CLIAMS:We claim:
1. A herbicidal microemulsion including herbicidally active compounds sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) and ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate in combination with water and atleast one non-aqueous polar solvent and atleast one non-polar solvent, wherein the sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) is in 4.5 - 7.5 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate is in 3.0 – 5.0% by weight of the composition, water is in 12.0 to 40.0% by weight of the composition and the non-aqueous polar solvent is in 15.0 – 28.0 % by weight of the composition and non-polar solvent is in 15.0 – 50.0% by weight of the composition and wherein the microemulsion comprises atleast one anionic surfactant in 1.6 to 5.0% by weight of the composition, atleast one non-ionic surfactant in 1.5 to 5.9% by weight of the composition and atleast one humectant in 5% by weight of the composition.
2. The herbicidal microemulsion as claimed in claim 1, wherein the microemulsion comprises sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) in 6.0 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate in 4.0% by weight of the composition, water in 12% by weight of the composition and non-aqueous polar solvent in 18.5 % by weight of the composition, non-polar solvent in 50.0% by weight of the composition, anionic surfactant in 3.0% by weight of the composition, non-ionic surfactant in 1.5% by weight of the composition and humectant in 5% by weight of the composition.
3. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the anionic surfactant is selected from ammonium lauryl sulfate, sodium lauryl sulfate, alkyl-ether sulfate such as sodium laureth sulfate or sodium myreth sulfate or docusate such as dioctyl sodium sulfosuccinate, perfluorooctanesulfonate or perfluorobutanesulfonate and linear alkylbenzene sulfonate such as Suprol T-60 or combinations thereof.
4. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-ionic surfactant is selected from selected from long chain alcohols exhibiting surfactant properties such as fatty alcohol, cetyl alcohol, stearyl alcohol, cetostearyl alcohol or oleyl alcohol, fatty vegetable oil ethoxylated such as NOIGEN EL40, glycerol alkyl ester such as glyceryl laurate or polyoxyethylene glycol and sorbitan alkyl ester such as polysorbate, cocamidemonoethanolamine, cocamidediethanolamine or dodecyldimethylamine oxide or combinations thereof.
5. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the humectant is selected from ethylene glycol, glycerol, sorbitol, propylene glycol, sodium lactate or calcium nitrate or combinations thereof.
6. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-aqueous polar solvent is selected from ketone, dimethylforamide, N- methyl -2-pyrolidine or aliphatic alcohol such as ethyl alcohol, isopropyl alcohol or n-butanol or combinations thereof.
7. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-polar solvent is selected from aromatic hydrocarbon such as benzene, toluene, chlorobenzene or C8-10 aromatic hydrocarbon solvent or combinations thereof.
8. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the anionic surfactant is linear alkylbenzene sulfonate.
9. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-ionic surfactant is fatty vegetable oil ethoxylated.
10. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the humectant is ethylene glycol.
11. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-aqueous polar solvent is n-butanol.
12. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-polar solvent is C9 solvent.
13. The herbicidal microemulsion as claimed in claim 1, which comprises 3% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate , 4.5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 25.0 % by weight n-butanol, 5.9% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60, 40.0% by weight deionized water, 5.0% by weight ethylene glycol and 15.0% by weight C9 solvent.
14. The herbicidal microemulsion as claimed in claim 1, which comprises 5% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 41.0% by weight C9 solvent, 1.5% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60, 12.9% by weight deionized water, 28% by weight n-butanol and 5% by weight ethylene glycol.
15. The herbicidal microemulsion as claimed in claim 1, which comprises 3.5% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 6.5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 38.0% by weight C9 solvent, 27.9% by weight deionized water, 5.0% by weight ethylene glycol, 1.5% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60 and 16% by weight n-butanol.
16. The herbicidal microemulsion as claimed in claim 1, which comprises 4.0% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 6.0% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 50.0% by weight C9 solvent, 12.0% by weight deionized water, 5.0% by weight ethylene glycol, 1.5% by weight NOIGEN EL 40, 3.0% by weight Suprol T- 60 and 18.5% by weight n-butanol.
17. A method for the preparation of a herbicidal microemulsion comprising mixing herbicidally active compounds sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) and ethyl (2RS)–2-[4–(6-chloroquinoxalin -2-yloxy) phenoxy] propionate with water and at least one non-aqueous polar solvent and atleast one non-polar solvent, wherein the sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) is in 4.5 - 7.5 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate is in 3.0 – 5.0% by weight of the composition, water is in 12.0 to 40.0% by weight of the composition and the non-aqueous polar solvent is in 15.0 – 28.0 % by weight of the composition and non-polar solvent is in 15.0 – 50.0% by weight of the composition and wherein the method also comprises mixing atleast one anionic surfactant in 1.6 to 5.0% by weight of the composition, atleast one non-ionic surfactant in 1.5 to 5.9% by weight of the composition and atleast one humectant in 5% by weight of the composition with the herbicidally active compounds and wherein the mixing is carried out under stirring at 25 - 30°C.
18. The method as claimed in claim 17, which comprises mixing sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) in 6.0 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate in 4.0% by weight of the composition, water in 12.0% by weight of the composition and non-a queous polar solvent in 18.5 % by weight of the composition, non-polar solvent in 50.0% by weight of the composition, anionic surfactant in 3.0% by weight of the composition, non-ionic surfactant in 1.5% by weight of the composition and humectant in 5% by weight of the composition.
19. The method as claimed in claim 17 or 18, wherein the anionic surfactant is selected from ammonium lauryl sulfate, sodium lauryl sulfate, alkyl-ether sulfate such as sodium laureth sulfate or sodium myreth sulfate or docusate such as dioctyl sodium sulfosuccinate, perfluorooctanesulfonate or perfluorobutanesulfonate and linear alkylbenzene sulfonate such as Suprol T-60 or combinations thereof.
20. The method as claimed in claim 17 or 18, wherein the non-ionic surfactant is selected from selected from long chain alcohols exhibiting surfactant properties such as fatty alcohol, cetyl alcohol, stearyl alcohol, cetostearyl alcohol or oleyl alcohol, fatty vegetable oil ethoxylated such as NOIGEN El 40, glycerol alkyl ester such as glyceryl laurate or polyoxyethylene glycol and sorbitan alkyl ester such as polysorbate, cocamide monoethanolamine, cocamidediethanolamine or dodecyl dimethylamine oxide or combinations thereof.
21. The method as claimed in claim 17 or 18, wherein the humectant is selected from ethylene glycol, glycerol, sorbitol, propylene glycol, sodium lactate or calcium nitrate or combinations thereof.
22. The method as claimed in claim 17 or 18, wherein the non-aqueous polar solvent is selected from ketone, dimethylforamide, N- methyl -2-pyrolidine and aliphatic alcohol such as ethyl alcohol, isopropyl alcohol or n-butanol or combinations thereof.
23. The method as claimed in claim 17 or 18, wherein the non-polar solvent is selected from aromatic hydrocarbon such as benzene, toluene, chlorobenzene or C8-10 aromatic hydrocarbon solvent or combinations thereof.
24. The method as claimed in claim 17 or 18, wherein the anionic surfactant is linear alkylbenzene sulfonate.
25. The method as claimed in claim 17 or 18, wherein the non-ionic surfactant is fatty vegetable oil ethoxylated.
26. The method as claimed in claim 17 or 18, wherein the humectant is ethylene glycol.
27. The method as claimed in claim 17 or 18, wherein the non-aqueous polar solvent is n-butanol.
28. The method as claimed in claim 17 or 18, wherein the non-polar solvent is C9 solvent.
29. The method as claimed in claim 17, which comprises mixing 3% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate , 4.5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 25.0 % by weight n-butanol, 5.9% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60, 40.0% by weight deionized water, 5.0% by weight ethylene glycol and 15.0% by weight C9 solvent.
30. The method as claimed in claim 17, which comprises mixing 5% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 41.0% by weight C9 solvent, 1.5% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60, 12.9% by weight deionized water, 28% by weight n-butanol and 5% by weight ethylene glycol.
31. The method as claimed in claim 17, which comprises mixing 3.5% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 6.5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 38.0% by weight C9 solvent, 27.9% by weight deionized water, 5.0% by weight ethylene glycol, 1.5% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60 and 16% by weight n-butanol.
32. The method as claimed in claim 17, which comprises mixing 4.0% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 6.0% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 50.0% by weight C9 solvent, 12.0% by weight deionized water, 5.0% by weight ethylene glycol, 1.5% by weight NOIGEN EL 40, 3.0% by weight Suprol T- 60 and 18.5% by weight n-butanol.
,TagSPECI:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
and
THE PATENTS RULES, 2003
As amended by the Patents (Amendment) Rules, 2014
COMPLETE SPECIFICATION
(Section 10 and Rule 13)
TITLE OF THE INVENTION
Herbicidal microemulsion for cotton crops and method for the preparation of the same

