a. High shear mixing of the additives along with mancozeb powder b. Wet-milling of the pre-mixed to get the intermediate slurry. c. Blending of the slurry obtained to get the final formulation Premilling stage The raw material used for the pre-milling stage is as follows SR.NO ADJUVANTS FUNCTION PERCENTAGE 1 Adjuvant 1 Wetting agent As described below 2 Adjuvant 2 Suspending/ dispersing agent As described below 3 Mancozeb Active ingredient Metal salt of dithiocarbamic acid polymeric 4 Additive Stabilizer Amine / aldehyde 5 Additive Anticaking agent Silica, natural polymers, glycerol's 6 Water to Q.S Wetting agents chosen from the group comprising condensates of alkyl naphthalene sulfonate, condensate of aryl sulfonic acid, sodium or potassium polycarboxylates, 8 ethoxylated tristyryl phenols phosphates and their salts, ethoxylated tristyryl phenols sulfates and their salts, or ammonium salt of polyoxyethylene, or a combination of these. Dispersing agents chosen from group comprising condensates of phenol sulphonic acid and their salts, condensates of alkyl aryl sulphonic acid and their salts, condensates of alkyl sulfonic acids and their salts, sodium salt of dodecyl sulfosuccinic acid half ester, salts of sulfonated and carboxylated kraft lignin or a sodium salt of dioctyl sulfosuccinate or a combination of these . The additives along with the active and water are subjected to a high shear mixing in a reactor designed with required temperature controls . The specially designed high shear mixer ensures that the mixing is homogeneous. The additives are added in a predetermined order over a definite period and sheared for the required time. MILLING STAGE The premix obtained form high shear mixing is subjected to a milling operation using a horizontal mill equipped with grinding media and a shaft with specified number of blades. The chamber temperature, back pressure, seal flushing water pressure, air pressure to operate diaphragm pump, compressed air output pressure are all critical parameters instrumental in obtaining the right quality of the product Total solids during the grinding stage is in the range of 55 to 60%. BLENDING STAGE Ingredients such as antifoaming agents, thickener are added at final stage to adjust the viscosity of the formulation. The blending operation consists of blending the slurry with suspending and anticaking agents to have a final product with very high suspension characteristics of greater than 85%, preferably greater than 95% and viscosity in the range of 200 to 1000 cps. An inert atmosphere is required for the operation. 9 Modifications can be made in the process which involves direct blending of powder with various additives to get aqueous based suspension concentrate Example no 1 Raw materials Percentage on w/w basis 1 Mancozeb powder 35.5 % 2 Dispersol-F 2.00% 3 Silica 2.00% 4 Sodium lingo sulphonate 5.00% 5 Hexamethylene tetramine 0.50% 6 Ethylene glycol 5.00% 7 Formaldehyde (37%) 1.00% 8 Antifoaming agent Napco NXZ 0.025% 9 Xanthan gum 0.02% 10 Water 48.95% (q.sO Total 100% w/w Premilling stage The following raw materials are charged as follows into caddy mill Distilled water, sodium lingo sulphoante, dispersol-F, Hexamethylene tetramine, silica, Mancozeb powder , ethylene glycol, formaldehyde and half quantity of antifoaming agent The aqueous slurry is grinded in horizontal mill at the rate of 5.5 L / min using zirconium beads having particle size of 1.1 mm. Temperature maintained during grinding 15 to 25 degree. After grinding the required quantity of gum solution (thickener and antifoaming agent is added and to arrive at the desired viscosity) Nitrogen is purged to the slurry before the material is packed. 10 Analysis of the final product Parameters Analysis (Zero day) Analysis after aging (54 degree for 14 days) 1 Active content (% w/w) 35.98% 34.2 2 Suspensibility (%w/w) 98.59% 97.90 3 Viscosity 300 cps 350 cps 4 ph 7.07 7.22 5 Manganese content 20.12% NA 6 Zinc content 2.78% NA 7 pourability Good Good 8 Sediment Nil Loose sediment which mixes on shaking Example no 2 Raw materials Percentage on w/w basis 1 Mancozeb powder 35.5% 2 Dispersol-F 2.00% 3 Silica 1.50% 4 Sodium ligno sulphonate 3.00% 5 Hexamethylene tetramine 0.50% 6 Ethylene glycol 5.00% 7 Formaldehyde (37%) 1.00% 8 Antifoaming agent Napco NXZ 0.025% 9 Xanthan gum 0.02% 10 Water 51.45%(Q.S) Total 100% w/w 11 Premilling stage The following raw materials are charged as follows into caddy mill Distilled water, sodium lingo sulphonate, naphthalene sulfonate formaldehyde condensate blend [dispersol-F [tm], Hexamethylene tetramine, silica, Mancozeb powder, ethylene glycol, formaldehyde and half quantity of antifoaming agent The average Particle size was 2.13 micron. Ph of 1% aqueous solution was = 7.21 The aqueous slurry is grinded in horizontal mill at the rate of 5.5 L / min using zirconium beads having particle size of 1.1 mm The particle size after grinding became 1.93 micron After grinding the required quantity of gum solution (thickener and antifoaming agent is added and to arrive at the desired viscosity) Nitrogen is purged to the slurry before the material is packed. Analysis of the final product Parameters Analysis (Zero day) Analysis after aging (54 degree for 14 days) 1 Active content (% w/w) 34.92% 33.83 2 Suspensibility (%w/w) 97.52% 97.48 3 Viscosity 210 cps 240 cps 4 ph 7.01 7.23 5 Manganese content 20.12% NA 6 Zinc content 2.78% NA 7 Pourability Good Good 8 Sediment Nil Loose sediment which mixes on shaking 12 No drop in suspensibility is observed after accelerated storage study (aging when stored at 54 degree c for 14 days) Example no 3 Raw materials Percentage on w/w basis 1 Mancozeb powder 35.5% 2 DD8 (Kraft lignin) 3.00% 3 Silica 2.00% 4 Hexamethylene tetramine 0.50% 5 Ethylene glycol 5.00% 6 Formaldehyde (37%) 1.00% 7 Antifoaming agent Napco NXZ 0.025% 8 Xanthan gum 0.02% 9 Water 52.95 % (Q.S) Total 100% w/w Premilling stage The following raw materials are charged as follows into caddy mill Distilled water, DD8, Hexamethylene tetramine, silica, Mancozeb powder , ethylene glycol, formaldehyde and half quantity of antifoaming agent The aqueous slurry is grinded in horizontal mill at the rate of 5.5 L / min using zirconium beads having particle size of 1.1 mm After grinding the required quantity of gum solution (thickener and antifoaming agent is added and to arrive at the desired viscosity) Nitrogen is purged to the slurry before the material is packed. 13 Analysis of the final product Parameters Analysis (Zero day) Analysis after aging (54 degree for 14 days) 1 Active content (% w/w) 34.23% 33.41% 2 Suspensibility (%w/w) 97.08% 96.86 3 Viscosity 250 cps 210 cps 4 ph 7.01 7.23 5 Manganese content NA NA 6 Zinc content NA NA 7 Pour ability Good Good 8 Sediment Nil No sediments No drop in suspensibility is observed after stability study. Use of DD8 surfactant improves the flow properties of the formulation, No sedimentation is observed after aging. The aqueous formulation has better bioefficacy than the existing commercial manufactured mancozeb powder. Determination of Suspensibility Suspensibility of the samples was determined with CIPAC standard water D as per the procedure of CIPAC method MT 161. Out line of Method A suspension of known concentration of the test item was prepared in CIPAC Standard Water D, placed in a measuring cylinder at a constant temperature and allowed to remain undisturbed for the specified time. The top 9/10ths were drawn off and the content of solids in the sediments in the bottom 1710th was determined. Determination of Active content is as per CIPAC 34/TC/M/3 (volume H) 14 Determination of Manganese and Zinc is as per CIPAC 34/TC/M/4 (volume H) In the all the examples mentioned above, suspensibility greater than 95% is obtained due to better particle size reduction . Comparison of suspension concentrate (aqueous based formulation with commercially Manufactured Mancozeb powder Mancozeb powder Mancozeb aqueous Mancozeb Mancozeb aqueous Commercially based formulation aqueous based based formulation manufactured (batch no 853) Example no 1 formulation Example no 2 Example no 3 1 Particle size distribution D10 D10 D10 D10 1.06 micron 0.75 micron 0.73 micron 0.74 micron D50 D50 D50 D50 2.92 micron 1.88 micron 1.93 micron 1.91 micron D90 D90 D90 D90 9.61 micron 3.60 micron 3.60micron 3.60 micron Suspensibility Suspensibility Suspensibility Suspensibility 2 74% 98.59% 97.52% 97.08% Data shows that due to the lower particle size, improvement in suspensibility is obtained. 