Title of Invention

A PROCESS FOR MANUFACTURING A SUBSTRATE

Abstract The invention relates to a process for manufacturing a substrate, at least one part of the surface of which has been rendered hydrophobic, having for this purpose a hydrophobic surface structure comprising an essentially mineral silicon-containing sublayer formed at least partly on the surface of the substrate, and an outer layer of hydrophobic agent grafted onto said sublayer, in which process said sublayer has received the outer layer of hydrophobic agent although it had a surface that was in an activated state before being brought into contact with said hydrophobic agent. The process being an activated surface of the silicon-containing mineral layer is obtained by carrying out an activation treatment in at least one pass, the coating layer of hydrophobic agent then being deposited, in at least one pass, on the surface, in the activated state, of the silicon-containing mineral layer formed at least partly on the surface of the substrate and said activation treatment is carried out under conditions that allow a silicon-containing layer to be etched, by the use of a plasma of at least one fluorine-containing gas chosen from SF6, CF4,C2F6 and other fluorinated gases, where appropriate combined with oxygen, it being possible for the oxygen to represent up to 50% by volume of the etching plasma.
Full Text SUBSTRATE, SUCH AS A GLASS SUBSTRATE, WITH A
HYDROPHOBIC SURFACE AND IMPROVED DURABILITY OF
HYDROPHOBIC PROPERTIES
The present invention relates to a substrate,
especially a glass substrate, the surface of which has
been rendered hydrophobic, with improved durability of
the hydrophobic properties.
Hydrophobic properties are sought for windows and
windshields in the transport field, in particular for
motor vehicles and aircraft, and also for glazing in
the building industry.
For applications in the transport field, rain-repellent
properties are sought, the water droplets on
windshields thus having to easily roll off the glass
wall so as to be removed, for example when the vehicle
is in motion due to the effect of the air or wind, and
to do so with the purpose of improving visibility and,
consequently safety, or for facilitating cleaning, or
for easily defrosting, etc.
F'or applications in the building field, the aim is
essentially to make cleaning easier.
For this purpose, the aim. is to have an angle of
contact of a water droplet with the substrate that is
greater than 60° or 70°, the water droplet having not
to be flattened or spread out. This is because glazing
is said to be functional as long as this angle is
qreater than 60° in the case of aircraft, and greater
than 70° in the case of automobiles. However, in
practice this angle should in all cases exceed 90°, the
ideal being to obtain droplets that roll off, allowing
the water to be removed so quickly as to be able to
dispense as far as possible with windshield wipers in
the automotive field.

Moreover, the improvement in hydrophobic properties
thus sought must not be to the detriment of the
preservation of the other properties, such as
resistance to mechanical stresses: resistance to shear
friction (standardized Opel test, carried out dry) ,
abrasion resistance (Taber test), resistance to wiping
by wipers (test simulating the cycles of wiper action);
resistance to environmental stresses (WOM test of UVA
resistance, or Xenon test; QUV test of UVB resistance
for aircraft; NSS (neutral salt spray) resistance test;
resistance to chemical stresses: test of resistance to
acid and basic detergents; and the optical properties.
To render a glass hydrophobic it is known to coat it
with a dense silica mineral layer serving as primer for
the' grafting of molecules having hydrophobic
properties, such as fluorosilane molecules. Thus,
European patent EP 0 545 201 describes the application
of a dense SiO2 layer applied by magnetron sputtering,
said SiO2 layer being subsequently coated with a
hydrophobic agent.
The filing company has discovered that the hydrophobic
properties of such a structure can be further improved,
in particular in their durability, with the other
properties mentioned above being at least maintained,
or even sometimes improved, if the coating of molecules
having hydrophobic properties is applied while this
layer is in an activated surface state, this activation
being able to be produced either by the actual
conditions under which the mineral layer is deposited,
or by a specific activation treatment.
Thus, the mineral layer (which is the sublayer in the
resulting final structure) may be deposited by vacuum
sputtering, especially magnetron sputtering, under
conditions that allow the layer to be left in an