APPLICANTS
Godrej Agrovet Limited, Pirojshanagar, Eastern Express Highway, Vikhroli (East), Mumbai 400079, an Indian company
and
Institute of Pesticide Formulation and Technology ( IPFT) , HSIDC, Sector 20, Udyog Vihar, Gurgaon-122016, a research institute under the Department of Chemicals and Petrochemicals, Ministry of Chemicals and Fertilizers, Government of India

INVENTORS
Sahu Pramod Kumar, Waghmare Samson, Ramraj Velaswamy Munuswamy, Tomar Ajeet Singh and Godrej Nadir Burjor, all of Godrej Agrovet Limited, Pirojshanagar, Eastern Express Highway, Vikhroli (East), Mumbai 400079
and
Patanjali Phool Kumar, Dubey Saurabh, Agarwal Amrish and Raza Syed Kalbey, all of Institute of Pesticide Formulation and Technology ( IPFT) , HSIDC, Sector 20, Udyog Vihar, Gurgaon-122016, all Indian Nationals

PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:
FIELD OF THE INVENTION
This invention relates to a herbicidal microemulsion for cotton crops and a method for the preparation of the same.

BACK GROUND OF THE INVENTION
Cotton has many uses and inevitability of cotton in clothing needs no mention. Cotton crop is a cash crop of major source of income to cotton crop cultivators. However, weeds in cotton fields cause heavy losses to the cotton crop. Therefore, controlling of the weeds in cotton fields is extremely important to improve the yield and quality of cotton. Trianthema portulacastrum, Digera arvensis, Amaranthus viridsi, Parthenium hysterophorus, Commelina benghalensis and Celosia argentia are known to be the major broadleaves weeds and Echinochloa spp, Dactyloctenium aegyptium, Dinebra Arabica and digitaria sanguinalis are known to be the major grass weeds in cotton fields.

Pyrithiobac-sodium [sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio] is a selective herbicide for effectively controlling the major broadleaves weeds like Trianthema sp, Digera sp, Amaranthus viridis, Parthemium hysterophorus, Commelina benghalensis and Celosia argentia in cotton crops. However, it is very poorly effective in controlling grass weeds like Echinochloa spp, Dactyloctenium aegyptium, Dinebra Arabica and digitaria sanguinalis in cotton crops. Pyrithiobac-sodium is soluble in water and is known to be used for effective control of the broad leaves weeds as aqueous solutions in weight percentages of 10 to 20. Pyrithiobac-sodium is of the following structural formula:

(The Pesticide Manual, 10th Edition, pages 888-889)

Quizalofop-ethyl [ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate) is a selective systemic herbicide for effectively controlling grass weeds like Echinochloa spp, Dactyloctenium aegyptium, Dinebra Arabica and digitaria sanguinalis in cotton crops. However, it is very poorly effective in controlling broad leaves weeds like Trianthema sp, Digera sp, Amaranthus viridis, Parthemium hysterophorus, Commelina benghalensis and Cclosia argentia in cotton crops. Quizalofop-ethyl is water insoluble and is known to be used for effective control of grass weeds in cotton crops as formulations with organic solvents such as C9 in weight percentages of 80 to 90. Quizalofop-ethyl is of the following structural formula

(The Pesticide Manual, 10th Edition, pages 898-899)

There are also other problems with the above herbicides. They are to be applied separately and individually to control the total weed flora (broad leaves weeds and grass weeds) in cotton crops. Application of the herbicides individually and separately is inconvenient, difficult and cumbersome. Quantities of the herbicides applied on cotton crops individually for effective control of the weeds are high. As a result, the cost is increased and wastage of valuable herbicides also occurs. Usage of large quantities of the herbicides also creates environmental hazards.

It is obvious that if both the above herbicides are made into a single phase formulation, atleast some of the above problems can be avoided. However, we are not aware whether any attempts have been made in the past by others to formulate the two herbicides into a single formulation. In order to improve cotton production and cotton quality, there is need for herbicidal formulations having broad spectrum herbicidal activity and excellent total weed flora control (control against both broad leaves weeds and grass weeds) in cotton crops and having other beneficial effects.

A main problem encountered while formulating the above two herbicides into a single phase formulation is that quizalofop-ethyl is soluble in organic solvent and the organic phase degrades in water in which pyrithiobac-sodium is soluble due to the neutral pH of 7 – 9 of water. Therefore, it is very difficult to formulate a stable single phase formulation of both the herbicides. In any case, we are not aware of any stable single phase formulation of quizalofop-ethyl and pyrithiobac-sodium.

Microemulsions or nanoemulsions are characterised by droplets of at least one order of magnitude smaller (10-100 nm) than those in coarse emulsions. Microemulsions are clear as compared to coarse emulsions which are cloudy. Microemulsions are formed spontaneously, whereas coarse emulsions ordinarily require vigorous stirring. Microemulsions have also other beneficial effects such as ultralow interfacial tension, large interfacial area , thermodynamic stability and ability to solubilize otherwise immiscible compounds. Microemulsion droplets are also stable with respect to separation into their components. Coarse emulsions may have a degree of kinetic stability, but ultimately separate into their components. Therefore, it is very advantageous and beneficial to have herbicidal formulations as microemulsions.

DESCRIPTION OF THE INVENTION
According to the invention there is provided a herbicidal microemulsion including herbicidally active compounds sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) and ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate in combination with water and atleast one non-aqueous polar solvent and atleast one non-polar solvent, wherein the sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) is in 4.5 - 7.5 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate is in 3.0 – 5.0% by weight of the composition, water is in 12.0 to 40.0% by weight of the composition and the non-aqueous polar solvent is in 15.0 – 28.0 % by weight of the composition and non-polar solvent is in 15.0 – 50.0% by weight of the composition and wherein the microemulsion comprises atleast one anionic surfactant in 1.6 to 5.0% by weight of the composition, atleast one non-ionic surfactant in 1.5 to 5.9% by weight of the composition and atleast one humectant in 5% by weight of the composition.

According to the invention there is also provided a method for the preparation of a herbicidal microemulsion comprising mixing herbicidally active compounds sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) and ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate with water and at least one non-aqueous polar solvent and atleast one non-polar solvent, wherein the sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) is in 4.5 - 7.5 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate is in 3.0 – 5.0% by weight of the composition, water is in 12.0 to 40.0% by weight of the composition and the non-aqueous polar solvent is in 15.0 – 28.0 % by weight of the composition and non-polar solvent is in 15.0 – 50.0% by weight of the composition and wherein the method also comprises mixing atleast one anionic surfactant in 1.6 to 5.0% by weight of the composition, atleast one non-ionic surfactant in 1.5 to 5.9% by weight of the composition and atleast one humectant in 5% by weight of the composition with the herbicidally active compounds and wherein the mixing is carried out under stirring at 25 - 30°C.

According to a variation of the invention, the sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) is in 6.0 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate is in 4.0% by weight of the composition, water is in 12% by weight of the composition and non-aqueous polar solvent is in 18.5 % by weight of the composition, non-polar solvent is in 50.0% by weight of the composition, anionic surfactant is in 3.0% by weight of the composition, non-ionic surfactant is in 1.5% by weight of the composition and humectant is in 5% by weight of the composition.

Typically, anionic surfactant or emulsifier is selected from ammonium lauryl sulfate, sodium lauryl sulfate, alkyl-ether sulfate such as sodium laureth sulfate, also known as sodium lauryl ether sulfate (SLES), or sodium myreth sulfate or docusate such as dioctyl sodium sulfosuccinate, perfluorooctanesulfonate (PFOS) or perfluorobutanesulfonate or linear alkylbenzene sulfonate (LAB) such as Suprol T-60 (manufactured by Supreme Surfactants Pvt Ltd, Haryana) or combinations thereof; nonionic surfactant or emsulsifier is selected from long chain alcohols exhibiting surfactant properties such as fatty alcohols, cetyl alcohol, stearyl alcohol, or cetostearyl alcohol (consisting predominantly of cetyl and stearyl alcohols) or oleyl alcohol, fatty vegetable oil ethoxylated such as NOIGEN EL40 (manufactured by Dai-Ichi Karkaria Ltd, Mumbai) glycerol alkyl ester such as glyceryl laurate or polyoxyethylene glycol and sorbitan alkyl ester such as polysorbate, cocamide MEA (monoethanolamine), cocamide DEA (diethanolamine) or dodecyldimethylamine oxide or combinations thereof; humectant is selected from ethylene glycol, glycerol, sorbitol, propylene glycol, sodium lactate or calcium nitrate or combinations thereof; non-aqueous polar solvent is other than ester ether based solvent having low solubility and is selected from ketone, dimethylforamide, N- methyl -2-pyrolidine or aliphatic alcohol such as ethyl alcohol, isopropyl alcohol or n-butanol or combinations thereof; non-polar solvent is selected from aromatic hydrocarbon such as benzene, toluene, chlorobenzene or C8-10 aromatic hydrocarbon solvent or combinations thereof.

Quizalofop-ethyl is water insoluble and crystallizes at room temperature and also during accelerated stability test at 54°C. Pyrithiobac-sodium is water soluble. According to the invention, the two active herbicides and the formulating agents comprising anionic surfactants, non-ionic surfactants, humectants, polar solvents and non-polar solvents are judiciously and ingenuiously selected in the weight percentages as stated above such that a microemulsion of both the active herbicides is formed and the active herbicides remain as a stable microemulsion. It has been found that quizalofop-ethyl in the microemulsion does not crystallize at room temperature or during accelerated stability test at 54°C. It has been further found that the water insoluble quizalofop-ethyl is solubilized within the hydrophobic core of the herbicidal microemulsion and that the water soluble pyrithiobac-sodium remains in the aqueous phase ie continuous phase in which it is highly soluble.

Although the two active herbicides are in two phases, aqueous and organic, the emulsion droplets go into nanosize and the two phases appear as a clear and stable single phase. It has been found to control broad leaves weeds and grass weeds in cotton crops very effectively thereby exhibiting broad spectrum herbicidal activity against the total weed flora. It is very convenient and easy to apply the microemsulsion on cotton crops as compared to the application of pyrithiobac-sodium and quizalofop-ethyl separately and individually. Percentages of the active herbicides in the microemulsions of the invention is less as compared to the percentages of the actives when applied individually. Therefore, the microemulsion of the invention is also cost effective. Both pyrithiobac-sodium and quizalofop-ethyl are known to be safe on cotton crops. The microemulsion of the invention comprising both the active ingredients is also found to be safe on cotton crops.

According to the invention the two active herbicides with the formulating agents in the selective weight percentages are formed into a stable microemulsion having the various advantages and beneficial effects of microemulsions. Stability of the microemulsion, broad spectrum herbicidal activity of the microemulsion, increased broad spectrum herbicidal activity of the microemulsion and increased broad spectrum herbicidal activity of the microemulsion with reduced amounts of the herbicides in the microemulsion, all clearly establish the synergistic effect of the microemulsion.

The following experimental examples are illustrative of the invention but not limitative of the scope thereof:

Formulation Example 1
Quizalofop-ethyl (3.0 parts by weight) was dissolved in and mixed with n-butanol (45.0 parts by weight), NOIGEN EL 40 (5.9 parts by weight) and Suprol T- 60 (1.6 parts by weight). Pyrithiobac-sodium (4.5 parts by weight) was dissolved in and mixed with deionized water (40.0 parts by weight), ethylene glycol (5.0 parts by weight) and C9 solvent (15.0 parts by weight). Both the solutions were mixed together to form a herbicidal microemulsion. The entire mixing was carried out under stirring at 25 - 30°C.

Formulation Example 2
Quizalofop-ethyl (5.0 parts by weight) was dissolved in and mixed with C9 solvent (41.0 parts by weight), NOIGEN EL 40 (1.5 parts by weight) and Suprol T- 60 (1.6 parts by weight). Pyrithiobac-sodium (5.0 parts by weight) was dissolved in and mixed with deionized water (12.9 parts by weight), n-butanol (28 parts by weight) and ethylene glycol (5.0 parts by weight). Both the solutions were mixed together to form a herbicidal microemulsion. The entire mixing was carried out under stirring at 25 - 30°C.

Formulation Example 3
Quizalofop-ethyl (3.5 parts by weight) was dissolved in and mixed with C9 solvent (38.0 parts by weight). Pyrithiobac-sodium (6.5 parts by weight) was dissolved in and mixed with deionized water (27.9 parts by weight), ethylene glycol (5.0 parts by weight), NOIGEN EL 40 (1.5 parts by weight), Suprol T-60 (1.6 parts by weight) and n-butanol (16.0 parts by weight). Both the solutions were mixed together to form a herbicidal microemulsion. The entire mixing was carried out under stirring at 25 - 30°C.

Formulation Example 4
Quizalofop-ethyl (4.0 parts by weight) was dissolved in and mixed with C9 solvent (50.0 parts by weight). Pyrithiobac-sodium (6.0 parts by weight) was dissolved in and mixed with deionized water (12.0 parts by weight), ethylene glycol (5.0 parts by weight), NOIGEN EL 40 (1.5 parts by weight), Suprol T-60 (3.0 parts by weight) and n-butanol (18.5 parts by weight). Both the solutions were mixed together to form a herbicidal microemulsion. The entire mixing was carried out under stirring at 25 - 30°C.

The herbicidal microemulsions of Examples 1 - 4 were found to be stable during accelerated stability study at 54°C for 14 days.

Efficacy Studies
Cotton crops were grown on plots under natural outdoor conditions and herbicidal microemulsions of the invention in different doses and pyrithiobac-sodium and quizalofop-ethyl were individually sprayed on the cotton crops at the 2-4 leaf stage, as foliar spray at an application rate of 500 liters water per hectare using knapsack sprayer with flat fan nozzle. The number of individual weeds present in the field was recorded at 15, 30 and 60 days after the application of the microemulsion in comparison with untreated control. The results were as shown in the following Tables 1 – 6:
 
TABLE 1
15 days after application
Treatment Dose
g a.i./ha Broad leaf weed Density (no./m2)
**A. viridis Parthenium sp Trianthema sp Digera sp Commelina sp Celosia sp
Pyrithiobac -sodium
62.5 1.00
(1.38) 4.33
(2.29) 1.67
(1.63) 1.67
(1.63) 3.33
(2.06) 1.67
(1.63)
Quizalofop-ethyl
50.0 6.67
(2.76) 8.33
(3.04) 7.67
(2.94) 4.67
(2.37) 3.67
(2.16) 8.00
(2.97)
Formulation Example 1 comprising pyrithiobac sodium@ 45g a.i./ha + Quizalofop-ethyl @ 30 g a.i. / ha 75.0 1.67
(1.63) 2.67
(1.88) 2.33
(1.82) 2.00
(1.72) 3.67
(2.16) 2.33
(1.82)
Formulation Example 4 comprising pyrithiobac sodium@ 60g a.i./ha + quizalofop-ethyl @ 40 g a.i. / ha 100.0 0.00
(1.00) 0.67
(1.28) 0.67
(1.28) 0.67
(1.28) 3.33
(2.07) 0.33
(1.14)

Control - 6.67
(2.74) 8.67
(3.09) 7.33
(2.88) 4.33
(2.29) 3.67
(2.15) 7.33
(2.87)
Figures in parantheses are √ (n+1) value;
** Amaranthus

TABLE 2
15 days after application
Treatment Dose
g a.i./ha Grass weed density (no./m2)
Dactyloctenium aegypticum Dinebra sp Digitaria sp Echinochloa.
colona
Pyrithiobac-sodium
62.5 3.33
(2.08 ) 3.33
(2.06) 3.67
(2.15) 4.67
(2.36)
Quizalofop-ethyl
50.0 1.33
(1.49) 1.67
(1.63) 0.67
(1.24 ) 1.00
(1.38)
Formulation Example 1 comprising pyrithiobac sodium@ 45g a.i./ha + Quizalofop-ethyl @ 30 g a.i. / ha 75.0 1.33
(1.52) 1.67
(1.61) 1.67
(1.63) 1.33
(1.52)
Formulation Example 4 comprising pyrithiobac sodium@ 60g a.i./ha + quizalofop-ethyl @ 40 g a.i. / ha 100.0 0.67
(1.28) 0.00
(1.00) 0.33
(1.14) 0.00
(1.00)

Control - 3.00
(1.99) 3.33
(2.06) 3.67
(2.16) 4.33
(2.29)
Figures in parantheses are √ (n+1) value

TABLE 3
30 days after application
Treatment Dose
g a.i./ha Broad leaf weed density (no./m2)
**A. viridis Parthenium sp Trianthema sp Digera sp Commelina sp Celosia sp
Pyrithiobac- sodium
62.5 34.00
(5.92) 3.33
(2.06) 3.67
(2.16) 3.00
(1.99) 4.33
(2.31) 6.67
(2.76)
Quizalofop-ethyl
50.0 19.00
(4.47) 10.00
(3.31) 12.00
(3.6) 12.00
(3.6) 8.67
(3.1) 7.00
(2.83)
Formulation Example 1 comprising pyrithiobac sodium@ 45g a.i./ha + Quizalofop-ethyl @ 30 g a.i. / ha 75.0 22.00
(4.80) 4.33
(2.31) 5.00
(2.43) 4.33
(2.31) 5.33
(2.51) 6.67
(2.76)
Formulation Example 4 comprising pyrithiobac sodium@ 60g a.i./ha + quizalofop-ethyl @ 40 g a.i. / ha 100.0 11.67
(3.55) 1.67
(1.63) 2.00
(1.72) 2.00
(1.72) 2.33
(1.82) 6.33
(2.71)

Control - 34.67
(5.96) 9.67
(3.24) 12.33
(3.64) 11.00
(3.46) 8.67
(3.10) 6.67
(2.76)
Figures in parantheses are √ (n+1) value
** Amaranthus

TABLE 4
30 days after application
Treatment Dose
g a.i./ha Grass weed density (no./m2)
Dactyloctenium aegypticum Dinebra sp Digitaria sp Echinochloa colona
Pyrithiobac-sodium
62.5 5.67
(2.57) 6.33
(2.7) 8.00
(2.99) 7.33
(2.88)
Quizalofop-ethyl
50.0 2.33
(1.82) 2.67
(1.9) 4.33
(2.3) 3.33
(2.08)
Formulation Example 1 comprising pyrithiobac sodium@ 45g a.i./ha + Quizalofop-ethyl @ 30 g a.i. / ha 75.0 2.67
(1.91) 3.33
(2.07) 5.33
(2.51) 4.00
(2.23)
Formulation Example 4 comprising pyrithiobac sodium@ 60g a.i./ha + quizalofop-ethyl @ 40 g a.i. / ha 100.0 1.67
(1.63) 1.00
(1.41) 1.00
(1.41) 1.67
(1.63)

Control - 5.67
(2.56) 6.67
(2.76) 8.33
(3.04) 7.33
(2.87)
Figures in parantheses are √ (n+1) value

 
TABLE 5
60 days after application
Treatment Dose
g a.i./ha Broad leaf weed density (no./m2)
**A. viridis Parthenium sp Trianthema sp Digera sp Commelina sp Celosia sp
Pyrithiobac-sodium
62.5 4.00
(2.23) 4.33
(2.31) 4.67
(2.37) 5.33
(2.52) 6.33
(2.68) 5.00
(2.45)
Quizalofop-ethyl
50.0 5.00
(2.43) 5.67
(2.57) 6.00
(2.63) 5.67
(2.57) 6.33
(2.68) 6.67
(2.76)
Formulation Example 1 comprising pyrithiobac sodium@ 45g a.i./ha + Quizalofop-ethyl @ 30 g a.i. / ha 75.0 3.33
(2.08) 3.67
(2.16) 4.67
(2.37) 3.33
(2.06) 6.67
(2.74) 4.00
(2.24)
Formulation Example 4 comprising pyrithiobac sodium@ 60g a.i./ha + quizalofop-ethyl @ 40 g a.i. / ha 100.0 3.00
(1.97) 3.00
(1.99) 4.00
(2.22) 2.67
(1.91) 6.67
(2.76) 4.00
(2.21)

Control - 16.00
(4.11) 17.00
(4.24) 20.33
(4.61) 14.00
(3.87) 16.67
(4.19) 17.0
(4.24)
Figures in parantheses are √ (n+1) value
** Amaranthus

TABLE 6
60 days after application
Treatment Dose
g a.i./ha Grass weed density (no./m2)
Dactyloctenium aegypticum Dinebra sp Digitaria sp Echinochloa colona
Pyrithiobac-sodium
62.5 5.67
(2.57) 5.33
(2.51) 5.00
(2.44) 4.00
(2.23)
Quizalofop-ethyl
50.0 4.33
(2.29) 3.67
(2.16) 4.33
(2.29) 3.67
(2.16)
Formulation Example 1 comprising pyrithiobac sodium@ 45g a.i./ha + Quizalofop-ethyl @ 30 g a.i. / ha 75.0 3.67
(2.16) 3.00
(1.99) 4.67
(2.38) 3.33
(2.08)
Formulation Example 4 comprising pyrithiobac sodium@ 60g a.i./ha + quizalofop-ethyl @ 40 g a.i. / ha 100.0 2.67
(1.9) 2.67
(1.91) 3.67
(2.16) 3.00
(1.99)

Control - 14.00
(3.86) 19.67
(4.54) 17.00
(4.23) 14.00
(3.86)
Figures in parantheses are √ (n+1) value

The study results in the above Tables 1 – 6 show that the microemulsions of the invention at lower dosages (lower percentages or concentrations) of the active herbicides in combination are very effective in controlling total weed flora (broad leaves weeds and grass weeds) in cotton crops as compared to Pyrithiobac-sodium and Quizalofop-ethyl individually. This also clearly shows the synergistic effect of the microemulsions of the invention.

Phytotoxicity and Crop Compatibility Studies

After spraying the microemulsions of the invention and Pyrithiobac-sodium and Quizalofop- ethyl individually on cotton crops as explained above, the cotton crops were continuously monitored and evaluated for phytotoxicity symptoms and crop health on a scale of 0 – 10 as shown in the following Table 7:

Table 7
Scale
Effect
Rate Crop description and condition
None 0 No injury, normal
Slight 1 Slight stunting, injury discoloration
2 Some stand loss, stunting or discoloration
3 Injury more pronounced but not persistent
Moderate 4 Moderate injury, recovery possible
5 Injury more persistent, recovery doubtful
6 Near severe injury, no recovery possible
Severe 7 Severe injury, stand loss surviving
8 Almost destroyed, a few plants surviving
9 Very few plants alive
Complete 10 Complete destruction

The results were as shown in the following Table 8 :

TABLE 8
Mean observation recorded after 1,3,5,10,15 and 30 days after application
Treatment Dose
g a.i./ha Phytotoxicity
Yellowing Necrosis Epinasty/
Hyponasty Vein
Clearing Scorching Wilting
Pyrithiobac- sodium
62.5 0 0 0 0 0 0
Quizalofop-ethyl
50.0 0 0 0 0 0 0
Formulation Example 1 comprising pyrithiobac sodium@ 45g a.i./ha + Quizalofop-ethyl @ 30 g a.i. / ha 75.0 0 0 0 0 0 0
Formulation Example 4 comprising pyrithiobac sodium@ 60g a.i./ha + quizalofop-ethyl @ 40 g a.i. / ha 100.0 0 0 0 0 0 0

Control - 0 0 0 0 0 0

Table 8 shows that there is zero effect of the herbicides on the crop plants either as microemulsion or individually thereby indicating that the microemulsion of the invention is safe to the cotton crops.

In all the above studies, pyrithiobac – sodium was used as 10% aqueous solution marketed by us as Hitweed. Quizalofop-ethyl was used as 5 % solution with C9 solvent and surfactant TericCO36 in 88:7 volume ratio.

 
We claim:
1. A herbicidal microemulsion including herbicidally active compounds sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) and ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate in combination with water and atleast one non-aqueous polar solvent and atleast one non-polar solvent, wherein the sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) is in 4.5 - 7.5 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate is in 3.0 – 5.0% by weight of the composition, water is in 12.0 to 40.0% by weight of the composition and the non-aqueous polar solvent is in 15.0 – 28.0 % by weight of the composition and non-polar solvent is in 15.0 – 50.0% by weight of the composition and wherein the microemulsion comprises atleast one anionic surfactant in 1.6 to 5.0% by weight of the composition, atleast one non-ionic surfactant in 1.5 to 5.9% by weight of the composition and atleast one humectant in 5% by weight of the composition.
2. The herbicidal microemulsion as claimed in claim 1, wherein the microemulsion comprises sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) in 6.0 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate in 4.0% by weight of the composition, water in 12% by weight of the composition and non-aqueous polar solvent in 18.5 % by weight of the composition, non-polar solvent in 50.0% by weight of the composition, anionic surfactant in 3.0% by weight of the composition, non-ionic surfactant in 1.5% by weight of the composition and humectant in 5% by weight of the composition.
3. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the anionic surfactant is selected from ammonium lauryl sulfate, sodium lauryl sulfate, alkyl-ether sulfate such as sodium laureth sulfate or sodium myreth sulfate or docusate such as dioctyl sodium sulfosuccinate, perfluorooctanesulfonate or perfluorobutanesulfonate and linear alkylbenzene sulfonate such as Suprol T-60 or combinations thereof.
4. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-ionic surfactant is selected from selected from long chain alcohols exhibiting surfactant properties such as fatty alcohol, cetyl alcohol, stearyl alcohol, cetostearyl alcohol or oleyl alcohol, fatty vegetable oil ethoxylated such as NOIGEN EL40, glycerol alkyl ester such as glyceryl laurate or polyoxyethylene glycol and sorbitan alkyl ester such as polysorbate, cocamidemonoethanolamine, cocamidediethanolamine or dodecyldimethylamine oxide or combinations thereof.
5. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the humectant is selected from ethylene glycol, glycerol, sorbitol, propylene glycol, sodium lactate or calcium nitrate or combinations thereof.
6. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-aqueous polar solvent is selected from ketone, dimethylforamide, N- methyl -2-pyrolidine or aliphatic alcohol such as ethyl alcohol, isopropyl alcohol or n-butanol or combinations thereof.
7. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-polar solvent is selected from aromatic hydrocarbon such as benzene, toluene, chlorobenzene or C8-10 aromatic hydrocarbon solvent or combinations thereof.
8. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the anionic surfactant is linear alkylbenzene sulfonate.
9. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-ionic surfactant is fatty vegetable oil ethoxylated.
10. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the humectant is ethylene glycol.
11. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-aqueous polar solvent is n-butanol.
12. The herbicidal microemulsion as claimed in claim 1 or 2, wherein the non-polar solvent is C9 solvent.
13. The herbicidal microemulsion as claimed in claim 1, which comprises 3% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate , 4.5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 25.0 % by weight n-butanol, 5.9% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60, 40.0% by weight deionized water, 5.0% by weight ethylene glycol and 15.0% by weight C9 solvent.
14. The herbicidal microemulsion as claimed in claim 1, which comprises 5% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 41.0% by weight C9 solvent, 1.5% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60, 12.9% by weight deionized water, 28% by weight n-butanol and 5% by weight ethylene glycol.
15. The herbicidal microemulsion as claimed in claim 1, which comprises 3.5% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 6.5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 38.0% by weight C9 solvent, 27.9% by weight deionized water, 5.0% by weight ethylene glycol, 1.5% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60 and 16% by weight n-butanol.
16. The herbicidal microemulsion as claimed in claim 1, which comprises 4.0% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 6.0% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 50.0% by weight C9 solvent, 12.0% by weight deionized water, 5.0% by weight ethylene glycol, 1.5% by weight NOIGEN EL 40, 3.0% by weight Suprol T- 60 and 18.5% by weight n-butanol.
17. A method for the preparation of a herbicidal microemulsion comprising mixing herbicidally active compounds sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) and ethyl (2RS)–2-[4–(6-chloroquinoxalin -2-yloxy) phenoxy] propionate with water and at least one non-aqueous polar solvent and atleast one non-polar solvent, wherein the sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) is in 4.5 - 7.5 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate is in 3.0 – 5.0% by weight of the composition, water is in 12.0 to 40.0% by weight of the composition and the non-aqueous polar solvent is in 15.0 – 28.0 % by weight of the composition and non-polar solvent is in 15.0 – 50.0% by weight of the composition and wherein the method also comprises mixing atleast one anionic surfactant in 1.6 to 5.0% by weight of the composition, atleast one non-ionic surfactant in 1.5 to 5.9% by weight of the composition and atleast one humectant in 5% by weight of the composition with the herbicidally active compounds and wherein the mixing is carried out under stirring at 25 - 30°C.
18. The method as claimed in claim 17, which comprises mixing sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio) in 6.0 % by weight of the composition, ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate in 4.0% by weight of the composition, water in 12.0% by weight of the composition and non-a queous polar solvent in 18.5 % by weight of the composition, non-polar solvent in 50.0% by weight of the composition, anionic surfactant in 3.0% by weight of the composition, non-ionic surfactant in 1.5% by weight of the composition and humectant in 5% by weight of the composition.
19. The method as claimed in claim 17 or 18, wherein the anionic surfactant is selected from ammonium lauryl sulfate, sodium lauryl sulfate, alkyl-ether sulfate such as sodium laureth sulfate or sodium myreth sulfate or docusate such as dioctyl sodium sulfosuccinate, perfluorooctanesulfonate or perfluorobutanesulfonate and linear alkylbenzene sulfonate such as Suprol T-60 or combinations thereof.
20. The method as claimed in claim 17 or 18, wherein the non-ionic surfactant is selected from selected from long chain alcohols exhibiting surfactant properties such as fatty alcohol, cetyl alcohol, stearyl alcohol, cetostearyl alcohol or oleyl alcohol, fatty vegetable oil ethoxylated such as NOIGEN El 40, glycerol alkyl ester such as glyceryl laurate or polyoxyethylene glycol and sorbitan alkyl ester such as polysorbate, cocamide monoethanolamine, cocamidediethanolamine or dodecyl dimethylamine oxide or combinations thereof.
21. The method as claimed in claim 17 or 18, wherein the humectant is selected from ethylene glycol, glycerol, sorbitol, propylene glycol, sodium lactate or calcium nitrate or combinations thereof.
22. The method as claimed in claim 17 or 18, wherein the non-aqueous polar solvent is selected from ketone, dimethylforamide, N- methyl -2-pyrolidine and aliphatic alcohol such as ethyl alcohol, isopropyl alcohol or n-butanol or combinations thereof.
23. The method as claimed in claim 17 or 18, wherein the non-polar solvent is selected from aromatic hydrocarbon such as benzene, toluene, chlorobenzene or C8-10 aromatic hydrocarbon solvent or combinations thereof.
24. The method as claimed in claim 17 or 18, wherein the anionic surfactant is linear alkylbenzene sulfonate.
25. The method as claimed in claim 17 or 18, wherein the non-ionic surfactant is fatty vegetable oil ethoxylated.
26. The method as claimed in claim 17 or 18, wherein the humectant is ethylene glycol.
27. The method as claimed in claim 17 or 18, wherein the non-aqueous polar solvent is n-butanol.
28. The method as claimed in claim 17 or 18, wherein the non-polar solvent is C9 solvent.
29. The method as claimed in claim 17, which comprises mixing 3% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate , 4.5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 25.0 % by weight n-butanol, 5.9% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60, 40.0% by weight deionized water, 5.0% by weight ethylene glycol and 15.0% by weight C9 solvent.
30. The method as claimed in claim 17, which comprises mixing 5% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 41.0% by weight C9 solvent, 1.5% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60, 12.9% by weight deionized water, 28% by weight n-butanol and 5% by weight ethylene glycol.
31. The method as claimed in claim 17, which comprises mixing 3.5% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 6.5% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 38.0% by weight C9 solvent, 27.9% by weight deionized water, 5.0% by weight ethylene glycol, 1.5% by weight NOIGEN EL 40, 1.6% by weight Suprol T- 60 and 16% by weight n-butanol.
32. The method as claimed in claim 17, which comprises mixing 4.0% by weight ethyl (2RS)–2-[4–(6-chloroquinoxalin-2-yloxy) phenoxy] propionate, 6.0% by weight sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio), 50.0% by weight C9 solvent, 12.0% by weight deionized water, 5.0% by weight ethylene glycol, 1.5% by weight NOIGEN EL 40, 3.0% by weight Suprol T- 60 and 18.5% by weight n-butanol.
Dated this 26th day of March 2015

(Jose M A)
of Khaitan & Co
Agent for the Applicants
Reg No IN/PA-44