Title of Invention	A SAFE DELIVERY SYSTEM FOR AGRICULTURALLY ACTIVE MATERIALS
Abstract	The present invesntion relates to a safe dilivery system of agriculturally active material. And also the present invention relates to a process for preparing microencapsulated suspension of agrculturally active material particularly that of Pyrethroids wherein the encapsulating agent is a Graft Copolymers of starch and atleast one monomer of Vinyl group.

Full Text

FORM 2 THE PATENTS ACT, 1970 As amended by the Patents (Amendment) Act, 2002 COMPLETE SPECIFICATION (See Section 10; Rule 13) TITLE A SAFE DELIVERY SYSTEM FOR AGRICULTURALLY ACTIVE MATERIALS APPLICANTS UNITED PHOSPHORUS LIMITED, a company incorporated under the Companies Act, 1956 having its registered office at 3-11, GIDC, Vapi-396 195, State of Gujarat, India and its corporate office at Uniphos House, 11th Road, C. D. Marg, Khar (West), Mumbai - 400 052, State of Maharashtra, India, an Indian Company. The following specification particularly describes the invention and the 1 0 MAY 2005 manner in which it is to be performed. ORGN 539/MUM/2004 10.5.2004 Granted Field of Invention: The present invention relates to a safe delivery system of agriculturally active material. And also the present invention relates to a process for preparing microencapsulated suspension of agriculturally active material particularly that of Pyrethroids wherein the encapsulating agent is a Graft Copolymers of starch and atleast one monomer of Vinyl group. Background and Prior Art of the Invention: In agrochemical industry insecticides are formulated as dust, emulsifiable concentrates, suspension concentrates, wettable powders or wettable granules, water dispersible granules, depending on the properties of the active ingredient, and the target pest species and market. In Insecticides such as Lambda Cyhalothrin, Cypermethrin, Fenvalerate, Permethrin, Alpha-cypermethrin, etc which are moderately toxic in the technical form, but have a high skin irritant property and in some cases may provoke an adverse skin reaction such as burning, tingling, numbness or prickling sensation or generally known as paraesthesia, during application of the insecticide, which is most pronounced in areas of operator"s face, hand, neck etc. For delivering such agriculturally active materials at the target, encapsulation or microencapsulation is one of the safe modes. Encapsulation or more specifically microencapsulation is increasingly being used to target specific insects, as it also provides a safer handling of toxic fungicides and insecticides. A microcapsule is a 10-3 m to 10-9 m diameter particle, composed of a core material and an outer wall (Tsuji, 1993). Microencapsulation of these kinds of agrochemicals can also be advantageous in providing the active material in relatively more concentrated form than the emulsifiable concentrate, wettable powder etc., at the same time reducing the amount of other ingredients such as surfactants, solvents, dye(s) etc. Microencapsulation of a number of different agriculturally active materials and pesticides has been known for many years by using various processes or techniques for microencapsulation. The general technology for forming microcapsules is divided into two classifications known as physical methods and chemical methods. The physical methods are spray coating, spray drying, pan coating, rotary disk atomization etc. The chemical microencapsulation methods are phase separation, interfacial polymerization, simple and complex coacervation method etc. The total process of microencapsulation covers three separate steps on a time scale. The first step consists of forming a wall around the core material. The second step involves keeping the core inside the wall material so that it does not release. Also the wall material must prevent the entrance of undesirable materials that may harm the core. And finally, it is necessary to get the core material out beginning at the right time, stage and at the right rate. The US pat. No. 4285720 granted to Stauffer Chemical Company, teaches a process for preparation of microencapsulated water-immiscible material, including pesticides and other agrochemicals, by interfacial polymerization techniques by using one or more polyisocyanates and producing microcapsules having a droplet size of from 0.5 to about 