Title of Invention

A MICROEMULSION FORMULATION OF DIPHENYL ETHER HERBICIDE

Abstract The present invention relates to aqueous micro emulsions pesticidal formulations and a process for producing aqueous micro emulsions pesticidal formulations of herbicidal active ingredient in both Oil and water phases, where the oily phase is emulsified or dispersed in water by an emulsifying system.Combination of surfactants found to give a good stable product and also showed improved bioefficacy when compared with commercial available product.
Full Text COMPLETE AFTER PROVISIONAL LEFT ON 29/ 3/ 06
FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE
Specification
(See section 10 and rule 13)
A MICROEMULSION FORMULATION OF DIPHENYL
ETHER HERBICIDE
INDOFIL CHEMICALS CO.
(a division of MODIPON LIMITED)
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 aqueous pesticidal formulations.
FIELD OF INVENTION
The present invention relates to stabilized concentrated or diluted emulsion of the type oil in water exhibiting a herbicidal activity and to a process for making the emulsions. More specifically, the invention envisages stable oil in water microemulsions, a herbicidal active ingredient in both Oil and water phases, where the oily phase is emulsified or dispersed in water by an emulsifying system.
I INTRODUCTION
Aqueous pesticidal formulations have attracted considerable interest in
recent years, because they possess certain advantages over non-aqueous
formulations. >
The advantage of an aqueous formulation includes reduction or elimination of organic solvents. This reduction or elimination of organic solvents results in reduced phytotoxicity, safer handling, and better compatibility with a greater variety of packaging materials and in some instances enhanced biological activity.
Micro emulsions present a unique class of thermodynamically stable liquid dispersions. Stability is attributed to presence of near or zero interfacial tensions at equilibrium and also a minimum or negative Gibb's free energy term for the system. In order to achieve low interfacial tensions, the use of several surfactants is usually required. Typically the selection of surfactants requires one surfactant to be soluble in the water phase and another to be soluble in the organic phase. Each one has only a marginal effect on the other and their combined effect may be large enough to reduce the interfacial tension to near zero at finite concentrations.
Advantages of micro emulsion are that there is a significant reduction of organic solvents resulting in reduced phytotoxicity, safer handling, enhanced biological activity.
2

This invention relates to a herbicidal composition containing Oxyfluorfen.

Oxyfluorfen
IUPAC: 2-chloro-a,a,a-trifluoro-p-tolyl 3-ethoxy-4-nitrophenyl ether
CAS: 2-chloro-l-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene
Formula: C15H11CIF3NO4
Activity: herbicides (nitrophenyl ether herbicides)

Structure:


Physical properties:
Appearance : Oxyfluorfen is a white to orange or red-
brown crystalline solid with a smoke-lie odour.
CAS Number : 42874-03-3
Molecular weight : 361.70
Water solubility : 0.1mg/L
Solubility in other solvents : v.s in most organic solvents (e.g
acetone, cyclohexanone, isophorone)
Melting point : 84 to 85 C
Oxyfluorfen is a selective pre- and post-emergence herbicide used to control certain annual broadleaf and grassy weeds in vegetables, fruit, cotton, ornamentals, and on non-crop areas ( e.g. rail and highway right-of-ways) . It is a contact herbicide and light is required for it to affect target plants. It is a general use pesticide (GUP).
Background of the invention
Commercially available herbicide compositions include a very large variety of active herbicide compounds. Herbicide compositions can be prepared
i
from a variety of different types of precursor compositions, and can be commercially available and used in a variety of different types of
3

compositions. This includes compositions referred to as wettable powders, water dispersible granules, granules, aqueous solutions, water soluble powders, emulsifiable concentrates, oil-based flowables, concentrated emulsions, suspo-emulsions, emulsions, suspensions, suspension concentrates, mixtures) dispersions, and microemulsions, as well as others. Any of these different types of compositions may have different advantages or disadvantages depending on what type of active ingredients the herbicide include.
Here, referring to liquid formulations in general and emulsions in specific, an emulsion is the result of dispersing one immiscible liquid in another, and is made relatively stable by means of one or more emulsifying agents, which are usually surface-active agents.
Emulsions may be categorized in two ways: first by the size of the dispersed particles (that is to say micro- vs. microemulsions) and second by the nature of which phase forms the dispersed droplets and which is the continuous phase (that is to say oil-in-water O/W, vs. water-in-oil, W/O. Both O/W and W/O micro-emulsions and macroemulsions are used for pesticidal compositions, the preference depending upon the system components and the required stability criteria. Macroemulsions generally have a dispersed droplet particle size from about 0.2 to about 50 microns. However, they are basically more unstable than a microemulsion ( Turning now to microemulsions, when a cosurfactant such as a medium chain length alcohol is added to a mixture containing oil, water and surfactant, the solubilisate (oil or water) can form a core surrounded by a layer of surfactant and cosurfactant molecules. The globules of oil-in-water or water-in-oil are almost all of the same size, being less than 200 nm (and possibly falling within the range of from 10 to 100 nm).
4

Microemulsions have a number of physical properties, which can be regarded, either singly or together as characteristic features of the formulation. They have: a typical way of scattering light. Rheology and rates of sedimentation may also be used to differentiate microemulsions from other emulsions.