15 Example no 4 Raw materials Percentage on w/w basis 1 Mancozeb powder 35.5% 2 Galoryl 505 1.0% 3 Sodium ligno sulphonate 2.00% 4 Sodium meta bisulphite 0.50% 5 Ethylene glycol 5.00% 6 MZ36 0.10% 7 Xanthan gum 0.20% 8 Water 55.47 % (Q.S) Total 100% w/w To the mancozeb powder taken in beaker all the ingredients are mixed and blended for two hours. Analysis of the final product Parameters Analysis Analysis Analysis after (Zero day) after aging (54 degree ± 2°C for 14 days) aging (54 degree °2C for 90 days) 1 Active content (% w/w) 36.2% 35.1% NA 2 Suspensibility (%w/w) 86.21% 86.96 NA 3 Viscosity 840 cps 1050 cps 1190 4 Ph 7.01 7.23 7.24 5 Manganese content NA NA NA 6 Zinc content NA NA NA 7 Pour ability Good Good Good 8 Sediment Nil No sediments No sediments. The material is easily shakeable 16 Example no 5 to 9 Raw materials Percentage on w/w basis Example no 5 Example no 6 No 7 No 8 9 Mancozeb powder 35.5% 35.5% 35.5% 35.5% 35.5% Galoryl 505 0.5% — — — Dispersol F ~ — — — 2.00% Lomar D 1.00% — — Sodium ligno sulphonate 1.00% 1.00% 1.00% 2.5% Sorophor FL — 0.5% 0.5% — Sorophor BSU — 0.2% 0.2% — Octylphenol ethyxolate 10 mole 0.5% Hexamethylene tetramine 1.00% 1.00% 1.00% 1.00% Sodium meta bisulphite 1.00% Ethylene glycol 5.00% 5.00% 5.00% 5.00% 5.00% MZ36 0.10% 0.10% 0.10% 0.10% 0.10% Xanthan gum 0.20% 0.22% 0.20% 0.15% 0.20% Water 57.20 % (Q.S) 56.18% (Q.S) 56.5% (Q.S) 56.55% (q.s) Total 100% w/w 100% w/w 100% w/w 100% w/w 100% 17 Example no 5 to 9 Procedure as per Example no 4 Analysis after aging at 54 degree for 14 days Viscosity Example no 5 Example no 6 No 7 No 8 9 Viscosity Zero day 900 cps 730 cps 490 cps 780 cps 800 cps After aging 1920 cps > 2000 cps > 2000 cps > 2000 cps > 2000 cps Pour ability Hard mass Hard mass, Hard mass, Hard mass, Hard mass, Vigorous Not not not not shaking required shakeable shakeable shakeable shakeable BIOEFFICACY TESTS OF MANCOZEB FLOWABLE 1) Study was carried out by Tamilnadu Agricultural University, Coimbatore to test the Bio-efficacy of Mancozeb Flowable against downy mildew of grapes (paneer variety) for one season Rabi 2002. Chemicals used and their doses were Mancozeb Flowable 0.4% (3.0 ml/lit), Mancozeb Flowable 0.5% ( 3.8 ml/lit) and Mancozeb Flowable 0.6% (4.6 ml/lit) and one standard fungicide Mancozeb 0.25% (2.5 g/lit). Plot sizes used for the study was five vines spaced at 3 X 3 m per treatment per replication and for three replications. Control plot was left untreated. The first spray was given immediately after disease appearance, which was one month after pruning. Three subsequent rounds of sprays were given at 10 days intervals. The observation on downy mildew incidence on leaf and berries was recorded using 0-9 scale and the percent disease index (PDI) was calculated. 18 IT was found that all the treatments significantly reduced the disease on leaves when compared to untreated control. Among the treatments, Mancozeb Flowable ( 0.6% ) recorded minimum disease on leaves , PDI being 13.37 followed by Mancozeb 0.5%, PDI being 18.15 and Mancozeb 0.4% - PDI 20.48. Standard fungicidal Mancozeb 0.25% recorded PDI of 22.45%. Similar trend was also noticed in case of fruit infection. Treatment with Mancozeb Flowable 0.6 % also resulted in maximum yield of fruits ( 17220.5 kg/ha) as compared to other treatments and untreated control. 2)Bio-efficacy testing of Mancozeb Flowable was carried out by Tamilnadu Agricultural University, Coimbatore against Late Blight ( Phytophthora infestans ) of Potato for one season - Main, 1999. Chemicals used were Mancozeb Flowable 0.4%, Mancozeb Flowable 0.5% and Mancozeb Flowable 0.6% and one standard fungicide Mancozeb wettable powder 0.25%. Potatoes of Kufri Jyoti variety were planted in a plot size of 10 sq.m. with 20 X 45 cm spacing. Six rounds of sprayings were done on appearance of the disease. The Late blight disease incidence was found to be on par in the treatments with Mancozeb Flowable at 0.4, 0.5, 0.6 per cent and Mancozeb wettable 0.25% and the mean disease grades on a 0-9 scale were 1.9, 1.9, 2.0 and 2.1 respectively. The highest mean disease grade of 3.0 was recorded b untreated control. All the treatments were on par with regard to yield except untreated control whereby the yield was approximately 60 % lesser than the treated crop. 3) Field experiments were conducted during kharif season of 2001-02 to study effect of fungicides on Banana Sigatoka caused by fungus Mycosphaerella musicola. The fungicides tested were Mancozeb Flowable (0.4, 0.5 & 0.6 %), Mancozeb wettable powder, emulsified formulation of propiconazole 25% and Hexaconazole 5%. The experiments were conducted during the rainy days in a randomized block design with 8 treatments and 3 replications using highly susceptible varieties of banana in Karnataka, Tamilnadu and Andhra Pradesh. Three- four sprays were given at 20-30 days intervals when initial typical disease symptoms were observed using high volume sprayer. Observations on the leaves were taken using 0-5 scale. 19 This investigation revealed that Mancozeb Flowable has shown more effective control of Banana Sigatoka than Mancozeb wettable powder among contact fungicides. Because of its very high suspensibility, smaller and uniform particle size, faster resuspensibility and high efficacy, Mancozeb can be used by farmers to get economical disease control. 4) Another study was carried out by National research centre for Banana, Trichy for two season viz. 2000-2001 and 2002-2003 to find out the efficacy and most effective concentration of Mancozeb Flowable against Sigatoka leaf spot disease of Banana. The chemicals used were Mancozeb Flowable 0.5%, Mancozeb Flowable 0.6%, Indofil M-45 (0.25%) and carbendazim (0.1%). The experiments were conducted in a randomized block design with 5 treatments and 4 replications each on a plot of approximately one acre. First spray was given as low volume spray using Power sprayer (200 liters per acre) and three subsequent sprays were of high volume using rocker sprayer (450 liters / acre) at 15- 28 days interval. The disease severity was recorded at the end of the treatment as per the Int. Musa Testing Prog. G.uidelines. Yield parameters and YLS ( youngest leaf spotted) were recorded and cost benefit ratios were analysed. Mancozeb Flowable sprayed plots recorded lowest disease severity, highest finger number and highest bunch weight. Additional yield per bunch was 5.3 kg and additional yield per acre was calculated to be 6360 kg providing a cost benefit of 36 as compared to unsprayed control. Results were found to be better for 0.6% than 0.5% concentration. None of the doses of Mancozeb Flowable tested showed any type of phytotoxicity symptom. The experiment was continued for the second season and the results of the first season were confirmed. 20 5) A study carried out by University of Agricultural Sciences, Dharwad tested the efficacy of Mancozeb Flowable against Sigatoka spot disease of Banana cv. Rajapuri. The chemicals used were : Mancozeb Flowable - 0.38 % Mancozeb Flowable - 0.46 % Mancozeb WP -0.25% Carbendazim 0.10% Companion 0.20 % Mineral oil 5. 0 % The experiments were conducted in a randomized block design with 6 treatments and 3 replications each on a plot of approximately one acre. First spray was given as low volume spray using Power sprayer (200 liters per acre) and three subsequent sprays were of high volume using rocker sprayer (450 liters / acre) at 25- 35 days interval. The mean data revealed that the lowest leaf spot index was recorded in the plants treated with Mancozeb 0.46%, highest being in the untreated control. Maximum yield was also found in the plants sprayed with Mancozeb 0.46%. 