|Title of Invention||
A NON DUSTY, FREE FLOWING, STORAGE STABLE SOLID COMPOSITION AND A PROCESS FOR ITS PREPARATION
|Abstract||A solid water dispersible granular composition of pesticide comprising up to 50% of at least one pesticide from pyrethroid class, more particularly a highly viscous liquid pyrethroid insecticide, permethrin, having the properties of excellent dispersibility and suspensibility, as well as the process of preparation of the composition are disclosed. Also the improved storage stability, dispersibility and suspensibility properties are discussed for this granular composition.|
|Full Text|| FORM 2
THE PATENTS ACT 1970
(39 Of 1970)
THE PATENT RULES, 2003
(See Section 10, rule 13)
A NON DUSTY, FREE FLOWING, STORAGE STABLE SOLID COMPOSITION AND A PROCESS FOR ITS PREPARATION
UNITED PHOSPHORUS LTD., A COMPANY REGISTERED UNDER INDIAN COMPANY'S ACT 1956 , HAVING ITS REGISTERED OFFICE AT 3 - 11, G.I.D.C., VAPI - 396 195, STATE OF GUJARAT, INDIA, INDIAN.
The following specification describes the invention:
Field of invention:
The proposed invention relates to a non dusty, free flowing, storage stable solid composition. This invention particularly relates to a non dusty, free flowing, storage stable solid composition comprising of at least one pesticide from pyrethroid class like cypermethrin, fenvalerate, permethrin, alphacypermethrin, betacypermethrin, zetacypermethrin, deltamethrin, cyfluthrin, bifenthrin, A-cyhalothrin, and/or bioresmethrin more particularly a highly viscous liquid insecticide like permethrin, cypermethrin, fenvalerate, lambda-cyhalothrin, bifenthrin. The solid compositions of the proposed invention have excellent storage stability, dispersibility and suspensibility even after comprising high concentrations of pesticides from pyrethroid class. The invention also relates to a process of preparing the said composition
Back ground and prior arts concerning the present invention :
Solid compositions like granules are mainly produced by methods such as kneading, extrusion granulation, impregnation, coating etc. Granules are more frequently applied to water surface or soil than directly applied to target crops. After application to water surface or soil, the active ingredient of granules dissolves/disperses in water or vaporizes to reach its action sites and displays the effect. It is therefore required that the same water dispersibility and suspensility as those at the time of formulation are maintained even after long term storage.
Dry powdery (like wettable powder WP and others) composition has disadvantages like presence of sediment at the bottom of dilution tank, choking of nozzle while spraying, lumping during storage and drift problem at the time of production, packing, transportation, storage, handling, dilution and use.
Generally, liquid formulation like emulsifiable concentrate (EC), soluble liquid (SL), micoremulsion (ME), and capsule suspensions (CS), etc., the composition involves the use of organic solvents like petroleum ether, hydrocarbon solvents, xylene, isopropyl alcohol etc., which may causes further problems like toxicity, irritation to human body
and /or other associated problems due to their physico-chemical properties like flash point, solvency with other materials, flammable and reactive nature.
All liquid compositions (like emulsifiable concentrate EC and others) which have been used in agriculture or veterinary applications comprising liquid pyrethroids of concentrations more than 20% are suffering with high volatility due to volatile contents and comprising flammable solvents. Most common organic solvents can be used as inert solvents. As liquid solvents, there are suitable in the main: aromatic hydrocarbons, such as xylene, toluene or alkyl naphthalenes; chlorinated aromatic hydrocarbons and chlorinated aliphatic hydrocarbons; such as chlorobenzenes, methylene chloride; aliphatic hydrocarbons, such as cyclohexane or paraffins, for example petroleum fractions, mineral and vegetable oils, alcohols, such as butanol or glycol as well as their ethers and esters, ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone; strongly polar solvents, such as dimethylformamide and dimethylsulphoxide. Some of these solvents are agriculturally unacceptable, and need to be used in low or high concentrations to produce formulations of desired strength, which can be diluted and applied to the target areas to control pest effect. Selection and use of the solvent is based on the solubility criteria for active ingredients which some times requires a single solvent or a combination of number of solvents as per the type and strength of the formulation product.
WO 9007275, discloses a dry herbicidal composition comprising a water soluble salt of N-phosphonomethylglycine as a water dispersible granule , water soluble granule , water dispersable powder or water soluble powder. The composition comprises a water soluble salt of N-phosphonomethylglycine and additionally one or more liquid surfactants. This invention requires a preparation of herbicidal water soluble salt during the process from its acid derivative (which is solid in physical form) or a water soluble salt (in solid physical form) as one of the main ingredient as raw material.
