Process for the production of photocatalytic coatings on substrates

Paint on the underlying layers

Hello full description

This application is a partial application of Application No. 0210544. Which was deposited in the Kingdom of Saudi Arabia on 8/23/1421 AH, corresponding to 11/19/2000 AD.

Background of the invention

The invention relates to a process for producing coated substrates with photocatalytic activity, and relates in particular, but not limited to, to a process for producing coated glass with photocatalytic activity as well as coated glass.

It is known that thin layers of paint consisting of one or more layers and having different properties are deposited on substrates, including substrates of glass. One property of interest is the photocatalytic activity that arises by the generation of light in a semiconductor from a hole-electron pair when the semiconductor is illuminated by light of a certain frequency. A hole-pair of electrons can be generated in sunlight and can react in humid air to form hydroxy and peroxy moieties on the surface of the semiconductor. Cracks oxidize organic soot on the surface. This property is used in self-cleaning substrates, especially in self-cleaning glass used in windows.

Titanium oxide may be an effective photocatalyst and can be deposited on substrates to form a transparent coating with self-cleaning photocatalytic properties. Photocatalytic titanium oxide coatings are disclosed in patents:

European Patent No. 901991-2 or International Patent Nos. 07069/97, 97/1.186 and 98/41480 and in:

and (1102 p.1, Nev. and 95-1,. Mention of a chemical vapor deposition process for depositing titanium oxide coatings on hot flat glass at a high deposition rate using a gaseous mixture of titanium chloride and an organic compound as an oxygen source to form titanium oxide coatings.

titanium oxide 0

It was thought that to provide good photocatalytic activity, relatively thick titanium oxide coatings must be deposited. For example, International Patent 0 4800 1 98/4 stated that a self-cleaning coating with photocatalytic activity must be thick enough to provide an acceptable level of effectiveness. It is preferable that the thickness of this coating be at least about 2 0 angstroms, and more preferably it should be Its thickness is at least about 500 angstroms (all measured thicknesses of titanium oxide coatings produced in Germany range from 400 angstroms to 2100 angstroms).

However, the problem with relatively thick titanium oxide coatings is the high reflection of visible light, and thus the penetration of visible light is relatively small. This problem was identified in a New Scientist article regarding coated glass windshields, where it was suggested that to reduce the effect of significant reflection, glass windshields should be coated with a black smooth coat or other material that does not reflect light off the coated glass windshield.

European Patent No. 901991-2a referred to above relates to photocatalytic glass panels with a titanium oxide coating having a special crystalline structure characterized by the presence of special peaks in their X-ray diffraction pattern. The standard specifies a range of coating thicknesses from 20 nm to 135 nm in all type examples and to be less photocatalytic for thin coatings than for larger thick coatings. The standard also expects a range of deposition temperatures ranging between a minimum of 300°C and a maximum of 750°C, but the best is temperatures that range between 400°C and 600°C. In all specific examples of the invention, the titanium oxide layer is deposited at a temperature that falls within and below this preferred range.

The applicants have found that by deposition of titanium oxide coatings at higher temperatures, especially at a temperature above 600°C, it is possible to obtain coatings with enhanced photocatalytic activity for a given thickness, which makes it possible to obtain the same photocatalytic activity with the use of coatings of a higher thickness. less. These thinner coatings tend to have a beneficially lower reflectivity of visible light and, apparently as a result of their higher deposition temperature, have improved durability, especially to friction and cyclic temperature changes in a humid atmosphere.

General description of the invention

Accordingly, the present invention provides a process for producing a coated substrate with photocatalytic activity comprising depositing a coating of titanium oxide on the surface of the substrate by contacting the surface of the substrate with a fluid mixture containing a source of titanium and a source of oxygen, the substrate being at a temperature 0 0 6 m at least,

Wherein the coated surface of the substrate has a photocatalytic activity greater than 5 x 10-3 cm-1 min-1 and a measured visible light reflectance on the coated side of 35% or less. It is preferable that the temperature of the substrate range between 625°C and 720°C, and it is more preferable that it range between 645°C and 720°C.

It is beneficial for the fluid mixture to include titanium chloride as a titanium source and an ester other than a methyl ester. Thus, in an embodiment, the present invention describes a process for producing a photocatalytic coating substrate which is ignited by depositing a coating of titanium oxide having a thickness of less than 40 nm on a surface by contacting the surface of the substrate with a fluid mixture comprising titanium chloride. chloride and ester other than methyl ester.