One of the best macroemulsions is on
means of differentiating microemulsion from the basis of particle or droplet size by using an appropriate particle size analyzer. Additionally the microemulsion formulation will be clear or translucent, except in the viscoelastic phase.
In the prior art use of Microemulsions of Diphenyl ethers using base as water are unknown, however, combinations of these diphenyl ether type herbicide with water soluble herbicide found in literature are briefed as below.
US5,565,409 disclosed a liquid concentrate herbicidal composition comprising: at least 15% by weight based on the total composition of N-
phosphonomethylglycine or of a salt thereof or of a mixture of salts thereof
i
(calculated as acid equivalent); a water-insoluble diphenyl ether type
herbicide (Oxyfluorfen or acifluorfen) in the ratio by weight of N-
phosphonomethylglycine a.e. to diphenyl ether type herbicide of from about
10:1 to about 100:1; about 5 to about 25% by weight of a surface active
component comprising a mixture of an alkoxylated fatty amine with a

surfactant chemically different from the alkoxylated fatty amine; 0 to about
10% by weight of solvent, the surface active component optionally with
admixture of the solvent being capable of dissolving the diphenyl ether
herbicide; about 1 to about 25% by weight of a compatibility agent; and
water if necessary to total 100%.
US 6,274,570 discloses a liquid pesticidal composition, which is substantially free of water, comprising a hydrophobic pesticide or mixture of pesticides dissolved in an organic solvent and comprising as surfactants (a) a castor oil ethoxylate having 30-50 mol ethoxylate, (b) a branched C.sub.8 -

C.sub. 18 alcohol ethoxylate having 5-10 mol ethoxylate, and (c) a tristyrenephenol-ethoxylate having 8-30 mol ethoxylate, or its phosphate or salt thereof. The compositions also include gels having a viscosity of 500 to 20,000 mPas and comprising additionally a gelling agent.
US 6,667,276 relates to surfactant systems for liquid aqueous or aqueous-organic formulations comprising a mixture of one or more basic co-surfactants and one or more surfactants from the group of the acidic phosphoric esters. The surfactant system makes possible the preparation of stable liquid formulations for active compounds, the formulations comprising (a) one or more water-soluble active compounds (type (a)) and (b) optionally one or more water-insoluble active compounds (type (b)), (c) optionally organic solvents, (d) the abovementioned surfactant system and water. The formulations are either single-phase aqueous or aqueous-organic formulations of type-(a) active compounds, for example glufosinate-ammonium or glyphosate (salts), or they are microemulsions of type-(a) and type-(b) active compounds, for example diphenyl ether herbicides.
OBJECT OF THE INVENTION
The object of the invention is to provide a microemulsion formulation of a diphenyl ether herbicide!.
Another object of the invention is to provide a microemulsion formulation of 2-chloro-a,a,a-trifluoro-p-tolyl 3-ethoxy-4-nitrophenyl ether (Oxyfluorfen).
Yet another object of the invention is to provide process for the preparation of a microemulsion formulation of Oxyfluorfen.
Yet another object of the invention is to provide a stable and improved bioeffective microemulsion formulation of Oxyfluorfen.
SUMMARY OF THE INVENTION
According to this invention, therefore there is provided a microemulsion
formulation of diphenyl ether herbicide comprising
6

