Title of Invention

METHOD FOR COATING A METAL SURFACE WITH AN ULTRAFINE LAYER

Abstract The present invention relates to a method for continuously coating a substrate in motion such as a metal strip made of steel, the coating formed being an ultra-fine film of a thickness between 10 and , deposited on the substrate: from a solution containing nanoparticles of oxides, in conditions of controlled pH, said substrate being at a temperature higher than 120°C, the total duration of the deposition being less than 5 seconds and preferably less an 1 second, wherein at least one chemical additive, called a "refiner" is incorporated into said solution, said refiner having, mutatis mutandis, the effect of restricting the formation of said coating.
Full Text Field of the invention
The present invention relates to the
improvement of the method described in international patent
application WO-A-03/048403 by the use of chemical additives
affecting the deposition reaction of an ultra-fine layer of
oxide nanoparticles. The addition of such compounds allows to
obtain layers of a thickness that is even less than in the
above-mentioned patent application, i.e. of a thickness of
typically less than lOOnm.
Technological background and the state of the art
The method described in application WO-A-
03/048403 Al is part of a global project intended to reduce
the production costs of pre-painted metal strips. In this
context, the metallurgists hope to incorporate the lacquering
process at the end of the galvanising line.
The main difficulty to obtain this result has
been to find a conversion treatment for the strip that is
fast enough to be put between the galvanising and the
painting treatment. The above-mentioned method has also been
considered as an alternative to treatments based on
chromates.
Being based on the use of the strip's residual
heat after galvanising and spinning, this method does not
require any external energy input in order to work.
On the installation side, it is preferably
carried out in the descending section that follows the zinc
bath. From a practical point of view, it can be installed in
place of the tank of demineralised water that completes the
cooling with jets of water steam. The compact deposition
system considered here may be a bath or a spray system (wave
of water, spraying with jets, etc.). Thus, with the help of
some modifications, the investment in the new equipment is
limited.
First approach: ultra-fine layer
Ultra-fine layers, typically less than 100 nm,
produced by the proposed method can only be considered for
solutions with a low concentration of particles, low strip
temperatures or even both. The possibility of also being able
to produce deposits of this type for solutions with high
concentrations of nanoparticles and/or at high temperature
would be very usefully for a simple in-line adaptation of the
method.
Moreover, this objective is crucial for
obtaining a deposit that perfectly adheres to the metal and
for good internal cohesion of the oxide layer. Indeed, for a
solution with a low concentration, the nanoparticles in
suspension are some distance from each other and thus have
little tendency to correctly agglomerate when the solvent
evaporates.
However, one problem caused by the use of
solutions with medium and high concentration is the formation
of localised excessive thicknesses that form a network of
very friable "ribs" on the surface of the oxide deposit, as
shown in Figure 1. These result from the preferential
precipitation at the interface between the solution and the
vapour phase caused during immersion, as diagrammatically
described in Figure 2. This can be seen both on the samples
produced in a bath (Figure 2. a) or by spraying (Figure 2.b)
and it is detrimental to the subsequent adhesion of paint.
Document JP-A-63 072887 teaches a method for
producing a steel strip by hot dipping showing excellent
resistance to corrosion and good mechanical resistance so
that, before the drying of the first layer made of zinc or
aluminium, an aqueous solution containing dissolved silica
and/or aluminium, lithium silicate, etc. is pulverised on the
surface of the strip so as to form an oxide layer comprising
Si02, A1203 or Li2SiO, separately or in a mixture. However, a
film of chromate is also formed on the oxide layer so as to
increase the resistance to corrosion and the adhesion of the
oxide layer, in contrast to the method of the previous
application WO-A-03/048403, which was free of hexavalent
chrome. This shows that good adhesion of the nanoparticles is
far from certain.
Document JP-A-62 166667 discloses a method for
forming an oxide layer on the surface of a steel strip coated
by hot dipping with a layer of Zn or of a Zn-Al alloy with
the aim of preventing deep grey discoloration of the strip. A
solution containing one or several of the oxides Zr02, Cr203,
A1203, Y203, Ce02, ZrBi04 and Sb203 is pulverised on the strip
after immersion and thus its temperature is ^ 100°C at a
concentration in the range of 1-100 mg/m2. The water is
evaporated by the intense heat of the steel strip, with the
formation of the oxide film. A film of chromate is then
formed on the above-mentioned oxide layer. It should be noted
that a check of the thickness of the layer is neither
considered nor described although this is crucial for good
adhesion of the deposit. It seems that the layer of chromate
is there to compensate for this omission.
Second approach: better stability of the solution depending
on the temperature
When the strip is plunged into the bath, it
transfers its heat to the colloidal solution. So as to avoid
overheating the latter and thus adversely affecting the bath,
it is clearly the intention to remove the excess energy by
means of external circulation and a heat exchanger. In fact,
despite the presence of this equipment, it has been noted
that the bath is adversely affected. It seems that the excess
heat retained at the metal-solution interface is responsible
for this and causes the precipitation of the solution.
So as to be able to guarantee a satisfactory
useful life of the bath, it is absolutely necessary to find a
method that allows to use the solution right up until the
solvent boils.
Third approach: a wider margin for manoeuvre
It is possible to adapt the cooling equipment
preceding the tank containing the colloidal solution or the
banks of sprays so as to be able to guarantee a constant
entry temperature over time. It is necessary to control this
parameter so as to guarantee constant thickness of the
deposit of nanoparticles on the substrate.
However, in order to be competitive relative to
a cold strip treatment placed on the same location, apart
from the control of the bath, which is common, it would be
preferable to be able to dispose of the need for precision in
the temperature or to reduce it. Thus, so that it is less of
a restriction to the user, this method should be able to
function with a relatively high level of uncertainty
regarding the temperature level.
Another disadvantage of an "immersion deposit"
treatment such as this in comparison with a cold method is
that it is, in addition to being affected by a change in the
temperature of the substrate, sensitive to a variation in the
thickness of the strip. In fact, at a given temperature, for
a given material, the quantity of thermal energy stored is a
function of the volume of the body, hence of the thickness in
the case of a flat product. In fact, on a galvanising line,
steel strips of different thicknesses can be processed.
Aims of the invention
The present invention aims to provide a method
for coating a metal with an ultra-fine protective film of
oxide, preferably of silicon, titanium, zirconium, cerium,
yttrium or antimony.
An additional aim of the invention is to allow
maximum flexibility of the method relative to the entry
temperature of the strip into the bath.
Another aim of the invention is to guarantee
reproducibility of the deposit in terms of thickness with a
light or heavy weight of the layer.
Another aim of the invention is to guarantee a
useful life of the solution that meets the metallurgist's
requirements.
Main characteristic elements of the invention
A first aspect of the present invention relates
to a method for continuously coating a substrate in motion
such as a metal strip made of steel, the coating formed being
an ultra-fine film of a thickness of between 10 and lOOnm,
deposited on the substrate:
- from a solution containing nanoparticles of oxides,
- in conditions of controlled pH,
- said substrate being at a temperature higher than 120°C,
- the total duration of the deposition being less than 5
seconds, preferably less than 1 second,
wherein at least one chemical additive, called a "refiner",
is incorporated into said solution, said refiner having,
mutatis mutandis, the effect of restricting the formation of
said coating.
In the context of the invention, the substrate
to be coated is either a bare metal, preferably steel,
stainless steel (or "inox"), aluminium, zinc or copper; or a
first metal coated with a second metal, preferably a steel
strip coated with a layer of zinc, aluminium, tin, or of an
alloy of at least two of these metals.
The nanoparticles comprise oxides, preferably
Si02, TiO2, Zr02, A1203, Ce02, Sb205, Y203, ZnO, Sn02 or mixtures
of these oxides, are hydrophilic and/or hydrophobic, have a
size of between 1 and lOOnm and are in the solution with a
content of between 0.1 and 10%, and preferably between 0.1
and 1%.
The concentration of refiner is between 1 and
20 g per litre (g/L) of solution, preferably between 5 and
lOg/L.
More particularly, the refiner used for the
deposit of silica nanoparticles is selected from the group of
compounds comprising catechin and its derivatives,
hydrofluoric and boric acids, borates, sodium and potassium
carbonates and hydrogen carbonates, ammonium hydroxide and
amines that are soluble in water. The refiner used for a
deposit of nanoparticles of stannous or stannic oxide is
selected from the group of compounds comprising borates,
potassium carbonates and hydrogen carbonates, ammonium
hydroxide and amines that are soluble in water. The refiner
used for the deposit of nanoparticles of cerium and zirconium
oxide is selected from the group of compounds comprising
hydrofluoric, boric and carboxylic acids, and preferably
formic, acetic, ascorbic and citric acids.
Still according to the invention, the pH of the
solution is adjusted so as to allow the pickling of surface
oxides from the metal substrate when it is in contact with
the solution, so as to give the particles a maximum
electrical charge in order to avoid any agglomeration in the
solution and so as to make the particles as reactive as
possible without destabilising the solution.
In particular, the pH of the solutions based on
nanoparticles of Si02, Sn02, Ti02, ZnO or Sb205 is alkaline and
is preferably between 9 and 13. The pH of the solutions based
on nanoparticles of Zr02, Ce02, Si02 or Sb2O5 is acidic and is
preferably between 1 and 5.
As an advantage, the pH of the solutions based
on a mixture of nanoparticles is adjusted so that the
solution is stable over time. Preferably, in the case of a
surface layer of the substrate comprising a component of
zinc, aluminium, iron, tin, chrome, nickel or copper, the pH
is chosen to be either alkaline or acidic.
According to a first preferred embodiment of
the invention, the deposit is achieved by immersing the
substrate for a controlled period of time in an immersion
tank containing the solution.
According to a second preferred embodiment of
the invention, the deposit is achieved by spraying the
solution onto the substrate by means of a nozzle, i.e. a
device, assisted or not, with gas under pressure, that sprays
droplets of the solution.
According to a third preferred embodiment of
the invention, the deposit is created by depositing the
solution on the substrate by means of a roller.
As an advantage, the solution that comes into
contact with the strip is kept at a temperature of less than
100°C, and preferably less than 80°C.
As a further advantage, the temperature of the
substrate at the start of the deposition is higher than 125°C
and lower than 250°C.
If the substrate already has a metallic coating
before treatment, the temperature of the substrate at the
start of the deposition is advantageously higher than 125°C
and lower by 30 to 100°C than the melting point of the
coating metal.
If the substrate has a metallic coating
produced by immersion, as in galvanisation by immersion, the
deposition is preferably achieved just after the deposition
of the metallic coating, before the substrate cools down.
Preferably, in the case of a substrate liable
to a too-high level of oxidation for this to be eliminated
during the deposition, the substrate is protected from
excessive contact with air by means of a neutral gas such as
nitrogen (N2)or argon.
Preferably again, the deposition is limited in
time by varying the depth of immersion in the case of
deposition in a solution or the length sprayed in the case of
spraying the solution with nozzles.
Still according to the invention, the solution
is an aqueous solution or comprises any other solvent capable
of effectively dispersing said nanoparticles.
As an advantage, agents for the improvement of
resistance to corrosion and/or adhesion to the substrate or
the paint and/or to improve the glide during formation are
added to the solution.
Provision can be made in the method of the
invention for the coated substrate to be rinsed after posttreatment
with water or with a solution based on organic
silanes or carboxylic acid with an ability to form a strong
link with the organic.
Preferably, the method of the invention
comprises the means for:
- continuously measuring and regulating the pH,
- ensuring the replenishment of the solution and the
elimination of surplus products of the reaction,
- ensuring the homogeneous mixture of the bath so as to avoid
turbulence on its surface.
According to an advantageous embodiment, the
temperatures of the strip and of the bath, the time the strip
remains in the bath, the concentration of nanoparticles in
the bath and the pH of the bath are controlled. If necessary,
the temperature of the strip, the length of spraying time,
the concentration of nanoparticles in the solution sprayed,
the spraying flow and the pH are equally controlled.
A second aspect of the present invention
relates to an installation for coating a steel strip,
comprising a device for obtaining a second coating layer on a
first coating layer obtained by hot dipping or by jet
spraying, by implementing the above-described method, wherein
said installation is located after elements ensuring the
spinning and solidification operations of the first coating
layer, said second coating layer being achieved in this
installation at a temperature lower by at least 100°C than
the temperature at which the first coating layer solidifies.
A third aspect of the present invention relates
to a flat or long metallurgical product, preferably a strip,
wire, profiled section or tube, coated with an ultra-fine
protective layer by means of the above-described method,
wherein said protective layer comprises nanoparticles of
oxide or of a mixture of these oxides, preferably A1203, Y203,
Si02, Sn02, Ti02, ZnO, Sb205, Zr02 or Ce02, and has a thickness
of less than lOOnm.
As an advantage, the invention relates to a
metallurgical product of the strip coated type as described,
the thickness of which, possibly the initial thickness before
the profiled section or tube is produced, is between 0.15 and
5mm.
Brief description of the Accompanying Figures
Figure 1, already mentioned, shows a scanning
electron microscope image of a surface treated according to
the invention, a layer of SiC>2 being deposited at a
concentration of 2% by weight.
Figures 2.a and 2.b already mentioned
diagrammatically show the potential precipitation zones when
the method of the invention is implemented, in a bath (a) or
with a spray (b) respectively.
Figure 3 diagrammatically shows the
development, measured with XPS, of the thickness of the
silica coating on galvanised steel, implemented according to
the present invention, depending on the temperature. The
coating is achieved by immersion in a solution of 2% of Si02,
with and without the effect of a refiner, in this case sodium
borate (5g/L).
Description of a preferred embodiment of the invention
The innovation introduced in the context of the
present invention is based on the principle of obtaining
ultra-fine layers of nanoparticles of oxides, where the
thickness of said layers is limited by the incorporation in
the bath of chemical additives that restrict the deposition
reaction, which for this reason are called "refiners" by the
Applicant.
The phenomenon of precipitation during the
deposition and the stability of the bath are based on the
same chemical principles. In fact, the precipitation by
immersion is a competition between two opposing mechanisms.
There is on the one hand the force that provides the
stability of the solution and thus allows the links between
the nanoparticles to be broken and on the other hand, the
force that .allows precipitation.
To control these phenomena as well as possible,
compounds comprising some highly specific chemical elements
are introduced into the solution.
The role of these compounds is to catalyse the
dissolution of the ultra-fine layer and thus to combat
massive and chaotic precipitation, i.e. to eliminate the
network of ribs on the surface of the oxide, for example.
These compounds are called "refiners" by the Applicant
because they allow to reduce the weight of the deposit layer.
From the chemical point of view, they are to some extent
"poisonous" to the deposition reaction.
The discovery of these compounds that restrict
the reaction allows to envisage qualities of deposit
equivalent to or better than those obtained by conventional
cold treatments.
They may allow, in a very wide range of
temperature of the strip, to obtain a homogeneous thickness
of deposit of nanoparticles (see Figure 3) and thus an
effective control of the weight of the layer of the deposit.
It is therefore of interest to note that the addition of
these types of chemical allows a deposition at lower
temperatures, possibly down to as low as 120°C.
Depending on their concentration, they can also
allow to obtain in the bath layers of ultra-fine thickness
for any concentration of nanoparticles.
This type of compound must be soluble in the
solvent in the ranges of pH of the colloidal solutions
envisaged and not cause destabilisation of the suspension. In
addition, thanks to their ability to break the internanoparticle
links, they may enhance the stability areas of
colloidal solutions, either in terms of temperature or of pH
or both.
In order to be of value, the effectiveness of
these compounds must increase with temperature.
According to the present invention, types of
mineral or organic chemicals are associated with one or
several types of nanoparticles. Thus, a refiner for silica is
not necessarily suited for zirconium oxide.
For the deposition of silica nanoparticles, the
most effective types are principally catechin, hydrofluoric
and boric acids or borates, sodium and potassium carbonates
and hydrogen carbonates, ammonium hydroxide and amines that
are soluble in water.
For stannous and stannic oxides borates,
potassium carbonates and hydrogen carbonates, ammonium
hydroxide and amines that are soluble in water will be
advantageously used.
Lastly, for cerium and zirconium oxides,
hydrofluoric, boric or carboxylic acid or formic, acetic,
ascorbic and citric acid will be used to advantage.
Once the deposit is formed, the surplus of the
nanoparticles that have not agglomerated under the effect of
the refiner and the residual refiners themselves can be
rapidly eliminated by a rinse.
It is also of interest to emphasise that in
order to conform to the logic of respecting the environment,
the compounds used are not carcinogenic.
Legend of the figures:-
Fig.2a: Treating solution
Overheated liquid, precipitation zone
Growing sphere of vapour
Metal
Fig.2b: Overheated solution, precipitation zone
Metal
Fig.3: Useful zone with refiners
Useful zone without refiners
Thickness (nm)
Temperature of the strip (°C)
Without refiners *
With refiners 4















WE CLAIM
1. Method for continuously coating a
substrate in motion, wherein substrate includes a metal
strip, the coating formed being an ultra-fine film of a
thickness of between 10 and l00nm, deposited on the
substrate:
from a solution containing nanoparticles of oxides of the
kind such as herein described,
in conditions of controlled pH,
said substrate being at a temperature higher than 120°C,
the total duration of the deposition being less than 5
seconds, preferably less than 1 second, wherein at least one chemical additive, referred to as refiner, is incorporated into said solution, wherein said refiner has effect of restricting the formation of said coating.
2. Method for continuously coating a substrate as claimed in Claim 1, wherein that substrate to be coated is either a bare metal, preferably steel, stainless steel, aluminium, zinc or copper, or a first metal coated with a second metal, preferably a strip of steel coated with a layer of zinc, aluminium, tin or an alloy of at least two of these metals.
3. Method for continuously coating a substrate as claimed in Claim 1 or 2, wherein said nanoparticles comprise oxides, preferably SiO2, TiO2, ZrO2, A12O3, CeO2, Sb2O5, Y2O3, ZnO, SnO2 or mixtures of these oxides, are hydrophilic and/or hydrophobic, have a size of between 1 and lOOnm and are in the solution with a content of between 0.1 and 10%, and preferably between 0.1 and 1%.
4. Method for continuously coating a substrate as claimed in any of Claims 1 to 3, wherein the concentration of said refiner is between 1 and 20 g per litre (g/L) of solution, preferably between 5 and l0g/L.
5. Method for continuously coating a substrate as claimed in any one of Claims 1, 3 or 4, wherein said refiner for the deposition of said nanoparticles of silica is selected from the group of compounds consisting of catechin and its derivatives, hydrofluoric and boric acids, borates, sodium and potassium carbonates and hydrogen carbonates, ammonium hydroxide and amines that are soluble in water.
6. Method for continuously coating a substrate as claimed in any one of Claims 1, 3 or 4, wherein said refiner for a deposition of said nanoparticles of stannous or stannic oxide is selected from the group of compounds consisting of borates, potassium carbonates and hydrogen carbonates, ammonium hydroxide and amines that are soluble in water.
7. Method for continuously coating a substrate as claimed in any one of Claims 1, 3 or 4, wherein said refiner for a deposition of said nanoparticles of cerium and zirconium oxides is selected from the group consisting of hydrofluoric, boric and carboxylic acids.
8. Method for continuously coating a substrate as claimed in Claim 7, wherein said refiner for a deposition of said nanoparticles of cerium and zirconium oxides is selected from the group of compounds consisting of formic, ascetic, ascorbic and citric acids.
9. Method for continuously coating a substrate as claimed in any one of the proceeding claims, wherein said pH of said solution is adjusted in a manner to allow the pickling of surface oxides from the metal substrate when it is in contact with said solution, to give a maximum electrical charge to the particles in order to avoid any agglomeration in said solution and to make the particles reactive without destabilising said solution.
10. Method for continuously coating a substrate as claimed in Claim 9, wherein said pH of said
solutions based on said nanoparticles of SiO2, SnO2, TiO2, ZnO or Sb2O5 is within alkaline range and is preferably between 9 and 13.
11. Method for continuously coating a substrate as claimed in Claim 9, wherein said pH of said solutions based on said nanoparticles of ZrO2, CeO2, SiO2 or Sb2O5 is within acidic range and is preferably between 1 and 5.
12. Method for continuously coating a substrate as claimed in Claim 10 or 11, wherein said pH of said solutions based on a mixture of said nanoparticles is adjusted in a manner that the solution thus obtained is stable.
13. Method for continuously coating a substrate as claimed in Claim 9, wherein the surface layer of the substrate contains a component of zinc, aluminium, iron, tin, chrome, nickel or copper, and said pH of said solution is within alkaline range.
14. Method for continuously coating a substrate as claimed in Claim 9, wherein the surface layer of the substrate contains a component of zinc, aluminium, iron, tin, chrome, nickel or copper, and said pH of said solution is within acidic range.
15. Method for continuously coating a substrate as claimed in Claim 1, wherein said deposit is formed by immersion of said substrate for a controlled period of time sufficient to form said deposit in an immersion tank comprising said solution.
16. Method for continuously coating a substrate as claimed in Claim 1, wherein said deposit is formed by spraying said solution onto said substrate by means of a nozzle, assisted or not, with gas under pressure, that is capable of spraying droplets of said solution.
17. Method for continuously coating a substrate as claimed in Claim 1, wherein said deposit is
formed by deposition of said solution on said substrate by means of a roller.
18. Method for continuously coating a substrate as claimed in Claim 1, wherein the solution that comes into contact with the strip is kept at a temperature lower than 100°C and preferably lower than 80°C.
19. Method for continuously coating a substrate as claimed in Claim 1, wherein the temperature of the substrate at the start of the deposition is higher than 125°C and lower than 250°C.
20. Method for continuously coating a substrate as claimed in Claim 19, wherein, if the substrate already has a metallic coating before the treatment, the temperature of the substrate at the start of the deposition is higher than 125°C and lower by 30 to 100°C than the melting point of the coating metal.
21. Method for continuously coating a substrate as claimed in Claim 20, wherein, if said substrate has a metallic coating made by immersion, preferably in galvanisation, said deposit is formed immediately after said deposition of the metallic coating, before said substrate cools down.
22. Method for continuously coating a substrate as claimed in Claim 21, wherein said substrate is protected from excessive contact with air by means of a neutral gas selected from nitrogen or argon.
23. Method for continuously coating a substrate as claimed in Claim 20 or 21, wherein said deposition is limited in time by varying the depth of immersion in the case of deposition in a solution or the length sprayed in the case of spraying the solution with nozzles.
24. Method for continuously coating a substrate as claimed in Claim 1, wherein said solution is one
of the aqueous solution or a solution comprising any other solvent capable of effectively dispersing said nanoparticles.
25. Method for continuously coating a substrate as claimed in Claim 1, wherein said solution optionally comprises agents for the improvement of resistance to corrosion and/or adhesion to the substrate or the paint and/or to improve the glide during formation of said deposit.
26. Method for continuously coating a substrate as claimed in Claim 1, wherein the coated substrate formed is rinsed after post-treatment by means of water or of a solution based on organic silanes or carboxylic acid with an ability to form a strong link with the organic.

27. Installation for the coating of a steel strip, comprising a device for obtaining a second coating layer on a first coating layer formed by hot dipping or by spraying with jets, by implementation of the method as claimed in any of the preceding claims 1 to 26, wherein said installation is located after elements ensuring the spinning and solidification operations of the first coating layer, said second coating layer being formed in this installation at a temperature lower by at least 100°C than the temperature at which the first coating layer solidifies.
28. Installation for the coating of a steel strip as claimed in Claim 27, wherein it comprises the means for:

- continuously measuring and regulating the pH,
- ensuring the replenishment of the solution and the elimination of surplus products of the reaction,
- ensuring the homogeneous mixture of the bath so as to
avoid turbulence on its surface.
29. A Metallurgical product including
flat or long metallurgical product, preferably a strip,
wire, profiled section or tube as and when coated with
protective layer by means of a method as claimed in any one
of the preceding Claims 1 to 26.
30. Method for continuously coating a substrate substantially as herein described and illustrated with the help of accompanying figures.

Documents:

3004-delnp-2006-abstract.pdf

3004-DELNP-2006-Claims-(07-12-2009).pdf

3004-DELNP-2006-Claims-(27-08-2010).pdf

3004-DELNP-2006-Claims-(31-05-2010).pdf

3004-delnp-2006-claims.pdf

3004-DELNP-2006-Correspondence-Others-(07-12-2009).pdf

3004-DELNP-2006-Correspondence-Others-(13-05-2010).pdf

3004-DELNP-2006-Correspondence-Others-(27-08-2010).pdf

3004-DELNP-2006-Correspondence-Others-(31-05-2010).pdf

3004-delnp-2006-correspondence-others-1.pdf

3004-delnp-2006-correspondence-others.pdf

3004-delnp-2006-correspondence-po.pdf

3004-delnp-2006-description (complete).pdf

3004-delnp-2006-drawings.pdf

3004-delnp-2006-form-1.pdf

3004-delnp-2006-form-18.pdf

3004-DELNP-2006-Form-2-(07-12-2009).pdf

3004-delnp-2006-form-2.pdf

3004-delnp-2006-form-26.pdf

3004-DELNP-2006-Form-3-(07-12-2009).pdf

3004-DELNP-2006-Form-3-(31-05-2010).pdf

3004-delnp-2006-form-3.pdf

3004-delnp-2006-form-5.pdf

3004-delnp-2006-pct-210.pdf

3004-delnp-2006-pct-301.pdf

3004-delnp-2006-pct-304.pdf

3004-DELNP-2006-Petition 137-(31-05-2010).pdf

abstract.jpg


Patent Number 243737
Indian Patent Application Number 3004/DELNP/2006
PG Journal Number 45/2010
Publication Date 05-Nov-2010
Grant Date 02-Nov-2010
Date of Filing 25-May-2006
Name of Patentee CENTRE DE RECHERCHES METALLURGIQUES ASBL-CENTRUM VOOR RESEARCH IN DE METALLURGIE VZW
Applicant Address AVENUE ARIANE 5 B-1200 BRUXELLES (BELGIUM).
Inventors:
# Inventor's Name Inventor's Address
1 LE CRAZ SEBASTIEN AVENUE ROGIER 32#51, B-4000 LIEGE (BELGIUM).
PCT International Classification Number C23C 2/26
PCT International Application Number PCT/BE2004/000157
PCT International Filing date 2004-11-02
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2003/0666 2003-12-17 Belgium