6) Similar study carried out by Bidhan Chandra Krishia Vishwavidyalaya, tested the bio- efficacy of Mancozeb Flowable against late and early blight of potato, late and early blight of tomato and downy mildew of cucurbit. Results clearly indicated that disease incidence and severity were reduced and yield of increased by spraying Mancozeb Flowable than in the control plot. The lowest disease incidence, disease severity and maximum yield were obtained by treatment with MZB Flowable 0.6% followed by MZB Flowable 0.5%, MZB Flowable 0.4%, MZB 75 WP 0.25%, MZB Flowable 0.3 and MAtcoO.25%.% 21 We Claim: 1. A process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility by employing Mancozeb in a powder form comprising the steps of; a) Mixing of water and additives in a high shear mixer along with Mancozeb powder to get homogenous premix; b) Wet milling of the premix to get the intermediate slurry; c) Blending of the slurry with suspending and antitacking agents to get the formulation. 2. The process as claimed in claim 1, wherein high shear mixing is carried out by mixing additives, water and Mancozeb powder in a reactor designed with required temperature control. 3. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in Claim 2, wherein, the additives are added in a predetermined order over a definite period and sheared for a required time. 4. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in Claim 1, wherein, the milling is carried out in a horizontal mill comprising a chamber, equipped with grinding media and a shaft with specified number of blades. 5. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in Claim 4 wherein, the chamber temperature, back pressure, air pressure, seal flushing water pressure, air pressure to operate diaphragm pump, compressed air output pressure are controlled in such a way that total solids during the grinding of milling stage is in the rate of 55-66%. 22 6. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, temperature maintained during grinding is 15-25 °C. 7. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, antifoaming agent and thickner are added at the blending stage to adjust the viscosity of the formulation. 8. The process for the preparation of Mancozeb suspension concentrate having low particle size low viscosity and high suspensibility as claimed in claim 1 and 7 wherein, suspending and antitacking agent added to get suspensibility greater than at least 85% and preferably greater than 95%. 9. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in Claim 8 wherein, suspending and anti tacking agent added to get viscosity in the range of 200-1000 cps. 10. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, the reaction condition is inert to carry out the process step. 1.1. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, the additives used are stabilizers and anti tacking agent. 12. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in Claim 11 wherein, the antitacking agent is selected from silica, natural polymers and glycerol. 23 13. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 11 wherein, the stabilizers selected from different amines and aldehydes, 14. Process claim 1 wherein, formulation comprises surfactant and optionally filters. 15. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 14 wherein, surfactant comprises emulsifying agent, dispersing agent and wetting agent. 16. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 15 wherein, the surfactant are selected from anionic surfactants and non ionic surfactants. 17. The process for the preparation of Mancozeb suspension concentrate having low particle size low viscosity and high suspensibility as claimed in claim 16 wherein, the anionic surfactant selected from a group of anionic surfactants such as sodium dodecyl benzene sulphoante, sodium, calcium or ammonium lignosulphoante ,sodium formaldehyde condensates polymer salt, (Lomar D),naphthalene formaldehyde condensate and sodium salt ( Morwet D 425) 18. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 16 wherein, the non ionic surfactant selected from a group of non ionic surfactants such as condensation products of ethylene oxide with alkyl phenols such as octyl phenol and nonyl phenol. 19. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 and 6 wherein, surfactant comprises at least one wetting agent selected from a group of wetting agents such as alkyl naphthalene sulfonates, phosphate esters , and / or at least one dispersing 24 agent such as those selected from the group of naphthalene condensates and ligno sulfonates. 20. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 and 6 where total content of surfactant ranges from 2-20% preferably 3-10%) by weight of the dry weight of the formulation. 21. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, suspension further comprises antifreeze agent selected from a group of antifreeze agents such as glycerin, glycols and silica. 22. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, suspension further comprises antifoaming agents and preferably non silicone oil. 23. The process for the preparation of Mancozeb suspension concentrate having low particle size low viscosity and high suspensibility as claimed in claim 1 wherein, suspension further comprises adhesive selected from a group of adhesives such as starch syrup, dextrose, sucrose, dextrin, polyvinyl acetate, and xanthan gum. 24. The process for the preparation of Mancozeb suspension concentrate having low particle size low viscosity and high suspensibility as claimed in claim 1 wherein, the wet milling step is carried out by using the wetting agent selected from a group of wetting agents comprising condensates of alkyl naphthalene sulfonate, condensate of aryl sulfonic acid, sodium or potassium polycarboxylates, ethoxylated tristyryl phenols phosphates and their salts, ethoxylated tristyryl phenols sulfates and their salts, or ammonium salt of polyoxyethylene, or a combination of these. 25 25. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, the suspending agent are dispersing agent selected from the group of condensates of phenol sulphonic acid and their salts, condensates of alkyl aryl sulphonic acid and their salts, condensates of alkyl sulfonic acids and their salts, sodium salt of dodecyl sulfosuccinic acid half ester, salts of sulfonated and carboxylated kraft lignin or a sodium salt of dioctyl sulfosuccinate or a combination of these . 26. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, the particle size obtained ranges from 0.73 to 4.42 micron. 27. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, pH required to carry out the process is 7.07 -7.23 28. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, the percentage of active content of Mancozeb in the suspension is from 33-36.5% 29. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed, in claim 1 wherein, the percentage of active content of manganese in the suspension before aging is from 20-21%. 30. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein the percentage of active content of Zinc in the suspension is from 2.5 - 3%. 31. Mancozeb suspension concentrate composition comprising synergistically effective amount of active ingredient ranging from 33-36.5 % of active content of Mancozeb 26 along with fungicidally acceptable additives, wetting agent, suspending or dispersing agent in aqueous media. 32. Process of preparation of Mancozeb suspension concentrate substantially as herein described with reference to the examples. 33. Manxozeb suspension concentrate substantially as herein described with reference to the examples. 27 ABSTRACT A process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility by employing Mancozeb in a powder form comprising the steps of; a) Mixing of water and additives in a high shear mixer along with Mancozeb powder to get homogenous premix; b) Wet milling of the premix to get the intermediate slurry; c) Blending of the slurry with suspending and antitacking agents to get the formulation. - 8 JUN 2005