a) bioeffective amount of 2-chloro-a,a,a-trifluoro-p-tolyl 3-ethoxy-4-nitrophenyl ether (Oxyfluorfen );
b) at least one surfactant having mass of about 1 % to about 50 % of the total mass of the microemulsion;
c) at least one cosurfactant having mass of about 1 % to about 30 % of
the total mass of the microemulsion;
i
d) at least one pigment having mass of about 0.1 % to about 2 % of the total mass of the microemulsion;
e) water having mass of about 1 % to about 50 % of the total mass of the microemulsion;
f) at least one water immiscible carrier having mass of about 1% to about 35% of the total mass of the microemulsion.
Preferably, the mass of Dxyfluorfen ranges from about 1% to about 10% of the total mass of the microemulsion and more preferably from about 1 % to about 8 % of the total mass of the microemulsion and yet more preferably from about 1 % to about 5 % of the total mass of the microemulsion.
Preferably, the mass of surfactant ranges from about 1 % to about 30% of the total mass of the microemulsion and more preferably from about 1% to about 25 % of the total mass of the microemulsion.
Preferably, the mass of cosurfactant ranges from about 1 % to about 25% of the total mass of the 'microemulsion and more preferably from about 1% to about 15 % of the total mass of the microemulsion.
Preferably, the mass of pigment ranges from about 1 % to about 1 % of the
total mass of the microemulsion and more preferably from about 0.1% to
i about 0.5 % of the total mass of the microemulsion.
Preferably, the mass of Water ranges from about 1 % to about 40 % of the total mass of the microemulsion and more preferably from about 1 % to about 30 % of the total mass of the microemulsion.
7

In accordance with one embodiment of the invention, the water immiscible carrier is at least one solvent selected from a group of solvents consisting of animal oil, vegetable oil, mineral oil , silicone oil , Butanol, Xylene and Cyclohexanone.
In accordance with another embodiment of the invention, the surfactant is at least one anionic, cationic, zwitterionic or nonionic surfactant selected from a group of compounds consisting of hydrocarbon sulphates, sulphonates and sulphamates, especially compounds wherein the hydrocarbon moiety is an alkyl or alkylaryl group, Phospate esters, tristyryl phenol ethoxylate, potassium salt ( soprophor FL) ( Rhodia chemicals), Ethoxylated castor oil j C EO- 40 ), Ethoxylated Octylphenol (EO-10 ), Ethoxylated Octyl phenol ( EO-70 ), Sorophor BSU (Rhodia chemicals) and Calcium dodecyl benzene sulphonate ( 70%).
In accordance with yet another embodiment of the invention, the cosurfactant is at least one aliphatic alcohols selected from a group of compounds consisting of primary aliphatic alcohols which may have a carbon content of from 5 to 12 or more carbon atoms, lower homologues
i
(for example C.sub.5 to C.sub.7 alcohols) and glycols selected from a group of compounds comprising of ethylene glycol , Propylene glycol, propylene glycol , urea and cosurfactant consisting of at least one Nonionic surfactants selected from a group of compounds comprising of ethylene oxide propylene oxide block copolymers , alcohol ethoxylates , ethoxylated octylphenol , nonyl phenol , ethoxylated castor oil ,Tristyryl phenol ethoxylate and water
soluble inorganic salts such as sodium chloride and magnesium sulfate.
i
In accordance with another embodiment of the invention, the pigment is at least one compounds selected from a group of compounds consisting of phthalocyanine pigments and preferably Pigment Green 7 In accordance with another aspect of the invention, there is provided a process for preparing a microemulsion formulation comprising the following steps of
8

a) dissolving Oxyfluorfen in a Water immiscible carrier at a temperature ranging from 15 degree C to 35 degree C to obtain a first solution;
b) dissolving at least one surfactant in the first solution at a temperature ranging from 15 degree C to 30 degree C to obtain a second solution;
c) adding water in the second solution with agitation at at a temperature ranging from 15 degree C to 25 degree C to obtain a macro emulsion;
i
d) adding the co surfactant in the macro emulsion with agitation at a temperature ranging from 15 degree C to 20 degree C to produce a clear micro emulsion;
e) and optionally adding Pigment in clear micro emulsion to give a coloured micro emulsion.
DETAILED DESCRIPTION OF THE INVENTION
To list a few, the formulation has a base as water which is an obvious one
over the standard formulation. Further, the decreased particle size
enhances the bioefficacy of the product. Lesser solvents render the
formulation environmentally safe.
Standard formulation available is Oxyfluorfen 23.5% EC which contains
around 70% solvent which is environmentally unsafe. The oil used in the
formulation need not merely be an "oil" in the sense of a petroleum
i
fraction, although such oils are included. The term "oil" is used to mean any
non-aqueous solvent in which a substance of interest is soluble and which is
immiscible with water; alternatively, the substance of interest may itself be
i the oil. This includes animal, vegetable, mineral or silicone or some other
organic solvent which is water-immiscible, such as an optionally
halogenated hydrocarbon.
The surfactant may be any typical emulsifier as found in most macroemulsion systems. The surfactant may be anionic, cationic,
i
zwitterionic or nonionic. Anionic surfactants are more frequently used. Suitable anionic surfactants include hydrocarbon sulphates, sulphonates and
9