Prior art, Japanese patent 2003095810, discloses the wettable granules comprising liquid Pesticidal active ingredient, solvent, emulsifier, dispersion agent and surfactant.This
invention requires the use of solvent so that the active ingredient gets uniformly distributed over the inert ingredients.
Prior art EP 127773, discloses a pesticidal composition comprisng a pesticide , an emulsifier or dispersing agent for the pesticide and a self dintegrating agent capable of effervesting or swelling on being contacted with water . The pesticide may be a synthetic pyrethroid. This invention requires a self disintegrating agent which is capable of effervesting or swelling on being contacted with water.
Thus there is a need for a non dusty, free flowing, storage stable solid compositions comprising pyrethroid type insecticides, more particularly semi viscous liquid pyrethroid which results in a stable dispersion in presence of water. The present invention takes care of all these problems of dry WP, solid/granular, tablet/pellets formulations given in prior art. The present invention provides a solid insecticidal composition having long activity and residual effectiveness and improved dispersibility and suspensibility .
Objectives of the invention:
Therefore the main objective of the proposed invention is to provide a non dusty, free flowing, storage stable solid composition devoid of the draw backs of the hitherto known composition
Another objective of the proposed invention is to provide non dusty, free flowing, storage stable solid composition having the properties of storage stablility, excellent dispersibility and suspensibility.
Yet another objective of the proposed invention is to provide a non dusty, free flowing, storage stable solid composition comprising at least one pesticide from pyrethroid class like cypermethrin, fenvalerate, permethrin, alphacypermethrin, betacypermethrin, zetacypermethrin, deltamethrin, cyfluthrin, bifenthrin, A-cyhalothrin, and/or bioresmethrin
Yet another objective of the proposed invention is to provide non dusty, free flowing, storage stable solid composition having the properties of excellent dispersibility and
suspensibility using at least a liquid surfactants selected from polyoxyethlene glycol ether group.
Another objective of the proposed invention is to provide non dusty, free flowing, storage stable solid composition having the properties of excellent dispersibility and suspensibility in solid form preferably in water dispersible granular form.
Another objective of the proposed invention is to provide a process for the preparation of non dusty, free flowing, storage stable solid composition having the properties of excellent dispersibility and suspensibility
Yet another objective of the proposed invention is to provide a process for the preparation of non dusty, free flowing, storage stable solid composition which is a relatively inexpensive and environmentally safe.
Yet another objective of the proposed invention is to provide a process for the preparation of non dusty, free flowing, storage stable solid composition in water dispersible granular form which are not prone to dust generation while filling in bags, transportation thereby avoiding polluting the environment.
Another objective of the proposed invention is to provide a process for the preparation of non dusty, free flowing, storage stable solid composition in water dispersible granular form by using the liquid pesticide.
Yet another objective of the proposed invention is to provide a process for the preparation of non dusty, free flowing, storage stable solid composition in water dispersible granular form by using at least the liquid pesticide and atleast one liquid surfactants.
Yet another objective of the proposed t invention is to provide a process for the preparation of non dusty, free flowing, storage stable solid composition without using any solvents.
The above mentioned objectives of the proposed invention have been achieved by our sustained R&D due to our finding that in solid composition comprising pyrethroids, the use of liquid surfactants selected from polyoxyethlene glycol ether group and when this composition is coated on a mixture of Kaolin and precipitated silica as an inert filler in selected ratio provides good dispersibility and suspensibility to the resulting solid composition This mixture of kaolin & precipitated silica acts as a carrier and anticaking agent due to their difference in adsorption and absorption property. The use of polyoxythelene glycol ether as one of the surfactant gives at least 60 % dispersibility and suspensibility
Summary of the proposed Invention
Accordingly, the proposed invention provides a non dusty, free flowing, storage stable solid composition which comprises a mixture of kaolin and precipitated silica having a coating of a composition comprising at least one pesticide selected from pyrethroid class like cypermethrin, fenvalerate, permethrin, alphacypermethrin, betacypermethrin, zetacypermethrin, deltamethrin, cyfluthrin, bifenthrin, A-cyhalothrin, and/or bioresmethrin and at least one liquid surfactants selected from polyoxyethlene glycol ether group.