unstable surface state, with the hydrophobic coating
being applied while the surface is still in this state
(generally applied immediately) , or by a specific
activation treatment (plasma excitation, etc.).
A first subject of the present invention is therefore a
substrate, at least one part of the surface of which
has been rendered hydrophobic, having for this purpose
a hydrophobic surface structure comprising an
essentially mineral silicon-containing sublayer and an
outer layer of hydrophobic agent grafted onto said
sublayer, characterized in that said sublayer has
received the outer layer of hydrophobic agent although
it had a surface that was in an activated state before
being brought into contact with said hydrophobic agent.
The term "activated" is understood to mean that said
surface has undergone a treatment which has modified
its electrostatic state (by production of charges)
and/or its chemical state (creation or destruction of
chemical functional groups), in order to increase the
reactivity of said surface, which treatment may go as
far as tearing the material of the surface, thus
creating irregularities. Moreover, as will be indicated
below, the layer of silicon-containing mineral material
that will constitute the sublayer in the final
structure may be obtained under conditions in which it
is directly in the activated state.
The sublayer may be a hard sublayer.
The substrate is especially formed by, or comprises in
its part intended to bear said mineral sublayer, a
plate, whether plane or with curved faces, of
monolithic or laminated glass, of glass-ceramic or of a
hard thermoplastic, such as polycarbonate. The glass
may be a toughened glass. An example of a curved plate
is a windshield. This may be in the assembled state.

The sub-layer of the hydrophobic coating may form part
of the substrate, the latter being formed by a plate,
whether plane or with curved faces, of monolithic or
laminated glass or of glass-ceramic, the composition of
which, at least on the surface, corresponds to that of
the essentially mineral silicon-containing sublayer. An
example of a substrate having such an integrated
sublayer is a glass dealkylized at least on its
surface. International applications WO-94/07806 and
WO-94/07807 describe this technology.
The silicon-containing sublayer is especially formed by
a compound chosen from SiOx, where x ≤ 2, SiOC, SiON,
SiOCN and Si3N4, it being possible for hydrogen to be
combined in all proportions with SiOx, where x ≤ 2,
SiOC, SiON and SiOCN. It may also contain aluminum, in
particular up to 8% by weight, or carbon, Ti, Zr, Zn
and B.
Mention may also be made of sublayers consisting of
scratch-resistant lacquers, such as polysiloxanes,
which have oeen applied as coating on polycarbonate
substrates.
The silicon-containing sublayer when its surface is in
the activated state has a thickness of between 20 nm
and 250 nm, especially between 30 nm and 100 nm and in
particular between 30 nm and 75 nm. It may have an RMS
roughness of between 0. 1 nm and 40 nm, in particular
between a few nm and 30 nm. It may have an actual
developed area at least 40% greater than the initial
plane area. Under an SEM microscope, said sublayer may
have the appearance of pumistone or of islands.
Moreover, the silicon-containing sublayer when its
surface is in the activated state advantageously has a
hardness such that it does not delaminate after 100

revolutions, and preferably up to 200 revolutions, in
the Taber test.
The hydrophobic agent may be chosen from:
(a) alkylsilanes of formula (I):
CH3(CH2)nSiRmX3-m (I)
in which:
- n ranges from 0 to 30, more particularly from
0 to 18;
- m = 0, 1, 2 o r 3 ;
- R represents an optionally functionalized
organic chain; and
- X represents a hydrolyzable residue, such as
an OR0 residue, where R° represents hydrogen;
or a linear, branched or cyclic, especially
C -C8, alkyl residue; or an aryl residue; or
such as a halo, for example chloro, residue;

(b) compounds with grafted silicone chains, such as
for example (CH3)3SiO[Si (CH3) 2O] q, with no
specific limitation as regards the chain length
(value of q) and the method of grafting;
(c) fluorosilanes, such as those of formula (II):
R1-A-SiRp2X3_p (II)
in which:
- R1 represents an especially C1-C9
monofluoroalkyl, oligofluoroalkyl or
perfluoroalkyl residue; or a monoaryl,
oligoaryl or perfluoroaryl residue;
- A represents a hydrocarbon chain, optionally
interrupted by a heteroatom such as O or S;
- R2 represents a linear, branched or cyclic,
especially C1-C8, alkyl residue, or an aryl
residue;
- X represents a hydrolyzable residue, such as
an OR3 residue, where R3 represents hydrogen
or a linear, branched or cyclic, especially
C1-C8, alkyl residue; or an aryl residue; or
such as a halo, for example chloro, residue;


An example of an alkylsilane of formula (I) is
octadecyl trichlorosilane (OTS).
The preferred hydrophobic agents are fluorosilanes (c),
in particular those of formula (II), particular
examples of the latter being those of formula:
CF3-(CF2)n-(CH2)2-Si(R4)3
in which:
R represents a lower alkyl residue; and
n is between 7 and 11.
The layer of hydrophobic agent has for example a
thickness of between 1 and 100 nm, preferably between 2
and 5 0 nm.
The layer of fluorosilane may have a weight per unit
area of grafted fluorine of between 0.1 fig/cm2 and
3.5 µg/cm2, in particular between 0.2 µg/cm2 and
3 µg/cm2 .
The subject of the present invention is also a process
for manufacturing a substrate as defined above,
characterized in that a coating layer of hydrophobic
agent is deposited, in at least one pass, on the
surface of a silicon-containing mineral layer formed at
least partly on the surface of the substrate, said
deposition of the hydrophobic agent taking place while
said surface is in the activated state.
An activated surface of the silicon-containing mineral
layer may be obtained by depositing it under conditions
in which its surface is obtained directly in the
activated state. This is what occurs if a silicon-
containing layer is deposited, cold, by PECVD (plasma
enhanced chemical vapor deposition) or by magnetron

