Title of Invention	A GLASS OR CERAMIC BASED SUBSTRATE PROTECTING ORGANIC POLLUTION
Abstract	A substrate (1) based on glass or ceramic having, on at least one part of one of its faces, a thin film (6) which is a coating that imparts a pronounced hydrophilic character such as a coating comprising at least partially crystalline titanium oxide, especially in anatase form, said substrate (1) having, on at least one part of its periphery, a mastic (3) comprising silicone-type components, wherein a barrier to the migration of the silicones (5, 7, 8) is, in addition, placed on the surface (2) of said thin film (6).

Title of Invention

A GLASS OR CERAMIC BASED SUBSTRATE PROTECTING ORGANIC POLLUTION

Abstract

A substrate (1) based on glass or ceramic having, on at least one part of one of its faces, a thin film (6) which is a coating that imparts a pronounced hydrophilic character such as a coating comprising at least partially crystalline titanium oxide, especially in anatase form, said substrate (1) having, on at least one part of its periphery, a mastic (3) comprising silicone-type components, wherein a barrier to the migration of the silicones (5, 7, 8) is, in addition, placed on the surface (2) of said thin film (6).

Full Text	FIELD OF THE INVENTION The present invention relates to a substrate whose surface is protected against organic pollution stemming from peripheral seals, in particular mastics comprising silicone-type materials. BACKGROUND OF THE INVENTION A substrate is composed of a metal, a metal alloy, a ceramic, a glass, oxide or essentially mineral material, especially, in the latter two cases, in the form of thin film coatings on a substrate, in particular a glass substrate. The invention takes on a particular significance when the substrate is transparent and requires a high optical quality, which is the case for a glass substrate, or a substrate made of glass equipped with one or more functional coating layers, in particular when these functional layers impart a hydrophilic character to said substrate. In many technical fields, assemblies and juxtapositions of various materials and of various components that are either traditional (concrete, bricks, steel or concrete beams, glass, etc.) or modern, prefabricated or synthetic (doors, windows, panels, plastics, etc.) are encountered and it is necessary to make provision for the interstices or joints between these different materials and components, as they have different dimensional variations depending on temperature or moisture variations and also different movements under the effect of the wind, bindings, weight of the structure, and flow of certain components. The word "joint" therefore denotes either the separation line and the packing or weatherstripping or an interstice between two elements whether they are of the same nature or of different nature, or a desired continuity solution, that is to say a rectilinear break created in a structure to absorb the differences in movement or in behavior. These joints must then be filled with weatherstripping products and the joint then also denotes the assembly of the interstice and of the weatherstripping product used to seal it. Among the weatherstripping products, a mastic is defined, within the meaning of the present invention, as a pasty, malleable, plastic or elastic material, applied in a joint and forming weatherstripping by adhering to the surfaces inside this joint. A large number of weatherstripping and sealing mastics contain silicone-type components (also known as polysiloxanes). The silicone mastics are characterized by their properties of elasticity, durability and adhesion onto many substrates, and are thus very frequently used to provide sealing for glazing onto all mediums, and also between sanitary components and walls. Silicones are also incorporated into the composition of many other mastics as plasticizers (to impart plasticity, even elasticity, to the material). Moreover, the addition of silicone oils (low molecular weight silicones) on the surface of the mastics facilitates their use. Thus, mastics containing silicone-type components are many and varied. It has turned out that silicone-type compounds always contain, in a greater or lesser proportion, low molecular weight polysiloxanes (often called "silicone oils") which have the property of migrating toward the surface of the mastics then onto the surface of the materials, making said surface polluted by the silicones very difficult to clean. This property comes from the fact that the silicones have a surface energy that is among the lowest known surface energies and may therefore very easily wet any type of surface, in particular high-energy surfaces. This problem appears particularly important when the surface has a hydrophilic character, as the silicone surfaces are extremely hydrophobic. When in contact with water, the polluted area becomes extremely visible in contrast with the unpolluted area, as the water perfectly wets the hydrophilic surfaces, creating a film of water, whereas the hydrophobic surfaces are not wetted by the water, the latter stagnating in the form of droplets. The hydrophilic surfaces may be linked to the surface state of the substrate. A clean glass or metal surface, for example, has a high surface energy and therefore a hydrophilic character, being expressed by a water contact angle of less than 15°. The surface hydrophilicity may also be due to coatings that are especially adapted for conferring this property. On substrates such as ceramics or glass, coatings comprising at least partially crystalline titanium oxide, especially in anatase form, give said substrate "superhydrophilicity" properties, characterized by a water contact angle of less than 5°, or even less than 1°. Such coatings, which have, in addition, photocatalysis properties, are for example described in Application EP-A-0 850 204. Other types of coatings have a hydrophilic character are also known. Mention will be made, for example, of coatings based on SiO2 and/or SiOC, in particular when they are textured, the texture having patterns of dimensions around 10 to 200 nm, especially in the form of nodules. OBJECT OF THE INVENTION The object of the invention is therefore to protect the surface of a substrate from pollution coming from mastics that comprise silicone-type components. SUMMARY OF THE INVENTION To that effect, the subject of the invention is a substrate having, on at least one part of its periphery, a mastic comprising silicone-type components, characterized in that a barrier