The process can be performed when the surface of the substrate comes into contact with the fluid mixture when the layer is formed

Infrastructure at a temperature ranging between 600°C and 750°C.

Preferably, the ester is an alkyl ester with an alkyl group with a hydrogen atom in the ß position (the alkyl group is derived from the alkyl ester of an alcohol during the synthesis of the ester and the hydrogen atom in the ß position is the hydrogen atom attached to the carbon atom, which is attached to the ß atom Oxygen in the ether link in the ester. The ester is preferably a carboxylate ester

ester 0

Suitable esters may be alkyl esters with a C1-C2 alkyl group, but preferably the ester is an alkyl ester with a C1-C2 alkyl group.

alkyl C2-4.

It is preferable that the ester be a compound with the formula:

RC-(O)-(O)-C(X)(X1)-C(Y)(Y)-R

where R and 'R represent hydrogen or an alkyl group, and . Suitable hydrogen esters that may be used in the process of the present invention include: ethyl formate, ethyl acetate, ethyl propionate, ethyl butyrate, n-propyl formate, n-propyl acetate, n-propyl propionate, n-propyl butyrate, isopropyl formate, isopropyl acetate. , isopropyl propionate, isopropyl butyrate, n-butyl formate, n-butyl acetate and t-butyl

acetate

The ester preferably includes an ethyl ester, and more preferably the ester includes an ethyl formate ester, ethyl acetate, or ethyl propionate. It is preferable for the ester to include ethyl acetate. ethyl acetate The fluid mixture may be in the form of a liquid, especially derived as a fine mist (a process often referred to as sputter deposition), but preferably the fluid mixture is a gaseous mixture. Often referred

To the deposition process performed using a gaseous mixture as a chemical vapor deposition (CVD) product. The preferred form of the CVD process is a laminar flow CVD process, although a turbulent flow CVD process can also be used. The process can be performed on substrates of various dimensions, including sheet-shaped substrates, especially on cut sheets of glass, or preferably directly during the flat glass production process on a continuous strip of glass. Thus, it is preferable to perform the process directly during the flat glass production process, and the substrate is a strip of glass. If the procedure is performed directly, it is preferable to perform it on the glass strip while it is in the flotation bath.

The advantage of performing the process directly is that the coatings are deposited. Directly it tends to be durable and has a particularly high friction resistance and resistance to chemicals.

Direct deposition is preferred, and other deposition processes can be performed at atmospheric pressure

Main.

In a particularly preferred embodiment, a process is provided for the production of highly durable coated glass with photocatalytic activity comprising depositing a layer of titanium oxide with photocatalytic activity on the surface of a substrate of glass by contact with the surface of the substrate at a temperature between 645°C and 720 m, preferably between 670 m and 720 m with a fluid mixture containing a titanium source.

As previously noted, the applicants have found that by depositing titanium oxide at a high temperature a coating with high catalytic activity for a fish can be produced, as the coatings are

Fewer thicknesses tend to have less reflectivity, and the invention also provides new products with a useful combination of high photocatalytic activity and low or moderate light reflectance. Thus, the present invention provides in another form a coated substrate with photocatalytic activity comprising a substrate having a coating of titanium oxide with photocatalytic activity on one of its surfaces, characterized by the fact that the coated surface of the substrate has a photocatalytic activity greater than 5 x 10-3 cm. -1 minute-1 and a reflection of visible light measured at the painted surface is 35% or

less.

High photocatalytic activity is advantageous because the amount of contaminants (including dirt) on the coated surface of a substrate with high photocatalytic activity will decrease faster than contaminants on substrates with relatively low photocatalytic activity. Relatively rapid removal of surface contaminants will also occur at low levels of UV light intensity. Photocatalytic activity for the purposes of this standard is determined by measuring the integral absorption loss rate of the infrared absorption peaks corresponding to the C-H stretches of a thin stearic film, formed on the coated substrate, illuminated by ultraviolet light from a UVA lamp having an intensity of about 32 W/m2 at the surface. The coated substrate and a peak wavelength of 351 nm. Stearic acid can be formed at the coated substrate by rotating a solution of stearic acid in methanol as mentioned below.