Full Text

FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE
Specification
(See section 10 and rule 13)
AQUEOUS FUNGICIDAL FORMULATION
INDOFIL CHEMICALS CO.
(a division of MODIPON LTD.)
an Indian Company
of Nirlon House, Dr. Annie Besant Road, Mumbai 400 025,
Maharashtra, India

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

This invention relates to an improved process of preparation of an aqueous fungicidal
formulation with excellent suspension properties and more particularly, fo the preparation of aqueous formulation of Mancozeb having an extremely low Ethyelene Thiourea content.
BACK GROUND
Mancozeb is a well - known fungicide and its method of preparation is described in US 1000137 . Mancozeb, or zinc salt of Maneb, is a result of various experiments carried out by different people to stabilize Maneb. Several references are cited which describe methods to stabilize Maneb such as US 3856836, US 2974156, US 3173832, which quote the use of formaldehyde, soluble zinc salts and Hexamethylene tetra amine to stabilize the formulation .
Mancozeb, technically is a Zinc Manganese salt of Ethylene bisdithiocarbamate (IUPAC Manganese ethylene bis (dithiocarbamate) (polymeric) complex). Compositions containing Mancozeb have been used for a long time in agriculture and horticulture for combating and / controlling injury to plants from fungal diseases. Generally the compositions are diluted in water prior to application and are sprayed on plants / fruit trees.
Various formulations types of Mancozeb include wet table powders, aqueous suspension concentrate and water dispersible granules.
It is very important that the pesticide formulated have good suspension characteristics. The practices of Indian farming where mixing of agricultural chemical into the tank mix is still at a rudimentary stage, and the use of sophisticated technologies of mixing and spraying are not affordable by the farmer, it becomes doubly important that the pesticide remains in uniform suspension until the period farmer sprays the chemical onto his fields.
2

This invention creates a formulation of Mancozeb with very high suspensibility features, low viscosity and caking issues.
Mancozeb has a higher stability when compared with individual salts that is Manganese or Zinc salt of ethylene bisdithiocarbamate.
According to that process, Mancozeb can be prepared by reaction of a manganese soluble salt with disodium salt or dipotassium salt of ethylene bisdithiocarbamate, which is further treated with a soluble zinc salt , formaldehyde. Alternatively, mancozeb can be prepared by precipitating ammonium ethylene bisdithiocarbamate (Amobam) with manganese salt and further treating it with soluble zinc salt. Nab am is the preferred salt because it yields maneb of lowest ETU content.
Usually, soluble ethylene bisdithiocarbamate is prepared by reacting together carbon disulfide, ethylene diamine and sodium hydroxide. The exact order of mixing of these products is not critical although some orders may be more convenient than others and lead to a higher concentrations of aqueous solutions of ethylene bisdithiocarbamate, these solutions being preferred for shipping and handling and also more stable than diluted solutions .
DETAILS OF PRIOR ART
In patent no GB 929210 claims made for a composition comprising a manganese salt of bisdithiocarbamic acid mixed with hexamethylene tetramine to reduce the tendency of the manganese salt to decompose. The composition is manganese salt of Bis dithiocarbamic acid and is in dry state. The process and the percentages of the raw materials have been claimed.
GB 996264 encompasses a method of preparation of manganese bisdithiocarbamate which is further complexed with either one of the following metal ions: Zinc, Copper, Iron, and carrying out the process of complex formation in various proportions. Formulations
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forming aqueous fungicidal composition comprising of finely divided metal complexed manganese bis dithiocarbamate (and/ or complexed with polyvalent metal ions as claimed in 1-4 ) according to claim 1 together with a wetting agent, a dispersing agent or stabilizer for the bisdithiocarbamate or mix mixture of two such additives using slurry as raw material.
ES 51587 claims about preparing a stabilized aqueous compositions of maneb treated with aqueous formaldehyde and aqueous solution of soluble zinc salt combined or in either order, and if necessary mixing the result with further water to obtain an aqueous compositions comprising maneb and 0.05 to 5% by weight of the total composition of formaldehyde and 0.05 to 5% by weight total composition, calculated as Zinc salt. The stabilized maneb composition has been worked out to be 10 - 50%. The process for preparation of this composition has been claimed where examples demonstrated are descriptive of complete process.
US 4185113
Claim for the composition comprising a metal salt of ethylene bisdithiocarbamate and selected from a group consisting of Zinc and Manganese, and 0.1 to 10% by weight based on the metal salt of cinnamic aldehyde to stabilize the formulation, both wettable powder and suspension concentrate have been described. The claims also are for the process of incorporation of cinnamaldehyde into the formulation.
EP 0257533
The claims are for the fungicidal formulation of Mancozeb, maneb, or Zineb using Ethylene propylene oxide block co-polymers with ehtoxylated and phosphatized alkanol or arylphenol salts . The details of the surfactants have been claimed. Further, other ingredients used for the formulation that is naphthalene sulfonate, formaldehyde, and mixture of lignosulfonate with monmorillionite is claimed .
4