to the migration of the silicones is placed on the surface of said substrate. The substrate may be made from a metal, metal alloy, ceramic, glass, oxide or essentially mineral material, especially, in the latter two cases, in the form of thin-film coatings on a substrate, in particular, a glass substrate. The substrate according to the invention is preferably a glass-based or ceramic-based substrate having, on at least one part of one of its faces, at least one thin film (in this case, the surface of the substrate is classed as the surface of the outer thin film, the only one capable of being polluted by the migration of the silicones), in particular a coating conferring a pronounced hydrophilic character such as a coating comprising at least partially crystalline titanium oxide, especially in anatase form, according to the teaching of the aforementioned Application EP-A-0 850 204. Such a coated substrate has photocatalytic and superhydrophilic properties, making it capable of self- cleaning owing to the removal of organic and mineral soiling under the combined effect of a stream of water, especially of rain, and visible and/or ultraviolet radiation, such as solar radiation. In the latter case, the silicone-based pollution is, indeed, able to constitute a poison for the self-cleaning activity of the coating. Within the scope of the present invention, the term "barrier" is understood to mean any means making it possible to limit, or even suppress, the migration of silicones. According to a first embodiment of the invention, the barrier to the migration of the silicones is based on a polymer, preferably an elastomeric mastic that does not comprise any silicone-based plasticizers. The polymer acting as a barrier is preferably deposited in the form of a bead onto the surface of the substrate to be protected, either in direct contact with the mastic comprising the silicone-type compounds, or opposite to and at a distance of a few millimeters from said mastic. This second option is the one which has the greatest advantages. The elastomeric mastic acting as a barrier to the migration of silicones is preferably based on an MS polymer. MS polymers are silyl-terminated polyethers. A nonlimiting example of such an MS polymer is the polymer composed of a polyoxypropylene chain terminated by dimethoxysilyl groups. Due to the absence of cohesive units in their main chain, these polymers have a high flexibility and often do not require the addition of plasticizers (and therefore no silicone- based plasticizers), or even of solvents. It appears, surprisingly and for the time being inexplicably, that such barriers effectively protect the surface of the substrate. Since silicone oils have the ability to wet any type of material, it was not imagined that such a barrier, being of whatever nature, could have a real effectiveness. Without wishing to be tied to any one scientific theory, the origin of the very high effectiveness of the polymers from the family of MS polymers could stem from strong interactions between the silicone oils and the silyl end groups of the MS polymer. The barrier may also be composed of a thick layer, the thickness of which is preferably between 100 nm and 2 micrometers, comprising at least partially crystalline titanium oxide, and preferably even almost completely crystalline titanium oxide in anatase form. This layer preferably has a large specific surface area: it may be, for example, a layer of silica deposited by a sol-gel type process at the periphery of the surface to be protected, said silica layer comprising titanium oxide particles, as described, for example in Application WO-A-03/087002. The effectiveness of such a barrier probably lies in its very high photocatalytic activity, such layers being capable of degrading the silicone molecules under visible or ultraviolet radiation, the kinetics of degradation occurring more rapidly than the kinetics of migration of said molecules. According to a second embodiment, the barrier to the migration of the silicones may be formed from a notch or a groove located on the surface of the substrate and opposite to the mastic that is a source of silicones. The groove or notch advantageously has a depth ranging from 10 to 200 micrometers and a width ranging from 100 micrometers to 2 millimeters. It appears that the groove acts as a trap for the silicone oils. The dimensions of the groove are adapted depending on the quantity of silicone which may migrate, and taking into account a possible embrittling effect when the substrate is made from a brittle material such as glass or a ceramic. A third embodiment of the invention, in the case where the substrate is composed of a glass-based or ceramic- based substrate coated with at least one thin film, consists in marginating said thin film, that is to say in removing the thin film at the periphery of said substrate by mechanical and/or chemical processes. The barrier to the migration of silicones is thus formed from a peripheral margination of the thin film. It has, indeed, been proved, in particular when the thin film is based on titanium oxide, that the silicones found it more difficult to migrate onto the glass surface than onto the surface of the film. A stronger interaction between the silicon atoms of the silicones and the glass surface is possibly the cause of such a phenomenon. To form an effective barrier, it is essential that the margination be such that there is a marginated zone which is not covered by the mastic, the width of said uncovered zone advantageously being greater than or equal to 0.5 cm, or even 1 or 2 cm. It is known to only marginate the zone covered by the mastic in order to avoid degrading the mastic with the thin film when the latter has a photocatalytic activity, but this does not prevent the silicones from the mastic from migrating to the surface of the thin film. Such a peripheral margination may be accompanied by the creation of a beveled edge, also called a chamfered edge. The present invention will be better understood on reading the detailed description below of nonlimiting exemplary embodiments and the accompanying figures. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS • Figure 1 illustrates a perspective view of a flat substrate having on one part of its periphery a mastic comprising silicone-type components; • Figure 2 illustrates a cross-sectional view of a substrate, placed on the surface of which is a barrier to the migration of silicones that is based on a polymer deposited in contact with the mastic comprising silicone-type components; • Figure 3 illustrates a cross-sectional view of a substrate possessing, on one of its faces, a thin film, placed on the surface of which is a barrier to the migration of silicones that is based on a polymer deposited at a distance of a few millimeters from the mastic comprising silicone-type components; • Figure 4 illustrates a cross-sectional view of a substrate possessing, on one of its faces, a thin film that is removed at the periphery; • Figure 5 illustrates a cross-sectional view of a substrate where the barrier to the migration of silicones is formed from a notch; and • Figure 6 illustrates a photograph of the surface of the substrate represented schematically in Figure 5. DETAILED DESCRIPTION OF THE INVENTION Figure 1 illustrates a perspective view of a flat substrate made of soda-lime-silicate glass 1 having, on one part of its periphery, a mastic 3 comprising silicone-type components. The silicone oils migrate to the surface 2 of said substrate 1, and create a polluted surface 4 that is extremely hydrophobic and difficult to clean. The substrate 1 from figure 2, represented here in cross section, on the other hand retains a clean surface 2 thanks to the use of a barrier to the migration of silicones 5 based on MS polymer, more particularly MS polymer composed of a polyoxypropylene chain terminated by dimethoxysilyl groups. The bead of MS polymer 5 is deposited here in direct contact with the mastic 3. Figure 3 illustrates a different embodiment, as the bead of polymer 5 acting as a barrier to the migration of silicones is deposited at about 5 millimeters from the mastic 3, a configuration that has an even greater effectiveness. In the case represented in the present figure, the substrate 1 also has on one of its faces, a thin film 6, the surface 2 of said substrate 1 then being classed as the surface of said thin film 6, as only this surface 2 is capable of being polluted by the silicones. The thin film 6 is here a coating of around 15 to 20 nanometers, based on predominantly crystalline titanium oxide in the crystallographic anatase form, deposited by a chemical vapor deposition (CVD) technique. This thin film 6 gives the surface 2 photocatalytic properties and a pronounced hydrophilic character. Since the substrate 1 is in this specific case made of soda- lime-silica glass, this thin film is advantageously placed not directly on the substrate 1 but on a sublayer that is a barrier to the migration of alkalis, not shown in the figure. The same type of substrate is presented in figure 4, but in this embodiment of the invention, the barrier to the migration of silicones is formed from a peripheral margination 7 of the thin film 6. This peripheral margination 7 has the effect of removing the thin film 6 at the periphery of the substrate, thus creating a marginated zone 7 that is free from the thin film 6 and not covered by the mastic 3. Figure 5 presents another embodiment according to the invention, according to which the barrier to the migration of silicones is a notch 8. The thin film 6 is of the same type as that presented in figure 3. The effectiveness of the latter embodiment is presented in the photograph of figure 6: the mastic 3 forms the black-colored part on the left of the figure, the groove 8 being positioned vertically approximately in the center of the figure. After sprinkling with water, the part of the surface 2 located on the left of the groove 8 has a very strong hydrophobic character that is expressed by high water contact angles and that is polluted by silicone oils. On the contrary, the part of the surface 2 located on the right of the groove is perfectly hydrophilic, therefore it is not polluted by silicone oils. The present invention is described in what has gone before by way of example. It is understood that a person skilled in the art is able to carry out various variants of the invention without so much as going outside the scope of the patent as defined by the claims. WE CLAIM: 1. A substrate (1) based on glass or ceramic having, on at least one part of one of its faces, a thin film (6) which is a coating that imparts a pronounced hydrophilic character such as a coating comprising at least partially crystalline titanium oxide, especially in anatase form, said substrate (1) having, on at least one part of its periphery, a mastic (3) comprising silicone-type components, wherein a barrier to the migration of the silicones (5, 7, 8) is, in addition, placed on the surface (2) of said thin film (6). 2. The substrate (1) as claimed in claim 1, wherein the barrier to the migration of the silicones (5) is based on an elastomeric mastic that does not comprise any silicone-based plasticizers. 3. The substrate (1) as claimed in any of the preceding claims, wherein the elastomeric mastic (5) is based on a silyl-terminated polyether. 4. The substrate (1) as claimed in claim 2 or 3, wherein the polymer acting as a barrier (5) is deposited in the form of a bead on the surface (2) of said substrate (1), in direct contact with the mastic (3) comprising silicone-type compounds. 5. The substrate (1) as claimed in claim 2 or 3, wherein the polymer acting as a barrier (5) is deposited in the form of a bead onto the surface (2) of said substrate (1), opposite to and at a distance of a few millimeters from said mastic (3). 6. The substrate (1) as claimed in claim 1, wherein the barrier to the migration of the silicones (8) is formed from a notch or a groove located on the surface (2) of said substrate (1) and opposite to the mastic that is a source of silicones (3). 7. The substrate (1) as claimed in claim 1, wherein the thin film (6) comprises at least partially crystalline titanium oxide, and in that the barrier to the migration of the silicones (8) is formed from a peripheral margination (7) of said thin film (6), said margination being such that there is a marginated zone (7) that is not covered by the mastic (3). ABSTRACT TITLE: A GLASS OR CERAMIC BASED SUBSTRATE PROTECTING ORGANIC POLLUTION A substrate (1) based on glass or ceramic having, on at least one part of one of its faces, a thin film (6) which is a coating that imparts a pronounced hydrophilic character such as a coating comprising at least partially crystalline titanium oxide, especially in anatase form, said substrate (1) having, on at least one part of its periphery, a mastic (3) comprising silicone-type components, wherein a barrier to the migration of the silicones (5, 7, 8) is, in addition, placed on the surface (2) of said thin film (6).