Preferably, the coated surface of the substrate should have a photocatalytic activity greater than 1 x 0 1 -2 cm-1 min-1, and more preferably greater than 3 x 0 1 -2 cm-1 min-1.

Low visible light reflection is advantageous because it is less distracting than high reflectivity, especially for underlying layers of glass. Low visible light reflectance corresponds to high transmittance, which is often required in architectural applications and especially in automotive glass manufacturing.

It is preferable for the painted substrate to have a visible light reflection measured at the painted side of 20% or less, more preferably 17% or less, and preferably 15% or less.

less.

In most embodiments of the invention the substrate is primarily transparent and in a preferred embodiment of the impregnation the substrate comprises an underlying layer of glass. The glass underlayment is usually an underlayment of soda lime glass.

When the substrate is a soda lime glass substrate or a substrate containing another alkali metal ion, it is preferable for the coated substrate to have an alkali metal ion-blocking substrate between the surface of the substrate and the catalytic titanium oxide coating. Optical. This reduces the tendency of the alkali metal ion to migrate to the photocatalytic titanium oxide coating, which is beneficial because it is known that alkali metal ion tends to poison semiconductor oxide coatings, reducing their effectiveness.

We may ignite the bottom layer that prevents the alkali metal ion on metal oxide, but it is preferable that the layer that prevents the alkali metal ion be silicon oxide. Silicon oxide may be silica

But it does not have to be in accordance with the chemical equation and may contain impurities such as carbon (often referred to as silicon oxycarbide and deposited as mentioned in British Patent 2199847-B) or nitrogen (often referred to as silicon oxynitride). ).

It is advantageous if the alkali metal ion blocking substrate is so thin that it does not have a significant effect on the optical properties of the coating, particularly by reducing the transparency of the transparent coating substrate or causing color interference during reflection or transmission. The appropriate thickness range will depend on the properties of the material used to form the alkali metal ion blocking layer (particularly the refractive index), but the thickness of the alkali metal ion blocking layer is usually less than 60 nanometers, and preferably less than 40 nm. When present, the alkali metal ion-blocking layer must be thick enough to prevent the transfer of alkali metal ion from the glass to the titanium oxide coating. titanium oxide

One of the advantages of the present invention is that the thickness of the titanium oxide coating with photocatalytic activity is small (it participates in the little reflection of visible light on the coated substrate), but the coated substrate still has excellent photocatalytic activity. It is preferable that the thickness of the titanium oxide coating be 30 nanometers or less, and it is preferable that its thickness range between approximately 2 and 20 nanometers.

The present invention is also useful because the deposition of a thin layer of titanium oxide coatings requires less product material and the layers can be deposited in a relatively short time. probably

It also has the appearance of a thin coating of titanium oxide that interferes with colors during reflection or transmission. However, a special advantage is that the visible light reflection of titanium oxide coating is low, which is especially important when the coated substrate is coated glass. The visible light transmittance required from coated glass usually determines the thickness of the titanium oxide coating.

The coated surface of the substrate should preferably have a static contact angle with water of 0.52 or less. Freshly prepared or cleaned glass has a hydrophilic surface (the static contact angle for water is less than approximately 4.0, which indicates that the surface is hydrophilic), but the organic matter quickly adheres to the surface, increasing the contact angle. A specific advantage of coated surfaces, especially coated glass types according to the present invention, is that if the coated surface becomes dirty, exposure to ultraviolet radiation of the appropriate wavelength will reduce the contact angle by scaling or destroying those contaminants. A further advantage is that water will diffuse across the surface with the low contact angle. Reducing the irreversible effect of water droplets on the surface (eg from rain) washing away any dirt or other contaminants that were not destroyed by the photocatalytic activity of the surface. The static contact angle of water is the angle defined by the interface of a water droplet on the glass surface and can be determined by a well-known method by measuring the diameter of a water droplet of a given size on the glass surface and calculating it using an iterative procedure.

The coated substrate should preferably have a opacity of 1% or less. This is beneficial because it allows for clear visibility through the clear coated substrate.