US 1000137
The patent claims a water insoluble co reacted manganese-metal ethylene bisdithiocarbamate consisting of at 1 least one of the following metal namely: cobalt, copper, iron, lead ,mercury, nickel and zinc and where in the mole ratio of manganese to other met al is from 40: 60 to 90: 10 with specific physical properties . Claim for the process for the active ingredient synthesis has been made claim for dispersions of bisdithiocarbamate in water together with wetting agent, or wetting with a dispersing agent.
US 4344890
Claimed is a process of preparation of stabilized aqueous compositions of salt of ethylene bisdithiocarbamate with water soluble manganese salt to obtain maneb and further mixing with maneb with formaldehyde and zinc and the improvements in the process to obtain the stabilized formulation is described.
US 6004570
Claims a dithiocarbamate composition where in the dithiocarbamate is mancozeb, maneb, Zineb, Propineb, Metiram, thiram, Ferbam, Metham or Dazomet and the composition is in form of a suspension concentrate or dust, Wettable powder or dispersible granules along with polyvinyl alcohol with a molecular range of 10,000 to 50,000 with a hydrolysis level of 50%.
FR 2610171
Claims a dithiocarbamate composition which contain manganese and / or zinc in percentages of 20 to 70%, 0.2 to 8 parts of at least one water soluble copolymer dispersing and stabilizer derived from an ethylenically unsaturated carboxylic acid or ethylenically unsaturated sulphonic acid salt, 0.2 - 3 parts of at least a protective agent from 0.5 to 3 parts of antifoamer, 0.03 to 2 parts of thickening agent and 0.2 to 5 parts of at least one surface active agent, the rest is made up of water .
5

DRAW BACKS
The formulations prepared above have drawbacks such as caking, high viscosity and low suspensiblity.
Mancozeb being a molecule displaying a thixotropy in aqueous conditions under varying degrees of temperature and humidity increases in viscosity parameter makes the formulation difficult to pour from application point of view. Further caking problem is encountered and the formulation cannot be shaken back into a suspension
SUMMARY OF INVENTION
The present invention describes a process of preparation of mancozeb suspension concentrate formulation having high suspension characteristics. Unlike all the other processes where the product of interest is prepared from maneb slurry, this process employs mancozeb in a powder form. The route for synthesis of Mancozeb, is in accordance to our patented process FN 186435. The trick of formulating the product with the above properties lies in thixotropy and viscosity issues not settling in during the process of formulation .
Further, the addition of suspending agent takes place at two stages, one the dry stage, to ensure complete coverage of the particles with the suspending agent to reduce the electro kinetic effect, and two, at the wet end , to give the formulation increased suspension characteristics .
A homogenization stage followed by Wet milling of the formulation using wetting, dispersing, anticaking and suspensibility enhancing agents is carried out to get the formulation into its final form.
The dithiocarbamates in aqueous formulation have various salts of dithiocarbamic acids in different concentrations ranging form 10 to 65%. Preferably, the dithiocarbamates are one or more components selected from ethylene bisdithiocarbamic acid, its alkali salt or
6

transition metal salt and its complexes. In accordance with a preferred embodiment of this invention, the ethylene bisdithiocarbamate has Manganese and Zinc as metal ions. Typically, the particulate composition has a particle range of 1 to 5 microns. The reduction in particle size is affected by subjecting the homogenized mixture to grinding media.
In addition to the active ingredient component the ingredients will normally include a surfactant component and optionally other components such as filler component to provide the desired active ingredient content and / or a suspending agent / wetting agent.
The term surfactant is used in the broad sense to include materials which may be referred to as emulsifying agents, dispersing agents and wetting agents and the surfactant component may comprise one or more surfactant selected from the anionic, nonionic type.
Examples of surfactants of the anionic type include sodium dodecyl benzene sulphoante, sodium, calcium or ammonium lignosulphoante, sodium formaldehyde condensates polymer salt, (Lomar D), Naphthalene formaldehyde condensate sodium salt (Morwet D 425 [tm])
Suitable non ionic type include for example condensation products of ethylene oxide with alkyl phenols such as octyl phenol, nonyl phenol.
Preferably the surfactant component will comprise at least one wetting agent such as those selected from alkyl naphthalene sulfonates, phosphate esters , and / or at least one dispersing agent such as those selected from the group of naphthalene condensates, ligno sulfonates.
Typically the total surfactant component will comprise from 2 to 20% and preferably from 3 to 10% by weight of the dry weight of the composition.
The dispersions or solutions can also contain adhesives, such as for example starch syrup, dextrose, sucrose, dextrin, poly vinyl acetate, Xanthan gum.
7

In addition the Suspension concentrates can contain antifreeze agents such as glycerin, glycols, silica. It also contains antifoaming agents such as silicone antifoaming agent.
DETAILS OF LAB PROCESS
The unit operations involved in the manufacture of Mancozeb suspension concentrate is as follows
a. High shear mixing of the additives along with mancozeb powder
b. Wet-milling of the pre-mixed to get the intermediate slurry.
c. Blending of the slurry obtained to get the final formulation
Premilling stage
The raw material used for the pre-milling stage is as follows

SR.NO ADJUVANTS FUNCTION PERCENTAGE
1 Adjuvant 1 Wetting agent As described below
2 Adjuvant 2 Suspending/ dispersing agent As described below
3 Mancozeb Active ingredient Metal salt of dithiocarbamic acid polymeric
4 Additive Stabilizer Amine / aldehyde
5 Additive Anticaking agent Silica, natural polymers, glycerol's
6 Water to Q.S
Wetting agents chosen from the group comprising condensates of alkyl naphthalene sulfonate, condensate of aryl sulfonic acid, sodium or potassium polycarboxylates,
8

ethoxylated tristyryl phenols phosphates and their salts, ethoxylated tristyryl phenols sulfates and their salts, or ammonium salt of polyoxyethylene, or a combination of these.
Dispersing agents chosen from group comprising condensates of phenol sulphonic acid and their salts, condensates of alkyl aryl sulphonic acid and their salts, condensates of alkyl sulfonic acids and their salts, sodium salt of dodecyl sulfosuccinic acid half ester, salts of sulfonated and carboxylated kraft lignin or a sodium salt of dioctyl sulfosuccinate or a combination of these .
The additives along with the active and water are subjected to a high shear mixing in a reactor designed with required temperature controls .
The specially designed high shear mixer ensures that the mixing is homogeneous. The additives are added in a predetermined order over a definite period and sheared for the required time.
MILLING STAGE
The premix obtained form high shear mixing is subjected to a milling operation using a horizontal mill equipped with grinding media and a shaft with specified number of blades. The chamber temperature, back pressure, seal flushing water pressure, air pressure to operate diaphragm pump, compressed air output pressure are all critical parameters instrumental in obtaining the right quality of the product Total solids during the grinding stage is in the range of 55 to 60%.
BLENDING STAGE
Ingredients such as antifoaming agents, thickener are added at final stage to adjust the viscosity of the formulation. The blending operation consists of blending the slurry with suspending and anticaking agents to have a final product with very high suspension characteristics of greater than 85%, preferably greater than 95% and viscosity in the range of 200 to 1000 cps. An inert atmosphere is required for the operation.
9

Modifications can be made in the process which involves direct blending of powder with various additives to get aqueous based suspension concentrate
Example no 1

Raw materials Percentage on w/w basis
1 Mancozeb powder 35.5 %
2 Dispersol-F 2.00%
3 Silica 2.00%
4 Sodium lingo sulphonate 5.00%
5 Hexamethylene tetramine 0.50%
6 Ethylene glycol 5.00%
7 Formaldehyde (37%) 1.00%
8 Antifoaming agent Napco NXZ 0.025%
9 Xanthan gum 0.02%
10 Water 48.95% (q.sO
Total 100% w/w
Premilling stage
The following raw materials are charged as follows into caddy mill
Distilled water, sodium lingo sulphoante, dispersol-F, Hexamethylene tetramine, silica,
Mancozeb powder , ethylene glycol, formaldehyde and half quantity of antifoaming agent
The aqueous slurry is grinded in horizontal mill at the rate of 5.5 L / min using zirconium beads having particle size of 1.1 mm. Temperature maintained during grinding 15 to 25 degree.
After grinding the required quantity of gum solution (thickener and antifoaming agent is
added and to arrive at the desired viscosity)
Nitrogen is purged to the slurry before the material is packed.
10

Analysis of the final product

Parameters Analysis (Zero day) Analysis after aging (54 degree for 14 days)
1 Active content (% w/w) 35.98% 34.2
2 Suspensibility (%w/w) 98.59% 97.90
3 Viscosity 300 cps 350 cps
4 ph 7.07 7.22
5 Manganese content 20.12% NA
6 Zinc content 2.78% NA
7 pourability Good Good
8 Sediment Nil Loose sediment which mixes on shaking

Example no 2

Raw materials Percentage on w/w basis
1 Mancozeb powder 35.5%
2 Dispersol-F 2.00%
3 Silica 1.50%
4 Sodium ligno sulphonate 3.00%
5 Hexamethylene tetramine 0.50%
6 Ethylene glycol 5.00%
7 Formaldehyde (37%) 1.00%
8 Antifoaming agent Napco NXZ 0.025%
9 Xanthan gum 0.02%
10 Water 51.45%(Q.S)
Total 100% w/w
11

Premilling stage
The following raw materials are charged as follows into caddy mill
Distilled water, sodium lingo sulphonate, naphthalene sulfonate formaldehyde condensate blend [dispersol-F [tm], Hexamethylene tetramine, silica, Mancozeb powder, ethylene glycol, formaldehyde and half quantity of antifoaming agent
The average Particle size was 2.13 micron. Ph of 1% aqueous solution was = 7.21
The aqueous slurry is grinded in horizontal mill at the rate of 5.5 L / min using zirconium beads having particle size of 1.1 mm
The particle size after grinding became 1.93 micron
After grinding the required quantity of gum solution (thickener and antifoaming agent is
added and to arrive at the desired viscosity)
Nitrogen is purged to the slurry before the material is packed.
Analysis of the final product

Parameters Analysis (Zero day) Analysis after aging (54 degree for 14 days)
1 Active content (% w/w) 34.92% 33.83
2 Suspensibility (%w/w) 97.52% 97.48
3 Viscosity 210 cps 240 cps
4 ph 7.01 7.23
5 Manganese content 20.12% NA
6 Zinc content 2.78% NA
7 Pourability Good Good
8 Sediment Nil Loose sediment which mixes on shaking
12

No drop in suspensibility is observed after accelerated storage study (aging when stored at 54 degree c for 14 days)
Example no 3

Raw materials Percentage on w/w basis
1 Mancozeb powder 35.5%
2 DD8 (Kraft lignin) 3.00%
3 Silica 2.00%
4 Hexamethylene tetramine 0.50%
5 Ethylene glycol 5.00%
6 Formaldehyde (37%) 1.00%
7 Antifoaming agent Napco NXZ 0.025%
8 Xanthan gum 0.02%
9 Water 52.95 % (Q.S)
Total 100% w/w
Premilling stage
The following raw materials are charged as follows into caddy mill
Distilled water, DD8, Hexamethylene tetramine, silica, Mancozeb powder , ethylene glycol,
formaldehyde and half quantity of antifoaming agent
The aqueous slurry is grinded in horizontal mill at the rate of 5.5 L / min using zirconium beads having particle size of 1.1 mm
After grinding the required quantity of gum solution (thickener and antifoaming agent is
added and to arrive at the desired viscosity)
Nitrogen is purged to the slurry before the material is packed.
13

Analysis of the final product

Parameters Analysis (Zero day) Analysis after aging (54 degree for 14 days)
1 Active content (% w/w) 34.23% 33.41%
2 Suspensibility (%w/w) 97.08% 96.86
3 Viscosity 250 cps 210 cps
4 ph 7.01 7.23
5 Manganese content NA NA
6 Zinc content NA NA
7 Pour ability Good Good
8 Sediment Nil No sediments
No drop in suspensibility is observed after stability study. Use of DD8 surfactant improves the flow properties of the formulation, No sedimentation is observed after aging. The aqueous formulation has better bioefficacy than the existing commercial manufactured mancozeb powder.
Determination of Suspensibility
Suspensibility of the samples was determined with CIPAC standard water D as per the
procedure of CIPAC method MT 161.
Out line of Method
A suspension of known concentration of the test item was prepared in CIPAC Standard
Water D, placed in a measuring cylinder at a constant temperature and allowed to remain
undisturbed for the specified time. The top 9/10ths were drawn off and the content of solids
in the sediments in the bottom 1710th was determined.
Determination of Active content
is as per CIPAC 34/TC/M/3 (volume H)
14

Determination of Manganese and Zinc
is as per CIPAC 34/TC/M/4 (volume H)
In the all the examples mentioned above, suspensibility greater than 95% is obtained due to better particle size reduction .
Comparison of suspension concentrate (aqueous based formulation with commercially Manufactured Mancozeb powder

Mancozeb powder Mancozeb aqueous Mancozeb Mancozeb aqueous
Commercially based formulation aqueous based based formulation
manufactured (batch no 853) Example no 1 formulation Example no 2 Example no 3
1 Particle size distribution
D10 D10 D10 D10
1.06 micron 0.75 micron 0.73 micron 0.74 micron
D50 D50 D50 D50
2.92 micron 1.88 micron 1.93 micron 1.91 micron
D90 D90 D90 D90
9.61 micron 3.60 micron 3.60micron 3.60 micron
Suspensibility Suspensibility Suspensibility Suspensibility
2 74% 98.59% 97.52% 97.08%
Data shows that due to the lower particle size, improvement in suspensibility is obtained.
15

Example no 4

Raw materials Percentage on w/w basis
1 Mancozeb powder 35.5%
2 Galoryl 505 1.0%
3 Sodium ligno sulphonate 2.00%
4 Sodium meta bisulphite 0.50%
5 Ethylene glycol 5.00%
6 MZ36 0.10%
7 Xanthan gum 0.20%
8 Water 55.47 % (Q.S)
Total 100% w/w
To the mancozeb powder taken in beaker all the ingredients are mixed and blended for two
hours.
Analysis of the final product

Parameters Analysis Analysis Analysis after
(Zero day) after aging (54 degree ± 2°C for 14 days) aging (54 degree °2C for 90 days)
1 Active content (% w/w) 36.2% 35.1% NA
2 Suspensibility (%w/w) 86.21% 86.96 NA
3 Viscosity 840 cps 1050 cps 1190
4 Ph 7.01 7.23 7.24
5 Manganese content NA NA NA
6 Zinc content NA NA NA
7 Pour ability Good Good Good
8 Sediment Nil No sediments No sediments. The material is easily shakeable
16

Example no 5 to 9

Raw materials Percentage on w/w basis Example no 5 Example no 6 No 7 No 8 9
Mancozeb powder 35.5% 35.5% 35.5% 35.5% 35.5%
Galoryl 505 0.5% — — —
Dispersol F ~ — — — 2.00%
Lomar D 1.00% — —
Sodium ligno sulphonate 1.00% 1.00% 1.00% 2.5%
Sorophor FL — 0.5% 0.5% —
Sorophor BSU — 0.2% 0.2% —
Octylphenol ethyxolate 10 mole 0.5%
Hexamethylene tetramine 1.00% 1.00% 1.00% 1.00%
Sodium meta bisulphite 1.00%
Ethylene glycol 5.00% 5.00% 5.00% 5.00% 5.00%
MZ36 0.10% 0.10% 0.10% 0.10% 0.10%
Xanthan gum 0.20% 0.22% 0.20% 0.15% 0.20%
Water 57.20 % (Q.S) 56.18% (Q.S) 56.5% (Q.S) 56.55% (q.s)
Total 100% w/w 100% w/w 100% w/w 100% w/w 100%
17

Example no 5 to 9 Procedure as per Example no 4
Analysis after aging at 54 degree for 14 days

Viscosity Example no 5 Example no 6 No 7 No 8 9
Viscosity
Zero day 900 cps 730 cps 490 cps 780 cps 800 cps

After aging 1920 cps > 2000 cps > 2000 cps > 2000 cps > 2000 cps
Pour ability Hard mass Hard mass, Hard mass, Hard mass, Hard mass,
Vigorous Not not not not
shaking required shakeable shakeable shakeable shakeable
BIOEFFICACY TESTS OF MANCOZEB FLOWABLE
1) Study was carried out by Tamilnadu Agricultural University, Coimbatore to test the Bio-efficacy of Mancozeb Flowable against downy mildew of grapes (paneer variety) for one season Rabi 2002. Chemicals used and their doses were Mancozeb Flowable 0.4% (3.0 ml/lit), Mancozeb Flowable 0.5% ( 3.8 ml/lit) and Mancozeb Flowable 0.6% (4.6 ml/lit) and one standard fungicide Mancozeb 0.25% (2.5 g/lit).
Plot sizes used for the study was five vines spaced at 3 X 3 m per treatment per replication and for three replications. Control plot was left untreated.
The first spray was given immediately after disease appearance, which was one month after pruning. Three subsequent rounds of sprays were given at 10 days intervals. The observation on downy mildew incidence on leaf and berries was recorded using 0-9 scale and the percent disease index (PDI) was calculated.
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IT was found that all the treatments significantly reduced the disease on leaves when compared to untreated control. Among the treatments, Mancozeb Flowable ( 0.6% ) recorded minimum disease on leaves , PDI being 13.37 followed by Mancozeb 0.5%, PDI being 18.15 and Mancozeb 0.4% - PDI 20.48. Standard fungicidal Mancozeb 0.25% recorded PDI of 22.45%. Similar trend was also noticed in case of fruit infection. Treatment with Mancozeb Flowable 0.6 % also resulted in maximum yield of fruits ( 17220.5 kg/ha) as compared to other treatments and untreated control.
2)Bio-efficacy testing of Mancozeb Flowable was carried out by Tamilnadu Agricultural University, Coimbatore against Late Blight ( Phytophthora infestans ) of Potato for one season - Main, 1999. Chemicals used were Mancozeb Flowable 0.4%, Mancozeb Flowable 0.5% and Mancozeb Flowable 0.6% and one standard fungicide Mancozeb wettable powder 0.25%. Potatoes of Kufri Jyoti variety were planted in a plot size of 10 sq.m. with 20 X 45 cm spacing. Six rounds of sprayings were done on appearance of the disease. The Late blight disease incidence was found to be on par in the treatments with Mancozeb Flowable at 0.4, 0.5, 0.6 per cent and Mancozeb wettable 0.25% and the mean disease grades on a 0-9 scale were 1.9, 1.9, 2.0 and 2.1 respectively. The highest mean disease grade of 3.0 was recorded b untreated control. All the treatments were on par with regard to yield except untreated control whereby the yield was approximately 60 % lesser than the treated crop.
3) Field experiments were conducted during kharif season of 2001-02 to study effect of fungicides on Banana Sigatoka caused by fungus Mycosphaerella musicola. The fungicides tested were Mancozeb Flowable (0.4, 0.5 & 0.6 %), Mancozeb wettable powder, emulsified formulation of propiconazole 25% and Hexaconazole 5%. The experiments were conducted during the rainy days in a randomized block design with 8 treatments and 3 replications using highly susceptible varieties of banana in Karnataka, Tamilnadu and Andhra Pradesh. Three- four sprays were given at 20-30 days intervals when initial typical disease symptoms were observed using high volume sprayer. Observations on the leaves were taken using 0-5 scale.
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This investigation revealed that Mancozeb Flowable has shown more effective control of Banana Sigatoka than Mancozeb wettable powder among contact fungicides. Because of its very high suspensibility, smaller and uniform particle size, faster resuspensibility and high efficacy, Mancozeb can be used by farmers to get economical disease control.
4) Another study was carried out by National research centre for Banana, Trichy for two
season viz. 2000-2001 and 2002-2003 to find out the efficacy and most effective
concentration of Mancozeb Flowable against Sigatoka leaf spot disease of Banana. The
chemicals used were Mancozeb Flowable 0.5%, Mancozeb Flowable 0.6%, Indofil M-45
(0.25%) and carbendazim (0.1%).
The experiments were conducted in a randomized block design with 5 treatments and 4
replications each on a plot of approximately one acre.
First spray was given as low volume spray using Power sprayer (200 liters per acre) and
three subsequent sprays were of high volume using rocker sprayer (450 liters / acre) at 15-
28 days interval.
The disease severity was recorded at the end of the treatment as per the Int. Musa Testing
Prog. G.uidelines. Yield parameters and YLS ( youngest leaf spotted) were recorded and
cost benefit ratios were analysed.
Mancozeb Flowable sprayed plots recorded lowest disease severity, highest finger number
and highest bunch weight. Additional yield per bunch was 5.3 kg and additional yield per
acre was calculated to be 6360 kg providing a cost benefit of 36 as compared to unsprayed
control. Results were found to be better for 0.6% than 0.5% concentration.
None of the doses of Mancozeb Flowable tested showed any type of phytotoxicity
symptom.
The experiment was continued for the second season and the results of the first season were
confirmed.
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5) A study carried out by University of Agricultural Sciences, Dharwad tested the efficacy
of Mancozeb Flowable against Sigatoka spot disease of Banana cv. Rajapuri. The
chemicals used were :
Mancozeb Flowable - 0.38 %
Mancozeb Flowable - 0.46 %
Mancozeb WP -0.25%
Carbendazim 0.10%
Companion 0.20 %
Mineral oil 5. 0 %
The experiments were conducted in a randomized block design with 6 treatments and 3
replications each on a plot of approximately one acre.
First spray was given as low volume spray using Power sprayer (200 liters per acre) and
three subsequent sprays were of high volume using rocker sprayer (450 liters / acre) at 25-
35 days interval.
The mean data revealed that the lowest leaf spot index was recorded in the plants treated
with Mancozeb 0.46%, highest being in the untreated control.
Maximum yield was also found in the plants sprayed with Mancozeb 0.46%.
6) Similar study carried out by Bidhan Chandra Krishia Vishwavidyalaya, tested the bio-
efficacy of Mancozeb Flowable against late and early blight of potato, late and early blight
of tomato and downy mildew of cucurbit.
Results clearly indicated that disease incidence and severity were reduced and yield of increased by spraying Mancozeb Flowable than in the control plot.
The lowest disease incidence, disease severity and maximum yield were obtained by treatment with MZB Flowable 0.6% followed by MZB Flowable 0.5%, MZB Flowable 0.4%, MZB 75 WP 0.25%, MZB Flowable 0.3 and MAtcoO.25%.%
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We Claim:
1. A process for the preparation of Mancozeb suspension concentrate having low particle
size, low viscosity and high suspensibility by employing Mancozeb in a powder form
comprising the steps of;
a) Mixing of water and additives in a high shear mixer along with Mancozeb powder to get homogenous premix;
b) Wet milling of the premix to get the intermediate slurry;
c) Blending of the slurry with suspending and antitacking agents to get the formulation.