Full Text

FIELD OF THE INVENTION
The present invention relates to a substrate whose surface is protected against organic pollution
stemming from peripheral seals, in particular mastics comprising silicone-type materials.
BACKGROUND OF THE INVENTION
A substrate is composed of a metal, a metal alloy, a ceramic, a glass, oxide or essentially mineral
material, especially, in the latter two cases, in the form of thin film coatings on a substrate, in
particular a glass substrate. The invention takes on a particular significance when the substrate is
transparent and requires a high optical quality, which is the case for a glass substrate, or a
substrate made of glass equipped with one or more functional coating layers, in particular when
these functional layers impart a hydrophilic character to said substrate.
In many technical fields, assemblies and juxtapositions of various materials and of various
components that are either traditional (concrete, bricks, steel or concrete beams, glass, etc.) or
modern, prefabricated or synthetic (doors, windows, panels, plastics, etc.) are encountered and
it is necessary to make provision for the interstices or joints between these different materials
and components, as they have different dimensional variations depending on temperature or
moisture variations and also different movements under the effect of the wind, bindings, weight
of the structure, and flow of certain components. The word "joint" therefore denotes either the
separation line and the packing or weatherstripping or an interstice between two elements
whether they are of the same nature or of different nature, or a desired continuity solution, that
is to say a rectilinear break created in a structure to absorb the differences in movement or in
behavior.

