Hydrophilic dlc on substrate with uv exposure

This invention is a division of US Patent Application Ser. No. 09 / 577,337 (currently US Patent No. 6,303,225) filed May 24, 2000, US Patent Application Ser. No. 09 filed July 5, 2001. It is a partial pending of / 899,176 and its disclosure is introduced here as a reference.

<u style="single">Hydrophilic DLC on UV-exposed substrates</u> The present invention relates to hydrophilic coaching containing diamond-like carbon (DLC) provided (directly or indirectly) on a substrate such as glass or plastic, and a method for producing the same. More specifically, the present invention relates to DLC-containing coaching that is exposed to at least ultraviolet (UV) irradiation so that the coaching becomes hydrophilic or more hydrophilic (reduces the contact angle θ of the coaching). ..

<u style="single">Background of the invention</u> It is often desired to provide hydrophilic coatings (eg, anti-fog coatings) on substrates such as automobile windshields, automobile windows, automobile mirrors, building mirrors, bathroom mirrors and the like. Such coaching can reduce the likelihood that water droplets will take a spherical form and deposit on the substrate, thereby improving visibility. In other words, hydrophilic coaching serves to reduce beaded condensate on the surface of the substrate (on the windshield of the car or the inner surface of the window). Hydrophilic coaching can reduce the formation of many tiny droplets of liquid and can scatter light on the substrate (ie, condense into a surface film as opposed to droplets).

Unfortunately, some hydrophilic coaching does not have the desired life and / or hardness and is not effective from a practical point of view of applications such as automobile windshields and / or other types of windows. Absent.

In that regard, (i) coated articles with hydrophilic properties (eg, coated glass or plastic substrates) and their manufacturing methods and / or (ii) windows and / or mirrors that are to some extent resistant to scratches, breakage, etc. It is clear that hydrophilic protection coaching of the substrate is needed in the art.

Different embodiments of the present invention are intended to meet any or all of the above-mentioned needs in the art, and / or other needs that will become apparent to those skilled in the art are provided in the following disclosure.

An object of the present invention is to provide a durable coated article that is less likely to cause or be affected by beaded liquid condensation. Examples of applications to which such hydrophilic coaching can be applied include, but are not limited to, automobile windshields, automobile backlights (ie, rear vehicle windows), automobile side windows, building windows, mirrors, and the like. ..

Another object of the present invention is to provide scratch resistant hydrophilic coaching for use in connection with coated articles.

Another object of the present invention is to dob at least one polarity-inducing dopant, such as boron (B) and / or nitrogen (N), onto diamond-like carbon (DLC) to form or provide hydrophilic coaching. That is. In one embodiment, the atomic percentage of a polarity-inducing dopant (eg, a B and / or N dopant that does not include an H dopant that may or may not be added because H is not a polarity-inducing dopant) is about 10. Not greater than%, more preferably not greater than about 5%, and most preferably not greater than about 4%. Polarity-inducing dopants make DLC more tetrahedral (ie, sp³For more graphite (more bonds), make it more graphite (eg sp²It is a dopant (which increases the number of bonds). The polarity-inducing dopant makes the DLC-containing layer more polar and then increases the surface energy, thereby making it hydrophilic coaching.

Another object of the present invention is that the coaching layer is sp²And sp³It is to provide a coated article containing both carbon-carbon bonds and having a wettability W for water of at least about 700 mN / m, more preferably at least about 750 mN / m, and most preferably at least about 800 mN / m. This is joules per unit area (mJ / m)²) Can be explained or measured.

Another object of the present invention is to reduce the contact angle θ of a DLC-containing layer or coaching by exposure to ultraviolet (UV) light. The contact angle before such exposure may or may not be hydrophilic, but in a specific example, after exposure, the post-UV contact angle is about 20 degrees or less, more preferably about 15 degrees or less, still more preferably about. It is 10 degrees or less, and even more preferably about 8 degrees or less.

Another object of the present invention is that the coaching layer is sp²And sp³Surface energy γ containing both carbon-carbon bonds, at least about 24 mN / m, more preferably at least about 26 mN / m, most preferably at least about 28 mN / m_CIs to provide a coated article having.

Another object of the present invention is that the DLC-containing layer of the coaching is not greater than about 10 degrees, more preferably no greater than about 8 degrees, even more preferably no greater than about 6 degrees, most preferably greater than about 4 degrees. It is to provide a coated article having a water contact angle θ that is not large (ie, before being subjected to environmental test, friction test, acid test, UV test, etc.). The initial contact angle θ of the article may be as low as 1 to 3 degrees in some specific examples. In one embodiment, the contact angle of an article increases over time with exposure to environmental factors (graphite sp).²(The CC bond may gradually disappear). In another embodiment, the contact angle of the article can decrease over time with exposure.

Another object of the present invention is to provide a hydrophilic DLC-containing layer for coating a substrate. At least part of the layer, less than about 70% of the bonds in that part of the layer are sp³Type, more preferably less than about 60% of binding sp³The type. Substantial portion of the bond remains graphite type or sp²Can be a type. The bonds in the layer may include, for example, carbon-carbon (CC) bonds, carbon-nitrogen (CN) bonds, carbon-boron (CB) bonds and / or carbon-hydrogen (CH) bonds. sp³Type bonds (eg CC bonds) serve to increase the hardness and scratch resistance of the coaching, while graphite sp.²Type bonds (eg CC, CN and / or CB bonds) make the coaching more hydrophilic and have a lower contact angle.

Another object of the present invention is to provide a coaching capable of forming a film-like accumulation-condensation type as opposed to a droplet-like one.

Yet another object of the present invention is hydrophobic coaching or amines (NH) near the surface of the layer to enhance hydrophilicity.₂) To form a functional group.