4000 microns which provides a controlled or sustained release (over weeks) of the active ingredients. This type of controlled released encapsulation is useful in case of soil application whereas in case of foliar applications fast release is required. US Pat. No. 6133197, granted to ZENECA Limited, describes a process of encapsulation of a water-immiscible material i.e. pyrethroid insecticide within discreet capsules of polyurea prepared from an aromatic diisocyanate. The untreated isocynate, if any, of said isocynates may cause skin/eye irritation due to its high toxicity Release rates are governed by the capsule particle size, the thickness of the wall and the permeability of the wall. Small particles with thin walls and low cross-linking density allow the fastest possible release. (Pesticide Outlook- April 2000) The present invention provides a process of encapsulation of agriculturally active material without using any diisocyanate / isocyanate, In particular, the present invention provides a process of encapsulation of agriculturally active material such as Pyrethroids with the Graft Copolymers of starch and at least one monomer of Vinyl group. These polymers used are biodegradable polymer. Starch is a cheap and natural polymer and is a renewable degradable carbohydrate biopolymer that can be taken from various sources by environmentally sound processes. Starch is hydrophilic and partially water soluble polymer, which is being used in the present invention as a polymer wall to the core material after grafting with a monomer of Vinyl group. Starch-based biodegradable low-density polyethylene (LDPE) films are used for graft copolymerization of vinyl acetate with cerie ammonium nitrate. (Polymer International, March 2004, vol. 53, no. 3, pp. 339-343(5)). Grafting vinyl acetate and starch acetate with high degrees of substitution copolymerized to prepare a kind of biodegradable material. [Qian, Xin (Dept. of Chem. Eng., Zhejiang Univ. of Technol.) June, 2002, China National Chemical Information Center] OBJECT OF THE INVENTION: One of the objects of the invention is to provide a safe delivery system of agriculturally active material by means of microencapsulation. Another object of the invention is to provide a process of microencapsulation of agriculturally active material/s. Yet another object of the invention is to provide a process of microencapsulation of agriculturally active material by Graft Polymerization. Another object of the invention is to provide a process of microencapsulation of agriculturally active material by starch graft polymerization so as to provide microcapsules of Lambda Cyhalothrin. Still another object of the invention is to provide a process of microencapsulation of agriculturally active material, resulting into the microcapsules of Lambda Cyhalothrin, wherein the encapsulating film is formed from Graft Copolymers of starch and at least one monomer of Vinyl group. Another object of the invention is to provide a process of microencapsulation of agriculturally active material/s by starch graft polymerization, with Vinyl Acetate Monomer in presence of a Free Radical Initiator. Another object of the invention is to provide a process of microencapsulation of Pyrethroids. Yet another object of the invention is to provide a process of encapsulation of Lambda Cyhalothrin and its microencapsules formation. And yet another object of the invention is to obtain microcapsules for safe delivery system of agriculturally active material by following the process of the invention. STATEMENT OF THE INVENTION: According to the present invention there is provided a safe delivery system of agriculturally active material by means of microencapsulation and another embodiment of the invention is to provide a process for preparing microcapsules of agriculturally active water immiscible material, comprising the steps of: (i) preparing an organic phase comprising an agriculturally active water immiscible material to be encapsulated and a solvent, in presence of at least one surfactant by continuously stirring to get a clear solution; (ii) preparing an aqueous phase comprising water, starch, a protective colloid, a biocide, with or. without an anti freezing agent and a surfactant, by heating the same at 65 - 85° C temperature for 15 - 45 minutes to get the aqueous phase in gelatinized form followed by cooling the system at room temperature (20 - 45° C); (iii) adding the organic phase of step (i) into the aqueous phase of step (ii) slowly with high shear to form an oil-in-water emulsion in which the oil droplets size is less than 5 microns; (iv) adding an initiator, to generate free radical and to maintain the pH between 2 - 5 of the emulsion of step (iii), and simultaneously purging an inert gas so as to keep the atmosphere, oxygen-free, at a temperature range between 15 - 30° C; (v) adding a monomer slowly at a constant rate such that a grafting reaction occurs at the interface of organic and aqueous phase, keeping the system at a temperature range of 15 - 30° C and forming the microencapsulated suspension; (vi) neutralizing the microencapsulated suspension of step (v) with an organic aliphatic amine and stirring the same for 30 - 60 minutes, after adding a structuring agent, to obtain the safe delivery system in form of microencapsulated suspension of agriculturally active material. DETAILED DESCRIPTION OF THE INVENTION: The present invention provides a safe delivery system of agriculturally active material by microencapsulation and describes a process for preparing microcapsules of agriculturally active water immiscible material, where outer wall of the capsulated core material is a natural modified polymer. The materials used for the microcapsule wall in this invention is starch grafted with atleast one monomer of vinyl group, which gives a biodegradable microcapsule wall material. The ratio between starch and monomer is 1:1 to 1:5 and preferably the ratio is 1:1 to 1:3 and more preferably is 1:1 to 1:2. The agriculturally active material, which is to be protected as per this invention, is Pyrethroids and more specifically Lambda Cyhalothrin. Starch is hydrophilic and partially water soluble polymer, which is being used in the present invention as a polymer wall to the core material after grafting with a monomer of Vinyl group. Starch used in the present invention which includes starch from corn, wheat, potatoes, rice, sago and sorghum, suitable starch derivatives can be starch ethers, starch esters, cross-link starch and oxidized starch. Monomer is any monomer polymerizable on the thinned gelatinized starch through a free radical initiator may be used to produce starch graft polymers. The suitable monomers for grafting are any monomer polymerizable on the thinned gelatinized starch through a free radical initiator may be used to produce starch graft polymers. The monomers or combination of monomers can be chosen so that starch graft co-polymers particles dispersed in aqueous continuous phase. These vinyl monomers such as vinyl halide, vinyl ethers, alkyl vinyl ketones, N-Vinyl carbzole, N-Vinyl pyrolidone, Vinyl pyrridine, styrene, alkyl styrene, acrylic acid, alkyl methylacrylates, acrylamides, substituted acrylamides, vinyledenehalides, itaconic acid, 1, 3-butadine and like among these acrylonitrile, methyl methacrylate, vinyl acetate, 2-ethyl hexyl acrylate and the lower alkyl acrylates such as methyl acrylates, ethyl acrylate, n-butyl acrylates are preferred when single monomer used to form graft polymer. The material which is encapsulated is an agriculturally active material preferably an insecticide particularly pyrethriod and more preferably Lambda Cyhalothrin. The encapsulated material may be a combination of two or more such ingredients. Surfactants can be anionic or non-ionic surfactant with HLB range about 12 -16 that is high enough to form stable oil/water emulsion. Suitable surfactants includes polyethylene glycol ethers of linear alcohol, ethoxylated nonyl-phenol, naphthalene sulphonates, salts of long chain alkyl benzene sulphonate, block-co-polymers of propylene oxide and ethylene oxide, and anionic /nonionic blends. Solvents are alkyl benzene, methylnapthalene, alkyl esters of pthalic acid, trimellitic acid, aromatic hydrocarban such as xylene, naphthalene mix of aromatics aliphatic or cycloaliphatic hydrocarbon such as hexane, heptane, phthalates, ketones such as cyclohexanone or acetophenone or chlorinated hydrocarbons, vegetable oils or mix of such two or more solvents. Free radical initiator is any polymerization initiator which acts to initiate free radical polymerization on gelatinized thinned starch to the substantial exclusion