sulphamates, especially compounds wherein the hydrocarbon moiety is an alkyl or alkylaryl group. Phosphate esters, trustily phenol ethoxylate, potassium salt (soprophor FL).
i
Another factor in determining the choice of surfactant is the type of microemulsion (w/o or o/w) to be produced. Low HLB surfactants (for example having an HLB of from 4 to 9, particularly 4 to 7) tend to stabilise w/o microemulsions and should therefore for preference be used for w/o
microemulsions and high HLB surfactants (for example having an HLB of
i
from 9 to 20, particularly 9 to 20) tend to stabilise o/w micro emulsions and should thus be used for o/w micro emulsions. HLB values may be measured
by standard techniques
j
After having made the initial selection (e.g. on the basis of HLB), further selection of the surfactant can be achieved by comparing the hydrophobic portion of the surfactant with the structure of the oil, as discussed above. Polar groups on the surfactant also play an important role and should be considered in the matching process.
Water-miscible formulations in accordance with the first aspect of the invention include a cosurfactant Two classes of cosurfactants are normally preferred for use, although others may be used. Aliphatic alcohols tend to be used to stabilise other formulations, including o/w microemulsions.
Nonionic surfactants form a more versatile group of cosurfactants. They can be balanced with the primary surfactant to give systems that are stable as micellar solutions and as both w/o and o/w microemulsions. A whole range of nonionics can be used, including ethylene oxide propylene oxide block copolymers, alcohol ethoxylates, ethoxylated octylphenol, nonyl phenol, ethoxylated castor oil, Tristyryl phenol ethoxylate.
Further, if required, a compatibility agent may be added to the formulation. THE compatibility agent predominantly belongs to the group of alchohols, particularly primary aliphatic alcohols and glycols are a preferred class. The
10

primary alcohols may have a carbon content of from 5 to 12 or more carbon atoms. Lower homologues (for example C.sub.5 to C.sub.7 alcohols) are used to stabilise certain formulations.
The relative proportions of the various ingredients of the formulations in accordance with the present invention can vary widely. The broad concentration ranges of the ingredients can be as follows:

Ingredient Broad w/v
Oil (including dissolved 1 to 35%
i substance if any)
Surfactant 1 to 35%
Compatibility Agent '. 1 to 15%
Water Q.S
In general the amounts of surfactant and cosurfactant should be kept as low as possible and the amount of water should be kept as high as possible. The above is subject always to the condition that the total number of percentage parts of the ingredients cannot exceed 100.
A water-insoluble oil-soluble substance which it is desired to formulate may be dissolved in the oil, although it is clear that the oil may itself be the water-insoluble oil soluble substance. This "substance of interest" can be anything which is convenient to be formulated in this manner (including other solvents). Pesticides such as synthetic pyrethroids and herbicides are particular candidates for, formulation by means of the present invention.
In principle, formulations in accordance with the invention can be made very simply by mixing the ingredients. Depending on the thermodynamic favourability of the system, the ingredients will tend to form a microemulsion, micellar solution or molecular solution. In practice, however, kinetic considerations may dictate that some agitation is preferably used to assist the mixing. Agitation may be by magnetic or mechanical means or in some cases ultrasonic.
11

This invention particularly relates to a process for making an Oxyfluorfen microemulsion formulation having a solvent (oil) 10 to 25 %, a compatibility agent 10 to 20% and surfactant 20 to 30% along with water 30 to 40%.
The order of addition of the ingredients is not critical but preferably:
Oil is added to the vessel, solid Oxyfluorfen is dissolved in the oil, a first
surfactant is added and dissolved in the oil, water is added and agitated to
give a macro emulsion,, then the co surfactant is added and the system is
agitated to produce a clear micro emulsion.
Modifications can be made to the process, which include the application of
i
heat and altering the degree of agitation.
The aqueous formulations of the invention are useful in many areas of
preservation and agricultural applications, depending on the activity of the
active ingredient. The micro emulsion concentrates of the invention can be
prepared by dissolving .solid active ingredient in an organic solvent to form
the oil phase. The surfactants can then be added to the oil phase, either
individually or in combination. The resulting mixture is gently stirred or
agitated to give micro emulsion concentrate.
The micro emulsions of the invention may be prepared by diluting a micro emulsion concentrate with water. Alternatively, a micro emulsion may be prepared directly without going through a concentrate form. This is accomplished by simply adding the desired amount of water along with surfactants and other auxiliaries in the same manner as described for the micro emulsion concentrates. Both methods of micro emulsion formation are preferred. Pigment may also be added in the formulation to give coloured appearance to the formulation.
The range of components is as follows (All parts by weight percent)
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Ingredient Broad w/v Preferred Most preferred
Active 1 to 10 1 to 8 1 to 5
Surfactant 1 to 50 1 to 30 1 to 25
Co Surfactant 1 to 30 1 to 25 1 to 15
Water 1 to 50 1 to 40 1 to 30
Pigment Oil to 2 0.1 to 1 0.1 to 0.5
The idea of the ratio of total surfactants to emulsified oil is important. The amount of surfactants required to emulsify an oil will depend on the amount of oil in the emulsion, more specifically the interfacial surface area which is proportional to the amount of emulsified oil at constant particle size. The micro emulsions described here have relatively low surfactant to oil ratios, about 1:1. If the ratio of surfactant to oil becomes say >5:1 the