Yet another object of the present invention is to meet one or more of the purposes and / or needs listed above.

Specific examples of certain embodiments of the present invention include Glass substrate; sp provided on the glass substrate³A layer of diamond-like carbon (DLC) with a carbon-carbon bond and a layer of DLC there are subjected to UV (UV) irradiation so that the layer has a contact angle θ with water droplets not greater than about 20 degrees. By providing a coated glass article consisting of exposed, it meets one or more of the purposes and needs listed above.

An ion beam deposit of a diamond-like carbon (DLC) -containing layer on the substrate and exposing the DLC-containing layer to ultraviolet (UV) irradiation is sufficient to reduce the contact angle θ of the layer by at least about 20%. It meets one or more of the purposes and / or needs listed above by providing a method of making a covering article comprising.

A further embodiment of the present invention is an object and / or necessity mentioned above by providing a coated article having a contact angle θ of 10 degrees or less and consisting of a DLC-containing layer supported by a glass substrate. Meet one or more of.

The present invention will now be described for certain embodiments with reference to the accompanying drawings.

<u style="single">In the figure</u> FIG. 1 is a vertical cross-sectional view of a coated article according to one embodiment of the present invention, wherein the glass or plastic substrate comprises a hydrophilic coating containing a DLC-containing layer.

FIG. 2 is a vertical cross-sectional view of a coated article according to another embodiment of the present invention, wherein the glass or plastic substrate comprises a hydrophilic coating containing a DLC-containing layer.

FIG. 3 is a vertical cross-sectional view of a coated article according to another embodiment of the present invention, wherein the glass or plastic substrate comprises a hydrophilic coating containing a DLC-containing layer.

FIG. 4 is a schematic view of a vertical cross-sectional portion showing a contact angle θ of a drop (eg, a fixed drop of water) on an uncoated glass substrate.

FIG. 5 is a partial schematic view of a vertical cross section showing a high contact angle θ of a drop on a coated article containing hydrophobic coaching for an article disclosed in, for example, Related Application 09 / 443,805.

FIG. 6 is a schematic vertical cross-sectional portion showing a low contact angle θ of a drop (eg, a fixed drop of water) on a coated article according to one embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view of a linear ion beam source that can be used in a embodiment of the present invention to deposit a DLC-containing hydrophilic layer.

FIG. 8 is a perspective view of the linear ion beam source of FIG. 7.

FIG. 9 is a flowchart showing the steps performed in another specific example of the present invention, in which the DLC-containing layer is subjected to ultraviolet (UV) light irradiation in order to reduce its contact angle θ.

<u style="single">Detailed description of a specific example of the present invention</u> References are specifically made here, where similar reference numbers indicate similar elements throughout the attachment.

One embodiment of the present invention is to provide a diamond-like carbon (DLC) -containing layer or coating on a substrate by allowing the resulting article and / or layer to have hydrophilic quality or properties to provide a coated article (eg, an automobile). For improving the hydrophilic quality of windshields, car backlights, car side windows, snowmobile windshields, building windows, mirrors, etc.). One way to provide DLC with hydrophilic properties is to dope the DLC with at least one polarity-inducing dopant (eg, nitrogen (N), boron (B) and / or any other suitable polarity-inducing dopant). Thus found, the DLC-containing layer can be made more polar to have higher surface energy, thereby becoming more hydrophilic.

In another embodiment of the invention, the DLC-containing layer (eg, having a contact angle θ of 5-100 degrees) is ultraviolet (UV) to make the contact angle θ of the DLC-containing layer lower, eg, below the hydrophilic range. It may be exposed to irradiation. The DLC-containing layer may optionally be exposed to water for the same amount of time as UV exposure to speed up the process of reducing the contact angle θ. Examples of UV exposure can be used either in combination with or separately from the above doping examples to provide hydrophilic coaching.

In the doping embodiment of the present invention, supplying at least one polarity-inducing dopant increases the polar component of the surface energy of the DLC-containing layer and then increases the surface energy of the entire layer. The higher the surface energy, the more hydrophilic the layer and the lower the contact angle θ. Thus, by increasing the surface energy via the dopant, the hydrophilicity can be improved and, as a result, the contact angle θ can be reduced.

Combining hydrophilicity with the use of an amorphous diamond-like carbon (DLC) layer / coating provided on the base substrate is sufficient for the article to be used in automobiles and other high exposure environments where durability is desired. It is provided in a coated article that can obtain a low contact angle θ as well as surface hardness and scratch resistance.

FIG. 1 is a vertical cross-sectional view of a coated article according to one embodiment of the present invention, wherein at least one diamond-like carbon (DLC) -containing protective coating or layer 3 is provided on the substrate 1. The coated article has an outer surface 9. The substrate 1 may be glass, plastic, ceramic or the like.

In a specific example of doping, the layer or coaching 3 contains at least one polarity-inducing dopant, which makes the bonds of the DLC-containing layer more polar, followed by higher surface energy and lower contact angle θ. Dopants are more graphite type or polar sp²Type join (eg C-Csp²Type join, C-Nsp²Type join and / or C-Bsp²Type bond) is formed in layer 3, therefore the layer is sp²Type and sp³Type (eg C-Csp³Includes both type) joins. When many of the bonds in layer 3 become polar, the water becomes more attracted by layer 3 because it is polar. Tetrahedral amorphous sp³Type CC bonds (ta-C) give layer 3 acceptable hardness and / or scratch resistance, while sp.²Type CC and C-dopant bonds improve the hydrophilicity of the layer. The substantial portion of carbon in layer 3 is preferably amorphous or irregular (eg, opposite to crystalline).