2. The process as claimed in claim 1, wherein high shear mixing is carried out by mixing additives, water and Mancozeb powder in a reactor designed with required temperature control.
3. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in Claim 2, wherein, the additives are added in a predetermined order over a definite period and sheared for a required time.

4. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in Claim 1, wherein, the milling is carried out in a horizontal mill comprising a chamber, equipped with grinding media and a shaft with specified number of blades.
5. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in Claim 4 wherein, the chamber temperature, back pressure, air pressure, seal flushing water pressure, air pressure to operate diaphragm pump, compressed air output pressure are controlled in such a way that total solids during the grinding of milling stage is in the rate of 55-66%.
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6. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, temperature maintained during grinding is 15-25 °C.
7. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, antifoaming agent and thickner are added at the blending stage to adjust the viscosity of the formulation.
8. The process for the preparation of Mancozeb suspension concentrate having low particle size low viscosity and high suspensibility as claimed in claim 1 and 7 wherein, suspending and antitacking agent added to get suspensibility greater than at least 85% and preferably greater than 95%.
9. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in Claim 8 wherein, suspending and anti tacking agent added to get viscosity in the range of 200-1000 cps.
10. The process for the preparation of Mancozeb suspension concentrate having low
particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, the
reaction condition is inert to carry out the process step.
1.1. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, the additives used are stabilizers and anti tacking agent.
12. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in Claim 11 wherein, the antitacking agent is selected from silica, natural polymers and glycerol.
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13. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 11 wherein, the stabilizers selected from different amines and aldehydes,
14. Process claim 1 wherein, formulation comprises surfactant and optionally filters.
15. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 14 wherein, surfactant comprises emulsifying agent, dispersing agent and wetting agent.
16. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 15 wherein, the surfactant are selected from anionic surfactants and non ionic surfactants.
17. The process for the preparation of Mancozeb suspension concentrate having low particle size low viscosity and high suspensibility as claimed in claim 16 wherein, the anionic surfactant selected from a group of anionic surfactants such as sodium dodecyl benzene sulphoante, sodium, calcium or ammonium lignosulphoante ,sodium formaldehyde condensates polymer salt, (Lomar D),naphthalene formaldehyde condensate and sodium salt ( Morwet D 425)
18. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 16 wherein, the non ionic surfactant selected from a group of non ionic surfactants such as condensation products of ethylene oxide with alkyl phenols such as octyl phenol and nonyl phenol.
19. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 and 6 wherein, surfactant comprises at least one wetting agent selected from a group of wetting agents such as alkyl naphthalene sulfonates, phosphate esters , and / or at least one dispersing
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agent such as those selected from the group of naphthalene condensates and ligno sulfonates.
20. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 and 6 where total content of surfactant ranges from 2-20% preferably 3-10%) by weight of the dry weight of the formulation.
21. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, suspension further comprises antifreeze agent selected from a group of antifreeze agents such as glycerin, glycols and silica.
22. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, suspension further comprises antifoaming agents and preferably non silicone oil.
23. The process for the preparation of Mancozeb suspension concentrate having low particle size low viscosity and high suspensibility as claimed in claim 1 wherein, suspension further comprises adhesive selected from a group of adhesives such as starch syrup, dextrose, sucrose, dextrin, polyvinyl acetate, and xanthan gum.
24. The process for the preparation of Mancozeb suspension concentrate having low particle size low viscosity and high suspensibility as claimed in claim 1 wherein, the wet milling step is carried out by using the wetting agent selected from a group of wetting agents comprising condensates of alkyl naphthalene sulfonate, condensate of aryl sulfonic acid, sodium or potassium polycarboxylates, ethoxylated tristyryl phenols phosphates and their salts, ethoxylated tristyryl phenols sulfates and their salts, or ammonium salt of polyoxyethylene, or a combination of these.
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25. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, the suspending agent are dispersing agent selected from the group of condensates of phenol sulphonic acid and their salts, condensates of alkyl aryl sulphonic acid and their salts, condensates of alkyl sulfonic acids and their salts, sodium salt of dodecyl sulfosuccinic acid half ester, salts of sulfonated and carboxylated kraft lignin or a sodium salt of dioctyl sulfosuccinate or a combination of these .
26. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, the particle size obtained ranges from 0.73 to 4.42 micron.
27. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, pH required to carry out the process is 7.07 -7.23
28. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein, the percentage of active content of Mancozeb in the suspension is from 33-36.5%
29. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed, in claim 1 wherein, the percentage of active content of manganese in the suspension before aging is from 20-21%.
30. The process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility as claimed in claim 1 wherein the percentage of active content of Zinc in the suspension is from 2.5 - 3%.
31. Mancozeb suspension concentrate composition comprising synergistically effective amount of active ingredient ranging from 33-36.5 % of active content of Mancozeb
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along with fungicidally acceptable additives, wetting agent, suspending or dispersing agent in aqueous media.
32. Process of preparation of Mancozeb suspension concentrate substantially as herein described with reference to the examples.
33. Manxozeb suspension concentrate substantially as herein described with reference to the examples.

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ABSTRACT
A process for the preparation of Mancozeb suspension concentrate having low particle size, low viscosity and high suspensibility by employing Mancozeb in a powder form comprising the steps of;
a) Mixing of water and additives in a high shear mixer along with Mancozeb powder to get homogenous premix;
b) Wet milling of the premix to get the intermediate slurry;
c) Blending of the slurry with suspending and antitacking agents to get the formulation.
- 8 JUN 2005

A PROCESS FOR THE PREPARATION OF MANCOZEB SUSPENSION CONCENTRATE AND PESTICIDE FORMULATION MADE BY THE PROCESS

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