compositions are better described as solubilized emulsions or micellar

solutions.
In addition , it may be necessary, in the use of the microemulsions or in
the preparation of the microemulsion , to use various adjuvants including
antifoam agents , such; as the commercially available silicone antifoam
emulsions and the like ,; antifreeze agents such as propylene glycol , urea
and the like , water soluble inorganic salts such as sodium chloride ,
magnesium sulfate and the like which are used to optimize the action of the
surfactant because it increases the concentration of the surfactant at the
interface of the microemulsion .
Table 1 and Table 2 shows the composition of microemulsion concentrates and microemulsions used in the following examples. These samples were prepared by dissolving the active ingredient in a solvent to yield an oil phase. To this oil phase were combined the desired surfactants and cosurfactants to yield the microemulsion concentrate samples. The microemulsions were prepared by diluting the concentrates with water.
Solvents used: 1. Butanol
13

2. Xylene
3. Cyclohexanone
Surfactants:
Surfactant a Ethoxylated castor oil (EO- 40) Surfactant b Ethoxylated Octylphenol (EO-10) Surfactant c Ethoxylated Octyl phenol ( EO-70 ) Surfactant d Sorophor FL (Rhodia chemicals) Surfactant e Sorophor BSU (Rhodia chemicals) Surfactant f Calcium dodecyl benzene sulphonate (70%) Surfactant g Tergitol XD (Union carbide chemicals)
Co-surfactant: Propylene glycol
Coloured pigment: Pigment Green 7 [Hostaperm Green GNX (Clariant)]

Testing micro emulsions,
a. Initial observation at ambient temperature
C : Clear appearance microemulsion
SO : slightly opalescent microemulsion
CL : cloudy appearance macroemulsion
b. Observation at 54 degree and cold ( zero degree)
The micro emulsion concentrate or the micro emulsion prepared is placed in an oven at 54 degree Celsius and another portion in a freezer at Zero degree Celsius. An observation is made after (24 hours). In case of accelerated storage study the observation is made after 14 days.
2. Aqueous dilutions
Dilutions are made with 0.5 ml of formulated sample with 99.5 ml water (342 ppm water). A rating scale of 0-4 is used to evaluate the clarity of the dilutions. The sample is evaluated immediately after the dilution. Because there can be tendency for coalescence of emulsified particles with time to give larger particles and a corresponding increase in opacity, a second reading is taken after 24 hours. The scale is defined as follows.
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0= perfectly clear, 1= opalescence, 2= cloudy /turbidity, 3= phase separation, 4=crystal formation
The following examples are given by way of illustration only and are not to be considered limiting in any manner (Table 1)

Experime nt Experim ent Experim ent Experim ent Experim ent Experime nt
A b c d e f
Active Ingredient 10.90 10.90 10.90 22.5 23.5 23.5
Solvent 2 30.5 25.2 22.7 19.0 10.4
Solvent 1 17.5 8.4 8.7 10.5 8
Solvent 3 33.6 36.35 32.1
Surfactant f i 6.55 12.6 17.4 9.5 11.65 10
Surfactant b 2.6 3.7 5.2 5.7 6.4 6
Surfactant c 8.7 11.7 5.2 6.7 8.00 6.8
Surfactant d 1.3 2.5 3.5 3.00 3.6 3.2
Wateri 21.95 25.00 26.4

lOOgm 100 gm 100 gm 100 gm 100 gm 100 gm

Initial appearance at Ambient temperature C C C C C C

Cold test at zero degree (After two hours) Fails Fails Fails Passes Passes Passes
Day one :— — Passes Fails Fails
Day seven -— — — Passes — —
Dilution study (one hour) 0 0 0 0 0 0