The dots in layer / coaching 3 in FIG. 1 indicate the dopant, indicating that the dopant is relatively flat and evenly distributed throughout the thickness of layer 3. As will be apparent above, the exemplary polarity-inducing dopants include, but are not limited to, nitrogen (N), boron (B), phosphorus (P), As, S, Sb, Ga, In and the like. Dopants such as N and B can be used alone or in combination to dope the DLC-containing layer 3 in certain embodiments so as to improve the hydrophilicity of the layer. Layer 3 functions hydrophilicly (ie, characterized by a low contact angle θ and / or high surface energy) to reduce the formation of beaded condensate on the coated article. Hydrophilic properties may be advantageous in environments such as bathroom mirror surfaces, automobile windshields or window interiors.

In a specific example of UV exposure (which can be done in combination with a specific example of doping or without doping), the DLC-containing layer 3 may or may not have the above dopant. More specifically, in a specific example of UV exposure, the deposited DLC-containing layer 3 may be hydrophilic and non-hydrophilic (ie, the deposited layer 3 has a contact angle θ of 5-100 degrees). Can have). Exposure of layer 3 to UV irradiation (and optionally water) reduces the contact angle of layer 3 (ie, to the hydrophilic range). Thus, with a significant amount of UV exposure, in a specific example of UV exposure, the contact angle θ of the DLC-containing layer 3 is preferably about 20 degrees or less, more preferably about 15 degrees or less, even more preferably about 10 degrees or less. , Most preferably about 8 degrees or less.

In one embodiment, the hydrophilic layer 3 can have a thickness of about 10 to 1000 angstroms, more preferably about 50 to 200 angstroms. In one exemplary embodiment, layer 3 is about 100 angstroms thick. Moreover, in one exemplary embodiment of the invention, layer 3 has an average hardness of at least about 10 Gpa, more preferably at least about 20 Gpa, even more preferably at least about 50 GPa, most preferably about 50-600 GPa. In one embodiment, layer 3 can have an average hardness of about 75 GPa. Layer 3 can have good wear resistance, a wear factor of about 0.05 to 0.20 (eg 0.15), and an average surface roughness not greater than about 0.3 nm. Sp in layer 3²Type and sp³The layer is preferably at least about 2.4 g / cm, as both type bonds are present.²(More preferably about 2.5-3.0 g / cm²) Has a density. Layer 3 is preferably corrosion resistant with sufficient moisture and / or heat. Layer 3 is a embodiment of the invention and can be inert to acids, alkalis, solvents, salts and / or water. Thus, layer 3 can act as a barrier to chemical attack on the underlying substrate 1 (eg, soda-lime-silica glass substrate).

The hydrophilic layer 3 has one surface exposed to air or air. In a specific example of doping, after layer 3 has been doped to make it more hydrophilic, it has a lower contact angle θ with the more adherent water droplets that would be without doping. In one example of doping, layer 3 is not greater than about 10 degrees, more preferably not greater than about 8 degrees, even more preferably not greater than about 6 degrees, most preferably not greater than about 4 degrees. It has an initial contact angle θ with water droplets. In a specific example, the contact angle can be lowered by about 1 to 3 degrees. As mentioned above, in certain examples of UV exposure, the contact angle of layer 3 can go from a non-hydrophilic range to a hydrophilic range with sufficient exposure to UV rays to the layer.

In a specific example of doping of the present invention, the amount of polarity-inducing dopant material (1 or more dopants) in the hydrophilic layer 3 is about 1-30% (atomic percent), more preferably about 1-10%, and even more. It is more preferably about 1 to 5% and most preferably about 1 to 4%. In one embodiment, the polarity-inducing dopant in layer 3 can be about 3-4% (atoms) of the atoms in layer 3. The balance can be C and / or H in some embodiments. In one example, increasing the percentage of dopant too much reduces the diamond-like properties of layer 3, and in one embodiment the layer is too graphite for practical use (eg, graphite makes the coaching darker and more transparent / transparent. Is reduced). Since the DLC-containing layer 3 is only doped with low amounts of polarity-inducing dopants such as B and / or N, many of the diamond-like properties of the bonds in layer 3 are preserved. Other types of dopants (eg H is not a polarity inducer) may or may not be in layer 3 in some embodiments.

The 13 exemplary configurations of the doped hydrophilic layer 3 are shown below in Chart No.1. This exemplary configuration can be applied to specific examples of doping, including any of the specific examples of FIGS.<tables num="1"><img file="JP4475952B2_D0001.tif" /></tables>

The layer or film 3 independently doped with N or B was found to be hydrophilic. However, it has also been found that when a mixture of dopants (eg N and B) is used to dope the DLC-containing layer 3, it causes surprising additional hydrophilic properties. In one embodiment, the ratio of N to B can be approximately 2: 1 (N: B). Other dopants can of course be used, and in specific examples of UV exposure, the dopant is optional.

The optical properties of layer 3, such as the N and K index of refraction and the Tauc optical bandgap, can be tailored / adjusted by varying the concentration or percentage of dopant in the layer / film. The optical bandgap can vary between 1.75 and 3.2 eV in some embodiments. The "n" index of refraction at 550 nm can vary, for example between 1.6 and 2.3, while the "k" index of refraction at 550 nm, for example between 0.01 and 0.1 in one embodiment (dielectric constant at GHz 4.7). Can change. In one embodiment, a high bandgap (eg 3eV or higher) and / or about 10⁶cm^-1A higher absorption coefficient means that such a film / layer 3 is ultraviolet (UV) absorbent. Strong binding energy also means strong UV resistance. In one embodiment, the UV transmission of layer 3 at 350 nm is no greater than about 40% (preferably no greater than about 35%).

In a specific example of doping in FIG. 1, the dopant can be fairly evenly distributed throughout the thickness of layer 3 as illustrated. For example, a dopant-containing gas can be supplied by an ion deposition apparatus during the entire process of the layer 3 deposition method.