and/or ion-beam sputtering.
This is because, in such processes, the growth of the
layer takes place using reactive species (ions,
radicals, neutrals, etc.) which combine to form the
coating. The surface of the coating is therefore by
nature in an off-equilibrium state. In addition, this
layer may be directly in contact with the plasma gas
during growth, which will further increase the activity
of the surface and its reactivity (as in the PECVD
process).
It is also possible to obtain an activated surface of
the silicon-containing mineral layer by carrying out an
activation treatment in at least one pass.
Advantageously, the hydrophobic agent is deposited
within the shortest possible time, preferably between 1
second and 15 minutes, after the activated surface has
been oblaimed.
An activation treatment may be carried out under
conditions that do not go as far as etching, by the use
of a plasma or an ionized gas, at reduced or
atmospheric pressure, chosen from air, oxygen,
nitrogen, argon, hydrogen, ammonia and mixtures
thereof, or by the use of an ion beam.
it is also possible to carry out an activation
treatment under conditions that allow a silicon-
containing layer to be etched, by the use of a plasma
of at least one fluorine-containing gas chosen from SF6,
CF4, C2F6 and other fluorinated gases, where appropriate
combined with oxygen, it being possible for the oxygen
to represent up to 50% by volume of the etching plasma.
Moreover, according to the present invention, the
activation carried out under conditions that allow the

silicon-containing layer to be etched by an activation
treatment, which does not cause additional etching but
does modify the chemical nature and/or the
electrostatic state of said layer, may be monitored.
The silicon-containing layer may be deposited, cold, on
the substrate by vacuum cathode sputtering, preferably
magnetron sputtering and/or ion beam sputtering, or by
low-pressure or atmospheric-pressure PECVD, or else
deposited hot by pyrolysis.
As examples of the deposition of the SiO2 sublayer, the
following method of implementation may be mentioned, in
which: a layer of SiO2 is deposited on bare glass or on
an assembled windshield by PECVD, using a mixture of an
organic or nonorganic, silicon-containing precursor,
such as SiH4, hexamethyldisiloxane (HMDSO),
tetraethoxysilane (TEOS) and 1,1,3,3-
tetramethyldisiloxane (TMDSO), and an oxidizer (O2, NO2,
CO2), the subsequent activation being carried out in the
same chamber or in a separate chamber.
The hydrophobic agent layer may be deposited by wiping-
on, evaporation or spraying of a solution containing
the hydrophobic agent, or by dipping, spin-coating,
flow-coating, etc., using a solution containing the
hydrophobic agent.
To manufacture glazing with a hydrophobic coating
according to the present invention, it will be possible
to use inter alia, one of the following three general
methods:
(1) the sublayer is deposited on the glass on a
glass manufacturing line using the "float" process
while the glass is being supported by the bath of
molten tin, or in a subsequent step, that is to say on
leaving the bath of molten tin, the conversion
operations are then carried out, such as bending,

toughening and/or assembling, especially by lamination,
in order to obtain plates of glass made up from one or
more sheets coated with the sublayer on at least one
face, the sublayer or sublayers supported by said
plates are then activated and, finally, a
functjona1ization by the hydrophobic agent of the
sublayer or sublayers thus activated is carried out.
The sublayer is generally deposited by PECVD or
magnetron sputtering;
(2) sheets of glass are manufactured by the float
process, said glass sheets are then converted by
operations such as bending, toughening and/or
assembling, especially lamination, in order to obtain
plates of glass made up from one or more sheets, the
sublayer is then deposited on at least one face of the
plates thus obtained, and the sublayer or sublayers are
then activated, followed by the functionalization by
the hydrophobic agent of the sublayer or sublayers thus
activated;
(3) the sublayer is deposited on at least one
face of glass sheets obtained upon leaving the float
process, these sheets thus coated with the sublayer or
sublayers are converted, limiting the techniques used
to those that do not damage said sublayer(s) (thereby
excluding bending and toughening as conversion
operations, but allowing assembling, especially by
lamination), and the sublayer or sublayers are then
activated, followed by the functionalization by the
hydrophobic agent of said sublayer or sublayers thus
activated.
The present invention also relates to rain-repellent
glazing comprising a substrate as defined above or
prepared by the process as defined above. Mention may
be made of glazing for buildings, including glazing for
shower cubicles, glass for electrical household
appliances, especially glass-ceramic hobs, glazing for
transport vehicles, especially for automobiles and