Dilution study ( twenty four hours ) 2 2 0 1 4 4

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When the active ingredient is in the range of 10 % to 20%, the sample fails either in cold test study or in dilution study. In Table no 2 microemulsions are formulated having Active content of 5% using various surfactants
Table no 2

1 2 3 4 5 6 7 8 9 10 11
Active content 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5
Solvent 3 36 44.6 38 10 12 28 20 28 28 26 26
Solvent 2 4.5
Propylene glycol 15 15 20 20 13 20 15 15^ 16 16
Surfactant f 14 14 14
Surfactant d 3 11 11 11
Surfactant e 2.5 1.5 1.5 1.5
Surfactant b 6 10 14 40 30 37 30
Surfactant c 7 7 7 6
Surfactant g 4 4 4 4
Water 12.5 25.5 20.5 16.5 28.1 28 28 27.95
Solvent 1 17
urea 2
Surfactant a 20 18 11 12 12
Coloured pigment 0.05
100 100 100 100 100 100 100 100 100 100 100
Initialappearance at Ambient temperature C C C C C C C C C C
Appearance after One year SO SO SO SO SO SO SO C C C

Cold test (zero degree)
Day one pass fails fails fails fails pass pass pass pass pass
Day seven pass -- ■ — — — pass pass pass pass pass

Dilution study (One hour) 0 0 0 0 0 0 0 0 0 0
Dilution study (after Twenty hours) 4 4 4 4 2 4 4 1 1 0

Stability study at54Degree (14days) C C C C C C C C C C
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Combination of surfactant a, d, e was found to give a good stable product, (no phase separation, clear and transparent). The sample formulated also showed improved bioefficacy when compared with commercial available sample of Oxyfluorfen 23.5% EC.
EXAMPLES
Bioefficacy results

Trial No. ■ To test the efficacy of Oxyfluorfen 5 ME on cotton against Trianthema sp
Test product • Oxyfluorfen 5% ME
Target Weed ■ Trianthema sp '
Crop • Cotton
Carpet Weed {Trianthema sp) is a major weeds of cotton in Punjab. Field experiments were conducted in a farmer's field as per details given below:

Variety ; Om-3 BT
Number of treatments ■ 8 j
Number of replications ■ Three
Water volume used ■ 200 L per acre
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Treatment Details:
The following treatments were evaluated.

PRODUCT Dosage (ml/ acre) Dose / Litre G a i/ acre
Oxyfluorfen 5% ME 940 4.7 47
Oxyfluorfen 5% ME 1175 5.8 58.75
Oxygold 23.5% EC (Existing formulation) 100 0.5 23.5
Oxygold 23.5 % EC (Existing formulation) 150 0.75 35.25
Oxygold 23.5 % EC (Existing formulation) 200 1.0 47
Oxygold 23.5 % EC (Existing formulation) 250 1.25 58.75
Paraquat Dichloride 24% SL Gramoxone (Syngenta) 1000 5 240.0
Control (Weedy Check/unsprayed)
METHODOLOGY:
Sprays of test chemicals were given as a post emergence application 30 days after sowing. Herbicides were applied with a knap sack sprayer using 500 litre of water per hectare. Fertilizers, irrigation and other cultural practices were applied i in accordance with standard local package of practices.
For taking observations; on weeds, the weed count was taken from 3 locations per replication using a quadrant (1ft X 1ft). The count was taken 20 & 40 days after application Dry weight of weeds (gm/ sq ft.) was also
18

recorded 20 and 40 days after application. The weeds from all the
treatments were removed and dried in sunlight and weighed on a Braun
Balance for their dry weight. Weed control efficiency was worked as
follows: i
Weed control efficiency = (Dry matter in control -dry matter in treatment)
X 100
Dry matter in control
Table . COMPARATIVE EFFICACY OF OXYFLUORFEN FORMULATIONS AGAINST TRIANTHEMA SP. IN COTTON.