In preferred embodiments, the coated surface of the substrate is so abrasion resistant that it remains photocatalytically active after three hundred strokes in the European standard abrasion test. It is preferable that the painted surface remains photocatalytic after being exposed to five hundred strokes in the European Standard Test for Friction, and it is even more preferable for the painted surface to remain photocatalytic after being exposed to a thousand strokes in the European Standard Test for Friction. This is advantageous because the self-cleaning coated underlayments according to the invention will often be used with a surface exposed to the weather (such as coated glass types having a coated surface of the glass as the exterior of a window) and where the coating is subject to friction.

The European Standard Test for Friction refers to the friction test mentioned in European Standard BS EN 1096 Part 2 of 1999 and includes the reciprocating movement of a cork pad at a specified speed and pressure on the surface of the sample.

In the current standard, a coated substrate is considered to still have photocatalytic activity if the static contact angle of water is reduced to less than 5 1 after exposure to European Standard for Friction and ultraviolet light (eg, 351 nm peak wavelength). To obtain this contact angle after rubbing the painted substrate requires less than 48 hours of exposure to approximately 32 watts/m2 of radiation. At the surface of the substratum. It is preferable that the haze of the coated substrate be 2% or less after being exposed to the European Standard for Friction.

Highly durable coated underlayments According to the present invention we may also be highly durable to periodic moisture (which is intended to have an effect similar to exposure to the elements).

Thus, in preferred embodiments of the invention, the coated surface of the substrate is so resistant to periodic exposure to moisture that it remains luminously effective after being subjected to two hundred cycles of periodic exposure to moisture testing. In the current standard, periodic exposure testing to moisture refers to:

A test in which the paint is periodically exposed to a temperature of 35°C to 75°C, then to 35 over a period of 4

Hours at a relative humidity of approximately 0.01%. The substrate is still photocatalytically effective if the static contact angle of water is reduced to less than 15 m after testing and exposure to ultraviolet light.

In another embodiment, the present invention provides a heavy-duty coated glass with photocatalytic activity comprising a substrate of glass having a coating on one of its surfaces, said coating comprising an alkali metal ion blocking substrate and a titanium oxide layer with photocatalytic activity, wherein the coated surface is The substrate is highly resistant to abrasion, so that it remains photoactive after being exposed to 300 strokes in the European standard abrasion test. In this model, it is preferable for the coated glass to have a reflection of visible light measured on the coated side of 35% or less, and it is preferable for the thickness of the titanium oxide layer with photocatalytic activity to be 30 nanometers or less. Thin coatings are extremely resistant to abrasion, which is surprising because it was previously thought that only relatively thick coatings would hold up well.

In yet another embodiment, the present invention provides a coated glass comprising a sublayer of glass with a coating of titanium oxide with photocatalytic activity on one of its surfaces, characterized by the fact that the coated surface of the glass has a photocatalytic activity greater than 4 x 1 -2 cm. -1 minute, preferably larger than 6 x 10-2 cm-1 minute-1, and that the coated glass has a reflectance of visible light measured on the coated side of less than 20%.

The coated substrates of the present invention have uses in many fields, for example for window glazing including a multiple glazing unit comprising a first glazing sheet of a coated substrate and a second corresponding glazing sheet with a spacer between them, or where the coated substrate is a coated glass such as a laminated glass comprising On a first glass film, a polymeric interlayer (eg of polyvinyl butyral) and a second glass film.

In addition to their uses in self-cleaning substrates (particularly self-cleaning glass used in windows), the coated substrates of the present invention may also be useful in reducing the concentration of atmospheric contaminants. For example, it may. Coated glass exposed to wavelengths in ultraviolet light (including the wavelengths found in sunlight) destroys atmospheric pollutants such as nitrogen oxides, ozone, and organic pollutants that adsorb on the coated surface of the glass. This use is particularly useful in open spaces of areas surrounded by tall buildings (such as city streets) where the concentration of organic pollutants is relatively high (especially in intense sunlight), and also where the available surface area of the glass is relatively large. Alternatively, coated glass can be used

(its inwardly painted surface) to reduce the concentration of air pollutants inside buildings, especially in administrative buildings that have a relatively high concentration of air pollutants. The invention is illustrated, but not limited to, by the following drawings.

Brief explanation of the drawings

Figure No. (1): It is a curve of coated glass with photocatalytic activity produced by a process according to the invention as a function of the thickness of the titanium oxide layer.

Figure No. (2): An illustration of direct deposition of coatings from chemical vapor according to the invention.

Detailed description

In Figure No. (1), coated glass types were produced using the CVD process directly, as mentioned in the examples below. The open circles (1) relate to the titanium oxide layers deposited using titanium tetrachloride as its producing material, and the crosses (2) relate to the oxide layers. Titanium oxide deposited using titanium tetraethoxide as its producing material.

Coatings can be applied directly to the glass substrate by chemical vapor deposition during the glass manufacturing process. Figure (2) shows a device commonly referred to as (10) which is useful in the direct production of coated glass types according to the present invention, and includes a float section (11), a LEHR annealing furnace (12), and a cooling section (13). . The buoyancy section (11) has a bottom (14) containing a bath of molten tin.

bath, a roof (6 1), unexposed side walls, and end walls (7 1), which provide an airtight space (18), in which a non-oxidizing atmosphere is maintained to prevent oxidation of the tin bath (15). While the device (10) is in operation, the molten glass (19) is poured into a mold on the brazier (20), flows from there down a standard wall (21), and then moves down onto the surface of the tin bath (15) forming a ribbon of float glass. glass ribbon (37), which is removed by lift-out rolls (22) and transported through the annealing furnace (12) and then through the cooling section (13).

The non-oxidizing atmosphere in the flotation section (11) is maintained by introducing a suitable gas such as a gas containing nitrogen and 2% by volume hydrogen into the area (18) through the conduits (23), which are effectively connected to the manifold (24). The deoxygenated gas is introduced into zone (18) from the ducts (23) at a rate sufficient to balance the gas losses (part of the deoxygenated atmosphere escapes from zone 8 1 by flowing down the end walls 7 1), so as to maintain a slightly positive pressure Above atmospheric pressure. The tin bath (15) and the enclosed zone (18) are heated by thermal radiation directed downwards from the heaters (25). The heating zone (18) is generally maintained at temperatures above 1330°F to 1400°F (721°C to 760°C). The atmosphere in the annealing furnace (12) usually contains air and does not include the cooling section. Atmospheric air is blown onto the glass by

Fans (26).

The apparatus (10) also includes coating means (27), (28), (29) and (30) placed respectively in the float area (11) above the float glass strip (37). The gaseous mixture is supplied

The product of the separate layers of paint is transferred to the corresponding coating media, which in turn directs the gaseous mixtures producing the layers to the surface of the float glass strip (37). The temperature of the float glass strip (37) is highest possible in the position of the coating medium (27) closest to the brazier (20) and is lowest possible in the position of the coating medium (30) closest to the annealing furnace (12). The invention is further illustrated by the following examples, in which coatings are applied by chemical vapor deposition by laminar flow in a flotation bath onto a moving strip of float glass during the glass production process. In the examples, two layers of paint are applied to the glass strip. All gas volumes were measured at pressure and temperature unless otherwise stated. The thickness of the aforementioned layers was determined by scanning electron microscopy using a high-resolution scanning electron microscope and making an optical model of the reflectance and transmittance spectrum of the coated glass. The thickness of the coatings was measured with a variation of approximately 5%. The transmittance and reflectance properties of the coated glass types were determined using a Hitachiu 0400 spectrophotometer. The values of a, b, and *L used herein for reflectance and/or transmittance colors of glass types refer to CIELab colors. The visible light reflectance and transmittance of coated glass types were determined using a D65 illuminator and a standard CIE25 viewing device according to ISO 06050(2 Parry Moon airmass). The haze of the glass types was measured using a WYK-Gardner Hazeguard haze meter.

The photocatalytic activity of the coated glass types was determined from the rate of decrease in the area of the infrared peaks corresponding to the CH stretches of the stearic acid film on the coated surface of the glass illuminated by UVA. A stearic acid film is formed on glass samples with an area of 7-8 cm2, by rotating 20 microliters of acid solution.