aircraft, in particular for windshields, side windows,
rear windows, wing mirrors, sunroofs, headlamp and rear
light optics, and ophthalmic lenses.
The following examples illustrate the present invention
without however limiting the scope thereof. In these
examples, the following abbreviations have been used:
PECVD: plasma enhanced chemical vapor
deposition;
SEM: scanning electron microscopy;
AEM: atomic force microscopy; and
AWR: aviation wiping rig.
EXAMPLE 1: Substrate having a hydrophobic surface
according to the invention with a silica
sublayer formed by PECVD
(a) Formation and characterization of the hard silica
sublayer
A thin silica (SiO2) layer was deposited on a clean
glass (measuring 300 x 300 mm2) in a low-pressure PECVD
reactor. Before each experiment, the residual vacuum
reached in the chamber was at least 5 mPa (5 x 10~5
mbar) . The gas mixture was then introduced into the
chamber. The gases used were pure silane (SiH4), nitrous
oxide (N2O) and dilution helium, the respective flow
rates of which were 18 sccm, 60 sccm and 60 sccm. The
total pressure in the reactor was then set at 9.99 Pa
(75 mTorr). In equilibrium, the plasma was struck by
biasing the gas diffuser with an average radiofrequency
(13.56 MHz) power of 190 W (bias voltage: ~ 45 V) . The
temperature of the substrate was kept at 25°C. The
thickness of silica thus deposited after 270 s was
about 5 0 nm.
The surface state of the PECVD silica observed in SEM
was characterized by small grains about twenty

nanometers in size, which, in places, formed circular
or elongate areas of additional thickness that were
hollow at their center.
Tne hardness of the silica obtained was characterized
using the following two tests:
firstly, the layer underwent an abrasion
treatment, during which the haze was measured according
to the standard ISO 3537; the abrasion was of the Taber
type, carried out by means of a CS10F abrasive wheel
with an applied force of 4.9 N (500 g) . The degree of
abrasion was denoted by the number of Taber
revolutions. The measured haze values are given in
Table 1 below; and
secondly, the hardness of the silica was
assessed by the Airco rating, the value being 10 -
0.18R in which R is the number of scratches, after a
given number of Taber revolutions, in a frame measuring
2.54 cm x 2.54 cm, visible on a photograph with a x50
magnification. The Airco ratings are also given in
Table i below.

These values characterize a hard SiO2 layer.
(b) Plasma_ treatment
The SiO2 layer was then subjected to a plasma treatment.
As in the case of the deposition experiments, a
residual vacuum of at least 5 mPa (5 x 10-5 mbar) was
again created in the chamber before the reactive gas

mixture was introduced. The gases used for the surface
treatment of the silica were C2F6 and oxygen, the
respective flow rates of which were 120 seem and
20 seem. The total pressure in the reactor was then set
at 26.66 Pa (200 mTorr). At the equilibrium, the plasma
was struck by biasing the gas diffuser with an average
radiofrequency (13.56 MHz) power of 200 W (bias
voltage: ~ 15 V) for a time of 900 s at room
temperature.
After 15 minutes of C2F6/O2 plasma treatment, the silica
layer was highly etched. Its surface had large blisters
a few tens of nanometers in size. The microroughness
obtained with this highly aggressive plasma (etching)
treatment was characterized by AFM, indicating an
apparent roughness on the scale of the fluorosilane
molecules subsequently grafted onto the silica.
The main microroughness parameters of the PECVD silica
measured by AFM are given in Table 2 below.

(c) Application of fluorosilane
After the surface of the PECVD silica had been plasma-

treated, a composition was wiped onto the specimens,
the composition having been produced 12 hours
beforehand in the following manner (the percentages are
in weight):
90% of propanol-2 and 10% of 0.3N HC1 were
mixed in water; and
added to the two aforementioned constituents
was 2% of the compound of formula C8F17(CH2) 2Si(OEt)3 (Et
= ethyl).
The weights per unit area of fluorine grafted onto the
surface of the various sublayers, determined by
electron microprobe, were:

The amount of fluorine grafted onto the etched SiO2
sublayer is remarkably high.
(d) Characterization of the hydrophobic substrate
obtained
The characteristics of the hydrophobic substrate
obtained were:
droplet contact angle: µwter ≥ 105°;
- optical properties: TL = 90.2%; RL = 8.44%;
absorption — 1.36%; haze = 0.2%;
detachment volumes: 13 µl at 90° and 22 µl at
45° (the angles being the angles of inclination of the
substrate to the horizontal).
Next, the above three types of fluorosilane-grafted
substrates were subjected to two types of mechanical
tests:
Taber test using a CS-10F abrasive wheel with a
load of 4.9 N (500 g);

Ope] test according to Building Standard
EN 1096-2 of January 2001, consisting in applying, to
part of the coated surface 9.4 cm in length - this part
being called a track - a felt 14 mm in diameter, 10 mm
in thickness and 0.52 g/cm2 in density, and a load of
39.22 MPa {400 g/cm2), the felt being subjected to a
translational movement (50 to-and-fro movements over
the entire track length per minute) combined with a
rotation of 6 revolutions/minute (1 cycle = 1 to-and-
fro movement).
The results of the Opel and Taber tests on the etched
and unetched PECVD layers compared with the flat glass
are given in Table 3 below.

The 87° value in the Opel test (5000 cycles) for the
case of the SiO2 sublayer is not sufficient.
Only the substrate with an etched SiO2 sublayer results
in a good compromise between the Opel test and the
Taber test [100 revolutions).
This substrate was therefore tested in the AWR,
consisting in moving an aircraft windshield wiper over
it along a 25 cm track in a transverse movement
consisting of two to-and-fro movements per second,

under a Load of 0.88 N/cm (90 g/cm) with a water spray
of 6 1/h.
A mean angle of about 80° ± 10° after 1 000 000 cycles
was measured, with only 26% of the area not functional
(µwater be 1 400 000 cycles, at which the mean angle was about
70° ± 10° with more than 35% of the area not
functional.
The substrate was also assessed by the following main
accelerated environmental tests:
WOM or Xenon test: 0.55 W/m2 irradiation at
340 ran;
- QUV: 16 h of UV-B (313 ran) at 70°C + 8 h at
40°C (> 95% residual humidity);
- NSS: exposure at + 35°C, 50 g/1 NaCl at 7 pH
according to the IEC 60 068 standard, part 2-11 Ka.
All the results are given in Table 4.

The etched PECVD sublayers made it possible to
maintain, in the QUV test, a µwater > 80° ± 6° after 7000
hours of exposure and a µwater ≥ 96° ± 3° after 2800
hours of exposure in the WOM.

EXAMPLE 2: Substrate having a hydrophobic surface
according to the invention with a silica
sublayer deposi ted by magnetron
sputtering
(a) Formation and characterization of the hard silica
layer
This example relates to the grafting of fluorosilane
onto an SiO2 sublayer formed by reduced-pressure
magnetron sputtering.
Three types of SiO2 were produced:
SiO2 under a pressure of 200 Pa (2 µbar) ; Ar
flow rate: 15 seem; O2 flow rate: 12 seem;
Si02 under a pressure of 400 Pa (4 ubar) ; Ar
flow rate: 27 seem; O2 flow rate: 12 seem;
SiO2 under a pressure of 800 Pa (8 µbar) ; Ar
flow rate: 52 seem; O2 flow rate: 15 seem.
The plasma was ignited by increasing the DC power from
0 to 2000 W at a rate of 20 W/s.
A presputtering operation consisted in applying, for 3
minutes, a 40 kHz pulsed DC power of 2000 W with 4 µs
between the pulses.
A target containing 92% silicon and 8% aluminum was
sputtered.
To obtain a 100 nm SiO2 coating in one pass, the run
speed of the substrate beneath the target was:
5.75 cm/min (200 Pa/2 µbar) , 5.73 cm/min (400 Pa/4 µbar)
and 5.53 cm/min (800 Pa/8 µbar).
The hardness of the 200 Pa (2 µbar) and 800 Pa (8 µbar)
magnetron SiO2 layers was measured as described in the
case of the PECVD SiO2 layers above: measurement of the

haze (in %) during a Taber abrasion test (ISO 3537),
Ai rco rating.
The results are given in Table 5 below.

These SiO2 layers produced by magnetron sputtering were
hard layers.
(b) Plasma treatment
Magnetron-deposited (400 Pa/4 µbar and 800 Pa/8 µbar)
silicas were plasma-etched (230 W/300 s) as follows:
1) SiO2 (400 Pa/4 µbar) : 30%-70% SF6 at
9.99 Pa/75 mTorr;
2) SiO2 (800 Pa/8 µbar): a) 20% O2/80% C2F6 at
26.66 Pa/200 mTorr; b) 50% O2/50% C2F6 at
26.66 Pa/200 mTorr.
(c) Fluorosilane application
The procedure was as described at (c) of Example 1.
Five specimens were subjected to various tests, as
described below:
1 SiO2 (400 Pa/4 µbar) sublayer plasma treated
according to 1) above and then the fluorosilane wiped
on in order to graft it (as described above);
II SiO2 (400 Pa/4 µbar) sublayer with no plasma
treatment and the fluorosilane wiped on, upon leaving

the magnetron line for preparing the SiO2;
III SiO2 (800 Pa/8 µbar) sublayer plasma treated
according to 2a) above and then the fluorosilane wiped
on;
IV SiO2 (800 Pa/8 µbar) sublayer plasma treated
according to 2b) above and then the fluorosilane wiped
on; and
V SiO2 (800 Pa/8 µbar) sublayer with no plasma
treatment and the fluorosilane wiped on, upon leaving
the magnetron line for preparing the SiO2.
The results are given in Table 6 below.

This table shows the very high performance in general,
and especially that of test III in the Taber test and
test TV in the Opel friction test.
EXAMPLK 3
The purpose of this example is to compare four
hydrophobic glasses:
VI specimen prepared according to Example 5b of

EP 799 873 Bl;
VII magnetron-deposited SiO2 (800 Pa/8 µbar)
sublayer (Example 2) plasma treated with 70 sccm of SF6,
30 sccm O2 at 9.99 Pa/75 mTorr, 230 W, 300 s, the
Lluorosi lane being wiped on;
VIII magnetron-deposited SiO2 (400 Pa/4 µbar)
sublayer (Example 2) plasma treated with 50 seem of
C2F6, 50 seem at 26.66 Pa/200 mTorr, 230 W, 300 s, the
fluorosilane being wiped on; and
IX fluorosilane application by wiping on, upon
.eavinq the magnetron-deposited (800 Pa/8 µbar) silica
production line.
Various tests were carried out on the specimens thus
formed, and the results are given in Table 7 below.

Specimens VI to IX that had undergone 50 000 AWR cycles
were subjected to an NSS test in the case of some of
them and to a QUV test in the case of the others.
The results are given in Table 8 below.


This shows the remarkable performance of specimen VII
in the combined AWR/NSS and AWR/QUV tests.
Specimens VIII and IX are slightly inferior to VII in
the AWR/NSS test combination and substantially inferior
i n the AWR/QUV combination, while still being at a high
level, unknown before the implementation of the
invention.
EXAMPLF 4
This example describes a particular treatment of the
magnetron-deposited (800 Pa/8 µbar) SiO2 sublayers.
This treatment comprised:
(1) Five minutes, treatment in Ar (80 seem,
19.98 Pa/150 mTorr), 200 W (35 V bias voltage) in order
to reduce any residual roughness;
(2) Flash surface treatment: duration (= 60 s in this example), C2F6, SF6, O2, H2;
(3) Fluorosilane application by wiping.
Specimens X to XV are described below by the

characteristics of their treatment step (2):
X: 26.66 Pa/200 mTorr, 230 W, 50 sccm C2F6,
5 0 sccm O2,-
XI: as X, except 100 sccm C2F6;
XI: as X, except 70 sccm SF6 and 30 sccm O2;
XIII: 9.99 Pa/75 mTorr, 203 W, 100 sccm SF6;
XTV: 7.99 Pa/60 mTorr, 230 W, 100 sccm O2; and
XV: 13.33 Pa/100 mTorr, 230 W, 75 sccm H2.
The amount of grafted fluorine [F] was determined by
electron microprobe, and then an Opel friction
resistance test was carried out. The results are given
in Table 9 below.

These results show that the friction resistance is not
directly correlated with the amount of grafted
fluorine, or with the roughness of the sublayer (since
the etched thicknesses do not exceed 16 nm, the
increase in roughness generated by the etching process
is in this case negligible). However, the fluorine
grafting mode plays a role that depends on the surface
treatment.
The invention has been described using the word

"substrate" . It should be understood that this
substrate may be a bare substrate, but it may also be a
substrate already provided with functionalities other
than the rain-repellent functionality, in particular
thanks to layers, and, in certain cases, the sublayer
accordinq to the invention may then already form part
of the layers that provide these other functionalities.

We Claim:
1. A process for manufacturing a substrate, at least one part of the surface
of which has been rendered hydrophobic, having for this purpose a
hydrophobic surface structure comprising an essentially mineral silicon-
containing sublayer formed at least partly on the surface of the substrate,
and an outer layer of hydrophobic agent grafted onto said sublayer, in
which process said sublayer has received the outer layer of hydrophobic
agent although it had a surface that was in an activated state before
being brought into contact with said hydrophobic agent, said process
being characterized in that:
- an activated surface of the silicon-containing mineral layer is obtained by
carrying out an activation treatment in at least one pass, the coating layer
of hydrophobic agent then being deposited, in at least one pass, on the
surface, in the activated state, of the silicon-containing mineral layer
formed at least partly on the surface of the substrate and
- said activation treatment is carried out under conditions that allow a
silicon-containing layer to be etched, by the use of a plasma of at least
one fluorine-containing gas chosen from SF6, CR4,C2F6 and other
fluorinated gases, where appropriate combined with oxygen, it being
possible for the oxygen to represent up to 50% by volume of the etching
plasma.

2. The process as claimed in claim 1, wherein the hydrophobic agent is
deposited within the shortest possible time, preferably between 1 second
and 15 minutes, after the activated surface has been obtained.
3. The process as claimed in one of claims 1 and 2, wherein the activation
carried out under conditions that allow the silicon-containing layer to be
etched by an activation treatment, which does not cause additional
etching but does still modify the chemical nature and/or the electrostatic
state of said layer, is monitored.
4. The process as claimed in one of the preceding claims, wherein the
silicon-containing layer is deposited, cold, on the substrate by vacuum
cathode sputtering, preferably magnetron sputtering and/or ion beam
sputtering, or by low-pressure or atmospheric-pressure PECVD (plasma-
enhanced chemical vapour deposition).
5. The process as claimed in claim4, wherein a layer of SiO2 is deposited, as
silicon-containing layer, by PECVD, using a mixture of an organic or
nonorganic, silicon-containing precursor, such as SiH4,
hexamethyldisiloxane, tetraethoxysilane and tetramethyldisiloxane, and an
oxidizer, the subsequent activation being carried out in the same chamber
or in a separate chamber.

6. The process as claimed in one of the preceding claims, wherein the
fluorosilane layer is deposited by wiping-on, evapouration or spraying of a
solution containing the fluorosilane, or by dipping, spin-coating, flow-
coating, etc., using a solution containing the fluorosilane.
7. The process as claimed in one of the preceding claims, wherein the
substrate is formed by a plate, whether plane or with curved faces, of
monolithic or laminated glass, of glass-ceramic or of a hard thermoplastic,
such as polycarbonate.
8. The process as claimed in one of the preceding claims, wherein said
sublayer is formed by a compound chosen from SiOx, where x SiON and SiOCN and Si3N4, it being possible for hydrogen to be combined
in all proportions with SiOx, where x 9. The process as claimed in one of the preceding claims, wherein the
silicon-containing sublayer contains aluminum, in particular up to 8% by
weight, or carbon Ti, Zr,Zn and B.

10.The process as claimed in one of the preceding claims, wherein the
silicon-containing sublayer when its surface is in the activated state has a
thickness of between 20 nm and 250 nm, especially between 30 nm and
100 nm and in particular between 30 nm and 75 nm.
11.The process as claimed in one of the preceding claims, wherein the
silicon-containing sublayer has, when its surface is in the activated state,
an RMS roughness of between 0.1nm and 40 nm, in particular between a
few nm and 30 nm.
12.The process as claimed in one of the preceding claims, wherein the
silicon-containing sublayer when its surface is in the activated state has an
actual developed area at least 40% greater than the initial plane area.
13.The process as claimed in one of the preceding claims, wherein the outer
layer of hydrophobic agent is based on a hydrophobic agent chosen from:
(a) alkylsilanes of formula (I):


in which:
- n ranges from 0 to 30, more particularly from 0 to 18;
- -m=0,1,2 or 3;
- R represents an optionally functionalized organic chain; and
- X represents a hydrolysable residue, such as an OR0 residue, where R0
represents hydrogen; or a linear, branched or cyclic, especially C1-C8, alkyl
residue; or an aryl residue; or such as a halo, for example chloro, residue;

(b) compounds with grafted silicone chains;
(c) flurosilanes, such as those of formula (II):

in which:
-R1 represents an especially C1-C9 monofluoroalkyl, oligofluoroalkyl or
perfluoroalkyl residue; or a monoaryl, oligoaryl or perfluoroaryl residue;
-A represents a hydrocarbon chain, optionally interrupted by a heteroatom
such as 0 or S;
R2 represents a linear, branched or cyclic, especially C1-C8, alkyl residue, or
an aryl residue; X represents a hydrolysable residue, such as an OR3 residue,
where R3 represents hydrogen or a linear, branched or cyclic, especially C1-C8
alkyl residue; or an aryl residue; or such as a halo, for example chloro,
residue; and
-p= 0,1 or 2.

