Substrate with photocatalytic coating

The first substrate with photocatalytic coating This application is a divisional application of the invention patent application with the filing date of September 19, 2001, the application number of 01819172.X, and the title of the invention "substrate with photocatalytic coating" .

TECHNICAL FIELD The present invention relates to a substrate that is generally transparent or translucent, and the substrate is especially made of glass, plastic or glass ceramic and provided with photocatalytic properties, thereby imparting antifouling function or more precisely Self-cleaning coating.

Important applications of these substrates involve glass products that can be used for various purposes, such as practical glass products, glass products for home appliances, car windows and windows of buildings.

The substrate is also suitable for mirror type (house mirror or car rearview mirror) reflective glass and front guard wall or curtain wall type emulsified glass.

Similarly, the present invention is also applicable to opaque substrates, such as ceramic substrates or any other substrates that are especially useful as building materials (metals, tiles, etc.). Regardless of the nature of the substrate, it is preferable to apply the present invention to basically Flat or slightly curved substrate.

Photocatalytic coatings have been studied, especially those based on titanium oxide crystallized in the form of anatase. Their ability to reduce contamination by organic sources or microorganisms under the action of UV radiation is very beneficial. They are usually also hydrophilic Features, which allows rainwater to remove inorganic pollutants by spraying water or external windows.

BACKGROUND OF THE INVENTION The type of coating with antifouling, bactericidal and algae killing properties has been described, especially in patent WO97/10186 describing several methods of preparing the coating.

SUMMARY OF THE INVENTION Therefore, the purpose of the present invention is to improve the technology of depositing such coatings, especially to simplify the technology. At the same time, the purpose of the present invention is to improve the appearance of the coating, especially to improve the optical properties of the substrate provided.

The subject of the present invention is first a process for depositing a coating with photocatalytic properties by sputtering, the coating containing at least part of the titanium oxide crystallized in the form of anatase on a transparent or translucent carrier substrate. The features of the present invention include sputtering on the substrate at a deposition pressure of at least 2 Pascals. Preferably at most 6.67 Pa and especially at least 2.67 Pa (that is to say at least 15 mtorr, especially at 20-50 millitor Between cares).

In fact, it is known from the above-mentioned patent W097/10186 that this type of coating can be deposited by sputtering. This is a vacuum technology, which in particular allows the thickness and stoichiometry of each deposited layer to be finely adjusted. Generally, it is enhanced by a magnetic field. Sputter deposition for higher efficiency. Sputtering may be reactive: In this case, a target that is basically metal is used, here is a target based on titanium (which may be alloyed with another metal or silicon), and In an oxidizing atmosphere, usually Ar/(h mixed gas

200510091711.5 Sputtering under the first atmosphere. Sputtering may also be non-reactive: At this time, a target called a ceramic target is used, which is already in the oxidized form of titanium (which may be alloyed).

However, the layer obtained by this type of technology is generally amorphous, and the function of the coating of the present invention is directly related to the fact that it must be crystallized in a large amount. This is the above-mentioned patent proposal, for example, it is necessary to perform at least 400 yi for about 30 minutes to A few hours of heat treatment to crystallize the layer (or increase the crystallinity).

The present invention has shown that pressure up to this value is particularly beneficial to the crystallization of the layer, and is beneficial to the density / roughness level, which has a significant impact on the level of photocatalytic performance of the coating. Sometimes annealing can also be selected. Specifically, the deposition pressure generally used for metal oxides is usually in the range of 2-8 mTorr (ie 0.27-1. 07Pa): therefore the pressure used in the present invention is significantly different from the pressure used in the field.

Within the scope of the present invention, it has been shown that by sputtering the layer not at room temperature but on a hot substrate, especially a substrate heated to at least 100 μm, it is possible to eliminate the post-deposition processing step, or at least make it arbitrary. Selected steps (and/or limited in time or temperature). This heating during the deposition process is selective, or an additional feature of the high pressure used above.