These joints must then be filled with weatherstripping
products and the joint then also denotes the assembly
of the interstice and of the weatherstripping product
used to seal it. Among the weatherstripping products, a
mastic is defined, within the meaning of the present
invention, as a pasty, malleable, plastic or elastic
material, applied in a joint and forming
weatherstripping by adhering to the surfaces inside
this joint.
A large number of weatherstripping and sealing mastics
contain silicone-type components (also known as
polysiloxanes). The silicone mastics are characterized
by their properties of elasticity, durability and
adhesion onto many substrates, and are thus very
frequently used to provide sealing for glazing onto all
mediums, and also between sanitary components and
walls. Silicones are also incorporated into the
composition of many other mastics as plasticizers (to
impart plasticity, even elasticity, to the material).
Moreover, the addition of silicone oils (low molecular
weight silicones) on the surface of the mastics
facilitates their use. Thus, mastics containing
silicone-type components are many and varied.
It has turned out that silicone-type compounds always
contain, in a greater or lesser proportion, low
molecular weight polysiloxanes (often called "silicone
oils") which have the property of migrating toward the
surface of the mastics then onto the surface of the
materials, making said surface polluted by the
silicones very difficult to clean. This property comes
from the fact that the silicones have a surface energy
that is among the lowest known surface energies and may
therefore very easily wet any type of surface, in
particular high-energy surfaces.

This problem appears particularly important when the surface has a hydrophilic character, as the
silicone surfaces are extremely hydrophobic. When in contact with water, the polluted area
becomes extremely visible in contrast with the unpolluted area, as the water perfectly wets the
hydrophilic surfaces, creating a film of water, whereas the hydrophobic surfaces are not wetted
by the water, the latter stagnating in the form of droplets.
The hydrophilic surfaces may be linked to the surface state of the substrate. A clean glass or
metal surface, for example, has a high surface energy and therefore a hydrophilic character,
being expressed by a water contact angle of less than 15°. The surface hydrophilicity may also
be due to coatings that are especially adapted for conferring this property. On substrates such as
ceramics or glass, coatings comprising at least partially crystalline titanium oxide, especially in
anatase form, give said substrate "superhydrophilicity" properties, characterized by a water
contact angle of less than 5°, or even less than 1°. Such coatings, which have, in addition,
photocatalysis properties, are for example described in Application EP-A-0 850 204. Other types
of coatings have a hydrophilic character are also known. Mention will be made, for example, of
coatings based on SiO2 and/or SiOC, in particular when they are textured, the texture having
patterns of dimensions around 10 to 200 nm, especially in the form of nodules.
OBJECT OF THE INVENTION
The object of the invention is therefore to protect the surface of a substrate from pollution
coming from mastics that comprise silicone-type components.
SUMMARY OF THE INVENTION
To that effect, the subject of the invention is a substrate having, on at least one part of its
periphery, a mastic comprising silicone-type components, characterized in that a barrier to the

migration of the silicones is placed on the surface of
said substrate.
The substrate may be made from a metal, metal alloy,
ceramic, glass, oxide or essentially mineral material,
especially, in the latter two cases, in the form of
thin-film coatings on a substrate, in particular, a
glass substrate. The substrate according to the
invention is preferably a glass-based or ceramic-based
substrate having, on at least one part of one of its
faces, at least one thin film (in this case, the
surface of the substrate is classed as the surface of
the outer thin film, the only one capable of being
polluted by the migration of the silicones), in
particular a coating conferring a pronounced
hydrophilic character such as a coating comprising at
least partially crystalline titanium oxide, especially
in anatase form, according to the teaching of the
aforementioned Application EP-A-0 850 204. Such a
coated substrate has photocatalytic and
superhydrophilic properties, making it capable of self-
cleaning owing to the removal of organic and mineral
soiling under the combined effect of a stream of water,
especially of rain, and visible and/or ultraviolet
radiation, such as solar radiation. In the latter case,
the silicone-based pollution is, indeed, able to
constitute a poison for the self-cleaning activity of
the coating.
Within the scope of the present invention, the term
"barrier" is understood to mean any means making it
possible to limit, or even suppress, the migration of
silicones.
According to a first embodiment of the invention, the
barrier to the migration of the silicones is based on a
polymer, preferably an elastomeric mastic that does not
comprise any silicone-based plasticizers.

The polymer acting as a barrier is preferably deposited
in the form of a bead onto the surface of the substrate
to be protected, either in direct contact with the
mastic comprising the silicone-type compounds, or
opposite to and at a distance of a few millimeters from
said mastic. This second option is the one which has
the greatest advantages.
The elastomeric mastic acting as a barrier to the
migration of silicones is preferably based on an MS
polymer. MS polymers are silyl-terminated polyethers. A
nonlimiting example of such an MS polymer is the
polymer composed of a polyoxypropylene chain terminated
by dimethoxysilyl groups. Due to the absence of
cohesive units in their main chain, these polymers have
a high flexibility and often do not require the
addition of plasticizers (and therefore no silicone-
based plasticizers), or even of solvents.
It appears, surprisingly and for the time being
inexplicably, that such barriers effectively protect
the surface of the substrate. Since silicone oils have
the ability to wet any type of material, it was not
imagined that such a barrier, being of whatever nature,
could have a real effectiveness. Without wishing to be
tied to any one scientific theory, the origin of the
very high effectiveness of the polymers from the family
of MS polymers could stem from strong interactions
between the silicone oils and the silyl end groups of
the MS polymer.
The barrier may also be composed of a thick layer, the
thickness of which is preferably between 100 nm and
2 micrometers, comprising at least partially
crystalline titanium oxide, and preferably even almost
completely crystalline titanium oxide in anatase form.
This layer preferably has a large specific surface
area: it may be, for example, a layer of silica
deposited by a sol-gel type process at the periphery of

the surface to be protected, said silica layer
comprising titanium oxide particles, as described, for
example in Application WO-A-03/087002. The
effectiveness of such a barrier probably lies in its
very high photocatalytic activity, such layers being
capable of degrading the silicone molecules under
visible or ultraviolet radiation, the kinetics of
degradation occurring more rapidly than the kinetics of
migration of said molecules.
According to a second embodiment, the barrier to the
migration of the silicones may be formed from a notch
or a groove located on the surface of the substrate and
opposite to the mastic that is a source of silicones.
The groove or notch advantageously has a depth ranging
from 10 to 200 micrometers and a width ranging from
100 micrometers to 2 millimeters.
It appears that the groove acts as a trap for the
silicone oils. The dimensions of the groove are adapted
depending on the quantity of silicone which may
migrate, and taking into account a possible embrittling
effect when the substrate is made from a brittle
material such as glass or a ceramic.
A third embodiment of the invention, in the case where
the substrate is composed of a glass-based or ceramic-
based substrate coated with at least one thin film,
consists in marginating said thin film, that is to say
in removing the thin film at the periphery of said
substrate by mechanical and/or chemical processes. The
barrier to the migration of silicones is thus formed
from a peripheral margination of the thin film. It has,
indeed, been proved, in particular when the thin film
is based on titanium oxide, that the silicones found it
more difficult to migrate onto the glass surface than
onto the surface of the film. A stronger interaction
between the silicon atoms of the silicones and the
glass surface is possibly the cause of such a

phenomenon. To form an effective barrier, it is essential that the margination be such that there
is a marginated zone which is not covered by the mastic, the width of said uncovered zone
advantageously being greater than or equal to 0.5 cm, or even 1 or 2 cm. It is known to only
marginate the zone covered by the mastic in order to avoid degrading the mastic with the thin
film when the latter has a photocatalytic activity, but this does not prevent the silicones from the
mastic from migrating to the surface of the thin film. Such a peripheral margination may be
accompanied by the creation of a beveled edge, also called a chamfered edge.
The present invention will be better understood on reading the detailed description below of
nonlimiting exemplary embodiments and the accompanying figures.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
• Figure 1 illustrates a perspective view of a flat substrate having on one part of its
periphery a mastic comprising silicone-type components;
• Figure 2 illustrates a cross-sectional view of a substrate, placed on the surface of
which is a barrier to the migration of silicones that is based on a polymer deposited in contact
with the mastic comprising silicone-type components;
• Figure 3 illustrates a cross-sectional view of a substrate possessing, on one of its
faces, a thin film, placed on the surface of which is a barrier to the migration of silicones that is
based on a polymer deposited at a distance of a few millimeters from the mastic comprising
silicone-type components;
• Figure 4 illustrates a cross-sectional view of a substrate possessing, on one of its
faces, a thin film that is removed at the periphery;
• Figure 5 illustrates a cross-sectional view of a substrate where the barrier to the
migration of silicones is formed from a notch; and

• Figure 6 illustrates a photograph of the surface of the substrate represented
schematically in Figure 5.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 illustrates a perspective view of a flat substrate made of soda-lime-silicate glass 1
having, on one part of its periphery, a mastic 3 comprising silicone-type components. The silicone
oils migrate to the surface 2 of said substrate 1, and create a polluted surface 4 that is extremely
hydrophobic and difficult to clean.
The substrate 1 from figure 2, represented here in cross section, on the other hand retains a
clean surface 2 thanks to the use of a barrier to the migration of silicones 5 based on MS
polymer, more particularly MS polymer composed of a polyoxypropylene chain terminated by
dimethoxysilyl groups. The bead of MS polymer 5 is deposited here in direct contact with the
mastic 3.
Figure 3 illustrates a different embodiment, as the bead of polymer 5 acting as a barrier to the
migration of silicones is deposited at about 5 millimeters from the mastic 3, a configuration that
has an even greater effectiveness. In the case represented in the present figure, the substrate 1
also has on one of its faces, a thin film 6, the surface 2 of said substrate 1 then being classed as
the surface of said thin film 6, as only this surface 2 is capable of being polluted by the silicones.
The thin film 6 is here a coating of around 15 to 20 nanometers, based on predominantly
crystalline titanium oxide in the crystallographic anatase form, deposited by a chemical vapor
deposition (CVD) technique. This thin film 6 gives the surface 2 photocatalytic properties and a
pronounced hydrophilic character. Since the substrate 1 is in this specific case made of soda-
lime-silica glass, this thin film is advantageously placed not directly on the substrate

1 but on a sublayer that is a barrier to the migration
of alkalis, not shown in the figure.
The same type of substrate is presented in figure 4,
but in this embodiment of the invention, the barrier to
the migration of silicones is formed from a peripheral
margination 7 of the thin film 6. This peripheral
margination 7 has the effect of removing the thin film
6 at the periphery of the substrate, thus creating a
marginated zone 7 that is free from the thin film 6 and
not covered by the mastic 3.
Figure 5 presents another embodiment according to the
invention, according to which the barrier to the
migration of silicones is a notch 8. The thin film 6 is
of the same type as that presented in figure 3.
The effectiveness of the latter embodiment is presented
in the photograph of figure 6: the mastic 3 forms the
black-colored part on the left of the figure, the
groove 8 being positioned vertically approximately in
the center of the figure. After sprinkling with water,
the part of the surface 2 located on the left of the
groove 8 has a very strong hydrophobic character that
is expressed by high water contact angles and that is
polluted by silicone oils. On the contrary, the part of
the surface 2 located on the right of the groove is
perfectly hydrophilic, therefore it is not polluted by
silicone oils.
The present invention is described in what has gone
before by way of example. It is understood that a
person skilled in the art is able to carry out various
variants of the invention without so much as going
outside the scope of the patent as defined by the
claims.

WE CLAIM:
1. A substrate (1) based on glass or ceramic having, on at least one part
of one of its faces, a thin film (6) which is a coating that imparts a
pronounced hydrophilic character such as a coating comprising at least
partially crystalline titanium oxide, especially in anatase form, said
substrate (1) having, on at least one part of its periphery, a mastic (3)
comprising silicone-type components, wherein a barrier to the
migration of the silicones (5, 7, 8) is, in addition, placed on the surface
(2) of said thin film (6).
2. The substrate (1) as claimed in claim 1, wherein the barrier to the
migration of the silicones (5) is based on an elastomeric mastic that
does not comprise any silicone-based plasticizers.
3. The substrate (1) as claimed in any of the preceding claims, wherein
the elastomeric mastic (5) is based on a silyl-terminated polyether.

4. The substrate (1) as claimed in claim 2 or 3, wherein the polymer
acting as a barrier (5) is deposited in the form of a bead on the
surface (2) of said substrate (1), in direct contact with the mastic (3)
comprising silicone-type compounds.
5. The substrate (1) as claimed in claim 2 or 3, wherein the polymer
acting as a barrier (5) is deposited in the form of a bead onto the
surface (2) of said substrate (1), opposite to and at a distance of a few
millimeters from said mastic (3).
6. The substrate (1) as claimed in claim 1, wherein the barrier to the
migration of the silicones (8) is formed from a notch or a groove
located on the surface (2) of said substrate (1) and opposite to the
mastic that is a source of silicones (3).
7. The substrate (1) as claimed in claim 1, wherein the thin film (6)
comprises at least partially crystalline titanium oxide, and in that the
barrier to the migration of the silicones (8) is formed from a peripheral
margination (7) of said thin film (6), said margination being such that
there is a marginated zone (7) that is not covered by the mastic (3).

ABSTRACT

TITLE: A GLASS OR CERAMIC BASED SUBSTRATE PROTECTING ORGANIC
POLLUTION
A substrate (1) based on glass or ceramic having, on at least one part of one of
its faces, a thin film (6) which is a coating that imparts a pronounced hydrophilic
character such as a coating comprising at least partially crystalline titanium
oxide, especially in anatase form, said substrate (1) having, on at least one part
of its periphery, a mastic (3) comprising silicone-type components, wherein a
barrier to the migration of the silicones (5, 7, 8) is, in addition, placed on the
surface (2) of said thin film (6).

Documents:

01827-kolnp-2007-abstract.pdf

01827-kolnp-2007-claims.pdf

01827-kolnp-2007-correspondence others 1.1.pdf

01827-kolnp-2007-correspondence others 1.2.pdf

01827-kolnp-2007-correspondence others.pdf

01827-kolnp-2007-description complete.pdf

01827-kolnp-2007-drawings.pdf

01827-kolnp-2007-form 1.pdf

01827-kolnp-2007-form 2.pdf

01827-kolnp-2007-form 3.pdf

01827-kolnp-2007-form 5.pdf

01827-kolnp-2007-gpa.pdf

01827-kolnp-2007-international exm report.pdf

01827-kolnp-2007-international publication.pdf

01827-kolnp-2007-international search report.pdf

01827-kolnp-2007-priority document 1.1.pdf

01827-kolnp-2007-priority document.pdf

1827-KOLNP-2007-(14-11-2011)-ABSTRACT.pdf

1827-KOLNP-2007-(14-11-2011)-AMANDED CLAIMS.pdf

1827-KOLNP-2007-(14-11-2011)-AMANDED PAGES OF SPECIFICATION.pdf

1827-KOLNP-2007-(14-11-2011)-CORRESPONDENCE.pdf

1827-KOLNP-2007-(14-11-2011)-DESCRIPTION (COMPLETE).pdf

1827-KOLNP-2007-(14-11-2011)-DRAWINGS.pdf

1827-KOLNP-2007-(14-11-2011)-EXAMINATION REPORT REPLY RECIEVED.pdf

1827-KOLNP-2007-(14-11-2011)-FORM 1.pdf

1827-KOLNP-2007-(14-11-2011)-FORM 2.pdf

1827-KOLNP-2007-(14-11-2011)-FORM 3.pdf

1827-KOLNP-2007-(14-11-2011)-FORM 5.pdf

1827-KOLNP-2007-(14-11-2011)-OTHER PATENT DOCUMENT.pdf

1827-KOLNP-2007-(14-11-2011)-OTHERS.pdf

1827-KOLNP-2007-CORRESPONDENCE 1.1.pdf

1827-KOLNP-2007-CORRESPONDENCE.pdf

1827-KOLNP-2007-EXAMINATION REPORT.pdf

1827-KOLNP-2007-FORM 18.pdf

1827-KOLNP-2007-FORM 3.pdf

1827-KOLNP-2007-FORM 5.pdf

1827-KOLNP-2007-GPA.pdf

1827-KOLNP-2007-GRANTED-ABSTRACT.pdf

1827-KOLNP-2007-GRANTED-CLAIMS.pdf

1827-KOLNP-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

1827-KOLNP-2007-GRANTED-DRAWINGS.pdf

1827-KOLNP-2007-GRANTED-FORM 1.pdf

1827-KOLNP-2007-GRANTED-FORM 2.pdf

1827-KOLNP-2007-GRANTED-SPECIFICATION.pdf

1827-KOLNP-2007-OTHERS.pdf

1827-KOLNP-2007-REPLY TO EXAMINATION REPORT.pdf

1827-KOLNP-2007-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

abstract-01827-kolnp-2007.jpg

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Patent Number

253604

Indian Patent Application Number

1827/KOLNP/2007

PG Journal Number

32/2012

Publication Date

10-Aug-2012

Grant Date

06-Aug-2012

Date of Filing

23-May-2007

Name of Patentee

SAINT-GOBAIN GLASS FRANCE

Applicant Address

18, AVENUE D'ALSACE, F-92400 COURBEVOIE

Inventors:

#	Inventor's Name	Inventor's Address
1	GARREC, RONAN	21, PLACE DE LA CROIX BLANCHE, F-60200 COMPIEGNE
2	MESSERE, RINO	RUE DU BOIS ROSINE, 32, B-5477 MODAVE, BELGIUM

PCT International Classification Number

C03C 17/30

PCT International Application Number

PCT/FR05/051016

PCT International Filing date

2005-11-30

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	0452845	2004-12-02	France