In the specific example of FIG. 2, the dopant is not uniformly distributed throughout the total thickness of the hydrophilic layer 3. Instead, as shown in FIG. 2, there is a significant portion of the dopant near the outer surface of layer 3 rather than near the interface between layer 3 and substrate 1. The presence of the dopant on or near the outer surface of layer 3 makes the bond near the layer surface more graphite. Thus, layer 3 still has the hydrophilic properties described here (eg, low contact angle). For example, in one embodiment, the outermost 10 angstrom (A) thickness portion of layer 3 (or the 10 nm thickness portion in the embodiment) has at least about 3% dopant atoms (eg, N, B, P). , As, Sb, Ga and / or In), more preferably at least about 5%, most preferably at least about 7%. The presence of these polarity-inducing dopant atoms near the coaching surface results in a more polar coaching surface. The rest of layer 3 (ie, the central and / or portion of layer 3 near the substrate or intermediate layer of layer 3) may or may be undoped DLC in some embodiments, instead Si, O or It may or may contain H-doped DLC. This is graphite sp²Many of the type bonds are localized on or near the outer surface of layer 3. Too many sps in layer 3²The presence of a type bond is not desirable because it reduces its transparency or dielectric properties, so in some embodiments, sp is at or near the outer surface where the contact angle θ of layer 3 needs to be reduced.²It is desirable to minimize the presence of type bonds.

In an exemplary embodiment of the invention (see the tenth exemplary composition listed above in Chart No. 1), C is doped with N and H, and the supply of N is an amine (NH).₂) It was found that functional groups were formed on or near the surface of layer 3. In such an amine group, for example, one of the N bonds is C (sp).²), And the other two N bonds are H. These amine groups enhance the hydrophilicity of layer 3, thus the coated article. In an exemplary amine-containing embodiment, the layer contains about 60-80% C, about 1-12% B, about 4-39% H (atoms), more preferably about 65-75. It can contain% C, about 5-10% B and about 15-30% H.

FIG. 3 is a specific example of the present invention, in which at least one intermediate layer 2 is made of the substrate 1 and one or more hydrophilic. It can be prepared between the sex layer 3 and the sex layer 3. Thus, both layer 3 and layer 2 are deposited and provided on substrate 1 in this embodiment. Any desired layer can be used as the intermediate layer 2. For example, the intermediate layer 2 may include a low E layer system, another DLC-containing layer, a silicon oxide layer, a silicon nitride layer and / or a titanium oxide layer in a specific example of the present invention. Term here<u style="single">"Up(</u>on<u style="single">)」</u>(Regarding that the layer is on the substrate or another layer) means that it is supported regardless of whether the other layer is in between. Thus, for example, the DLC-containing layer 3 is provided directly on the substrate 1 as shown in FIGS. 1-2, or has a low E or other layer in between and is provided on the substrate 1 as shown in FIG. be able to. Illustrative layered systems (all or part of these coachings) that can be used as low E or other coaching 2 on substrate 1 between layer 3 and substrate are US Pat. Nos. 5,837,108, 5,800,933, 5,770,321, U.S. Pat. Shown and / or described in any of the same 5,557,462, 5,514,476, 5,425,861, 5,344,718, 5,376,455, 5,298,048, 5,242,560, 5,229,194, 5,188,887 and 4,960,645. All of these are introduced here as references.

In one embodiment, at least part of the DLC-containing layer 3 has about 70% or less of the binding in the layer, sp.³Type, more preferably less than about 60% binding in the layer sp³It is a type and therefore this part of the layer can reach hydrophilic properties. In one preferred embodiment, about 50% or less of the binding in layer 3 is sp.³Type (eg sp³Type CC bond), or in other embodiments, it may only be on the outside or near the outer surface of layer 3. Substantial part of the bond remains graphite or sp²The type. The bonds in the layer may include, for example, carbon-carbon (CC) bonds, carbon-nitrogen (CN) bonds, carbon-boron (CB) bonds and / or carbon-hydrogen (CH) bonds. sp³Type bonds (eg CC bonds) have the ability to increase the hardness and scratch resistance of the coaching, while graphite sp.²Type binding (eg, CC, CN and / or CB binding) makes the coaching more hydrophilic and has a lower contact angle. Different technique is graphite sp²We have found that it can be used to increase the number of type bonds, but but not limited to a) doping as discussed here, b) heating the underlying substrate during the layer 3 deposition process. And / or c) include utilizing higher ion energy eV energy (eg, about 200-600 eV, most preferably about 375-425 eV) during the layer 3 deposition process. The amine functional groups discussed above can also function to enhance the hydrophilic properties of the article. The higher eV energy used during the layer 3 ion deposition process is sp.³Less type binding, sp²There will be more type bindings. Techniques b) and / or c) may be used here in combination with doping to obtain hydrophilic properties.

In one embodiment, the DLC-containing layer 3 and / or coaching system on substrate 1 is at least about 75%, preferably at least about 85%, most preferably at least about 95% transparent or permeable to visible light. is there.

When the substrate 1 is glass, the glass has a thickness of about 1.5 to 5.0 mm, preferably about 2.3 to 4.8 mm, and most preferably about 3.7 to 4.8 mm. Ordinary soda lime silica glass can be used as the substrate 1 in one embodiment, such glass is available on the market from Garden Industries, Corporation of Auburn Hills, Michigan. In one other embodiment of the invention, the substrate 1 may be borosilicate glass or a substantially transparent plastic. In yet another embodiment, an automobile window (eg, windshield, backlight or side window) containing any of the above glass substrates laminated on a plastic substrate forms a window, and thus is such a substrate. It may be combined with any of the coaching systems of FIGS. 1 to 3 provided on the surface to form the substrate 1. In other embodiments, the substrate 1 is a window (eg, a car windshield, a residential window, a commercial building window, a car side window, a vacuum IG window, a car backlight or back window, etc.) and / Or may include first and second glass sheets of any of the above glass materials laminated together for use in other environments.