This kind of heating has at least five advantages: τ saves energy during the manufacturing process; f makes it possible to use substrates that cannot withstand heat treatment at 400 or 500°C, at least without deterioration; if annealing needs to be applied to the substrate and photocatalysis A barrier layer that prevents the components from diffusing from the substrate (alkali metal type when made of glass) is inserted between the coatings. A thinner barrier layer may be used, or even no barrier layer may be used at all, because of the corrosion of the heat treatment of the present invention. The performance is much lower than the annealing operation;

-Shorter manufacturing cycle (because the heat treatment of the substrate is significantly shortened and performed at a significantly lower temperature); eliminates the storage requirements for the "semi-finished products" to be annealed.

However, this layer is very similar to the photocatalytic level of the coating deposited and then annealed.

However, this is not the expected result, because so far, what has been conceived is that the extended annealing operation is essential for the growth of seed crystals in the amorphous oxide matrix. This has not always been the case: thermal deposition has Facilitate the direct deposition of at least partially crystallized layers.

The "hot deposited coating is crystallized in the anatase form in preference to the rutile form (the anatase form of titanium oxide has much better photocatalytic properties than the rutile or brookite form).

200510091711.5 The first non-obvious. The present invention can be implemented in various alternative ways, depending in particular on the type of sputtering equipment available. Therefore, the substrate can be heated outside the vacuum chamber before the actual deposition. When the deposition chamber is equipped With special heating equipment, the substrate can also be heated during the deposition process. Therefore, the substrate can be heated before the sputtering layer and/or at the same time as the sputtering. It can also be heated gradually during the deposition process, or only the deposition can be heated Part of the layer thickness (e.g. upper part).

When the layer is sputtered, the substrate temperature is 150°C-350°C, preferably at least 200°C and especially 210°C-280°C^<The advantage. Surprisingly, it may be sufficient Crystallized layer without heating the substrate to the temperature usually used for annealing operations, that is, at least 400 -500 ° C.

Generally, when the coating is basically based on titanium oxide (Ti6) and deposited by sputtering ("hot" or at room temperature), it has a relatively high refractive index-greater than 2 or greater than 2.1 or greater than 2. 15 or 2. 2. Usually 2.15-2. 35 or 2. 35-2. 50 (may be slightly lower than the stoichiometric amount), especially 2.40-2.45. This is a rather special feature of this type of deposition, because other technologies are used , For example, the same type of coating deposited by sol-gel technology tends to be more porous and has a significantly lower refractive index (below 2 and even lower than 1.8 or 1.7). The present invention is through sputtering A layer with porosity and/or roughness (especially RMS roughness) between 2. 5-1 Onm can be obtained, thereby improving the photocatalytic performance. Therefore, they can have a refractive index of about 2.15 or 2.35, which is less than usual The value obtained by sputtering is indirect evidence of its porosity. From an optical point of view, this is an advantage, because for a certain thickness of a layer, a layer with a low refractive index has less appearance and reflection.

It has been found that the fact of "cold" deposition followed by annealing or "hot" deposition affects the crystal structure of the coating. Therefore, it is very surprising that the coatings of the present invention that are "hot" and/or high pressure deposited generally have a coating of less than or equal to 50 Or 40 or 30nm, especially between 15-30nm or 20-4nm between the average crystallite size of TiO2. When using standard deposition pressure, the coating deposited in a standard way, especially "cold" deposition and subsequent annealing The coating tends to contain larger size crystallites, that is, at least 30 or 4Onm and generally between 40-5 Onm.

On the other hand, according to a variation of the present invention, if the layer is deposited at room temperature but under high pressure, and then an annealing operation is performed, the size of the crystallites is smaller than that of the coating thermally deposited at high pressure or low pressure ( 20-40nm).