According to another aspect of the proposed invention , there is provided a process for the preparation of a non dusty, free flowing, storage stable solid composition which comprises:
(i) mixing an active ingredient selected from at least one pesticide selected from
pyrethroid class like cypermethrin, fenvalerate, permethrin, alphacypermethrin,
betacypermethrin, zetacypermethrin, deltamethrin, cyfluthrin, bifenthrin, A-cyhalothrin,
and/or bioresmethrin with at least a at least one liquid surfactants selected from
polyoxyethlene glycol ether group to obtained a liquid mixture;
(ii) mixing the powder of kaolin , precipitated silica , wetting agent, dispersing agent,
and a binder;
(iii) adding the liquid mixture obtained in step (i) to a mixing vessel containing the
powder prepared described in step (ii);
(iv) mixing thoroughly the ingredients of step (iii);
(v) granulating the resulting mixture obtained in step (iv);
(vi) sieving, if required, to obtain the desired sizes of the solid composition; and
(vii) drying, if required, the resulting solid composition .
By the term Polyoxyethlene glycol ether is meant a surfactants having a comparable hydrophilic chains length than those of most other surfactants and they are flexible. They bind water avidly by hydrogen bond acceptor interactions with ether-linked oxygens. These long, strongly hydrated flexible chains are relatively incompressible and form a barrier to hydrophobic surfaces approaching one another. As emulsifying and /or dispersing agents there are suitable: for example non-ionic and anionic emulsifiers, such as polyoxyethylene-fatty acid esters, polyoxyethylene-fatty alcohol ethers, for example alkylaryl polyglycol ethers, alkylsulphonates, alkylsulphates, arylsulphonates and their hydrolysis products. More precisely, the use of polyoxyethlene glycol ether in this case provides a solid composition with at least 60 % dispersibility and suspensibility despite high concentrations of viscous liquid pesticide. A mixture prepared by adding active ingredient with atleast one polyoxyethylene glycol ether surfactant helps to cover the treated surface area uniformly.
By the term "wetting agent" is meant a compound which permits the granule to rapidly wet into the water, and, more precisely, a compound which, when mixed in selected proportions with agriculturally active compounds, in the form of granules, give a mixture which has a wettability time of less than 2 minutes. This wetting agent can be an ionic or non-ionic agent or a mixture of such surface-active agents.
Compounds which are usable as wetting agents and which can be cited are, for example, the alkylarylsulphonate-type salts, in particular the alkali metal alkylnaphthalene sulphonates, the salts of polycarboxylic acids, polycondensates of ethylene oxide with fatty alcohols or with fatty acids or with fatty amines, or substituted phenols (in particular alkylphenols or arylphenols), and salts of esters of sulphosuccinic acids.
By the term "dispersing agent" is meant a compound which ensures that the particles remain suspended in the application mixture and which allows rapid disintegration of the granule in the water. More precisely, by dispersing agent is meant a compound which, when intimately mixed in selected proportions with agriculturally active compounds , in the form of granules, gives a mixture which has a suspensibility of more than 50%. The dispersing agent can be an ionic or non-ionic agent or a mixture of such surface-active agents.
As compounds which are suitable as dispersing agents there may be cited, for example, arylsulphonate-type polymers, in particular the alkali metal polynaphthalenesulphonates obtained by condensation of (alkyl)arylsulphonates with formaldehyde, the lingo sulphonates, the polyphenylsulphonates, salts of polyacrylic acids, salts of lignosulphonic acids, salts of phenolsulphonic acids or naphthalenesulphonic acids, taurine derivatives (in particular alkyltaurates), phosphoric esters of alcohols or of polycondensates of ethylene oxide and phenols, esters of fatty acids and polyols, and the derivatives of the preceding compounds which have sulphate, sulphonate and phosphate functions.
The term "binders" refers to all binders which are suitable for solid compositions such as in water-dispersible solid formulations. The following are preferably suitable in this context: methylcellulose, sugars, dextrin, starch, alginates, glycols, polyvinyl pyrrolidone, ligninsulphonate, gum arabic, polyvinyl alcohol and polyvinyl acetate, water, or a solution containing dissolved wetting and dispersing agents.
In the step additional inert fillers may be used . Such " inert fillers " refer to a solid organic or inorganic material, natural or synthetic, with which the active substance is combined so as to facilitate the specific application of the granulated product This filler is therefore generally inert and acceptable. The filler can be selected for example from amongst clay, diatomaceous earth, kaolin clay, the natural or synthetic silicates, silica, precipitated silica, soluble or insoluble mineral salts, organic derivatives, and polysaccharide compounds such as starch, cellulose, aliginates, soluble mineral salts, sugars and lactose or a combination thereof. The inert fillers which can be used are
hydrophilic fillers which have a disintegrating action, that is to say which facilitate the adsorption as well as absorption of active ingredient and also facilitate the dispersion and suspension of the granule according to the invention in the presence of water.