When the substrate 1 of any of the above materials is coated with at least the DLC-containing layer 3 according to any of the specific examples of FIGS. Has characteristics. That is, visible transmittance (III, A) greater than about 60% (preferably greater than about 70%, most preferably greater than about 80%), UV (ultraviolet) transmittance of about 38% or less, about 45% or less. Total sunlight transmittance and IR (infrared) transmittance of about 35% or less (preferably about 25% or less, most preferably about 21% or less). Methods for measuring visible light (Visible), "total solar", UV and IR transmission are described in US Pat. No. 5,800,933.

The hydrophilic performance of the coaching / layer 3 in any of the above embodiments is a function of contact angle θ, surface energy γ and / or wettability or adhesion energy W. The surface energy γ of the layer 3 can be calculated by measuring its contact angle θ. An exemplary contact angle θ is shown in FIGS. 4-6. The hydrophilic coaching or layer system 3 according to the embodiment of the present invention is on the substrate of FIG. 6, while there is no coaching of any kind on the substrate of FIG. 4, and hydrophobic on the substrate of FIG. There is coaching. For convenience purposes, Figures 4 and 6 illustrate the lack of coaching. In order to measure the contact angle in one embodiment, a water-like liquid epiphytic drop 31 is placed on the substrate as shown in FIGS. 4-6. A contact angle θ between the drop 31 and the article below appears, defining the angle θ at the point of contact depending on the interfacial tension between the three phases. The contact angle θ is larger in FIG. 5 than in FIG. 4 because the coaching layer on the substrate of FIG. 5 is hydrophobic (that is, it has a higher contact angle). However, because of the present invention, the contact angle θ in FIG. 6 is lower than any of FIGS. 4 to 5.

In general, the surface energy γ of layer 3 or any other article / layer_CCan be determined by the addition of polar and dispersion components as follows. γ_C= γ_CP+ γ_CD(γ_CPIs the polar component of layer / coaching, γ_CDIs the dispersion component of layer / coaching). The polar component of surface energy represents surface interactions primarily based on bipolarity, while the dispersed components represent van der Waals forces based, for example, electron interactions. Generally speaking, the surface energy γ of layer 3_CThe higher the value, the more hydrophilic the layer (and the covering article), and the lower the contact angle θ.

Adhesive energy (or wettability) W can be understood as the interaction between polarity and polarity and dispersion and dispersion between the outer surface 9 of the coated article and a liquid such as water above it. γ^PIs the product of the polar aspects of the surface tension of the liquid and the surface tension of the article, γ^DIs the product of the dispersion force of the surface tension of the liquid and the surface tension of the article. In other words, γ^P= γ_LP^*γ_CP; And γ_D= γ_LD^*γ_CD(γ_LPIs the polar aspect of a liquid (eg water), γ_CPIs the polar aspect of coaching / layer 3, γ_LPIs the dispersion aspect of a liquid (eg water), γ_CDIndicates that it is a coaching / layer 3 distributed aspect. The adhesion energy (or effective interaction energy) can be determined by the following equation using the augmented Hawks equation. W = [γ_LP^*γ_CP]^1/2+ [γ_LD^*γ_CD]^1/2= γ_l(1 + cosθ) (Γ in the formula_lIs the surface tension of the liquid and θ is the contact angle). The W of the two materials (eg, layer 3 and the water above it) is a measure of wettability that indicates how hydrophilic the layer or coating is.

Here, when analyzing the degree of hydrophilicity of the layer 3 or the covering article with respect to water, γ with respect to water_LPIs 51 mN / m, γ_LPIs known to be 22 mN / m. In one embodiment of the invention, the polar aspect γ of the surface energy of layer 3_CPIs at least about 5, more preferably at least about 7, and most preferably about 7 to 10 (which can vary or adjust between 5 and 15 in some embodiments) and is the dispersion aspect Y of the surface energy of layer 3._CDIs about 16 to 22 mN / m (more preferably about 18 to 20 mN / m).

According to a specific example of the present invention, using the above numbers, the surface energy γ of layer 3_CIs at least about 24 mN / m, more preferably at least about 26 mN / m, most preferably at least about 28 mN / m, and the adhesion energy W between water and layer 3 is at least about 600 mN / m, more preferably about 700 ~. It is 1,300 mN / m, more preferably about 750 to 950 mN / m, and most preferably about 800 to 950 mN / m. Adhesion energy W and surface energy γ of layer 3_CThese high values and the low initial contact angle θ that can be achieved exemplify the improved hydrophilic properties of the coated article according to different embodiments of the present invention.

As shown in FIG. 4, the initial contact angle θ between the normal glass substrate 1 and the attached water droplet 31 on it is typically about 22 to 24 degrees (in some cases, it may be as low as 18 degrees). ). Therefore, ordinary glass substrates are not as hydrophilic as the specific examples of the present invention. Moreover, here layer 3 provides scratch resistance and / or high durability. The usual ta-C layer, which is not doped on the glass substrate, is not as hydrophilic as the specific examples of the present invention. The invention here reduces that the contact angle of the ta-C-containing layer 3 improves the hydrophilicity of the coated article, as shown by the low contact angle θ in FIG.

Another advantage associated with one layer 3 according to one embodiment of the invention is that the layer 3 can be electrically conductive to reduce the likelihood of static electricity generation. This decrease in resistivity is believed to be due to the doping described herein. For example, before doping, the resistivity of the ta-C layer is, for example, 10.⁸On the other hand, after doping, the resistivity can be reduced to, for example, about 500 ohms / cm or less, more preferably about 100 ohms / cm or less, most preferably about 0.01 to 50 ohms / cm.