Stearic acid in methanol (8.8 x 10-3 mol/dm3) on a coated glass surface at a speed of 0 0 0 2 revolutions/min for 1 minute. The infrared spectrum was measured during permeation and the peak height corresponding to the CH stretch (at approximately 0 270-3000 cm-1) of the stearic acid membrane was measured, and the corresponding peak area was determined from a peak area versus height calibration curve. The coated side of the glass was illuminated by a 351-UVA lamp with a peak wavelength of 351 nm and an intensity at the surface of the coated glass of approximately 32 W/m2 (obtained from Q-panel Co., Claveland, Ohio, USA). The peak wavelength is 351 nm and the intensity at the coated glass surface is about 32 W/m2. The photocatalytic activity in this standard is expressed as the rate of decrease in area of IR peaks (in cm-1 min-1) or 90% (min-1) which is the UV exposure time specified to reduce the peak height (absorption) of a peak in the wavelength area to 10% of Its original value.

The static contact angle of water for coated glass types was determined by measuring the diameter of a water droplet (volume ranging from 1 to 5 μl) placed on the surface of the coated glass after being irradiated by a UVA351 lamp for approximately 2 hours (unless otherwise noted). Examples (1-15):

A 1 mm thick strip of floated soda lime glass progressing in an annealing furnace at 3.00 m/h was coated with two layers of paint as the strip moved through the flotation bath at a temperature of the glass between 650°C and 670°C. The flotation bath atmosphere involves the flow of a gaseous mixture of nitrogen and 9% hydrogen at a pressure of 0.15 mbar.

Layer 1 (the first layer to be deposited on the glass) was a layer of silicon oxide. Layer 1 was deposited by contacting a gaseous mixture of monosilane (SiH4, 60 mL/min), oxygen (120 mL/min), ethylene (360 mL/min), and nitrogen (8 L/min) and tunneling it parallel to the glass surface in The direction of its movement using a coating device such as that mentioned in English Patent Specification No. 1507966 (referred to specifically as Figure (2) and the corresponding description on page 3, line 73 through page 4, line 75) and the path of movement of the gaseous mixture across the glass surface is about 0.15 metres. The extraction was carried out at a pressure of approximately 0.9-1.2 mbar. A strip of glass with an edge width of 10 cm is coated at a point where the temperature is about 670°C. The thickness of the silica layer ranges between 20 and 25 microns.

Layer 2 (the second layer to be deposited) was titanium oxide. Layer 2 was deposited by mixing two separate gas streams comprising titanium tetrachloride in a flowing nitrogen carrier gas, ethyl acetate in a flowing nitrogen carrier gas, and mass tunneling of nitrogen at a rate of 8 L/min (the flow rate was measured At 9070 g/in2) in a gaseous mixture, it was then delivered through the lines while maintaining it at approximately 250 C to a coating device consisting of an oil-cooled dual-flow coating medium. The pressure of the carrier nitrogen gas and the mass flow nitrogen gas was about 9070 g/in2. The gaseous mixture comes into contact with the glass surface and passes parallel to it, before, after, and along the glass strip. The pre-trajectory path of the gaseous mixture was about 0.15 metres, and the post-trajectory path was about 0.15 metres, with the exit at a pressure of about 0.15 mbar. Titanium chloride has been withdrawn

and ethyl acetate in separate streams of flowing carrier nitrogen gas by passing through bubble-forming media containing titanium chloride or ethyl acetate. Then the flow rates of nitrogen carrier gases are mentioned in Table (1) (flow rates were measured at 9070 g/inch2). The titanium tetrachloride bubble-forming medium was kept at 69°C, and the ethyl acetate bubble-forming method was kept at 42°C. Estimated flow rates for drawn titanium tetrachloride and drawn ethyl acetate are also given in Table 1 for each of the examples (1-15). The properties of the two-layer coatings were measured. The values for the thickness of layer 2 (titanium oxide layer), the values/reflectance of visible light measured on the coated side, L*, and the transparency of the coated glass types are given in Table 2 for examples (1-5). The haze of each type of analyzer glass was less than 0.2%. The photocatalytic activity and static contact angle with water were determined for the coated glass types. The initial peak height and initial peak area of the IR peaks corresponding to the CH stretches of stearic acid, the photocatalytic activity, and the 90t% static contact angle of water for examples (1-15) are given in Table (3). Surprisingly, the effect of the thickness of the titanium oxide layer was

Slightly affected photocatalytic activity.

Examples (16-19):

The analysis (6 1-19) was performed under the same conditions as (1-15) except that the bath pressure was about 0.11 mbar, and the output for deposition of the silica undercoat (layer 1) was at 0.7 mbar. Bar, and the titanium tetrachloride bubble formation medium was kept. titanium

tetrachloride at a temperature of about 100°C, the ethyl acetate bubbling medium was kept at about 45°C, and the connecting lines were kept at about 220°C. The flow rates of the nitrogen carrier gas, the estimated flow rates of the calculated titanium tetrachloride, and the drawn ethyl acetate for each of the examples (16-19) are given in Table (1).

Estimated thickness values for layer 2 (titanium oxide layer), visible light reflectance values measured on the coated side, L*, and haze of the coated glass types are given in Table 2 for each of the examples (16-19).

The initial peak height and initial peak area of the IR peaks corresponding to the CH stretches of stearic acid, the photocatalytic activity, 90t%, and the static contact angle of water for each of the examples (16-9 1) are given in Table 3.

The photocatalytic activity of Examples (16-19) was not substantially greater than that of Examples (1-15) despite the larger (and therefore more reflective) titanium oxide coatings.

<img file="SA2064B1_D0001.tif" />

<img file="SA2064B1_D0002.tif" />

<img file="SA2064B1_D0003.tif" />

Examples (20-27):

The electrophoresis (0 2 - 27) was carried out under the same conditions as the experiments (1 - 15), except that layer 2 was deposited from a gaseous mixture containing titanium tetraethoxide drawn in a nitrogen carrier gas by passing the carrier gas through a bubble formation medium containing On titanium tetraethoxide it was kept at 0 7 1 h. The flow rates of the carrier gas nitrogen (measured at 0 2 lb/in2) and titanium tetraethoxide are listed in Table (4) for each of the examples (0 2-27). The mass flow rate of nitrogen was 8.5 L/min (measured at 20 psi). The properties of the two-layer coatings were measured. The values of the thickness of layer 2 (titanium oxide layer), the values of visible light reflection measured on the coated side, and the haze values of the coated glass types are mentioned in Table (5) for examples (0 2 - 27). The haze of each type of coated glass was less than 0.7%.

The photocatalytic activity and static water contact angle of the coated glass types were determined. The initial peak height, its initial area, the IR peaks corresponding to the CH stretches, the t90%, the photocatalytic activity, and the steric contact angle of water are mentioned as examples (20-27) in

Table No. (6). Examples (28 and 29):

Examples (28 and 29) were performed under the same conditions as Examples (0 2-27) except that the titanium tetraethoxide bubble formation medium was kept at 168°C and the pressure was

Bath 0.11 mbar. Data related to examples (28 and 29) equivalent to the example data were mentioned

(20-27) in Tables (4), (5) and (6).

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<img file="SA2064B1_D0005.tif" />

a is not measured

<img file="SA2064B1_D0006.tif" />

a is not measured

Examples (30-42):

In models (30-42), two-coat CVD coatings are applied directly to the entire 132-inch (3.35 m) strip of float glass in the float bath during the production process.

Flat glass The device used for paint deposition is illustrated in Figure (2). The atmosphere of the flotation bath contains nitrogen and 2% by volume hydrogen. The bathroom pressure was high

0.15 mbar.

The two-layer coating consists of a silicon oxide impression first deposited on the surface glass strip, and a titanium oxide layer is deposited on the silicon oxide layer. The material chemistry of the vanity mixtures used to deposit the paint was the same as that used in examples (1-15). The layer deposition temperature was varied by using

Different coating methods (27), (28), (29), and (30) (referring to Figure 2). The coating medium (27) was placed closest to the furnace with the highest temperature, and the coating medium (30) was placed closest to annealing as it is the coldest. Then, in Examples (30-33) and (42), two coating methods (28 and 29 in Examples 30 and 33 and 27 and 28 in Example 42) are used to deposit the silicon oxide coating. The advantage of using two coating media to deposit a silicon oxide layer is that longer cycle times can be used. The gaseous mixture used to deposit the silicon oxide layer in examples (0.3-41) consists of the following gases at the following flow rates: helium (250 l/min), nitrogen (285 l/min), and monosilane (2.5 l/min), ethylene (15 l/min), and oxygen (10 l/min). For example (42) done

Use the same gases and flow rates except for monosilane (2.3 l/min), ethylene (13.8 l/min) and oxygen (9.2 l/min). When two coating methods are used to deposit the silicon oxide layer in examples (30-42), then the aforementioned flow rates are used for each coating method.

In cases (30-42) the deposition temperatures (i.e. the temperature of the flat glass strip under the corresponding coating medium for each of the coating media (27-30)) were as shown in Table (7). The temperatures in Table (7) varied approximately ± The output of each method was 0 5 m (± 28 m).

Coating at approximately 2 mbar.

<img file="SA2064B1_D0007.tif" />

Titanium tetrachloride (TiCl4) and ethyl acetate were drawn into separate carrier streams of nitrogen/helium gases. A thin film evaporator was used to evaporate TiCI4. Liquid TiCI4 was kept in a high-pressure container (about 5 psi). This was used to deliver fluid to a standard pump and a Coriolis force flow measurement system. The standard flow is then fed from the produced material to...

Thin film evaporator at 10°F (43°C). The TiCI4 is then drawn into the carrier gas (helium) and delivered to the mixing point down the lines at 250 F (120 C). Ethyl acetate was delivered in a similar manner. The ethyl acetate was kept in a high-pressure container (about 5 psi). This1 was used to deliver fluid to a standard pump and Coriolis force flow measurement system. The standard flow of the produced material is then fed to the thin film evaporator at a temperature of 268 F (131 C). The evaporated ethyl acetate was then drawn into a carrier gas (helium/nitrogen mixture) and delivered to the mixing point down the lines at 250°F.

(121 AD).

The gaseous streams of TiCI4 and ethyl acetate were combined to form a gaseous mixture used to deposit the titanium oxide layer. This mixing point was just before the coating medium.

The linear speed of the float glass strip, the deposition temperature of silicon oxide, the deposition temperature of titanium oxide layers, the flow rates of mass flow carrier gas N2/He, and the flow rates of TiCI4 and ethyl acetate were mentioned for examples (30-42). ) in Table No. (8).

The coated flat glass strip was cooled and sectioned, and the optical properties and photocatalytic activity of the samples were determined. Table No. (9) contains the haze, optical properties during transmission and reflectance (percentage of reflection/transmission of visible light and color coordinates using the IAP system) of the samples. Coated glass types are subjected to friction testing according to BSEN 1096, in which a sample measuring 0.30 mm x 0.30 mm is rigidly fixed at its four corners to the test table to ensure that the sample cannot move. A new cut cork pad is then installed

With the dimensions mentioned in BSEN 1096 Part 2 of 1999 in the test finger and lowered onto the glass surface. The load pressure on the test finger is then set at 4 Newtons and the test begins. The finger is allowed to move reciprocatingly across the sample for 500 rapid runs. 60±6 strokes/min. After the end of this friction, the sample is taken out and examined optically for photocatalytic activity. The sample is considered to have passed the test if the results of friction are a change in transmittance that does not exceed ±5% when measured at 550 nm and the coated substrate remains photocatalytic, which means that after the test and exposing it to ultraviolet light for two hours, the static contact angle of water is reduced to less. From 5 1.

Types of glass were also exposed to periodic exposure to humidity, in which the coating was exposed to a temperature cycle of 35°C to 75°C to 35°C for 4 hours at approximately 100% relative humidity. The static contact angle of water for coated glass types after being produced and exposed to UV radiation for 130 minutes with a 351 UVA lamp at approximately 32 W/m2 and after 300 and/or 0 0 5 and/or 0 0 0 1 stroke is reported in the European Standard Friction Test In Table (01). The contact angle of the rubbed samples was determined after being exposed to radiation for two hours. Samples deposited at high temperatures of 1330-1250°F (1 72-677°C) were photocatalytically effective even after 1000 runs in the European Standard Tribulation Test or after 200 cycles of cyclic exposure to moisture. The photocatalytic activity is stated in terms of t90% for coated glass types after production, after 300, 500 and/or 1000 cycles of the European standard friction test and after 200 cycles of periodic exposure to moisture test in Table No. (11).In Table No. (11). The term effective indicates that the coated glass types had photocatalytic activity but their t90% was not determined.

<img file="SA2064B1_D0008.tif" />

<img file="SA2064B1_D0009.tif" />

a Not measured

<img file="SA2064B1_D0010.tif" />

&amp; Not measured

<img file="SA2064B1_D0011.tif" />

a Not measured