The photocatalytic activity of the layer deposited at room temperature and high pressure and then annealed is much better than that of the coating deposited at room temperature and low pressure and then annealed: the other conditions are the same, ^ |

200510091711.5 The performance of the first coating, especially in the case of "cold" deposition, has a significant impact.

Heating this layer while growing results in the formation of microstructures that contribute to the roughness and/or porosity that are beneficial to the photocatalytic performance. To some extent this is not the case when using high deposition pressures (for example, with "cold Annealing after deposition) is the same.

Measured by atomic force microscopy on the same surface with a spacing of 2 microns, the process of the present invention (by thermal and/or high pressure deposition) may make the resulting coating have an RMS roughness (mean square root):

-At least 2nm, especially at least 2.5nm and preferably between 2.8nm-4. 6nm, at this time deposition at room temperature and high pressure (2-5pa) within the scope of the present invention, followed by annealing operation;

-At least 4nm, especially at least 5nm and preferably between 5. 5nm-6. Onm, this time is high pressure or low pressure thermal deposition (at about 250Γ) but not annealing.

By comparison, at room temperature and standard pressure (especially 2X10^-3Millibar, ie 0.2pa) The roughness of the deposited and then annealed coating is only 2mn at most: This confirms that the use of high pressure can achieve surprisingly high roughness of the sputtered deposited layer, thereby improving the photocatalytic performance of the coating .

It is advantageous for the coating to have a geometric thickness of less than 15nm, especially 80-12nm or 10-25nm. The result is that even when the coating is very thin, it has sufficient photocatalytic performance (at least for some applications) , And also has the optical advantage of almost no reflection.

It can be seen from the above that the sputtering of the coating can be reactive or non-reactive sputtering. In both cases, the target to be sputtered can be doped, especially at least one metal can be doped. This can be optional One or more metals from Nb, Ta, Fe, Bi, Co, Ni, Cu, Ru, Ce, Mo, Al.

The deposition method of the present invention can be used to deposit one or more thin layers, especially one of the thin layers that have optical, antistatic, anti-color, anti-reflection, hydrophilic or protective functions or improve the roughness of the coating with photocatalytic properties. Or multiple steps before or after. Therefore, it has been found that it may be advantageous to deposit (at least) one layer to make it particularly rough, for example by pyrolysis or sol-gel, and then deposit a photocatalytic coating; then the coating Tend to "follow" the roughness of the bottom layer, and in fact also have obvious roughness, while the layer deposited by sputtering tends to be less rough. Therefore, it is possible to form multiple layers, which have a chemical vapor deposition (CVD) Si02, SiOC or SiON type lower layer (for example, with a roughness of at least 5 or 10nm), and then a sputtered photocatalytic layer.

Therefore, the present invention includes the deposition of one or more layers (including at least the photocatalytic layer) by sputtering and the deposition by techniques including thermal decomposition, especially pyrolysis (in liquid, gas or powder phase) or sol-gel technology. Any combination of other layers of the layer · From the above, it can be seen that the TiO2-based photocatalytic coating has a high refractive index. This means that they have

200510091711.5 is reflective, and the carrier substrate that gives them is usually regarded as an aesthetically unattractive reflective appearance. In addition to the bright characteristics, the color of the reflection is not ideal. It is not easy to improve the appearance of the reflection, because the light The catalytic function imposes limitations-the coating must generally be in contact with the external environment to receive UV radiation and reduce external pollution. Therefore, it cannot cover the low refractive index layer (unless the layer is very thin and/or porous). In order to be fully effective Must have a special minimum thickness.

Therefore, another part of the present invention is to improve the reflective appearance of the substrate without affecting the photocatalytic activity of the coating, especially by reducing its light reflection as much as possible and/or as much as possible to make it reflect achromatic colors.

Therefore, the subject of the present invention is also a transparent or translucent substrate as defined above, which has a photocatalytic coating on at least a part of at least one surface thereof, and the photocatalytic coating includes titanium oxide crystallized at least partially as anatase. The coating has a high refractive index of at least 2 or 2.1 or 2.2. According to the present invention, the coating is considered to form part of a multilayer comprising a thin anti-reflection layer, which is the last layer (ie It is said that the layer is farthest from the carrier substrate). The anti-reflection multilayer is composed of alternating high refractive index and low refractive index layers, so in the case of the present invention, the final layer is a layer with a high photocatalytic index. For convenience Use of the term "anti-reflection": generally used when the desired light reflection is less than the value of the substrate itself. Within the scope of the present invention, it is more problematic to limit the increase in light reflection due to the use of titanium oxide-containing coatings.

Within the scope of the present invention, the term "layer" is understood to mean a single layer or a superimposed layer. If it is a superimposed layer, its total thickness is considered to be the sum of the thickness of each layer, and the total refractive index is considered to be the sum of the thickness of each layer. The average value of the refractive index. This also applies to photocatalytic coatings. It can also be applied to other high refractive index layers.

Within the scope of the present invention and as described above, the term "anti-reflection" is understood to mean the function of reducing the light reflection value of the coated substrate and/or weakening its reflection color, in particular so as to make the color as light or achromatic as possible. Function, that is, as aesthetically attractive as possible (in this case, it can also be said to be an "inverse color" effect).

This is a completely independent and unexpected change from conventional anti-reflection multilayers. This is because in a known way, these multilayers alternate with high refractive index and low refractive index layers, and finally a low refractive index layer (refractive index It is completed as close as possible to the refractive index of air (equal to 1), and is usually a layer based on SiO2, MgF2, etc. However, in the present invention, the multilayer is completed with a high refractive index layer at the end, which is quite abnormal. However, by appropriately selecting the characteristics of each layer, the special anti-reflection multilayer can significantly weaken the inherent reflection characteristics of the high refractive index Tiil·, and give the substrate an acceptable reflection color (achromatic, avoiding red or other destined Aesthetically attractive warm gray

200510091711.5 The first tone is gray, blue or especially green) The refractive index of the photocatalytic coating is greater than or equal to 2. 30, especially between 2. 35-2. 50 or between 2.40-2.45 (from the above It can be seen that it is also possible to deposit to have a refractive index of only 2.10-2. 30) is advantageous · preferably deposited by sputtering · The optical thickness and the thickness of other layers of multiple layers are advantageously selected to reduce the light reflection of the substrate It has been shown that the optimal optical thickness is preferably in the λ/2 region, where λ is about 580nm. This corresponds to an optical thickness between 250-350nm, especially between 270-310nm, and a geometric thickness between 80-120nm It has been confirmed that the geometric thickness range is sufficient to obtain the photocatalytic activity considered to be sufficient (in fact, the photocatalytic activity depends on many parameters, including the thickness and surface roughness, the crystalline morphology of the layer, Its porosity, etc.). It is also possible to use a substantially thinner layer, especially a layer with a geometric thickness between 10-25nm.

Whether the coating is deposited by "hot" sputtering or cold sputtering at room temperature and then annealing determines the size change of the crystallites contained in it as described above (from the above, it can be seen that when "hot" sputtering is usually less than 30nm, and when About 30-50nm or more when sputtering at room temperature and standard pressure).

In the simplest embodiment of the present invention, the anti-reflection multilayer includes three layers, which in turn are a high refractive index layer, a low refractive index layer, and a high refractive index photocatalytic layer. The high refractive index of multiple layers other than the photocatalytic coating The rate layer generally has a refractive index of at least 1.9, especially between 1.9-2. 3 or between 1.9-2.2. The layer can be made of zinc oxide, tin oxide, zirconium oxide, aluminum nitride or silicon nitride. Also It can be made from a mixture of at least two of these compounds.

The optical thickness of these high refractive index layers is selected. Their optimal optical thickness is preferably in the λ/10 region, where λ is about 580nm. This corresponds to an optical thickness between 4 and 68 nm, especially between 53 and 63 nm. Between, and the geometric thickness is between 20-40nm, especially between 25-35nm. A smaller thickness can also be selected, especially between 20-48nm.

The refractive index of the low refractive index layer is generally between 1.4-1.75, especially between 1.45-1.65. For example, they can be based on silicon oxide, aluminum oxide or a mixture of these two. The choice of optical thickness of these low refractive index layers Yes: Their optimal optical thickness is preferably in the λ/20 region, where λ is about 580 nm. This corresponds to an optical thickness between 20-79 nm, especially 19-39 nm, especially 25-35 nm Between, and the geometric thickness is between 12-5 0nm, especially between 15-30nm, such as between 20-28nm.

In the above-mentioned three-layer multilayer, according to other variations, it is possible to replace the high refractive index layer with a refractive index "centered", that is, a layer whose refractive index is preferably greater than 1.65 and less than 1.9.

200510091711.5 The low refractive index layer sequence. The preferred range of its refractive index is between 1.75-1.85. The layer may be based on silicon oxynitride and/or aluminum oxynitride. It may also be based on low refractive index oxides such as Si (H and at least one oxide with higher refractive index such as S11O2, ZnO, ZrO₂, Ti (l· mixture (the relative ratio between oxides makes the refractive index adjustable).

It is also possible to use this intermediate layer to replace the first sequence of high refractive index layer / low refractive index layer, for example, containing not three layers but five or seven layers.

The optical thickness of these intermediate refractive index layers is selected. Their optimal optical thickness is preferably in the λ/4 region, where λ is about 580nm. This corresponds to an optical thickness between 120-150nm, especially 125-135nm, And the geometric thickness is between 65-80nm, especially between 68-76nm.

As mentioned above, the selection of these various optical thicknesses takes into account the overall appearance of the reflection of the substrate: not only try to reduce the light reflection value Rl but also give it a hue that is now considered to be aesthetically attractive (that is, cool colors instead of yellow or Red), and has the smallest possible intensity. Therefore, the best compromise must be found to make the overall reflective appearance of the substrate better. Based on the application, it is more preferable to reduce the R1 value [sic] or more preferably to select a specific reflection chromaticity Response (for example, quantified by the a* and b* values of the L, a*, b* chromaticity system, or quantified by the dominant wavelength related to color purity).

Advantageously, all layers of the anti-reflective multilayer are sputter deposited one by one on the same production line. According to an optional variant of the present invention, it is possible to insert a barrier layer between the substrate and the anti-reflective multilayer to block Substances that easily diffuse out of the substrate. When the substrate is made of glass, these barrier layers are especially Granville metals. For example, the barrier layer is based on silicon oxide (or silicon oxycarbide): Si(h, and The known method is to deposit SiOC by chemical vapor deposition (CVD). Its thickness is preferably at least 50nm, for example between 80-20nm. When choosing this type of material with a relatively low refractive index (about 1.45-1.55) However, based on the optical point of view, it is generally quite "achromatic. Silicon oxide may contain a small amount of elements especially selected from Al, C, and N. The present invention also relates to glass products (glazing), especially single-layer glass [rigid Substrate), laminated glass products and multiple glass products of double glass type, which include at least one substrate coated in the above-mentioned manner.

Due to the anti-reflection effect of the present invention, it is preferred that the light reflection value Rl (on the multilayer side) of the glass article is maintained at most 20%, especially at most 18%. Preferably the light reflection has a pleasant blue or green hue, They have negative a* and b* values in the (L, a*, b*) chromaticity system and especially their absolute value is less than 3 or 2. 5. Therefore, the color of this hue is both pleasing to the eye and low-intensity light

200510091711.5 No.

color.

The glass article may also include one or more other functional coatings (by sputtering or pyrolysis or sol-gel deposition), which are either on the same surface of the substrate provided with the photocatalytic coating, or on the substrate The opposite side of the glass material, or the surface of another substrate combined with the first substrate in a glass component (double-glazed or laminated glass product). It is also possible to obtain a glass/air-filled void/glass-type double-glazed component , It has a photocatalytic coating on the outer surface of the window glass, and a multilayer containing one or more silver layers on the inner surface (toward the gas-filled pore). The same type of configuration is suitable for laminated glass products.

Other functional coatings can especially be antifouling coatings, solar protection coatings, low-emissivity coatings, thermal coatings, hydrophobic coatings, hydrophilic coatings, anti-reflective coatings or antistatic coatings or other photocatalytic coatings. Layers, etc. Special mention is made of one or more silver layers, or a layer of-Luo layer, or titanium nitride or dislocation nitride layer composed of solar protection or low-radiation multilayer. For the layer based on metal nitride CVD technology can be used.

The present invention will be described in detail using non-limiting explanatory examples.

Specific embodiments Example 1 and Comparative Example 1 are about the sputtering thermal deposition of the photocatalytic Ti02 layer. Example 1 The following were deposited on 4mm thick transparent quartz-sodium-lime glass: 80-nmSiOC deposited by CVD first Layer, followed by a 90-nm TiO? photocatalytic second layer (Al: Si obtained by reactive sputtering of Al-doped Si target material can also be used (h layer instead of SiOC layer.) Sputtering enhanced by magnetic field To deposit the Ti02 layer. This is a reactive sputtering from a titanium target in the presence of oxygen. The glass is preheated to a temperature of about 220°C-250°C. In the process of sputtering the layer, use the target The heater on the opposite side of the material keeps the temperature constant within the fluctuation range of 5°C.

The resulting Ti02 layer has a refractive index of 2.44. It crystallizes in the form of anatase (and may also include amorphous regions), and its average crystallite size is less than 25nm.

The photocatalytic activity was quantified using the palmaric acid test: this includes depositing a certain thickness of palmic acid on the photocatalytic coating, and during the entire test process, exposing the layer to a surface energy density of about 50W/m\365nm Center UV radiation, and then press I according to the following equation to measure the disappearance rate of palm press 1 acid:

V (nm/h)=[(palmitonic acid thickness nm)]/[2tt/2,*loss(h)] The photocatalytic activity of the layer of the invention obtained by this calculation formula is at least 10mn/b, especially at least 20nm/h, especially between 20-100nm/h, it depends on the pressure and temperature

200510091711.5 Selection of the product parameter.

Thus, the light reflection Rl of the glass coated with these two layers under the D65 light source is 23%, and the a* and b* values in the (L, a*, b*) chromaticity system are about 17 and 18, respectively.

Therefore, the photocatalytic activity of this layer is effective, but its optical appearance is still obviously highly reflective, and its chromaticity is too strong.

It should be noted that the conventional annealing operation (at least 400 °C for one or several hours) after deposition may enhance the photocatalytic activity of the layer.

Comparative Example 1 Example 1 was repeated, but this time the Ti02 layer was deposited on an unheated substrate and then treated at about 500 ° C-550 ° C for four hours. In addition, the lower layer of Si02 was thickened to lOOnm. The morphology of this layer is a little different, and its average crystallite size is somewhat greater than 30nm.

Its photocatalytic activity is similar to that of the unannealed layer of Example 1, but if a smaller Si% lower layer thickness is selected, it is less than that of Example 1. Therefore, this confirms that the "thermal" deposition of the present invention may be "eliminated" Usually too long annealing operation will not damage the performance of the layer. This also confirms the auxiliary advantage of the present invention: due to thermal deposition and eliminating the annealing operation, in order to obtain the same photocatalytic performance, it is possible to use a thinner barrier layer The bottom layer (therefore, again leading to a reduction in the manufacturing cost of the product).

Example 2 and the following examples relate to the high refractive index Ti (h photocatalytic layer, especially the layer deposited by sputtering added to the anti-reflective multilayer to improve its optical properties.

Example 2-(Realized) The following multilayers were deposited on 4mm thick quartz-sodium-lime float glass: glass/SiN/Si02/TiOi

30nm 22nm 104nm (geometric thickness) SiN layer is deposited from Al-doped Si target by reactive sputtering in the presence of nitrogen (1).

In the presence of oxygen by reactive sputtering from Al-doped Si target deposition of Si (h layer (2).

Thermally deposited photocatalytic Ti02 layer (3) according to the method described in Example 1.

Optionally, an additional layer can be inserted between the glass and the SisM layer. This layer is a Si(h layer of about 100am) similar to the other SiO2 layer (2) mentioned above. It actually has no effect on the optical properties of the substrate. It can be used as a barrier layer to the glass. This is optional, especially due to the anti-reflective coating under the photocatalytic layer, that is, layers (1) and (2) in addition to their optical properties, themselves It also constitutes a very satisfactory barrier layer: these two layers have formed a 100-iim

200510091711.5 The first barrier layer for substances that easily diffuse out of glass.

The photocatalytic activity of layer 3 is 80nm/h. Alternatively, the method described in Comparative Example 1 can be cold deposited and then annealed Ti (h layer.

For such a multilayer, the reflection results on the multilayer side are as follows:

<td>Rl (under D65 light source) =</td><td>17. 3%</td>

<td>a* (Rl)=</td><td>-2</td>

<td>b* (Ri)=</td><td>-2. 8</td>

<td>λύ (the dominant wavelength of light reflection) =</td><td>494nm</td>

<td>pe (reflected color purity)=</td><td>2. 5%.</td>

This shows that compared with Example 1, the shoe value is significantly reduced and a blue-green lower intensity color is obtained at this time. In short, the reflective appearance is aesthetically and significantly improved.

Example 3 This is very similar to Example 2, the only change is that the thickness of the Ti02 layer is slightly reduced. The layers deposited at this time are as follows: Glass/Si₃N4^（17SiO₂ /Ti02

30nm 22nm 99nm (geometric thickness).

The light reflection results are as follows (the same as those in Example 2):

Rl = 17. 9% a*=-0. 8 b*=-0. 7 λά =494nm pe = 0.8%.

Therefore, there is a slightly different tradeoff in this example, the value of Ri increases slightly and the absolute value of a* and b* decreases slightly.

Example 4 (Simulation) This is very similar to Example 2, the only change is the thickness of the first layer of SiN: glass/SisN,/Si02/Ti0₂⑶

25nm 22nm 104nm (geometric thickness).

The light reflection results are as follows (the same as those in Example 2):

Ri = 15. 8%

200510091711.5 No.

<td>a*=</td><td>0</td>

<td>b *=</td><td>-9</td>

<td>L =</td><td>475nm</td>

<td>pe =</td><td>4. 9%.</td>

At this time, the Ri value is greatly reduced, but the reflected color changes the color tone. Example 5 (simulation/contrast) At this time compared with Example 2, all thicknesses are changed.

Obtain: Glass/SisM/Si(l·/Ti02

28nm 30nm 75nm (geometric thickness).

<td colspan="2">The light reflection results are as follows:</td>

<td>Rl =</td><td>25. 8%</td>

<td>a*==</td><td>^—0. 3</td>

<td>b*=</td><td>-0. 7</td>

<td>kd =</td><td>492nm</td>

<td>pe =</td><td>0. 5%.</td>

The reflection color of the winter tube substrate is satisfactory, but its Ri value is indeed significantly higher than 20%, which is too high: the selected thickness is not optimal.

Example 6 (Simulation/Comparison) The layer thickness of this example is even more different from the layer thickness recommended by the present invention. The multilayer is like

T: Glass/Si₃N/^l7SiO₂⁽²⁾ /Ti02 (Geometric thickness)

The light reflection structure of 20nm 20nm 60nm is as follows:

<td>Rl =</td><td>30%</td>

<td>a*=b*=</td><td>2. 37. 2</td>

<td>λύ =</td><td>587nm</td>

<td>pe =</td><td>14%.</td>

200510091711.5 This multilayer has both a high Rl value and an unsatisfactory stronger reflection color, so its reflective appearance is not satisfactory.

Example 7 (Realized) The stack at this time is as follows: Glass/Sn02/Si(l·/Ti02

30nm 27nm 105nm (geometric thickness).

Therefore, with SW instead of SiN, the Snih layer is deposited from a tin target by reactive sputtering in the presence of oxygen.

The light reflection results are as follows:

Rl= 17.4% a*= -2. 8 b*= λ&lt;ι = pe

-2. 7

496nm

2. 8%.

The reflection appearance is similar to the results obtained in Example 2. Example 8 (simulation) At this time, a single layer of silicon oxynitride SiON with a refractive index of 1.84 replaces the first two layers.

<td colspan="2">Therefore, the multiple layers are as follows:</td>

<td>Glass/SiON/TiOz</td><td></td>

<td>72nm lOlnm</td><td>(Geometric thickness).</td>

<td>The light reflection results are as follows:</td><td></td>

<td>Rl =</td><td>17. 4%</td>

<td>a*=</td><td>0</td>

<td>b*=</td><td>-1. 08</td>

480nm

1%.

λ&lt;ι =

<img file="CN100415669C_D0001.tif" />

Therefore, its reflective appearance is satisfactory.

Example 9 (simulation) Example 8 was repeated, but the refractive index of the SiON layer used at this time was 1. 86.

As a result, the reflection appearance is slightly improved:

200510091711. 5th

<td>Rl =</td><td>17. 8%</td>

<td>a*=</td><td>-1. 1</td>

<td>b*=</td><td>*~1. 5</td>

<td>λά Η</td><td>494nm</td>

<td>pe =</td><td>1. 3%.</td>

Example 10 (implemented) The multilayers are as follows: Glass/Si3/Si02/Ti02/Ti02

24nm 17. 5nm 24nm 92.5nm Therefore, the final high refractive index "layer" is the stack of SiN layer and Ti(h layer. The light reflection Rl on the multilayer side is between 16. 5-17. 5%, and The photocatalytic activity is in the range of 80nm/h.

Example II (Implemented) Repeat the multilayer type of Example 3, but with different thicknesses. The multilayer at this time is: Glass/SiN/Si02/Ti02

14. 5nm 43nm 14. The light reflection of the 5nm multilayer side is between 13-16%. If each layer of the stack changes 3%, the optical change of the substrate thus coated is as follows:

ARl: 0.8%

Aa* (Rl): 0.3

Ab* (Rl): 1. 3.

This example shows a photocatalytic activity of about 15-20 nm/h.

This embodiment is useful in several ways: it is very insensitive to thickness changes, and therefore can be easily manufactured on an industrial scale. Even if the titanium oxide layer is very thin, it still has sufficient photocatalytic performance. From a chromaticity point of view, it is Satisfactory.

In summary, the present invention has developed a new method for vacuum deposition of a layer containing photocatalytic Ti(l··························································································································· Large-scale manufacturing, and significantly weakens Tith's reflection without reducing its photocatalytic performance. It is possible to obtain glass products that reflect blue or light green, while maintaining a consistent photocatalytic layer thickness of 100 nanometers. Also. It is possible to choose a significantly thinner photocatalytic layer of 12-30nm.

200510091711.5 The two aspects of the present invention (products and processes) can also be applied to photocatalytic coatings that do not contain Ti(h) in the same way.

Therefore, the present invention suggests that these coatings should be deposited "thermally", or alternatively, they can be deposited at room temperature followed by appropriate heat treatment. Preferably, the specific deposition pressure should be controlled so that the resulting vacuum deposited layer has unusual characteristics, resulting in significant Antifouling performance·