s. Dose Weed count Dry weight (g) Weed
N Treatment (ml/ (per sq . feet)* (per sc |. feet) control
o acre) efficiency (%)
20 40 20 40 20 40
i DAS** DAS DAS DAS DAS DAS
1 Oxyfluorfen 5 940 1.89 2.56 0.58 1.44 83.2 74.5
ME i (1.70) (1.89) (1.25) (1.56)
2 Oxyfluorfen 5 ME 1175 0.78 (1.33) 1.33 (1.52) 0.16 (1.08) 0.63 (1.28) 95.5 88.8
3 Oxyfluorfen 100 2.78 3.67 1.11 2.22 67.7 60.8
23.5 EC (1.94) (2.16) (1.45) (1.79)
4 Oxyfluorfen 150 2.44 3.55 0.90 1.83 73.8 67.7
23.5 EC (1.85) (2.13) (1.37) (1.68)
5 Oxyfluorfen 200 2.00 2.89 0.71 1.44 79.3 74.5
23.5 EC (1.72) (1.97) (1.30) (1.56)
6 Oxyfluorfen 23.5 EC 250 1.78 (1.66) 2.00 (1.73) 0.64 (1.28) 1.33(1. 53) .81.3 78.4
Paraquat dichloride
7 24% SL Gramoxone (Syngenta) 1000 1.11 (1.45) 1.67 (1.63) 0.19 (1.09) 0.89 (1.38) 94.5 84.1
Control i
8 (weedy Check / Unsprayed) - ! 6.11 (2.65) 8.89 (3.14) 3.44 (2.10) 5.67 (2.57) - -
CD(P=0.05) i 0.30 0.17 0.18 0.22
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* Mean of three replications; **DAS: Days after spray Figures in parentheses are square root transformed values
RESULTS
The results (Table 1) indicate the following
1) After 20 days of herbicide application Oxyfluorfen ME @ 1175 ml/
acre (58.75 g ai/ acre) was found to be superior (0.78 weeds per
square feet) as compared to Oxyfluorfen 23.5 EC @ 250 ml/ acre
(58.75 g ai/ acre) recoding 1.78 weeds/ sq feet.
i
2) On the 40th day Oxyfluorfen 5% ME @ 1175 ml/ acre was once again
effective over Oxyfluorfen @ 250 ml/ acre.
i
3) On the basis of dry weight Oxyfluorfen ME was found most superior
@ 1175 ml/ acre to Oxyfluorfen 23.5 EC @ 250 ml/ acre (0.16 vs
0.64 g/ sq feet) ,
i
4) Weed control efficiency calculated at 20 and 40 days after
transplanting further established the fact that Weed control efficiency of Oxyfluorfen 5% ME is in the range 88 to 95 per cent as compared to 78 to 81% with the conventional EC (Ox gold 23.5 % EC) formulation
20

We Claim:
1. A microemulsion formulation of diphenyl ether herbicide comprising
i
a) bioeffective amount of 2-chloro-a,a,a-trifluoro-p-tolyl 3-
ethoxy-4-nitrophenyl ether (Oxyfluorfen );
b) at least one surfactant having mass of about 1 % to about 50 % of the total mass of the microemulsion and preferably from about 1 % to about 30 % and more preferably from about 1 % to about 25 %;
c) at least one cosurfactants having mass of about 1 % to about 30 % of the total mass of the microemulsion and preferably from about 1 % to about 25 % and more preferably from about 1 % to about 15 %;
d) optionally at least one Pigment having mass of about 0.1 % to about 2 % of the total mass of the microemulsion and preferably from about 0.1 % to about 1 % and more preferably from about 0.1 % to about 0.5 %;
e) water having mass of about 1 % to about 50 % of the total mass of the microemulsion;
f) at least one water immiscible carrier having mass of about 1% to about 35% of the total mass of the microemulsion.
!
2. A microemulsion formulation as claimed in claim 1, wherein the mass of Oxyfluorfen ranges from about 1 % to about 10 % of the total mass of the microemulsion preferably from about 1 % to about 8 % and more preferably from about 1 % to about 5 %.
3. A microemulsion formulation as claimed in any one of the preceding claims, wherein the water immiscible carrier is at least one solvent selected from a group of solvents consisting of animal oil, vegetable oil, mineral oil , silicone oil , Butanol, Xylene and Cyclohexanone.
4. A microemulsion formulation as claimed in any one of the preceding claims, wherein the surfactant is at least one selected from a group of
21

compounds consisting of anionic, cationic, zwitterionic or nonionic surfactant hydrocarbon sulphates, sulphonates and sulphamates, especially compounds wherein the hydrocarbon moiety is an alkyl or alkylaryl group, Phospate esters, tristyryl phenol ethoxylate, potassium salt (soprophor FL) (Rhodia chemicals), Ethoxylated castor oil( EO-40), Ethoxylated Octylphenol ( EO-10 ), Ethoxylated Octyl phenol (EO-70), Sorophor BSU '(Rhodia chemicals), Calcium dodecyl benzene sulphonate ( 70%) and Tergitol XD.
5. A microemulsion formulation as claimed in any one of the preceding claims, wherein the cosurfactant is at least one compound selected from a group of compounds consisting of aliphatic alcohols which have a carbon content of at least 5 carbon atoms, lower homologues (for example C.sub.5 to C.sub.7 alcohols), glycols such as ethylene glycol , Propylene glycol, ethylene oxide, propylene oxide block copolymers, alcohol ethoxylates, ethoxylated octylphenol, nonyl phenol, ethoxylated castor oil, Tristyryl phenol ethoxylate and water soluble inorganic salts such as sodium chloride and magnesium sulfate.
6. A microemulsion formulation as claimed in any one of the preceding claims, wherein the pigment is at least one compounds selected from a group of compounds of consisting of phthalocyanine pigments.
7. A process for preparing a microemulsion formulation as claimed in any one of the preceding claims comprising the steps of

a) dissolving Oxyfluorfen in a Water immiscible carrier at a temperature ranging from 15 degree C to 35 degree C to obtain a first solution;
b) dissolving at least one surfactant in the first solution at a temperature ranging from 15 degree C to 30 degree C to obtain a second solution;
c) adding water in the second solution with agitation at a temperature ranging from 15 degree C to 25 degree C to obtain a macro emulsion;
22

d) adding a co surfactant in the macro emulsion with agitation at a temperature ranging from 15 degree C to 20 degree C to produce a clear micro emulsion;
e) and optionally adding pigment in the clear micro emulsion to give coloured micro emulsion.
8. A composition and a process for preparing the composition substantially as herein described and illustrated with reference to the examples, graphs and figures.
Dated this 29th day of March, 2006.

MOHAN DEWAN
OF R.K. DEWAN & COMPANY
APPLICANTS' PATENT ATTORNEY
23

ABSTRACT
The present invention ; relates to aqueous micro emulsions pesticidal formulations and a process for producing aqueous micro emulsions pesticidal formulations of herbicidal active ingredient in both Oil and water phases, where the oily phase is emulsified or dispersed in water by an
i
emulsifying system. Combination of surfactants found to give a good stable product and also showed improved bioefficacy when compared with commercial available product.

Documents:

422-mum-2005-abstract (complete).doc

422-mum-2005-abstract (complete).pdf

422-mum-2005-abstract(granted)-(17-3-2010).pdf

422-mum-2005-assignment(16-4-2008).pdf

422-mum-2005-cancelled pages(3-9-2009).pdf

422-mum-2005-claims (complete).doc

422-mum-2005-claims (complete).pdf

422-MUM-2005-CLAIMS(3-9-2009).pdf

422-mum-2005-claims(amanded)-(3-9-2009).pdf

422-mum-2005-claims(granted)-(17-3-2010).pdf

422-MUM-2005-CORRESPONDENCE(29-12-2009).pdf

422-mum-2005-correspondence(3-7-2009).pdf

422-MUM-2005-CORRESPONDENCE(3-9-2009).pdf

422-mum-2005-correspondence(ipo)-(17-3-2010).pdf

422-mum-2005-correspondence-received-ver-070406.pdf

422-mum-2005-correspondence-received.pdf

422-mum-2005-description (complete).pdf

422-mum-2005-description (provisional).pdf

422-mum-2005-description(granted)-(17-3-2010).pdf

422-mum-2005-form 13(16-4-2008).pdf

422-mum-2005-form 18(24-7-2007).pdf

422-mum-2005-form 2(granted)-(17-3-2010).pdf

422-mum-2005-form 2(title page)-(granted)-(17-3-2010).pdf

422-MUM-2005-FORM 26(13-12-2010).pdf

422-MUM-2005-FORM 26(3-9-2009).pdf

422-mum-2005-form 6(13-12-2010).pdf

422-mum-2005-form-1.pdf

422-mum-2005-form-2 (complete).doc

422-mum-2005-form-2 (complete).pdf

422-mum-2005-form-2 (provisional).doc

422-mum-2005-form-2 (provisional).pdf

422-mum-2005-form-26.pdf

422-mum-2005-form-3.pdf

422-mum-2005-form-5.pdf

422-MUM-2005-OTHER DOCUMENT(13-12-2010).pdf


Patent Number 239402
Indian Patent Application Number 422/MUM/2005
PG Journal Number 13/2010
Publication Date 26-Mar-2010
Grant Date 17-Mar-2010
Date of Filing 04-Apr-2005
Name of Patentee INDOFIL CHEMICALS CO., (a Division of Modipon Ltd.)
Applicant Address Nirlon House, Dr.Annie Besant Road, Mumbai- 400 025,
Inventors:
# Inventor's Name Inventor's Address
1 JAYAPRAKASH GOPALKRISHNAN RAO Shivalik C.H.S., Lokdhara,C-7/402, Kalyan(East), Maharashtra,India.
PCT International Classification Number A01N37/38,A01N37/36
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA