Title of Invention

A PROCESS FOR PPREPERATION OF NANO ZINC OXIDE PARTICLES

Abstract A process for the preparation of nano zinc oxide particles comprising dissolving a zinc metal precursor in a solvent to obtain a first solution; dissolving a base in an alcohol to obtain an alkali solution; and adding the alkali solution to the first solution over a predetermined period of time to obtain nano zinc oxide particles in solution.
Full Text FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
1. Title of the invention
A PROCESS FOR PPREPERATION OF NANO ZINC OXIDE PARTICLES
2. Applicants)
Name Nationality Address
TATA CHEMICALS LIMITED INDIA BOMBAY HOUSE, 24 HOM1 MODI STREET, MUMBAI-400001


3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it is
to be performed.

The invention relates to a process for preparing nano particles. More particularly the invention relates to a process for the preparation of nano zinc oxide particles.
DESCRIPTION OF RELATED ART
Zinc Oxide is used for various purposes including as a white pigment, as a catalyst, as a constituent of anti-bacterial skin protection ointment, sunscreens and wood varnishes. Zinc oxide is also known as wide band gap semiconductor and is well suited for emissive devices. Materials used for blocking UV radiation are required to be transparent to the visible part of the solar radiation while blocking the harmful UV radiation and nano zinc oxide is considered favorable in this regard. The term 'nano' or 'nano particle' is generally used to refer to particles having a diameter of less than about 1 OOnm.
Though numerous processes are known for the synthesis of nano zinc oxide particles, such processes are not scalable in an efficient manner and do not produce free flowing nano zinc oxide particle powders. This limitation is often a significant deterrent in the commercialization of nano zinc oxide particles.
The essential process for the synthesis of nano zinc oxide is a basic alcoholic hydrolysis of zinc metal precursor and most known processes describe the synthesis of nano zinc oxide particles in an alcohol or an alcohol-water mixture as the medium of reaction. Such processes involve dissolving the metal precursor by heating or boiling the alcohol with reactions carried out at elevated temperatures. As these families of precursors have poor solubility in alcohols; the processes require heating them to high temperatures, typically the boiling points in the case of alcohols. Examples of such processes may be found in US 6710091; US2006/0222586; US2003/0172845; and in Koch et.al Chemical Physics Letters, 122- 507,1985.


It would be useful to identify a process by which free flowing nano zinc oxide particles may be formed and that such a process be scalable to allow for large scale production of nano zinc oxide particles.
SUMMARY
The invention relates to a process for the preparation of nano zinc oxide particles comprising dissolving a zinc metal precursor in a solvent to obtain a first solution; dissolving a base in an alcohol to obtain an alkali solution; and adding the alkali solution to the first solution over a predetermined period of time to obtain nano zinc oxide particles in dispersion.
In accordance with an aspect of the invention the dispersion containing nano zinc oxide particles is refrigerated to allow for stable storage.
In accordance with an aspect of the invention the dispersion containing nano zinc oxide particles is used for ultra violet coating of glass.
In accordance with an aspect of the invention a non solvent is added to the dispersion to precipitate nano zinc oxide particles in solution.
In accordance with an aspect of the invention the solution so obtained by adding a non solvent is further processed for the extraction of nano zinc oxide particles comprising transferring the solution containing nano zinc oxide particles to a separating means for settling the nano zinc oxide particles, removing the settled nano zinc oxide particles from the separating means and centrifuging and drying the nano zinc oxide particles so removed to obtain dry nano zinc oxide particles.
The invention also relates to a process for the preparation of nano zinc oxide particles comprising dissolving zinc acetate dehydrate {Zn(OAc)2} in N, N dimethyl formamide [DMF] to obtain a first solution; dissolving a base in alcohol to obtain an alkali solution;


and adding the alkali solution to the first solution over a predetermined period of time to obtain nano zinc oxide particles.
In accordance with an aspect of the invention the base is sodium hydroxide and the alcohol is ethanol.
In accordance with an aspect of the invention the centrifuged nano zinc oxide particles are dried over phosphorous pentaoxide in a vacuum desiccator.
The invention relates to a process for the preparation of nano zinc oxide particles comprising dissolving zinc acetate dehydrate {Zn(OAc)2} in N,N dimethyl formamide [DMF] to obtain a first solution; dissolving sodium hydroxide in ethanol to obtain an alkali solution; adding the alkali solution to the first solution over a predetermined period of time to obtain nano zinc oxide particles in dispersion; adding acetone to the dispersion to precipitate nano zinc oxide particles; transferring solution containing nano zinc oxide particles to a separating means to allow the nano zinc oxide particles to settle; removing the settled nano zinc oxide particles from the separating means; decanting excess solution present in the nano zinc oxide particles removed from the separating means; and centrifuging the nano zinc oxide particles.
DESCRIPTION OF PREFERRED EMBODIMENTS
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment described and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the process, and such further applications of the principles of the invention therein being contemplated as would normally occur to one skilled in the art to which the invention relates.


It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.
A method to synthesize nano zinc oxide particles in a single-phase organic medium is disclosed. The process in accordance with the principles of the invention preferably involves dissolving the zinc metal precursor in a solvent followed by the addition of a basic-alcohol solution to obtain nano zinc oxide particles. More specifically, the process involves dissolving the zinc metal precursor in a solvent such as N,N dimethylformamide (DMF) to obtain a first solution, dissolving a base in an alcohol to obtain an alkali solution, and the addition of the alkali solution to the first solution to obtain nano zinc oxide particles.
The following description refers to certain specific compounds such as alcohols, bases; solvents and non solvents to explain the principles of the invention. The invention however is not restricted to such compounds as any equivalent chemical compound may be utilized to achieve the desired end result as taught by the invention.
In the following description zinc acetate dehydrate has been employed as the source of zinc while the solvent employed is N,N dimethylformamide (DMF). The zinc acetate dehydrate is dissolved in N,N dimethylformamide (DMF) to obtain a first clear solution. A second solution is prepared independently by dissolving sodium hydroxide in ethanol to get an alkali solution. The alkali solution is added to the zinc acetate solution in a controlled manner and over a predetermined period of time to ensure that only nano zinc oxide particles are formed.
To precipitate or cause sedimentation of the nano zinc oxide particles a non-solvent such as acetone, hexane, heptane and toluene, or any similar members of their family, or


any combination of them is preferably added to the reaction mixture. On the addition of the non-solvent the nano zinc oxide particles eventually settle down.
It is preferred that the manner of addition of the alkali solution to the first solution is not a dumping operation, but spread over a period of time that is appropriate to dehydrate the zinc hydroxide formed after the addition of the alkali solution, such that nano zinc oxide particles in dispersion is obtained. Preferably such process may be executed by adding the alkali at a rate of approximately 1 % of alkali a minute continuously, or alternatively by adding predetermined amounts of the alkali at specific intervals spread apart by a predetermined period, such as a time interval of 5 to 10 minutes and adding 5% to 10% of the alkali at each interval. Accordingly the process of addition may be spread over 50 to 100 minutes depending on the percentage of reaction completion required to get appropriate particle size and yield.
The base used for the preparation of the alkali solution may be any OH" or NH" group containing basic compound particularly an alkali metal one like NaOH, KOH, LiOH, tetramethylammonium hydroxide or any other member of the similar family, preferably sodium hydroxide.
The alcohol may be a monoalcohol or polyalcohol particularly ethanol, methanol, propanol or any other member of the alcohol family, preferably ethanol The reactions involved in the process may be summarized as:
Zn(CH3COO")2 + 2NaOHZn(OH)2 + 2CH3COONa (1)
Zn(OH)2  ZnO +H20 (2)


As shown by equation 1, zinc acetate reacts with sodium hydroxide to provide zinc hydroxide and sodium acetate. The zinc hydroxide is dehydrated to provide nano zinc oxide and water.
In accordance with an aspect of the invention, a process for the extraction of the nano zinc oxide particles at industrial scale is disclosed. The use of non solvent for precipitation of the nano particles provides for a simple way to extract particles at high throughput. The process involves sedimentation followed by decantation, centrifugation and finally drying of nano particles over phosphorus pentaoxide in a vacuum desiccator.
The nano particles are obtained early on in the process as dispersion. Subsequent processing is done to this dispersion to obtain nano zinc oxide particles as dry powder. The dispersion so obtained containing nano zinc oxide particles is extremely stable under refrigeration. In accordance with an aspect, the dispersion may be used for applying ultra violet coatings on glass, metals and wood etc. The dispersion may be applied directly as a thin coating on glass. As the dispersion is transparent the films applied to glass are also transparent. Moreover, the dispersion in solvent such as DMF is very stable and the process of preparing the dispersion is economical and provides significant advantages in subsequent glass coating.
In accordance with an aspect, the dispersion so prepared may be transferred to a glass manufacturing facility under refrigeration or maybe prepared at the glass manufacturing facility.
The refrigeration temperatures may be kept preferably between 0 C to 4 C or even below.
In accordance with an aspect, it is preferred that on completion of the addition of the alkali solution to the zinc acetate solution, the reaction mixture is stirred to ensure that the reaction is complete and that all the zinc acetate is converted to nano zinc oxide. The


formation of nano zinc oxide particles may be monitored by doing intermediate UV visible spectroscopy.
In accordance with an aspect, the solution containing nano zinc oxide particles is transferred to a separating means to allow the nano zinc oxide particles to settle; removing the settled nano zinc oxide particles from the separating means; decanting excess solution present in the nano zinc oxide particles removed from the separating means; and centrifuging the nano zinc oxide particles.
The separating means may for example be a separating funnel. The centrifuged nano zinc oxide particles may be vaccume dried over phosphorus pentaoxide.
In accordance with an embodiment, the process may be used to obtain capped nano zinc oxide particle powders. The cappant is preferably added to the metal precursor, such as the zinc acetate solution, prior to the addition of the alkali solution that allows for capping the nano zinc oxide particles as soon as they are formed. Any known organic and inorganic molecules including alkylamines like octylamine, dodecylamine, hexadecylamine; polyvinyl pyrrolidone (PVP), alkanethiols, carboxylic acids, phosphines, substituted phosphines, phosphine oxides and substituted phosphine oxides may be employed for capping the nano zinc oxide particles. The process allows for the introduction of a cappant without requiring any alteration or modification to the basic process for the production of nano zinc oxide particles.
The exactly molar process allows for the continuous production of the nano zinc oxide particles and thus enables the large scale production of riano zinc oxide particles.
The dissolving of the zinc metal precursor in DMF provides for significant advantages including no requirement of heating the reaction mixture, easily scalable process for high concentrations, the production of dry nano zinc oxide particles at high throughput and a narrow particle distribution.


The high solubility of the zinc metal precursor in DMF at room temperature allows for high production rate of nano zinc oxide particles.
The nano zinc oxide particles obtained are perfectly dry powder which is a significant advantage of the process. Moreover, the final product is an odorless, white free flowing nano zinc oxide particle powder. UV visible spectroscopy on the final product in the dry powder form indicated that all powders are transparent to visible radiation and block the UV radiation. A TEM on the powders indicated that the particle size varies between 5 nm to 50 nm depending upon the concentration and reaction completion done. The entire synthesis process is carried out at room temperature.
The simplicity of the process, particularly the absence of any heating requirements and the perfectly molar reactions, involving stirring and decantation operations, allows the process to be easily scaled up to any volume.
The following examples are provided to explain and illustrate certain preferred embodiments of the process of the invention.
Example 1
65.847 grams of Zn(OAc)2 was dissolved in 3 L of DMF to obtain the first solution. 12 grams of NaOH was dissolved in 1.5 L of ethanol, to obtain the alkali solution. 1.2 L of the alkali solution was slowly added to the first solution in order to synthesize nano zinc oxide particles. After the addition is complete, the reaction mixture is stirred for some more time. To this solution of nano zinc oxide particles 18 L of acetone was added in order to precipitate out the nano zinc oxide particles. The solution turned milky white on addition of acetone. This solution is then transferred to separating funnels so that particles settle down. Later on these settled particles are removed from the funnels. The excess solvent from the


removed particles is decanted out and the remaining milky solution is centrifuged. The wet solid obtained is dried over phosphorus pentaoxide in vacuum desiccators.
Example 2
54.87 grams of Zn(OAc)2 was dissolved in 2.5 L of DMF to obtain the first solution. 16 grams of NaOH was dissolved in 2 L of ethanol, to obtain the alkali solution. 1.875 L of the alkali solution was slowly added to the first solution in order to synthesize nano zinc oxide particles. After the addition is complete, the reaction mixture is stirred for some more time. To this solution of nano zinc oxide particles 17.5 L of acetone was added in order to precipitate out the nano zinc oxide particles. The solution turned milky white on addition of acetone. This solution is than transferred to separating funnels so that particles settle down. Later on these settled particles are removed from the funnels. The excess solvent from the removed particles is decanted out and the remaining milky solution is centrifuged. The wet solid obtained is dried over phosphorus pentaoxide in vacuum desiccators
Example 3
54.87 grams of Zn(OAc)2 was dissolved in 2.5 L of DMF to obtain the first solution. 16 grams of NaOH was dissolved in 2 L of ethanol, to obtain the alkali solution. 1.875 L of the alkali solution was slowly added the first solution in order to synthesize nano zinc oxide particles. After the addition is complete, the reaction mixture is stirred for some more time. To this solution of nano zinc oxide particles 6.56 L of acetone was added in order to precipitate out the nano zinc oxide particles. The solution turned milky white on addition of acetone. This solution is then transferred to separating funnels so that particles settle down. Later on these settled particles are removed from the funnels. The excess solvent from the removed particles is decanted out and the remaining milky solution is


centrifuged. The wet solid obtained is dried over phosphorus pentaoxide in vacuum desiccators
Example4
54.87 grams of Zn(OAc)2 was dissolved in 2.5 L of DMF to obtain the first solution.20 grams of NaOH was dissolved in 2.5 L of ethanol, to obtain the alkali solution. 2.250 L of the alkali solution was slowly added to the first solution in order to synthesize nano zinc oxide particles. After the addition is complete, the reaction mixture is stirred for some more time. To this solution of nano zinc oxide particles 7.125 L of acetone was added in order to precipitate out the nano zinc oxide particles. The solution turned milky white on addition of acetone. This solution is then transferred to separating funnels so that particles settle down. Later on these settled particles are removed from the funnels. The excess solvent from the removed particles is decanted out and the remaining milky solution is centrifuged. The wet solid obtained is dried over phosphorus pentaoxide in vacuum desiccators
Example 5
109.74 grams of Zn(OAc)2 was dissolved in 2.5 L of DMF to obtain the first solution. 40 grams of NaOH was dissolved in 2.5 L of ethanol, to obtain the alkali solution. 2.250 L of the alkali solution was slowly added to the first solution in order to synthesize nano zinc oxide particles. After the addition is complete, the reaction mixture is stirred for some more time. To this solution of nano zinc oxide particles 7.125 L of acetone was added in order to precipitate out the nano zinc oxide particles. The solution turned milky white on addition of acetone. This solution is then transferred to separating funnels so that particles settle down. Later on these settled particles are removed from the funnels. The excess solvent from the


removed particles is decanted out and the remaining milky solution is centrifuged. The wet solid obtained is dried over phosphorus pentaoxide in vacuum desiccators
Example 6
164.61 grams of Zn(OAc)2 was dissolved in 2.5 L of DMF to obtain the first solution.60 grams of NaOH was dissolved in 2.5 L of ethanol, to obtain the alkali solution. 2.250 L of the alkali solution was slowly added to the first solution in order to synthesize nano zinc oxide particles. After the addition is complete, the reaction mixture is stirred for some more time. To this solution of nano zinc oxide particles 7.125 L of acetone was added in order to precipitate out the nano zinc oxide particles. The solution turned milky white on addition of acetone. This solution is then transferred to separating funnels so that particles settle down. Later on these settled particles are removed from the funnels. The excess solvent from the removed particles is decanted out and the remaining milky solution is centrifuged. The wet solid obtained is dried over phosphorus pentaoxide in vacuum desiccators.
Example 7
21.94 grams of Zn(OAc)2 was dissolved in 1.0 L of DMF to obtain the first solution. 8 grams of NaOH was dissolved in 1.0 L of ethanol, to obtain the alkali solution. 37.07 grams of dodecylamine (DDA) was added to 300 ml toluene and this solution was added to the first solution. 0.9 L of the alkali solution was slowly added to the first solution in order to synthesize nano zinc oxide particles. The solution turned milky white on addition of the base due to formation and precipitation of DDA capped nano zinc oxide particles. After the addition is complete, the reaction mixture is stirred for some more time. This solution is then transferred to separating funnels so that particles settle down. Later on these settled


particles are removed from the funnels. The excess solvent from the removed particles is decanted out and the remaining milky solution is centrifuged. The wet solid obtained is dried over phosphorus pentaoxide in vacuum desiccators
Example 8
21.94 grams of Zn(OAc)2 was dissolved in 1.0 L of DMF to obtain the first solution.8 grams of NaOH was dissolved in 1.0 L of ethanol, to obtain the alkali solution .25.8 grams of octylamine (OA) was added to the first solution. 0.9 L of the alkali solution was slowly added to the first solution in order to synthesize nano zinc oxide particles. The solution turned milky white on addition of the base due to formation and precipitation of OA capped nano zinc oxide particles. After the addition is complete, the reaction mixture is stirred for some more time. This solution is then transferred to separating funnels so that particles settle down. Later on these settled particles are removed from the funnels. The excess solvent from the removed particles is decanted out and the remaining milky solution is centrifuged. The wet solid obtained is dried over phosphorus pentaoxide in vacuum desiccators.
Example 9
43.898 grams of Zn(OAc)2 was dissolved in 2.0 L of DMF to obtain the first solution. 17.6 grams of NaOH was dissolved in 2.2 L of ethanol, to obtain the alkali solution. 51.7 grams of octylamine (OA) was added to the first solution. 2.0 L of the alkali solution was slowly added to the first solution in order to synthesize nano zinc oxide particles. The solution turned milky white on addition of the base due to formation and precipitation of OA capped nano zinc oxide particles. After the addition is complete, the reaction mixture was stirred for some more time. This solution is then transferred to separating funnels so


that particles settle down. Later on these settled particles are removed from the funnels. The excess solvent from the removed particles is decanted out and the remaining milky solution is centrifuged. The wet solid obtained is dried over phosphorus pentaoxide in vacuum desiccators.


We claim:
1. A process for the preparation of nano zinc oxide particles comprising dissolving a zinc metal precursor in a solvent to obtain a first solution; dissolving a base in an alcohol to obtain an alkali solution; and adding the alkali solution to the first solution over a predetermined period of time to obtain nano zinc oxide particles in dispersion.
2. A process for the preparation of nano zinc oxide particles comprising dissolving a zinc metal precursor in a solvent to obtain a first solution; adding a capping agent to the first solution; dissolving a base in an alcohol to obtain an alkali solution; and adding the alkali solution to the first solution over a predetermined period of time to obtain capped nano zinc oxide particles in dispersion.
3. A process as claimed in claim 1 or 2 wherein the solution containing nano zinc oxide particles is refrigerated to allow for stable storage.
4. A process as claimed in any preceding claim wherein the solution containing nano zinc oxide particles is used for ultra violet coating of glass.
5. A process as claimed in claim 1 further comprising adding a non solvent to the reaction mixture of the first solution and the alkali solution to precipitate nano zinc oxide particles in solution.


6. A process as claimed in claim 5 comprising transferring the solution containing nano zinc oxide particles to a separating means for settling the nano zinc oxide particles, removing the settled nano zinc oxide particles from the separating means and centrifuging and drying the nano zinc oxide particles so removed to obtain dry nano zinc oxide particles.
7. A process for the preparation of nano zinc oxide particles comprising dissolving zinc acetate dehydrate in N,N dimethyl formamide to obtain a first solution; dissolving a base in alcohol to obtain an alkali solution; and adding the alkali solution to the first solution over a predetermined period of time to obtain nano zinc oxide particles.
8. A process as claimed in claim 7 wherein the base is sodium hydroxide.
9. A process as claimed in claim 7 wherein the alcohol is ethanol.
10. A process as claimed in claims 7, 8 or 9 wherein the solution containing nano zinc oxide particles is refrigerated to allow for stable storage.
11. A process as claimed in claim 10 wherein the solution containing nano zinc oxide particles is used for ultra violet coating of glass.
12. A process as claimed in claim 7, 8 or 9 comprising adding acetone to the reaction mixture of the first solution and the alkali solution to precipitate nano zinc oxide particles in solution.


13. A process as claimed in claim 7,8 or 9 comprising adding a cappant to the first solution prior to the addition of alkali solution to the first solution.
14. A process as claimed in claim 12 or 13 further comprising transferring solution containing nano zinc oxide particles to a separating means to allow the nano zinc oxide particles to settle; removing the settled nano zinc oxide particles from the separatingmeans; decanting excess solution present in the nano zinc oxide particles removed from the separatingmeans; and centrifuging the nano zinc oxide particles.
15. A process as claimed in claim 12 or 13 wherein the centrifuged nano zinc oxide particles are dried over phosphorous pentaoxide in a vacuum desiccators.
16. A process for the preparation of nano zinc oxide particles comprising dissolving zinc acetate dehydrate in N,N dimethyl formamide to obtain a first solution; dissolving sodium hydroxide in ethanol to obtain an alkali solution; adding the alkali solution to the first solution over a predetermined period of time to obtain nano zinc oxide particles in solution; adding acetone to the solution to precipitate nano zinc oxide particles; transferring solution containing nano zinc oxide particles to a separating means to allow the nano zinc oxide particles to settle; removing the settled nano zinc oxide particles from the separating means; decanting excess solution present in the nano zinc oxide particles removed from the separating means; and centrifuging the nano zinc oxide particles.


17. A process for the preparation of nano zinc oxide particles substantially as herein described.




ABSTRACT
A process for the preparation of nano zinc oxide particles comprising dissolving a zinc metal precursor in a solvent to obtain a first solution; dissolving a base in an alcohol to obtain an alkali solution; and adding the alkali solution to the first solution over a predetermined period of time to obtain nano zinc oxide particles in solution.


Documents:

480-mum-2008-abstract.doc

480-mum-2008-abstract.pdf

480-MUM-2008-AUSTRALIAN DOCUMENT(9-1-2013).pdf

480-MUM-2008-CANADA DOCUMENT(9-1-2013).pdf

480-MUM-2008-CHINA DOCUMENT(9-1-2013).pdf

480-MUM-2008-CLAIMS(AMENDED)-(9-1-2013).pdf

480-MUM-2008-CLAIMS(MARKED COPY)-(9-1-2013).pdf

480-mum-2008-claims.doc

480-mum-2008-claims.pdf

480-MUM-2008-CORRESPONDENCE(10-1-2011).pdf

480-MUM-2008-CORRESPONDENCE(11-3-2011).pdf

480-MUM-2008-CORRESPONDENCE(24-7-2013).pdf

480-MUM-2008-CORRESPONDENCE(28-4-2008).pdf

480-MUM-2008-CORRESPONDENCE(30-5-2013).pdf

480-MUM-2008-CORRESPONDENCE(6-11-2009).pdf

480-mum-2008-correspondence-received.pdf

480-mum-2008-description (complete).pdf

480-MUM-2008-EP DOCUMENT(9-1-2013).pdf

480-MUM-2008-FORM 1(28-4-2008).pdf

480-MUM-2008-FORM 18(6-11-2009).pdf

480-MUM-2008-FORM 2(TITLE PAGE)-(10-3-2008).pdf

480-MUM-2008-FORM 3(10-1-2011).pdf

480-MUM-2008-FORM 3(10-3-2008).pdf

480-MUM-2008-FORM 3(11-3-2011).pdf

480-MUM-2008-FORM 3(24-7-2013).pdf

480-MUM-2008-FORM 3(28-4-2008).pdf

480-MUM-2008-FORM 3(9-1-2013).pdf

480-MUM-2008-FORM PCT-IB-373(9-1-2013).pdf

480-MUM-2008-FORM PCT-ISA-210(9-1-2013).pdf

480-mum-2008-form-1.pdf

480-mum-2008-form-2.doc

480-mum-2008-form-2.pdf

480-mum-2008-form-3.pdf

480-MUM-2008-KOREAN DOCUMENT(9-1-2013).pdf

480-MUM-2008-PETITION UNDER RULE-137(24-7-2013).pdf

480-MUM-2008-POWER OF AUTHORITY(28-4-2008).pdf

480-MUM-2008-REPLY TO EXAMINATION REPORT(9-1-2013).pdf

480-MUM-2008-US DOCUMENT(9-1-2013).pdf


Patent Number 257026
Indian Patent Application Number 480/MUM/2008
PG Journal Number 35/2013
Publication Date 30-Aug-2013
Grant Date 27-Aug-2013
Date of Filing 10-Mar-2008
Name of Patentee TATA CHEMICALS LIMITED
Applicant Address BOMBAY HOUSE, 24 HOMI MODI STREET, MUMBAI
Inventors:
# Inventor's Name Inventor's Address
1 SACHIN PARASHAR TATA CHEMICALS LIMITED, INNOVATION CENTRE, ANMOL P S NO 270, 1 & 2 FLOOR, BANER, PUNE-411 045.
PCT International Classification Number C01G9/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA