MXPA06009574A - Substrate, such as a glass substrate, with a hydrophobic surface and improved durability of hydrophobic properties - Google Patents

Abstract

The invention relates to a substrate of which at least one part of the surface thereof has been rendered hydrophobic and, for said purpose, has a hydrophobic surface structure consisting of an essentially-mineral silicon-containing sub-layer and an outer layer comprising a hydrophobic agent which is grafted onto said sub-layer. The invention is characterised in that the outer hydrophobic agent layer is applied to the sub-layer while the surface of the latter is in an activated state before being brought into contact with said hydrophobic agent. The invention also relates to rain-repellent glass comprising onesuch substrate, which is particularly suitable for use in the automobile, aviation, construction, electric household appliance and ophthalmic lens industries.

Description

SUBSTRATE, LIKE A GLASS SUBSTRATE, WITH A HYDROPHOBIC SURFACE AND IMPROVED DURABILITY OF THE HYDROPHOBIC PROPERTIES The present invention relates to a substrate, especially a glass substrate, whose surface has been transformed into hydrophobic, with improved durability of hydrophobic properties.

The hydrophobic properties are sought for windows and windshields in the field of transport, in particular for motor vehicles and aviation, and also for glazing in the construction industry.

For applications in the field of transport, rain-repelling properties are sought, thus having raindrops that slide easily from the glass wall so that they are removed, for example, when the vehicle is in motion due to the effect of air or wind, and that they do so "with the purpose of improving visibility, and consequently safety, or to facilitate cleaning, or to defog easily, etc.

For applications in the field of. construction, the goal is essentially to facilitate cleaning.

For this purpose, the objective is to have a contact angle of a drop of water with the substrate such that it is greater than 60 ° or 70 °, so that the water drop is not crushed or splashed. This is due to the fact that the glaze is considered functional insofar as this angle is greater than 60 ° in the case of aviation, and higher than 70 ° in the case of automobiles. However, in practice this angle should in all cases exceed 90 °, ideally obtaining drops that roll, allowing the water to be removed as quickly as possible to dispense, as much as possible, with the. windshield wipers in the automotive field.

In addition, the improvement in hydrophobic properties that is sought thus should not be to the detriment of the conservation of other properties, such as resistance to mechanical stresses: resistance to shear friction (Opel standardized test, performed in dry ), resistance to abrasion (Taber test), resistance to cleaning by cleaners (test that simulates the cycles of the cleaning action); resistance to environmental stresses (WOM test of UVA resistance, or Xenon test, QUV test of UVB resistance for aviation, resistance test NSS (acronym in English for neutral salt spray), resistance to chemical stresses: test of resistance to acidic and basic detergents, and optical properties.

To produce a hydrophobic glass, it is known that it is covered with a dense layer of silica mineral that serves as a sealer for the grafting of molecules that have hydrophobic properties, such as fluorosilane molecules. Thus, European Patent EP 0 545 201 describes the application of a dense layer of Si02 applied by magnetron electronic deposition, the layer of Si02 subsequently being covered with a hydrophobic agent.

The applicant company has discovered that the hydrophobic properties of such a structure can be improved, in particular in its durability, at least by preserving, or sometimes improving, the other properties mentioned above, if, the shell of molecules having hydrophobic properties is applied. while it is - layer is in an activated state of surface, this activation can be produced either through the current conditions - under which the mineral layer is deposited, or through a specific activation treatment.

Therefore the mineral layer (which is the sublayer in the resulting final structure) can be deposited by vacuum electronic deposition, especially with magnetron electronic deposition, under conditions that allow the layer to be left in an unstable surface state, being applied the hydrophobic cover while the surface is still in this state (usually applied immediately), or through a specific activation treatment (plasma excitation, etc.).

A first subject of the present invention is therefore a substrate, at least a part of the surface of which has been transformed into hydrophobic, having for this purpose a surface hydrophobic structure comprising an essentially mineral sub-layer containing silicon and a outer layer of hydrophobic agent grafted to the sublayer, characterized in that the sublayer has received the outer layer of hydrophobic agent although it had a surface that was in an activated state before being put in contact with the hydrophobic agent.

It is understood that the term "activated" means that the surface has undergone a treatment that has modified its electrostatic state (by production of charges) and / or its chemical state (creation or destruction of functional chemical groups), to increase the reactivity of the surface, treatment that can reach to the tearing of the material of the surface, creating therefore irregularities. In addition, as will be indicated below, the layer of silicon-containing mineral material, which will constitute the sub-layer in the final structure, can be obtained under conditions in which it is directly in the activated state.

The sublayer can be a hard sublayer.

The substrate is especially formed by, or comprises in its part designed to carry the mineral sublayer, a plate, either flat or with curved faces, of monolithic or laminated glass, of glass-ceramic or of a hard thermoplastic, such as a polycarbonate. The glass can be a hardened glass. An example of a curved plate is a windshield. This can be in the assembled state.

The sub-layer of the hydrophobic cover can form part of the substrate, the latter being formed by a plate, either flat or with curved faces, of monolithic or laminated glass or glass-ceramic, whose composition, at least on the surface, corresponds to that of the essentially mineral sub-layer containing silicon. An example of a substrate that has such a layer integrated is a glass that is at least at least on its surface. The International Applications WO 94/07806 and WO 94/07807 describe this technology.

The sub-layer containing silicon is especially formed by a compound selected from SiO x, where x < 2, SiOC, SiON, SiOCN - and Si3N4, it being possible for hydrogen to be combined in all proportions with SiOx, where x = 2, with SiOC, with SiON and with SiOCN. It can also contain aluminum, in particular up to 8% per weight, or carbon, Ti, Zr, Zn and B.

Sublayers consisting of scratch-resistant lacquers, such as polysiloxanes, which have been applied as coatings on polycarbonate substrates, should also be mentioned.

When the sub-layer containing silicon has its surface in the activated state, it has a thickness between 20 nm and 250 nm, especially between 30 nm and 100 nm, and n particularly between 30 nm and 75 nm. It can have an RMS roughness between 0.1 nm and 40 nm, in particular between a few nm and 30 nm. It can have a developed real area at least 40% larger than the initial flat area. Under a SEM microscope, the sublayer has the appearance of pumice or islands.

In addition, 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 selected from: (a) alkylsilanes of the formula (I): CH3 (CH2) nSYRmX3-m (D where: - n has a scale from 0 to 30, more particularly from 0 to 18; = 0, 1, 2 or 3; - R represents an optionally functionalized organic chain, and - X represents a hydrolyzable residue, such as a residue 0R °, where R ° represents hydrogen, or a linear, branched or cyclic alkyl residue , especially from Ci-Cß; or an aryl residue; or a residue such as a halo, for example chlorine; (b) compounds with grafted silicone chains, such as for example (CH 3) 3 SiO [Si (CH 3) 20] q, without specific limitation with respect to the length of the chain (value of q) and of the grafting method; (c) fluorosilanes, such as those of the formula (II): R ^ A-SiRp ^ s-p (II) wherein: - R1 represents a residue especially of Ci-Cg of monofluoroalkyl, oligofluoroalkyl or perfl? oroalkyl; 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 alkyl residue, especially Ci-Cs, or an aryl residue; - X represents a hydrolyzable residue, such as a residue OR3, where R3 represents hydrogen or a linear, branched or cyclic alkyl residue, especially of C? ~ G8; or an aryl residue; or a halo residue, such as for example chlorine; and - p = 0, 1 or 2.

An example of an alkylsilane of the formula (I) is octadecyltrichlorosilane (OTS).

The preferred hydrophobic agents are the fluorosilanes (c), in particular those of the formula (II), the particular examples of the latter being those of the formula: • CF3- (CF2) n- (CH2) 2 -YES (R) Where: - R4 represents a lower alkyl residue; Y - n is between 7 and 11.

The hydrophobic agent layer has, for example, a thickness between 1 and 100 nm, preferably between 2 and 50 nm.

The fluorosilane layer can have a weight per unit area of grafted fluorine of between 0.1 μg / 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 method for manufacturing a substrate as defined above, characterized in that a cover layer of hydrophobic agent is deposited, at least in one step, on the surface of a mineral layer containing silicon, formed at least partially on the surface of the substrate, the deposition of the hydrophobic agent taking place while the surface is in the activated state.

An activated surface of the mineral layer containing silicone can be obtained by depositing it under conditions in which its surface is obtained directly in the activated state. This is what happens if a layer containing silicon is deposited, cold, through PECVD (abbreviations in English of chemical vapor deposition improved by plasma) or by electronic deposition by magnetron and / or ion beam.

This is because, in these procedures, the - layer development takes place using reactive species (ions, radicals, neutrals, etc.) that combine to form the cover. The surface of the cover is therefore naturally in a state of imbalance. In addition, this layer can be directly in contact with the plasma gas during development, which further increases 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 performing an activation treatment in at least one step.

Advantageously, the hydrophobic agent is deposited within the least possible time, preferably between 1 second and 15 minutes, after the activated surface has been obtained.

Activation treatment can be performed under conditions that do not go as far as etching, through the use of a plasma or ionized gas, at atmospheric or reduced pressure, selected from air, oxygen, nitrogen, argon, hydrogen, ammonia and mixtures of them, or through the use of an ion beam.

It is also possible to carry out an activation treatment under conditions that allow a silicon-containing film to be recorded, with the use of a plasma of • less a gas containing chlorine, selected from SFd, CF, C2F6 and other fluorinated gases, when appropriate combined with oxygen, it being possible that oxygen represents up to 50% by volume of the etching gas.

In addition, according to the present invention, - activation can be monitored, performed under conditions that allow recording the silicon-containing layer, through an activation treatment that does not cause additional etching but still modifies the chemical nature and / or the electrostatic state of the layer.

The silicon-containing layer can be deposited, cold, on the substrate by electron vacuum cathode deposition, preferably by electronic magnetron deposition and / or ion beam electron deposition, or by PECVD at low pressure or at atmospheric pressure, or in instead of being deposited by electrolysis.

As examples of the deposition of the sublayer of SiOz, the following method of implementation can be mentioned, in which: a layer of Si02 is deposited on the uncovered glass or on a windshield assembled by PECVD, using a mixture of an organic or inorganic precursor containing silicon, such as SiH4, - hexamethyldisiloxane (HMDSO), tetraethoxysilane (TEOS) and 1, 1, 3, 3-tetramethyldisiloxane (TMDSO), and an oxidant (02, N02, C02), the subsequent activation being carried out in the same chamber or in a separate chamber.

The hydrophobic agent layer can be deposited by sliding contact, evaporation or sprinkling of a solution containing the hydrophobic agent, or by dipping, coverage by rotation, coverage by flow, etc, using a solution containing the hydrophobic agent.

To manufacture the glaze with a hydrophobic cover 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 in a glass manufacturing line using the " "floating" while the glass is being supported by the molten tin bath, or in a subsequent step, that is, by leaving the molten tin bath, conversion operations are performed, such as bending, hardening and / or assembled, especially by inaction, to obtain glass plates made of one or more sheets covered with the sub-layer on at least one side, then the sub-layer or the sub-layers supported by the plates are activated and, finally, It is done. functionalization through the hydrophobic agent of the sublayer or the sublayers thus activated. The sublayer is generally deposited by PECVD or by electronic magnetron deposition; (2) The glass sheets are manufactured by the flotation process, then these glass sheets are converted by operations such as bending, hardening and / or assembling, especially lamination, to obtain glass plates made of one or more sheets, then the sublayer is deposited on at least one side of the plates thus obtained, and the sublayer or sublayers are then activated (s), followed by functionalization - through the hydrophobic agent of the sublayer or sublayers thus activated; (3) the sublayer is deposited on at least one side of the glass sheets obtained upon leaving the flotation process, then the sheets thus covered with the sublayer or the sublayers are converted, limiting the techniques used to those that do not damage the ( s) sublayer (s) (thus excluding bending - and hardening as conversion operations, but allowing assembly, especially by rolling), and the sublayer or sublayers are then activated, followed by functionalization through the hydrophobic agent the sublayer or sublayers thus activated (s).

The present invention also relates to a rain repellent glaze comprising a substrate as defined above or prepared by the process defined above. The glazing for buildings, including glazing for shower cubicles, glass for domestic electrical applications, especially glass-ceramic shelves, glazing for transport vehicles, especially for automobiles and aviation, in particular for windshields, side windows, rear windows, can be mentioned. , wing mirrors, sunroof, ceiling lamps and taillights, and ophthalmic lenses.

The following examples illustrate the present invention without however limiting the competence thereof. In these examples, the following abbreviations have been used: PECVD: improved chemical vapor deposition with plasma; SEM: electron scanning microscopy; AFM: atomic force microscopy; and AWR: aviation cleaning equipment.

EXAMPLE 1: Substrate with hydrophobic surface according to the invention, with a sub-layer of silicon formed through PECVD. (a) Formation and characterization of the hard silica sublayer. A layer of silica (Si02) was deposited on a clean glass (measuring 300 x 300 mm2) in a PECVD reactor at low pressure. 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 (N20) and helium dilution, the respective flow ratios were 18 sccm, 60 sccm and 60 sccm The total pressure in the reactor was set at 9.99 Pa (75 mTorr) In equilibrium, the plasma was directed by polarizing the diffuser of gas with an average power of 190 W of radio frequency (13.56 MHz) (polarization voltage: ~ 45 V). The temperature of the substrate was maintained at 25 ° C. He /% thickness of the silica thus deposited after 270 s, was 50 nm.

The state of the PECVD silica surface observed in the SEM was characterized by small grains about twenty nanometers in size, which, in some places, formed circular or elongated areas of additional thickness that were hollow in the center.

The hardness of the obtained silica was characterized using the following two tests: - first, the layer went through an abrasion treatment, during which the haze was measured in accordance with the ISO 3537 standard; the abrasion was of the Taber type, made by means of an abrasive wheel CS10F with an applied force of 4.9 N (500 g). The degree of abrasion was denoted by Taber's number of revolutions. The measured haze values are given in Table 1 below; Y - second, the hardness of the silica was evaluated by the record of Aireo, being the value of 10 - 0.18R, where R is the number of scrapes, after a given number of revolutions of Taber, in a frame that measured 2.54 cm x 2.54 cm, visible in a photograph with magnification of x50. The Aireo records are also given in Table 1 below.

Table 1: characterization of the Si0 sublayer.

These values characterize a hard layer of Si02. (b) Plasma treatment. Then the Si02 layer was subjected to plasma treatment.

As in the case of deposition experiments, a residual vacuum of at least 5 mPa (5 x 10 ~ 5 mbar) was first created in the chamber before introducing the reactive gas mixture. The gases used for the "treatment of the silica surface were C2Fd and oxygen, whose respective flow ratios were 120 sccm and 20 sccm.The total pressure in the reactor was then set at 26.66 Pa (200 mTorr). At equilibrium, the plasma was directed by polarization of the gas diffuser with an average power of 200 W of radio frequency (13.56 MHz) (polarization voltage ~ 15 V) for a time of 900 s at room temperature.

After 15 minutes of plasma treatment with C2F6 / 02, the silica layer was highly etched. Its surface had large bubbles a few tenths of a nanometer in size. The micro-roughness obtained with this treatment of highly aggressive plasma (etching) was characterized by AFM, indicating an apparent roughness in the scale of the fluorosilane molecules subsequently grafted onto the silica.

The main parameters of the micronoughness of the PECVD silica measured by AFM are given in Table 2 below.

Table 2 ? Zmax * is the maximum peak / valley amplitude (c) Application of fluorosilane After the surface of the PECVD silica had been treated with plasma, the composition that had been produced 12 hours in advance was put in sliding contact on the specimens. , as follows (percentages are by weight): -90% propanol-2 and 10% HCl 0.3 N mixed with water; and - 2% of the compound of the formula C 8 F 7 (CH 2) 2 Si (OEt) 3 (Et = ethyl) was added to the two above-mentioned constituents.

The weights per unit area of the fluoride grafted on the surface of the various sublayers, determined by electron micro-test, were: - on flat glass (with sublayer of Si02 gel sealant): 0.15 μg / cm2 - on Si02 (PECVD ): 0.369 μg / cm2 - on recorded Si02 (PECVD): 1,609 μg / cm2.

The amount of fluoride grafted onto the engraved SiO2 layer is remarkably high. (d) Characterization of the obtained hydrophobic substrate The characteristics of the hydrophobic substrate obtained were: - drop contact angle: μagUa - 105 °; - optical properties: TL = 90.2%; RL = 8.44%; absorption = 1.36%; haze = 0.2%; - separation volumes: 13 μl at 90 ° and 22 μl at 45 ° (the angles being the angles of inclination of the substrate on the horizontal).

Then, the three types of substrates above grafted with fluorosilane 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); - Opel test according to the Standard of Construction EN 1096-2 of January 2001, consisting of applying, to a part of the covered surface of 9.4 cm in length - part of which is known as a track - a felt of 14 mm in diameter, 10 mm in thickness and 0.52 g / cm2 of density, and a load of 39.22 MPa (400 g / cm2), the felt being subjected to a movement of translation (50 round trips) over the entire length of the track per minute) combined with a movement of rotation of 6 revolutions / minute (1 cycle = 1 round trip).

The results of the Opel and Taber tests on the recorded and non-recorded PECVD layers, compared with flat glass, are given in Table 3 below.

Table 3 * Specimen prepared according to the Example 5b of Patent EP 799 873 Bl.

The value of 87 ° in the Opel test (5000 cycles) for the case of the sub-layer of Si02, is not enough.

Only the substrate with a sub-layer of recorded Si02 results in a good compromise between the Opel test and the Taber test (100 revolutions).

Therefore this substrate was tested in the AWR, consisting of moving an aviation windshield wipers over the windshield along a 25 cm track in a transverse movement consisting of two back and forth movements per second, under a load of 0.88. N / cm (90 g / cm) with a water sprinkler of 6 1 / h.

An average angle of 80 ° ± 10 ° was measured after 1,000,000 cycles, with only 26% of the non-functional area (μagua <60 °). The functionality limit was measured to be of 1,400,000 cycles, at which the average angle was about 70 ° + 10 ° with more than 35% of the non-functional area.

The substrate was also evaluated with the following accelerated main environmental tests: - WOM or Xenon test: 0.55 W / m2 irradiation at 340 nm; - QUV: 16 h UV-B (313 nm) at 70 ° C + 8 h at 40 ° C (> 95% residual humidity); - NSS: exposure to + 35 ° C, 50 g / 1 of NaCl at pH 7 according to the IEC 60 068 standard, part 2-11 Ka.

All the results are given in Table 4 Table 4 * Specimen prepared according to Example 5b of EP Patent 799 873 Bl.

The recorded PECVD sublayers made it possible to maintain, in the QUV test, a μagua > 80 ° ± 6 ° after 7000 hours of exposure and one μagUA - 96 ° ± 3 ° after 2800 hours of exposure in the WOM.

EXAMPLE 2: Substrate with a hydrophobic surface according to the invention with a sublayer of silica deposited by magnetro electronic deposition. (a) Formation and characterization of the hard layer of silica This example relates to the grafting of fluorosilane in a SiO2 sublayer formed by electron deposition by magnetron at reduced pressure.

Three types of Si02 were produced: - Si02 under a pressure of 200 Pa (2 μbar); Ar flow ratio: 15 sccm; flow ratio of 02 ': 12- sccm; - Si02 under a pressure of 400 Pa (4 μbar); Ar flow ratio: 27 sccm; flow ratio of 02: 12 sccm; - Si02 under a pressure of 800 Pa (8 μbar); Ar flow ratio: 52 sccm; flow ratio of 02: . sccm The plasma was inflamed increasing the power of the DC from 0 to 2000 W at a rate of 20 W / s.

A previous electronic deposition operation consisted in applying, for 3 minutes, a power of 2000 W of CD pulsed at 40 KHz with 4 μs between the pulses.

A blank containing 92% silica and 8% aluminum was subjected to electronic deposit.

To obtain in one step a cover of Si02 of 100 nm,. the run speed of the substrate below 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 layers of 200 Pa (2 μbar) and 800 Pa (8 μbar) of Si02 per magnetron was measured • as described in the case of the PECVD layers of Si02 above: measurement of the haze (in%) during a Taber abrasion test (ISO 3537), Aireo record.

The results are given in Table 5 below.

Table 5 These layers of SI02 produced by electronic magnetron deposition were hard layers. (b) Plasma treatment. The silicas deposited by magnetron (400 Pa / 4 μbar and 800 Pa / 8 μbar) were recorded with plasma (230 W / 300 co or follow: 1) Si02 (400 Pa / 4 μbar): 30% -70% SF6 at 9-99 Pa Pa / 75 mTorr; 2) Si02 (800 Pa / 8 μbar): a) 20% O2 / 80% C2F6 a 26. 66 Pa / 200 mTorr; b) 50% O2 / 50% C2F6 at 26.66 Pa / 200 mTorr. (c) Fluorosilane Application The procedure was described in (c) of Example 1.

Five specimens were subjected to several tests, as described below: I. Sublayer Si02 (400 Pa / 4 μbar) treated with plasma according to 1) above and then by sliding contact with fluorosilane above to graft JLó (as described above); 'II. Sub-layer Si02 (400 Pa / 4 μbar) without plasma treatment and fluorosilane by sliding contact on leaving the magnetron line to prepare Si02; III. Sub-layer Si02 (800 Pa / 8 μbar) treated according to 2a) above and then fluorosilane by sliding contact on top; IV. Sub-layer Si02 (800 Pa / 8 μbar) treated according to 2b) above and then fluorosilane by sliding contact on top; Y V. Sublayer Si02 (800 Pa / 8 μbar) without plasma treatment and fluorosilane by sliding contact above, when leaving the magnetron line to prepare Si02.

The results are given in Table 6 below.

Table 6 This table shows the very high performance in general, and especially that of test III in the Taber test and that of test IV in the Opel friction test.

EXAMPLE 3. The purpose of this example is to compare four hydrophobic glasses: SAW. Specimen prepared according to the Example 5b of EP 799 873 Bl; VII. Sub-layer Si02 (800 Pa / 8 μbar) deposited by magnetron (Example 2), treated with plasma with 70 sccm of SF6, 30 sccm of 02 to 9.99 Pa / 75 mTorr, 230 W, 300 s, being placed by sliding contact, on , fluorosilane; VIII. Sub-layer Si02 (400 Pa / 4 μbar) deposited by magnetron (Example 2), treated with plasma with 50 sccm of C2F6, 50 sccm of 26.66 Pa / 200 mTorr, 230 W, 300 s, being placed by sliding contact, above, the fluorosilane; Y IX. Application of fluorosilane by sliding contact, when leaving the production line of silica deposited by magnetron (800 Pa / 8 μbar).

Several tests were performed on the specimens thus formed, and the results are given in Table 7 below.

Table 7 The percentage of degraded area (μwater < 60 °) was evaluated after 50,000 AWR cycles.

Specimens VI to IX that had passed the 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.

Table 8 This shows the remarkable performance of specimen VII in the combined AWR / NSS and AWR / QUV tests.

Specimens VIII and IX are slightly lower than VIII in the combination of AWR / NSS tests and substantially lower in the AWR / QUV combination, though. they are still at a high level, unknown before the implementation of the invention.

EXAMPLE 4. This example describes a particular treatment of Si02 sublayers deposited by magnetron (800 Pa / 8 μbar).

This treatment comprised: (1) Five minutes of treatment in Ar (80 sccm, 19.98 Pa / 150 mTorr), 200 W (35 V polarization voltage), to reduce any residual roughness; (2) Surface treatment by flash-duration = 60 s (= 60 s in this example), C2F6, SF6, 02, H2; (3) Application of fluorosilane by sliding contact.

The specimens X to XV are described below through the characteristics of their treatment of step (2): X: 26.66 Pa / 200 mTorr, 230 W, 50 sccm of C2F6, 50 sccm of 02; XI: as X, except for 100 sccm of C2F6, "XII: as X, except for 70 sccm of SF6 and 30 sccm of 02, XIII: 9.99 Pa / 75 mTorr, 203 W, 100 sccm of SF6, XIV: 7.99 Pa / 60 mTorr, 230 W, 100 sccm of 02, and XV: 13.33 Pa / 100 mTorr, 230 W, 75 sccm of H2.

The amount of fluorine [F] grafted was determined by electron micro-test, and then a test of • Opel friction resistance was performed. The results are given in Table 9 below, Table 9 These results show that the resistance to friction is not directly correlated with the amount of fluoride grafted, - or with the roughness of the sublayer (since the recorded thicknesses do not exceed 16 nm, the increase in roughness generated by the etching process it is in this case insignificant). However, the fluorine grafting mode plays a role that depends on the treatment of the surface.

The invention has been described using the word "substrate". With this it should be understood that this substrate can be a substrate not covered, but it can also be a. substrate that is already provided with other functionalities than the rain repellency functionality, in particular thanks to the layers and, in certain cases, the sublayer according to the invention can then already form part of the layers providing these other functionalities .

Claims (29)

1. CLAIMS 1. Substrate, at least a portion of whose surface has been rendered hydrophobic, having for this purpose a surface hydrophobic structure comprising an essentially mineral sub-layer containing silicon and an outer layer of hydrophobic agent grafted to the sub-layer, characterized in that the sub-layer It has received the outer layer of hydrophobic agent although it had a surface that was in an activated state before being put in contact with the hydrophobic agent.
2. 2. Substrate according to claim 1, characterized in that the sublayer is a hard sublayer. Substrate according to any of claims 1 and 2, characterized in that it is formed by a plate, either flat or with curved faces, of monolithic or laminated glass, of glass-ceramic or of a hard thermoplastic, such as polycarbonate. Substrate according to claim 3, characterized in that the sub-layer of the hydrophobic cover forms part of the substrate, the latter being formed by a plate, either flat or with curved faces, of monolithic or laminated glass or of glass-ceramic, whose composition, at least on the surface, it corresponds to that of the essentially mineral sub-layer containing silicon. 5. Substrate according to claim 4, characterized in that the substrate is a glass unallayed at least on its surface. 6. Substrate according to one of claims 1 to 5, characterized in that the sublayer is formed by a compound selected from SiOx, where x = 2, SiOC, SiON, SiOCN and Si3N4, it being possible for hydrogen to combine in all the proportions with the SiOx, where x = 2, with the SiOC, with the SiON and with the SiOCN. Substrate according to one of claims 1 to 6, characterized in that the sub-layer containing silicon contains aluminum, in particular up to 8% by weight, or carbon, Ti, Zr, Zn and B. 8. Substrate according to one of the claims 1 to 7, characterized in that the sublayer it contains. silicon, when its surface is in the activated state, has a thickness between 20 nm and 250 nm, especially between 30 nm and 100 nm and in particular between 30 nm and 75 nm. Substrate according to one of claims 1 to 8, characterized in that the sub-layer containing silicon has, when its surface is in the activated state, a roughness of RMS between 0.1 nm and 40 nm, in particular between a few nm and 30 nm. Substrate according to one of claims 1 to 9, characterized in that the sub-layer containing silicon, when its surface is in the activated state, has a real area of development at least 40% greater than the area of the initial plane. Substrate according to one of claims 1 to 10, characterized in that the silicon-containing sub-layer, when its surface is in the activated state, has a hardness such that it does not delaminate after 100 revolutions, and preferably up to 200 revolutions, in the Taber test. Substrate according to one of claims 1 to 11, characterized in that the outer layer of hydrophobic agent is based on a hydrophobic agent - selected from: (a) alkylsilanes of the formula (I): CH3 (CH2) nSiRmX3- m (I) where: - n has one. scale from 0 to 30, more particularly from 0 to 18; - = 0, 1, 2 or 3; - R represents an optionally functionalized organic chain; and - X represents a hydrolyzable residue, such as a 0R ° residue, where R ° represents hydrogen; or a linear, branched or cyclic alkyl residue, especially Ci-Cs; or an aryl residue; or a residue such as a halo, for example chlorine, (b) compounds with grafted silicone chains, (c) fluorosilanes, such as those of the formula. (II) .: R1-A-SÍRp2X3-p (II) . wherein: - R1 represents a residue especially of Ci-C9 of monofluoroalkyl, oligofluoroalkyl or perfluoroalkyl; 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 alkyl residue, especially Ci-Cs, or an aryl residue; X represents a hydrolyzable residue, such as a residue OR3, where R3 represents hydrogen or a linear, branched or cyclic alkyl residue, especially C? ~ C8; or an aryl residue; or a halo residue, such as for example chlorine; and - p = 0, 1 or 2. • 13. Substrate according to one of claims 1 to 12, characterized in that the hydrophobic agent layer has a thickness between 1 and 100 nm, preferably between 2 'and 50 nm. 14. Substrate according to one of claims 1 to 13, characterized in that the hydrophobic agent layer has a weight per unit area of grafted fluorine of between 0.1 μg / cm2 and 3.5 μg / cm2"15. Process for manufacturing a substrate as defined in one of claims 1 to 14 , characterized in that a cover layer of hydrophobic agent is deposited, in at least one step, on the surface of a mineral layer containing silicon at least partially on the surface of the substrate, the deposition of the hydrophobic agent taking place while the surface is in the activated state 16. Process according to claim 15, characterized in that an activated surface of the mineral layer containing silicon is obtained, depositing it under conditions in which its surface is obtained directly in the activated state. claim 15, characterized in that an activated surface of the silicon-containing mineral layer is obtained, performing a treatment activation in at least one step. Method according to one of claims 15 to 17, characterized in that the hydrophobic agent is deposited in the shortest possible time, preferably between 1 second and 15 minutes, after the activated surface has been obtained. Method according to any of claims 17 and 18, characterized in that the activation treatment is carried out under conditions that do not go as far as the engraving, through the use of a plasma or an ionized gas, under reduced pressure or atmospheric , chosen from among air, oxygen, nitrogen, argon, hydrogen, ammonia and mixtures thereof, or with the use of an ion beam. 20. Process according to any of claims 17 and 18, characterized in that an activation treatment is carried out under conditions that allow a silicon-containing layer to be etched, through the use of a plasma of at least one fluorine-containing gas, chosen from between SF6, CF, C2F6 and other fluorinated gases, when appropriate combined with oxygen, it being possible for oxygen to represent up to 50% by volume of the etching plasma. The method according to claim 20, characterized in that the activation performed under conditions that allow the silicon-containing layer to be recorded by an activation treatment, which does not cause additional etching but that still modifies the chemical nature and / or the electrostatic state of the layer. 22. Procedure as claimed in one of the. claims 15 to 21, characterized in that the silicon-containing layer is deposited, cold, on the substrate by electron deposition by vacuum cathode, preferably by electron deposition by magnetron and / or electron deposition by ion beam, or by PECVD ( deposition by chemical vapor improved with plasma), or instead it is deposited hot by pyrolysis. Method according to claim 22, characterized in that an Si02 layer is deposited, as a silicon-containing layer, through PECVD, using a mixture of an organic or inorganic precursor containing silicon, such as SiH, hexamethyldisiloxane, tetraethoxysilane and tetramethyldisiloxane, and an oxidant, the subsequent activation being carried out in the same chamber or in a separate chamber. -24. Method according to one of claims 15 to 23, characterized in that the fluorosilane layer is deposited by sliding contact, evaporation or sprinkling of a solution containing fluorosilane, or by immersion, rotating cover, flow cover, etc. , using a solution containing fluorosilane. Method according to one of claims 15 to 24 for the manufacture of glaze having a hydrophobic cover, characterized in that the sublayer is deposited on the glass in a glass manufacturing line using the glass. "float" procedure while the glass is being supported by the molten tin bath, or in a subsequent step, that is, when leaving the molten tin bath, in which the conversion operations, such as bending, hardening and / or assembly, especially by rolling, are then carried out to obtain glass plates made from a or more sheets covered with the sublayer on at least one side, in which the sublayer or sublayers supported by the plates are then activated and in. that, finally, a functionalization is carried out. through the hydrophobic agent of the sublayer or the sublayers thus activated (s). Method according to one of claims 15 to 24 for the manufacture of glaze having a hydrophobic cover, characterized in that the glass sheets are manufactured by the flotation process, in which the glass sheets are then converted through operations such as bending, hardening and / or assembling, especially lamination, to obtain glass plates made of one or more sheets, in which the sublayer is then deposited on at least one side of the plates thus obtained, and in which the sublayer or sublayers are then activated (s), followed by functionalization through the hydrophobic agent of the sublayer or the sublayers thus activated (s). Method according to one of claims 15 to 24, characterized in that the sublayer is deposited on at least one side of the glass sheets obtained after leaving the flotation process, in which those sheets thus covered with the layer or sublayers are converted , limiting the techniques used to those that do not damage the sublayer (s), and in which the sublayer or sublayers are then activated, followed by functionalization through the hydrophobic agent of the sublayer or sublayers thus activated (s) . 28. Rain repellent glaze comprising a substrate as defined in one of claims 1 to 14, or manufactured by the process as defined in one of claims 15 to 27. 29. Application of the glaze as defined in the claim 28 as a glaze for the automotive, aviation, construction, domestic electrical appliance and ophthalmic lens industries.