of initiation of homo or co-polymerization of the monomer or mixture of monomer utilized to form starch graft co-polymer is suitable initiator. Ceric ammonium nitrate is example of such initiator; the combination of hydrogen peroxide and acetate ion is also useful initiator. The protective colloid can be selected from a wide range of materials which must have the property of absorbing on the surface of oil droplets. The suitable colloid include one or more methyl cellulose, polyvinyl alcohol, poly-acrylamide, poly (methyl vinyl ether/maliec anhydride), graft co-polymers, alkali metals and alkaline earth metals of alkyl naphthalene sulphonate preferably, however the protective colloid is selected from alkali metals and alkaline earth metals of alkyl naphthalene sulphonate. Antifreezing agent is being used to make the formulation workable in any atmosphere. Antifreezing agent may include ethylene glycol, diethylene glycol, propylene glycol, glycerol etc. Biocide is selected from Methyl paraban, ethyl paraban, formaldehyde, glutaraldehyde, 2-bromo-2-nitropropane-l, 3 diol, 4, 4 dimethyloxazolide, 7-ethybicyclo oxazolide and others. Neutralizing agent is an organic aliphatic amine such as tri-ethanol amine. Structuring agent is selected from xanthan gum, guar gum, arabic gum, HPMC, CMC and others. The process for preparing microencapsules of agriculturally active water immiscible material comprises the following steps: Firstly preparing an organic phase comprising an agriculturally active water immiscible material to be encapsulated and a solvent, in presence of at least one surfactant by continuously stirring to get a clear solution. The second step is to prepare an aqueous phase comprising water, starch, a protective colloid, a biocide, with or without an anti freezing agent and a surfactant, by heating the same at 65 - 85° C temperature for 15-45 minutes to get the aqueous phase in gelatinized form followed by cooling the system at room temperature (20 - 45° C). In third step is of adding the organic phase of first step into the aqueous phase of second step slowly with high shear to form an oil-in-water emulsion, in which the oil droplets size is less than 5 microns The forth step is of adding an initiator to generate free radicals to maintain the pH of the emulsion of third step between 2-5, and simultaneously purging an inert gas so as to keep the atmosphere, oxygen-free, at a temperature range between 15 - 30° C The fifth step is of adding a monomer slowly at a constant rate such that a grafting reaction occurs at the interface of organic and aqueous phase, while maintaining the system at a temperature range of 15 - 30° C and forming the microencapsulated suspension The sixth step is of neutralizing the microencapsulated suspension of fifth step with an organic aliphatic amine and stirring the same for 30 - 60 minutes after adding a structuring agent to obtain the desired microencapsulated suspension of agriculturally active material Examples: Following the invention is illustrated by the non-limiting examples of preparing the composition of the present invention Examples: 1 1) Organic phase: a) Lambda Cyhalothrin (Purity 95%) - 52.63 g (active content) b) Solvesso-200 - 52.00 g (Solvent) c) Calcium salt of alkyl benzene sulfonic acid - 10.00 g (anionic surfactant) d) Polyoxyethylene Nonyl phenol-9 moles - 10.00 g (Nonionic Surfactant) 2) Aqueous Phase: a) Starch - 05.00 g (Polymer) b) PEG - 25.00 g (Antifreezing agent) c) GeroponTA 72 - 10.00 g (Anionic surfactant) d) Emulsol 101 - 50.00 g (Dispersant) e) Methyl paraban - 05.00 g (Biocide) f) Xanthan gum (2% gel) - 20.00 g (Structuring agent) g) Vinyl acetate - 10.00 g (Monomer) h) Ceric ammonium nitrate (10 % in 1 Normal HN03) - 20.00 g (Initiator) i) Triethanol amine - 2.500 g (pH modifier) j) Water - QS (Diluent) 500.00 g The Above composition can be prepared by following the described method: The organic phase was prepared by mixing 52.63 g of Lambda Cyhalothrin technical in 52.00 g Solvesso-200 alongwith 10.00 g of Calcium salt of alkyl benzene sulfonic acid (anionic surfactant) and 10.00 g of Polyoxyethylene Nonyl phenol-9 moles (Nonionic Surfactant) by continuously stirring to get a clear solution; The aqueous phase was prepared by dissolving 10.00 g of Geropon TA-72 and 25.00 g of PEG along with 50.00 g Emulsol-101 and 5.00 g Starch in water and this was heated to 70-90 °C to form gelatinize mass, which was cooled to 15-30°C; The organic phase was added into the aqueous phase (ii) slowly with high shear to form an oil-in-water emulsion in which the oil droplets size is less than 5 microns and 20.00 g free radical initiator was added into this emulsion and stirred while an inert gas (N2) was purged to keep the oxygen-free atmosphere. The system was maintained at a temperature range of 22-25 C and at a pH maintained at 2.9-3.0 with the help of using concentrated HN03. Thereafter 10 g of Vinyl acetate monomer was added at a constant rate into such that a grafting reaction occurs at the interface of organic and aqueous phase, while maintaining the system at a temperature range of 15 -30 C and microencapsulated suspension is formed. After completion of the reaction, neutralize the whole mass with 2.50g of Triethanaolamine. Thereafter, 20.00 g of Xanthan gum (2% gel) was added to the whole mass. Stirring the whole mass for an additional 30 - 60 minutes to get microcapsules of Lambda Cyhalothrin of the present invention in which the oil droplet size is less than 5 microns. Examples: 2 1) Organic phase: l)Lambda Cyhalothrin (Purity 95%) - 105.00 g (active content) 2)Solvesso-200 -100.00 g (Solvent) 3) Calcium salt of alkyl benzene sulfonic acid - 12.00 g (anionic surfactant) 4) Polyoxyethylene Nonyl phenol-9 moles - 12.00 g (Nonionic Surfactant) 2) Aqueous Phase: a) Starch -08.00g (Polymer) b) PEG - 25.00 g (Antifreezing agent) c) GeroponTA 72 - 10.00 g • (Anionic surfactant) d) Emulsol 101 - 50.00 g (Dispersent) e) Methyl paraban - 05.00 g (Biocide) f) Xanthangum - 20.00 g (Structuring agent) g) Vinyl acetate - 16.00 g (Monomer) h) Ceric ammonium nitrate (10 % in 1 Normal HN03) - 20.00 g (Initiator) i)Triethanol amine - 2.500 g (PH modifier) i) Water -QS (Diluent) 500.00 g The above composition can be prepared by following the method as described in Example -1 except keeping the system at 25°C and pH 3.2 (adjusted by using concentrated HN03) after initiator was added. Examples: 3 1) Organic phase: a) Lambda Cyhalothrin (Purity 95%) - 158.00 g (active content) b) Solvesso-200 - 150.00 g (Solvent) c) Calcium salt of alkyl benzene sulfonic acid - 15.00 g (anionic surfactant) d) Polyoxyethylene Nonyl phenol-9 moles - 15.00 g (Nonionic Surfactant) 2) Aqueous Phase: a) Starch - 12.00 g (Polymer) b) PEG - 25.00 g (Antifreezing agent) c) GeroponTA 72 - 10.00 g (Anionic surfactant) d) Emulsol 101 - 50.00 g (Dispersent) e) Methyl paraban -05.00g (Biocide) f) Xanthan gum -20.00g (Structuring agent) g) Vinyl acetate - 24.00 g (Monomer) h) Ceric ammonium nitrate (10 % in 1 Normal HN03) - 20.00 g (Initiator) i) Triethanol amine - 2.500 g (pH modifier) j) Water -QS (Diluent) 500.00 g The above composition can be prepared by following the method as described in Example -1 except keeping the system at 25°C and pH 3.8 (adjusted by using concentrated HNO3) after initiator was added. Examples: 4 5) Organic phase: a) Lambda Cyhalothrin (purity 95%) - 52.63 g (active content) b) Solvesso-200 - 52.00 g (Solvent) c) Calcium salt of alkyl benzene sulfonic acid - 10.00 g (anionic surfactant) d) Polyoxyethylene Nonyl phenol-9 moles - 10.00 g (Nonionic Surfactant) 6) Aqueous Phase: a) Starch - 05.00 g (Polymer) b) PEG - 25.00 g (Antifreezing agent) c) GeroponTA 72 - 10.00 g (Anionic surfactant) d) EmulsollOl - 50.00 g (Dispersent) e) Methyl paraban -05.00g (Biocide) f) Xanthan gum -20.00g (Structuring agent) g) Vinyl acetate - 10.00 g (Monomer) h) Ceric ammonium nitrate (10 % in 1 Normal HN03)- 02.00 g (Initiator) i) Triethanol amine - 2.500 g (pH modifier) i) Water -QS (Diluent) 500.00 g The above composition can be prepared by following the method as described in Example -1 except keeping the system at 25°C and pH 4.0 (adjusted by using concentrated HNO3) after initiator was added. Examples 5 1) Organic phase: a) Lambda Cyhalothrin (purity 95%) - 52.63 g (active content) b) Solvesso-200 - 52.00 g (Solvent) c) Calcium salt of alkyl benzene sulfonic acid - 10.00 g (anionic surfactant) d) Polyoxyethylene Nonyl phenol-9 moles - 10.00 g (Nonionic Surfactant) 2) Aqueous Phase: a) Starch - 05.00 g (Polymer) b) PEG - 25.00 g (Antifreezing agent) c) GeroponTA 72 - 10.00 g (Anionic surfactant) d) Emulsol 101 - 50.00 g (Dispersent) e) Methyl paraban -05.00g (Biocide) f) Xanthan gum -20.00g (Structuring agent) g) Vinyl acetate - 10.00 g (Monomer) h) Ceric ammonium nitrate (10 % in 1 Normal HN03)- 10.00 g (Initiator) i) Triethanol amine - 2.500 g (pH modifier) i) Water -QS (Diluent) 500.00 g The above composition can be prepared by following the method as described in Example -1 except keeping the system at 25°C and pH 3.0 (adjusted by using concentrated HNO3) after initiator was added. We claim: 1) A process for preparing microencapsulated suspension for safe delivery system of agriculturally active material, comprising the steps of: (i) preparing an organic phase comprising an agriculturally active water immiscible material to be encapsulated and a solvent, in presence of at least one surfactant by continuously stirring to get a clear solution; (ii) preparing an aqueous phase comprising water, starch, a protective colloid, a biocide, with or without an anti freezing agent and a surfactant, by heating the same at 65 - 85° C temperature for 15 - 45 minutes to get the aqueous phase in gelatinized form followed by cooling the system at room temperature (20 - 45° C); (iii) adding the organic phase of step (i) into the aqueous phase of step (ii) slowly with high shear to form an oil-in-water emulsion in which the oil droplets size is less than 5 microns; (iv) adding an initiator to generate free radicals to maintain the pH of the emulsion of step (iii) between 2-5, and simultaneously purging an inert gas so as to keep the atmosphere, oxygen-free, at a temperature range between 15-30° C; (v) adding a monomer slowly at a constant rate such that a grafting reaction occurs at the interface of organic and aqueous phase, keeping the system at a temperature range of 15 - 30° C and forming the microencapsulated suspension; (vi) neutralizing the microencapsulated suspension of step (v) with an organic aliphatic amine and stirring the same for 30 - 60 minutes after adding a structuring agent to obtain the safe delivery system in form of microencapsulated suspension of agriculturally active material. 2) The process as claimed in claim 1, wherein the monomer is selected from Vinyl group. 3).The process as claimed in claim 1 or claim 2, wherein the monomer is vinyl acetate monomer. 4) The process as, claimed in claim 1, wherein the starch, monomer ratio is 1:1 to 1:5. 5) The process as claimed in claim 1 or claim 4, wherein the starch, monomer ratio is 1:1 to 1:2. 6) The process as claimed in claim 1, wherein the initiator is a free radical initiator. 7) The process as claimed in claim 1 or claim 6, wherein the initiator is eerie ammonium nitrate. 8) The process as claimed in claim 1, wherein the surfactant is an anionic surfactant or non-ionic surfactant or a combination thereof. 9) The process as claimed in claim 1, wherein the biocide is selected from methyl paraban, ethyl paraban or butyl paraban. 10) The process as claimed in claim 1, wherein the protective colloid is selected from alkyl metals or alkaline earth metals of alkyl naphthalene sulphonate. 12) The process as claimed in claim 1, wherein the agriculturally active materil is a pyrethriod. 13) The process as claimed in claim 1 or claim 12, wherein the agriculturally active material is Lambda Cyhalothrin. 14) Microcapsules for safe delivery system of agriculturally active material is prepared by following the process as claimed in any of the above mentioned claims. Dated this 10th day of May, 2004 M. B. TRIVEDI Company Secretary United Phosphorus Limited, UNIPHOS HOUSE, 11th Road. C. D. Marg, Khar (west), Mumbai-400052, India.

Documents:

539-mum-2004-abstract(10-5-2005).doc

539-mum-2004-abstract(10-5-2005).pdf

539-mum-2004-claims(granted)-(10-5-2005).doc

539-mum-2004-claims(granted)-(10-5-2005).pdf

539-mum-2004-correspondence(10-10-2007).pdf

539-mum-2004-correspondence(ipo)-(17-12-2007).pdf

539-mum-2004-form 1(10-5-2004).pdf

539-mum-2004-form 1(10-5-2005).pdf

539-mum-2004-form 18(13-10-2006).pdf

539-mum-2004-form 2(granted)-(10-5-2005).doc

539-mum-2004-form 2(granted)-(10-5-2005).pdf

539-MUM-2004-FORM 3(1-7-2011).pdf

539-mum-2004-form 3(10-10-2007).pdf

539-mum-2004-form 3(10-5-2004).pdf

539-mum-2004-form 3(10-5-2005).pdf

539-mum-2004-form 5(10-5-2005).pdf

539-mum-2004-form-pct-isa-210(10-5-2004).pdf

539-MUM-2004-PETITION UNDER RULE 137(1-7-2011).pdf