Layer 3 can have a permittivity of about 8-12, preferably about 10, at 10 kHz and a permittivity of about 2-6, preferably about 4, at 100 MHz. In one example, layer 3 is about 10⁶Can have the strength of dielectric breakdown. In terms of thermal properties, layer 3 is about 9x10^-6It can have a coefficient of thermal expansion of / C and a thermal conductivity of about 0.1 WcmK.

FIGS. 7-8 show an exemplary line or direct ion beam source 25, depositing on layer 3 and cleaning the substrate 1 or adding a DLC-containing layer to add doping atoms according to different embodiments of the present invention. Can be used for surface plasma treatment. The ion beam source 25 includes a gas / power inlet 26, a track anode 27, a grounded cathode magnet 28, a magnet pole 29 and an insulator 30. A 3kV DC power supply can be used for source 25 in one embodiment. Source ion deposition results in a substantially uniform deposition of DLC-containing layer 3 in terms of thickness and stoichiometry.

The ion beam source 25 is based on a known gridless ion source design. The source consists of a liner shell (which is the cathode and is grounded), inside which there is a concentric anode (which is the positive potential). The composition of the cathode-anode and the magnetic field 33 causes a close drift condition. The magnetic field arrangement also provides an anode layer that allows the line ion beam source to work absent without an electron emitter. The ion source in the anode layer can operate in reaction mode (eg, with oxygen and / or nitrogen). The source includes a metal housing with slits in the shape of a race track, as shown in FIGS. 7-8. The hollow housing is at ground potential. The anode electrode is provided inside the cathode body (electrically insulated) and is located directly below the slit. The anode can be coupled to a positive potential as high as 3,000 volts. Both electrodes can be water cooled in a specific example.

The feedstock gas is supplied through the cavity 41 between the anode and the cathode. The linear ion source can also have a labyrinth system that uniformly distributes the precursor gas in its length direction and spreads it at supersonic speed inside the anode-cathode space. Electrical energy then destroys the gas to produce plasma in the source. Ions are released and directed to the substrate 1 where layer 3 grows. The ion beam radiating from the slit is substantially uniform in the longitudinal direction and has a Gaussian profile in the lateral direction. An exemplary ion 34 is shown in FIG. Sources of length as much as 0.5-3 m can be made and used, but sources of different lengths are predicted in different embodiments of the present invention. The electron layer 35 is shown in FIG. 7 to complete the circuit, thereby allowing the ion beam source to function properly.

The DLC-containing hydrophilic layer 3 of the substrate 1 (the substrate may have another layer (eg, layer 2) provided in advance).<u style="single">Top and base 1</u>An exemplary method of depositing on top will be described here. This method is for illustrative purposes only and is not intended to be limited to this method. The energy and / or the directivity provided by the ion beam deposition technique used in the layer 3 deposition method causes layer 3 to deposit layer 3 fairly uniformly on all surfaces of the underlying structure.

The top surface of the substrate 1 can be cleaned with the first line or direct ion beam source before layer 3 is formed on the substrate 1. For example, argon (Ar) gas or Ar / O₂Glow discharge (or CF) in a mixture of₄Plasma) can be used as a source for removing impurities on the surface of the substrate. It is preferable not to use oxygen or fluorocarbons, as doping with N and / or B atoms will take place in the next step. Such interactions are physical-chemical in nature. The power density is, for example, 1 watt / cm.²Is. The substrate 1 can be cleaned by, for example, sputter cleaning, prior to the actual deposition of layer 3. Cleaning can be performed in one embodiment, but not in other embodiments of the present invention.

The method of depositing the DLC-containing layer 3 on the substrate 1 can then be performed using a ray ion beam source and the corresponding deposition technique (see eg, ray ion beam 25), as illustrated in FIGS. 7-8. it can. The ion beam source 25 (which may be the same or different from the cleaning ion beam source) is in the ta-C-containing layer 3 (hydrogenation in one embodiment) on the substrate 1 and in the dopant (eg N and /). Or B) is deposited. Illustrated supply gases that can be used are nitrogen gas, diboran gas and / or C.₂H₂It is gas.

Instead, layer 3 uses a filtered cathodic vacuum arc ion beam apparatus (FCVA-IB), as disclosed in Veerasamy, Cambridge 1994, Tetrahedral Amorphous Carbon Deposition, Characterisation and Electronic Properties. Can be deposited using. This deposition method can be reached immediately after plasma cleaning of the substrate 1 using the same deposition chamber or other chamber. With such a technique, a cathode arc discharge of an ultrapure carbon target can be performed, for example, &lt;10.^-6It can be triggered by the base vacuum of the tor. The essentially Hoechst carbon target can be machined into cylindrical electrodes with a diameter of about 90 mm and a depth of about 50 mm. The conditions for arc discharge can be, for example, 70A and 17V. The pressure in the cathode arc method can be in the range of one tenth of m torr. One, two or more dopant gases can be introduced into the donut-shaped bend region at the same time. Examples of gases are diborane (including dopant B) and nitrogen. The gas flow can be regulated by a series of two mass flow controllers with needle valves. Diborangus can flow independently via such a controller. The powder is bound to a mixture of the dopant gas diborane and nitrogen by plasma collision, and this mixture is introduced via a mass flow controller at the bend of the magnet filter. An example of a donut-shaped magnetic field is 100 m Tesla. Energy carbon ions and high energy electrons dissociate the gas mixture into highly reactive energy ions with UV irradiation in the arc. In general, only ionic species (eg C, N and B) form a donut-shaped magnetic field in the filter, while neutral and macroparticles are filtered out. A bundle of ionized atoms is transferred to the growing surface on the substrate 1 to form layer 3. Ion energy can vary independently in grit with negative potential or RF bias on the substrate, harmonizing the physical properties of layer 3. The range of self-bias potential is, for example, -1,000 to + 1,000V. In one embodiment, a window of 120-200 V per ionic species can be used. The partial pressure used during the deposition method is, for example, 10.^-6~10^-4Toru. 10 examples of parameters that can be used for such deposition methods^-6Base pressure, 0 ~ 5sccm N²Gas, 0 ~ 2sccm B₂H₄The arc power is 1,000 W at room temperature for the gas and the substrate 1. In this way, a layer 3 containing a B and / or N-doped amorphous DLC is formed on the substrate 1.

The hydrophilic properties of layer 3 can be enhanced in certain embodiments using plasma treatment or grafting procedures that add polar functional groups on the surface of layer 3 to alter the chemical reactivity on the surface, while , The body properties of the layer remain virtually unaffected. In such a specific example, nitrogen gas (N₂) Plasma can be used to enhance hydrophilicity at a pressure of about 1 mT.

In one example, a ta-C film with a thickness of 10-50 nm was deposited on a quartz substrate with a planar array of 20 μm Ni electrodes intertwined with each other. These electrodes were made by conventional lithographic techniques. Next, the effect of absorbed molecules on the electrical properties of the ta-C doped film was studied using ICV properties. A strong sensitivity of ICV properties was found in the presence of water and alcohol. The high sensitivity of the capacitance with respect to the water vapor concentration as well as its fast response to water molecules suggested surface bonding of high polar components. Layer 3 of ta-C: N: B also has a high density as evidenced by the high plasmon peak at about 32.9 eV.

If you want to hydrogenate layer 3, for example, a carrier gas (eg C) through a precursor monomer (eg TMS or 3MS) where the dopant gas is held at about 70 ° C (well below the flash point).₂H₂) Can be bubbled. Acetylene supply raw material gas (C₂H₂), In certain embodiments, are used to prevent or minimize / reduce polymerization and to obtain adequate energy to allow carbon and / or hydrogen ions to permeate and sub-implant the article, thereby layer 3 To grow. Other suitable gases containing polarity-inducing dopant gas can also be used in the source that creates the ions 34.

As mentioned above, it has been found that in addition to doping, it can be made essentially more hydrophilic as a function of how it is deposited on substrate 1. The temperature of the substrate 1 can be raised during the deposition method (eg to about 100-300 ° C). Another way to make the layer more hydrophilic is sp³To reduce the binding content, the ionic energy used in the deposition method is increased to, for example, about 200-500 eV, most preferably about 400 eV. In another embodiment of the invention (an embodiment of doping and / or UV exposure), the base portion of layer 3 is ion beam deposited at rather high ion energy (eg, 750-1500 eV per two C atoms), followed by ion beam deposition. Ion energy to deposit on top of layer 3 sp on the surface of layer 3²Lower to lower levels (eg 10-200 eV per two C atoms) to increase CC bonds.

While the ion beam deposition technique is preferred in one embodiment, other methods of deposition can also be used in different embodiments. For example, a filtered cathode vacuum arc ion beam technique can be used to deposit in layer 3 as described above. Moreover, in other embodiments, a sputtering technique can also be used to deposit layer 3 on substrate 1.

FIG. 9 is a flowchart showing a process performed according to a specific example of ultraviolet (UV) exposure of the present invention (which may or may not be doped in a different specific example of the present invention). First, the DLC-containing layer 3 is ion-beam-deposited on the substrate 1 in step S1. The DLC-containing layer 3 may or may not be doped as described above. Except for the non-doped potential, the DLC-containing layer 3 is as described in any of the above specific examples of the present invention. Layer 3, which is deposited from the beginning, may or may not be hydrophilic. For example, layer 3 can have a contact angle θ somewhere in the range of 5-100 degrees. The DLC-containing layer 3 can be deposited directly on the substrate 1 (see FIG. 1) or, instead, on the other layer on the substrate 1 as described above (see FIG. 3). Following the deposition of DLC-containing layer 3, layer 3 is exposed to UV irradiation / radiation in the S2 step. This exposure to UV irradiation can be done during the manufacturing process (eg, a UV source that emits UV radiation to layer 3 is installed in a device with an ion beam source used to deposit layer 3). (Can), and / or, instead, UV exposure can be done in the air (eg, place the article coated with layer 3 outside sunlight / rain). In each case, the DLC-containing layer 3 is exposed to UV irradiation that reduces the contact angle θ of layer 3. Optionally, water may be used in layer 3 during UV exposure to speed up the contact angle reduction process. The result of the decrease in contact angle θ is shown by S3.

It is noted that UVA appears to work well to reduce contact angles by exposing to layer 3. The "A" type of UV (low energy) is wavelengths in the range of 315 to 380 nm (near UV). Following and / or during UV exposure, the film retains scratch resistance and hardness (eg, even after 600 hours of QUV), and the film thickness does not change substantially (ie, does not change by more than 0-5%). ..

UV exposure of the DLC-containing layer 3 involves oxidation, forming a layer / portion of a thin carbon oxide on the surface of layer 3 (including, for example, -C = O and / or OC = O bonds). This thin, at least partially oxidized surface layer has a significant amount of attraction to water molecules (polar bonds), thus explaining its hydrophilicity. This thin carbon oxide-containing layer / moiety can be about 1-30 Å thick, more likely / preferably about 5-15 Å thick (in this regard, the high frequency dots of layer 3 in FIG. 2 , Used to represent a thin carbon oxide moiety on the upper surface of the entire layer 3. In this sense, UV will dope the surface of the DLC layer 3 with oxygen). This thin carbon oxide is believed to seal the rest of layer 3 from the atmosphere to prevent further oxidation (hard sp in the bulk of layer 3).³The bulk of the carbon-carbon bond is resistant to oxidation, and the layer retains its scratch resistance, etc.). This sealing prevents the bulk decomposition of layer 3 while at the same time providing hydrophilic properties (ie, low contact angle). With respect to UV exposure, the layer also reduces the tendency for dust to be attracted to it.

<u style="single">UV exposure example</u> The following examples were made for the purpose of demonstrating one non-limiting practice of one specific example of UV exposure of the present invention according to FIG. Acetylene (C) on a clean glass substrate with a thickness of 2 mm₂H₂) Feed source gas (145 sccm) was used at a linear velocity of 100 inches / min and the DLC layer 3 was ion beam deposited to a thickness of 14.69 angstroms (Å) at 2990 V and 0.57 amp. Layer 3 was not doped with dopants B, N, etc. on it. What was obtained was a DLC layer 3 with a-taC = H having an initial contact angle θ of 73.47 degrees. The coated article was then exposed to QUV for 86 hours (combination of UV irradiation and water). The QUV machine was heated for 2 hours (about 60 ° C) and moisture (ie water), followed by UV light exposure (UV light / irradiation was from a UVA340 fluorescent bulb that perfectly matched the UV spectrum of sunlight. ) Was set to a 2-hour cycle. Following QUV exposure, the coated article containing the substrate 1 with the DLC layer 3 had a reduced contact angle θ until it reached 19.12 degrees. Thus the contact angle can be seen as reduced by about 74% (ie 73.47-19.12 = 54.35; 54.35 / 73.47 = 0.7398 or about 74%). Further UV exposure will further reduce the contact angle. Thus, although the DLC layer 3 as deposited was not hydrophilic, the contact angle θ of the article dropped to the hydrophilic range (ie less than 20 degrees) after sufficient UV exposure. UV exposure can be seen as significantly reducing the contact angle of layer 3 to the hydrophilic range of &lt;= 20 degrees.

In a specific example of an embodiment of the present invention, the DLC-containing layer 3 has a contact angle θ of layer 3 of at least about 20%, more preferably at least about 30%, and even more preferably at least about 50%. (See example above) is exposed to UV irradiation (and optionally water / humidity) sufficient to reduce at least about 70% (eg UV exposure).

The term QUV is used herein with UV irradiation using a QUV-accelerated weathering tester available from The Q-Panel Company, Cleveland, Ohio to simulate sunlight / rain / moisture. Mention that it means being exposed to water. This QUV machine exposes the covering article to UV irradiation / light using a fluorescent UV lamp and simulates rain and dew with concentrated moisture. Covered articles are tested using QUVs with alternating light and moisture cycles at controlled elevated temperatures (typically from 50-90 ° C). During the condensation cycle, the water reservoir at the bottom of the test chamber is heated to produce steam, which keeps the chamber at about 100% relative humidity.

The advantages of certain embodiments of the present invention are, for example, any of the advantages listed above, the hydrophilic nature of the article / layer, the ability of layer 3 to resist high temperatures without burning, and the potential for electrostatic buildup. The fact that such a reduction in resistance and deposition methods can be performed at low temperatures such as room temperature in some specific examples, high deposition rates (eg&gt; 2 nm / s) that can be used, and large area deposition (eg&gt;&gt; 1 square mate fact that measurably Le), high uniformity electrolyte resistant deposition apparatus capable of coaching within 5-8% of a curved surface of the substrate 1, the smoothness of the layer 3 which do not exist many any pinholes, a conformal layer 3 Ability to achieve growth, ability to use layer 3 in combination with other underlayers such as low E layer or silicon nitride layer or silicon oxide layer, and / or ion energy and / or gas used during the deposition method. Includes the ability to vary and harmonize the properties of the layers. Given the above disclosure, many other features, modifications and improvements will be apparent to those skilled in the art. Therefore, such other features, modifications and improvements are considered as part of the invention whose scope of the invention is determined by the following claims.

<figref num="1">FIG. 5 is a vertical cross-sectional view of a coated article according to one embodiment of the present invention, wherein the glass or plastic substrate comprises a hydrophilic coating containing a DLC-containing layer.</figref><figref num="2">FIG. 5 is a vertical cross-sectional view of a coated article according to another embodiment of the present invention, wherein the glass or plastic substrate comprises a hydrophilic coating containing a DLC-containing layer.</figref><figref num="3">FIG. 5 is a vertical cross-sectional view of a coated article according to another embodiment of the present invention, wherein the glass or plastic substrate comprises a hydrophilic coating containing a DLC-containing layer.</figref><figref num="4">It is a schematic of the vertical cross section which shows the contact angle θ of a drop (eg, a fixed drop of water) on an uncoated glass substrate.</figref>

<figref num="5">For example, it is a vertical cross-sectional partial schematic showing a high contact angle θ of a drop on a coated article containing hydrophobic coaching for an article disclosed in Related Application 09 / 443,805.</figref><figref num="6">FIG. 5 is a schematic vertical cross-sectional view showing a low contact angle θ of a drop (eg, a fixed drop of water) on a coated article according to one embodiment of the invention.</figref><figref num="7">FIG. 5 is a vertical cross-sectional view of a linear ion beam source that can be used in a embodiment of the present invention to deposit a DLC-containing hydrophilic layer.</figref><figref num="8">It is a perspective view of the linear ion beam source of FIG.</figref><figref num="9">It is a flowchart which shows the process performed by another specific example of this invention, and the DLC-containing layer is subjected to ultraviolet (UV) light irradiation in order to reduce the contact angle θ.</figref>