14.The process as claimed in one of the preceding claims, wherein the layer
of hydrophobic agent has a thickness of between 1 and 100 nm,
preferably between 2 and 50 nm.
15.The process as claimed in one of the preceding claims, wherein the layer
of hydrophobic agent has a weight per unit area of grafted fluorine of
between 0.1 µg/cm2 and 3.5 µg/cm2.


The invention relates to a process for manufacturing a substrate, at least one
part of the surface of which has been rendered hydrophobic, having for this
purpose a hydrophobic surface structure comprising an essentially mineral
silicon-containing sublayer formed at least partly on the surface of the substrate,
and an outer layer of hydrophobic agent grafted onto said sublayer, in which
process said sublayer has received the outer layer of hydrophobic agent although
it had a surface that was in an activated state before being brought into contact
with said hydrophobic agent. The process being an activated surface of the
silicon-containing mineral layer is obtained by carrying out an activation
treatment in at least one pass, the coating layer of hydrophobic agent then being
deposited, in at least one pass, on the surface, in the activated state, of the
silicon-containing mineral layer formed at least partly on the surface of the
substrate and said activation treatment is carried out under conditions that allow
a silicon-containing layer to be etched, by the use of a plasma of at least one
fluorine-containing gas chosen from SF6, CF4,C2F6 and other fluorinated gases,
where appropriate combined with oxygen, it being possible for the oxygen to
represent up to 50% by volume of the etching plasma.

Documents:

02325-kolnp-2006-abstract.pdf

02325-kolnp-2006-claims.pdf

02325-kolnp-2006-correspondence-1.1.pdf

02325-kolnp-2006-correspondence.pdf

02325-kolnp-2006-description complete.pdf

02325-kolnp-2006-form 1.pdf

02325-kolnp-2006-form 2.pdf

02325-kolnp-2006-form 3.pdf

02325-kolnp-2006-form 5.pdf

02325-kolnp-2006-g.p.a.pdf

02325-kolnp-2006-international publication.pdf

02325-kolnp-2006-international search authority report.pdf

02325-kolnp-2006-pct request form.pdf

02325-kolnp-2006-priority document.pdf

2325-KOLNP-2006-ABSTRACT 1.1.pdf

2325-KOLNP-2006-AMANDED CLAIMS.pdf

2325-kolnp-2006-correspondence.pdf

2325-KOLNP-2006-DESCRIPTION (COMPLETE) 1.1.pdf

2325-KOLNP-2006-EXAMINATION REPORT REPLY RECIEVED.pdf

2325-kolnp-2006-examination report.pdf

2325-KOLNP-2006-FORM 1 1.1.pdf

2325-kolnp-2006-form 18.pdf

2325-KOLNP-2006-FORM 2 1.1.pdf

2325-KOLNP-2006-FORM 3 1.1.pdf

2325-kolnp-2006-form 3.pdf

2325-KOLNP-2006-FORM 5 1.1.pdf

2325-kolnp-2006-form 5.pdf

2325-KOLNP-2006-FORM-27.pdf

2325-kolnp-2006-gpa.pdf

2325-kolnp-2006-granted-abstract.pdf

2325-kolnp-2006-granted-claims.pdf

2325-kolnp-2006-granted-description (complete).pdf

2325-kolnp-2006-granted-form 1.pdf

2325-kolnp-2006-granted-form 2.pdf

2325-kolnp-2006-granted-specification.pdf

2325-kolnp-2006-others-1.1.pdf

2325-KOLNP-2006-OTHERS.pdf

2325-KOLNP-2006-PETITION UNDER RULE 137.pdf

2325-kolnp-2006-reply to examination report.pdf

2325-kolnp-2006-translated copy of priority document.pdf


Patent Number 247404
Indian Patent Application Number 2325/KOLNP/2006
PG Journal Number 14/2011
Publication Date 08-Apr-2011
Grant Date 05-Apr-2011
Date of Filing 17-Aug-2006
Name of Patentee SAINT- GOBAIN GLASS FRANCE
Applicant Address "LES MIRORIS" 18 AVENUE D' ALSACE F-92400 COURBEVOIE
Inventors:
# Inventor's Name Inventor's Address
1 DURAN, MAXIME C/O SAINT-GOBAIN RECHERCHE 39, QUAL LUCLEN LEFRANC 93300 AUBERVILLEIRS
2 HUIGNARD, ARNAUD C/o SAINT-GOBAIN RECHERCHE 39, QUAL LUCLEN LEFRANC 93300 AUBERVILLEIRS
PCT International Classification Number C03C 17/42
PCT International Application Number PCT/FR2005/050119
PCT International Filing date 2005-02-23
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 0450343 2004-02-24 France