Besides the product used for granulation the product ( first compound) may contain at least a second active compound of a type which differs from the first compound, which has the aim of widening the spectrum of the first one. In the case of agro chemicals used the first and second compounds may be a contact pesticide, which act by contact with the plants/pests. This second agent may be present in the solid composition prepared by the process of the proposed invention in an amount between 0.1 to 40.0 %. The first agricultural compound may be present in quantities , preferably between 0.1 to 50.0 %, the other ingredients in the end product being the wetting agent, dispersing agent and inert filers. Besides the above-described ingredients the granulated product may also contain 10.0 to 99.80 % of suitable additives, such as antifoams, sequestering agents, stabilisers, penetrating agents, adhesives, anti-caking agents, colorants, and others.
The process of the proposed invention is generally carried out starting with the mixing of an active ingredient, with at least a polyoxyethlene glycol ether surfactants to obtained a liquid mixture. There after the preparation of the powders of wetting agent, dispersing agent, binder and inert fillers by mixing is done. This mixing of the powders may be done in suitable mixers.
According to the proposed invention adding of the liquid mixture is done over the powder prepared. After complete addition of the liquid mixture these ingredients are mixed thoroughly to obtain a homogenous powdery mixture. This powdery mixture can also be considered as one of the form of invented solid composition which is in the form of powder. If the granulated product is required then continuing the mixing for an additional time, after spraying was over. There after granulation of the mixture is performed by using water as a granulating liquid. Then separating the fine particles, required and oversized particles. If required, the fine and oversized particles are recycled and drying the granules, as required, in a drier like equipment like Fluidized bed dryer to a moisture content below 2 % w/w. Again sieving the dried granules by using vibratory
sieve to finally remove any fine and or oversize granules. The fine and the oversize separated particles can be recycled to the granulator after drying and grinding to suitable particle size.
According to the proposed invention, the powder taken in the container of the apparatus is mixed with granulating liquid, from 1 to 30%, preferably 5 to 15 % of the required quantities .This moistened powder has the consistency of a non drifting dust. This is further processed in the container with the addition of remaining quantity of the granulating liquid in such a way as to obtain the granulated product.
The granules prepared by the process according to the proposed invention are therefore concentrated products. The granulated agricultural products which are prepared according to the process of the proposed invention , which are diluted by the agriculturalists in containers which contain water for application. These diluted mixtures are usually applied at 5 to 10001/ha.
In the proposed invention no solvent is used during solid composition preparation and formulation which eliminates the possibility of flammability during handling, processing, storage and transportation and irritation to skin of human body.
In present invention active ingredients used may be in the range of 0.1- 50% by weight of composition, .The solid composition has a long activity both quick-acting property and residual effectiveness and improved in stickiness, fluidity and bulkiness, also from the view point of physical properties of the formulation.
One of the solid proposed composition includes:
Ingredients % w/w
POE of alkyl ether contains Nonyl phenol ethoxylate (Atlox 4896) 2.75
Rhodacol 60 BE 0.83
Precipitated Silica 10.00
Supragil WP 5.00
Atlox Metasperse 550 S 8.00
Agnique DMF 111 S 0.05
Total 100.00% w/w
The characteristic outcome of the employment of the process of the proposed invention is the dispersing and wetting of almost 100% of the particles with a minimum of water.
The present invention has the following advantagous characteristics
• a wettability time of less than 4 minutes, preferably less than 2 minutes;
• a dispersibility of more than 60 %, preferably more than 80.0 %;
• a suspensibility of more than 60 %, preferably more than 70%;
• a storage stability of more than one year, preferably two years.
• It is a non dusty operation.
• The processing is done without the addition of an organic solvent.
• The amount of the granulating liquid used in the process is very less.
• The process affords complete control on the size of the granules produced.
• The processing time is short as compared to the known processes.
• The drying time is short as compared to conventional spray drying process.
• The drying temperature is also less leading to energy savings as compared to conventional processes.
The process do not require the grinding of the active ingredient along with the
The process affords multi material processing leading to better solid and
granulated product of combined active ingredients.
The process helps to convert the liquid viscous pesticide into solid composition
The process enables full and complete process control of granulation to produce
products in a narrow size range in a single pass. Single pass means the primary
yield with substantially little/no recycle employed.
The granules do not require specialized driers.
Dated this 26th day of April, 2007.
(Mr. M. B. TRIVEDI) COMPANY SECRETARY, UNITED PHOSPHOROUS LTD.
|Indian Patent Application Number||802/MUM/2007|
|PG Journal Number||04/2012|
|Date of Filing||26-Apr-2007|
|Name of Patentee||UNITED PHOSPHORUS LIMITED|
|Applicant Address||UNIPHOS HOUSE, 11TH ROAD, C.D. MARG, KHAR (WEST), MUMBAI-400052,|
|PCT International Classification Number||A01N53/02,C07D307|
|PCT International Application Number||N/A|
|PCT International Filing date|