Photocatalytically-activated self-cleaning oven

Description: TECHNICAL FIELD [Detailed description of the invention]

Photocatalyst activation self-cleaning equipment Cross-reference of related applications This application is the provisional US patent application serial number (Ser) filed on March 14, 1997. ial No.) Claims the rights of 60 / 040,565. March 1, 1997 Provisional US patent application serial number 60 / 040,566 filed on 4th and photocatalyst Charles B. Greenberg (Che) on activated self-cleaning articles and their manufacturing methods Formal US patent applications filed on the same day, such as rles B. Greenberg), are published in the book. It is relevant to the application and is incorporated herein by reference. Background of the invention Field of invention The present invention generally relates to self-cleaning equipment, especially photocatalyst-activated self-cleaning equipment and the like. Regarding the manufacturing method and usage of such equipment. Description of related technology To name a few, conventional gas or electric ovens, microwave heating furnaces (electronic ovens) , Toaster oven, refrigerator, freezer, dishwasher, washing machine, clothes drying Various major household appliances such as machines are stored on various inner and outer surfaces of such appliances. Often requires cleaning to remove accumulated organic pollutants. Generally this This is done by hand with various cleansers and detergents, often rubbed and wiped It is achieved by doing. To avoid such manual cleaning, some self-clea Equipment (of ning, self-cleaning), especially ovens, is now available. Self-cleaning type -Bun heats the cooking room of the oven to a very high temperature for a long time, and the oven charge By burning and removing organic food residues on the surface of the oven cooking room Only the inside is clean. Such self-cleaning equipment has some drawbacks. One drawback is the equipment at self-cleaning temperature Is the substantial energy cost required to raise and maintain. For example, non Self-cleaning ovens operate at maximum temperatures of approximately 260 ° C (500 ° F), whereas self-cleaning ovens operate at maximum temperatures of approximately 260 ° C (500 ° F). Self-cleaning oven during self-cleaning operates at temperatures above 649 ° C (1200 ° F) To do. Another drawback is that such equipment is equipped to withstand high cleaning temperatures. Increasing costs associated with equipping and such high temperatures over time on the equipment itself Includes harmful effects. Another drawback is that high temperature self-cleaning is usually limited to the inside of the cooking room. It is being done. A method for removing organic contaminants from the surface that does not require high temperatures is available. .. In particular, titanium dioxide is photocatalytically-ac on the substrate. tivated self-cleaning, photocatalytically activated self-cleaning) (hereinafter " A surface (called "PASC") can be given. Titanium dioxide P on a glass substrate Publications on forming ASC coatings include US Pat. No. 5,595,813. "Photooxidable self-cleaning transparent titanium dioxide film on glass" (Photoo) xidative Self-cleaning Transparent Titanium Dioxide Films on Glass), J. Includes Mater, Res., Vol.10, No.11, pp.2842-48, Nov. (1995). Further In general, the library catalog of patents and treatises on photocatalytic oxidation of organic compounds is described in B. "Photocatalytic removal of harmful compounds from water and air" by Bleke et al. Bibliography of Work On The Photocatalytic Removal of H azardous Compounds from Water and Air), and October 1995 latest version and 1 Reported in the latest version in October 996. U.S. Pat. No. 5,308,458 of Urwen et al. Ultraviolet rays of fluid organic material existing on the surface of a disk coated with a titanium dioxide film A method for decomposing photocatalytically degradable organic substances, including exposure to lines, is described. So The disk rotates and moves organic substances outward in the radial direction across the surface of the disk. U.S. Pat. Nos. 5,256,616, 5,194,161 of Heller et al. No. 4 and No. 4,997,576 are all of the photocatalytic oxidation of organic compounds on water. Describe the materials and methods for this. Heller floated on the water, for example spilled oil Disclosed are floating beads coated with titanium dioxide for oxidizing organic compounds. A hand-cleaning machine that is recognized for its PASC coating technology To manufacture PASC equipment that eliminates the shortcomings of vessels or currently available self-cleaning equipment There is no disclosure about the use of such materials. Outline of the invention The present invention relates to a self-cleaning device and a method of manufacturing and using the device. The vessel is photocatalytic to self-clean organic contaminants that have accumulated on the surface of one or more devices. Activated by. Self-cleaning equipment has a PASC coating on the surface to be self-cleaning Have. In one embodiment, the device photocatalytically activates the PASC coating. It has a chemical radiation source that self-cleans the surface. Chemical radiation sources are incorporated into the structure of the equipment It may be sown or separate. A brief description of the drawing FIG. 1 is a perspective view of the PASC product of the present invention, particularly the PASC oven. FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1 and adhered to the door of the device of FIG. It is a vertical sectional view of PASC coating. FIG. 3 illustrates the sodium ion diffusion barrier layer under PASC coating, FIG. It is the same view as the top view. Description of preferred embodiments Note that similar members have the same reference numbers in the drawings description. I want to be taken care of. With respect to FIG. 1, the PASC oven 10 is shown. Oh Bun 10 has been selected to illustrate the invention, the following description will be brief. Therefore, although it is related to the oven 10, the present invention is limited to the oven. You will find that it includes all major household appliances. In addition The following explanation is mainly about forming the PASC coating in the cooking room 14 of the oven 10. Related, but to make the outer surface of oven 10 photocatalytic self-cleaning, oven Allow that any or all of the 10 outer surfaces may be coated with PASC. Will be able to. Oven 10 has a cooking room 14, which has five integrally connected walls and A box-shaped container that can be opened and closed with a door. In particular, the cooking room 14 has the opposite side walls 16 And the inner surface of 18 (shown in the image); floor 20; above floor 20 facing Wall 22; rear wall 24; and hinged door 26 facing the rear wall 24 And it is determined by the door 26; when in the closed position. The walls and floor of the cooking room 14 Doors are generally made of metal coated with a layer of paint or enamel. heat A layer 27 of insulating material is placed on one or more of the inner surfaces of the walls, floors and doors of the cooking room 14. The cooking room 14 is thermally insulated. Layer 27 of the heat insulating material itself is it If present, paint or ena to form a self-supporting oven 10. It is surrounded by a box-shaped container (not shown) made of mel-coated metal. Is typical. The oven 10 is formed when the door 26 is in the open position, as shown in FIG. It has a full-face plate 28 that surrounds the opening to the cooking room 14. Full plate 28 Gives a sealing surface for the seal 30, which seal 30 takes around the inner surface of the door 26 It is attached and extends around it, and when the door 26 is in the closed position, the inner surface of the door 26 A seal is formed between the surface plate 28 and the front surface plate 28. The door 26 is a metal outer sheet 29 that surrounds the insulating material 27, which is generally shown by the imaginary line. The sheet 29 may be a paint or enamel-coated metal sheet. Door 2 6 is mounted by hinge 32 and is generally held in frame 36 Now you can see inside the cooking room 14 when you have the Ming 34 and the door 26 is in the closed position. It is done. The oven 10 has some additional parts including a heating mechanism, a temperature control mechanism, etc. However, they are unnecessary to understand the invention and are therefore shown in the drawings. It will be admitted that it is not. According to the present invention, the oven 10 is an inner surface and / or outside of the oven 10. It has a PASC coating attached on one or more of the side surfaces. For example, cooking room 14 One or more of the inner surfaces of, eg, side walls 16 and 18, floor 20, top wall 22, after The wall 24, the door 26, and the transparent body 34 may have a PASC coating. Full board 2 8 may also have a PASC coating adhered on it. I'll explain it in more detail below. As such, the left side of FIG. 2 illustrates PASC coatings on various inner surfaces of door 26. In contrast, the right side of FIG. 2 shows the PAS on both the inner and outer surfaces of the door 26. The C coating is illustrated. But besides those surfaces of door 26, other than oven 10 If the inner or outer surface of the door contains a PASC coating, this is related to the door 26. It is acknowledged that the PASC coating may be included in the same manner as described here. Will be. In particular, a cross section through the door 26 along line 2-2 of FIG. 1 is shown in FIG. An example is a door 26 having a transparent body 34 maintained entirely in the center of 6. The door 26 has an outer sheet 29 that faces the inner surface 38 of the door 26 as a whole. Has, it is inserted between them, as shown by the phantom in Figure 2. It has a contained insulating material 27. Inner surface 38 is outer coated with enamel layer 40 with You may be. PASC on the inner surface of door 26, on the left side of Figure 2, as follows: The coating is shown. PASC42 is also attached on top of the enamel layer 40 Shown as, PASC coating 43 is attached on the frame 36, transparent body 3 It is shown that PASC coating 44 is attached on the inner surface of 4. Alternatively, P on the inner surface of the door 26, as shown on the right side of FIG. In addition to the ASC coatings 42, 43 and 44, the outer surface of the door 26 is PAS as follows: Has a C coating. The outer sheet 29 of the oven 10 is also covered with PASC coating 46. It may have been. Similarly, the outer surface of the transparent body 34 is covered with PASC coating 48. The outer surface of the frame 36 may also be coated with the PASC coating 50. Right side of Figure 2 The embodiment shown in is a PASC coating on both the inner and outer surfaces of the oven 10. Given, but in another aspect, for example, if self-cleaning is desired or required. , PASC coating may be included only on the inner or outer surface of oven 10. It will be acknowledged. Many substrates, especially glass substrates, contain sodium ions, which are such tables. It may move from the surface into the coating attached on such a substrate, especially its Elevated temperature of such substrate [eg, at least about 400 ° C (752 ° F)] Move if maintained at. When sodium ions move into the PASC coating, The photocatalytic self-cleaning activity of such a coating is reduced, if not eliminated. This process Is generally referred to as "sodium poisoning" or "sodium ion poisoning" of PASC coating. being called. Sodium ion poisoning is thick enough to prevent it from moving through the coating. Make an ASC coating or Natori between the substrate and the PASC coating that adheres to it Prevented by interposing a umion diffusion barrier layer (hereinafter referred to as "SIDB" layer) Can be Provisional U.S. Patent Application Serial Number filed March 14, 1997 No. 60 / 040,566 and Charles B. Greenberg et al. "Photocatalytic activation" Photocatalytically-Activated Self-Cleaning Artic Le And Method Of Making Same), a formal US patent application filed on the same day (Hereinafter referred to as "Application for Greenberg, etc."), PA by these methods A detailed description of reducing or eliminating sodium ion poisoning of SC coatings include. FIG. 3 shows PASC coatings on various inner and outer surfaces of the door 52. Door 52 The only difference is that it contains a SIDB layer between each of the PASC coatings and the surface of the door 52. The PASC coating is attached to the surface of the door as follows. With respect to the embodiment shown on the left side of FIG. 3, there is an enamel layer 40 and a PASC coating 42. Intervened between SIDB layer 54, frame 36 and PASC coating 43. Between the inner surface of the SIDB layer 55 and the transparent body 34 and the PASC coating 44 Has SIDB layer and PASC coating on the inner surface, including the present SIDB layer 56 Door 52 to do is shown. In another aspect of the invention, as shown on the right side of FIG. 3, on the inner surface of the door 52, above. In addition to the PASC coating and SIDB layer mentioned in, the door 52 has the PASC coating 46 and the outside. SIDB layer 58 interposed between the side sheet 29, and frame 36 and PASC coating 5 The outer surface of the SIDB layer 60 and / or the transparent body 34 interposed between 0 and P It has a SIDB layer 62 interposed between it and the ASC coating 48. Figures 2 and 3 and related descriptions relate to doors 26 and 52, but door 26 and As shown above 52, the same sequence of sodium ion diffusion barrier layer and PASC coating In this case, such layers and coatings may be applied to the side wall 16 of the cooking room 14. And 18, floor 20, top wall 22, rear wall 24, or outside of oven 10. Applicable even on the surface will be recognized by those skilled in the art. PASC coatings suitable for the present invention generally include photocatalytically activated self-cleaning oxides, especially Titanium oxide, iron oxide, silver oxide, copper oxide, tungsten oxide, aluminum oxide, Silicon oxide, zinc nitrate, molybdenum oxide, zinc oxide, strontium titanate, and And their mixtures may be selected, but not limited to them. Metal oxide is gold It will be appreciated by those skilled in the art that it also includes oxides or suboxides of the genus. The preferred PASC coating is titanium dioxide. Titanium dioxide is amorphous and 3 It is present in crystalline form, anatase, rutile and brookite, respectively. Oxidation Titanium, especially anatase phase titanium dioxide, is preferred. Because it is the strongest This is because it shows PASC activity. That is, it is suitable for photocatalytic activation self-cleaning Shows forbidden bandwidth (ie about 360 nm) and has excellent chemical and physical durability Because. In addition, it is transparent in the visible region of the spectrum, as a transparent material. It makes it useful to use. The rutile type also shows PASC activity. Anatase And (or) the combination of the rutile phase with the brookite and / or the amorphous phase is also possible. As long as the combination of the above shows PASC activity, it is acceptable in the present invention. Photocatalytic activity Sexualization self-cleaning activity is generated and examined for measurement and surface self-cleaning is imparted. A review of what constitutes a sufficient level of PASC is described below. The SIDB layer conforming to the present invention includes cobalt oxide, chromium oxide, iron oxide, and acid. Tin oxide, silicon oxide, titanium oxide, zirconium oxide, fluorine-doped tin oxide, azium oxide Metallic acids such as luminium, magnesium oxide, zinc oxide, and mixtures thereof Amorphous or crystalline metal oxides including compounds are included. For the mixture, magnesi Includes, but is limited to, um / aluminum oxide and zinc / tin oxide It's not something. Metal oxides may contain metal oxides or suboxides , Will be recognized by those skilled in the art. Apart from consideration of sodium ion poisoning, PASC coating is acceptable It must be thick enough to give the possible level of PASC activity. PA There is no absolute value that makes the SC coating "acceptable" or "unacceptable". Because Whether or not the PASC coating has an acceptable level of PASC activity depends on the PASC subject. According to the purpose and conditions of using the covering article and the performance criteria selected in relation to that purpose. Because it is decided. Generally, the thicker the PASC coating, the greater the PASC activity. Give a degree. In addition, other considerations increase the transparency of the article for aesthetic or optical reasons. The emphasis may be on giving a much thinner coating. For example, table PA if surface contaminants are expected to collect on the surface of the article and are more easily removed The SC coating can be made even thinner. Purple expected to irradiate PASC coating The duration and intensity of the outside line, eg, when the article is exposed to more UC light If expected, the PASC coating can be made thinner and still sufficient PA SC activity can be given. Other factors such as the nature of the substrate, eg, the substrate is P Whether or not the ASC coating is poisoned with sodium ions also depends on the thickness of the PASC coating. It influences the consideration. PASC coatings are preferred for a wide variety of applications Or at least about 200 Å, preferably at least about 400 Å, more preferably Is at least about 500 Å thick. If the substrate is a piece of float glass At least formed directly on the float glass piece without using the SIDB layer The PASC coating, which is an anatase titanium dioxide PASC coating with a thickness of approximately 500 Å, , About 2 ~ 5 × 10^-3cm^-1Minutes^-1Gives a PASC reaction rate in the range of. The range mentioned above PASC kinetics are acceptable for a wide range of applications. SIDB layer thickness required to prevent poisoning by sodium ions in the PASC coating The chemistry of the SIDB layer, the temperature at which the substrate maintains the properties of the substrate, and Natori The rate of movement of um ions from the substrate, the thickness of the PASC coating, and the given application, By several factors, including the photocatalytic activity required for most applications typically Although it varies, to prevent sodium ion poisoning of the PASC coating layer, SIDB Layer thickness ranges in the range of about 100 Å, preferably at least about 250 Å, more preferred Or should be at least about 500 Å. The PASC coating and / or SIDB layer conforming to the present invention can be obtained by the sol-gel method. , Or by spray pyrolysis, or chemical vapor deposition (hereinafter referred to as "CVD"), or Orb by Gnetron Sputtering Vacuum Deposition Method (hereinafter referred to as "MSVD") It can be formed on various surfaces of PASC coating and / or SI The DB layer is used after manufacturing the parts and before assembling them in the oven 10 or assembling them. After standing, it can be formed on the surface of the parts of the oven 10. Alternatively, The PASC coating and / or SIDB layer is formed on a flat raw material, which is then It may be formed into 10 parts. However, the flat raw material is used in the oven 10. How to form parts, or how to assemble those parts together to form oven 10 The law is the PASC coating and / or SID formed on the various surfaces of those parts. The B layer shall not be damaged to the extent that it can be recognized. Generally, a colloidal suspension (sol) is formed using the sol-gel method, and the surface is surfaced at about room temperature. Adapt to the top and then apply heat to convert to a gel. Especially the PASC coating is titanium dioxide Titanium metal-containing precursor when formed by the sol-gel process with PASC coating The quality is applied on the surface to be coated. Titanium metal-containing precursors are crystallized It is in the form of a sol solution containing no alcohol solvent. The sol solution is in an alcohol solvent Titanium may be contained as a titanium alkoxide in the above, and it is made self-cleaning. Apply by spraying, rotating or dipping coating on the surface of oven 10. Then sol Solution, generally at a rate of about 50 ° C / min, about 100-400 ° C (212 ° F-752) ° F), preferably to a temperature of at least about 500 ° C (932 ° F), then Generally maintained at that temperature for about 1 hour, the sol solution is calcined and crystalline titanium dioxide PAS Make a C coating (gel). If the PASC coating is formed by spray pyrolysis, it is placed in an aqueous medium. It is formed as a suspension of a relatively water-insoluble organometallic coating reaction. For spray pyrolysis For more applicable aqueous media, use a chemical wetting agent to suspend in the aqueous medium. Contains a turbid metallic acetylacetone compound. The metal-containing film is thermally decomposed and adhered. Aqueous suspensions for use are described in US Pat. No. 4,719,127, especially in column 2. Lines 16-4, Line 48 (this is incorporated herein by reference). It is described in. Metallic acetylacetone is jet mill and / or wet Milling into particles smaller than about 10 microns by methods known in the art such as wet milling can do. Metallic Acetylacetone [For example, Titanium Dioxide PASC Titanyl acetylacetoneate for coating (TiO (C)₅H₇O₂)₂)], Then Add to an aqueous medium containing a wetting agent with stirring, thereby forming an aqueous suspension. .. The relative concentration of metal acetylacetone in an aqueous suspension is generally the aqueous suspension. It is in the range of about 5 to 40% by weight. The aqueous medium of the aqueous suspension is distilled water or deionized. It is preferably water. Any surface with relatively low effervescence for a suitable wetting agent It is also included in the activator. Wetting agents are anionic, non-ionic and cationic compositions. However, nonionicity is preferable. Wetting agent is added at about 0.24% by weight It is typically added, but can be about 0.01% to 1% or more. Aqueous suspension thermally decomposes metal acetylacetone and crystallized metal oxide PAS The temperature at which the C coating is formed, for example at least about 400 ° C (752 ° F), is more favorable. The substrate is maintained at least about 500 ° C (932 ° F). It is sent to the surface by a pyrolysis sprayer. Composition and concentration of aqueous suspension to be pyrolyzed and sprayed , The linear velocity of the substrate passing under the spray pyrolysis device, or conversely the spray pyrolysis device on the stationary surface. Passage speed, number of pyrolysis spray guns, area to be covered, spray pressure or volume, spray imitation The temperature of the surface of the substrate at the time of adhesion of the pyrolysis spray aqueous suspension is all determined by this method. The final thickness of the metal oxide PASC coating formed on the various surfaces of Bun 10 It will be recognized that it affects the morphology. Formed by spray pyrolysis PASC coatings are provisional US patent application serial number 60 / 040,566 and gree It is described in the application of Nberg et al. The PASC coating of titanium dioxide is a carrier gas delivered onto the surface of oven 10. It is applied by the CVD method as a titanium metal-containing precursor contained in it, but during that time, Pyrolysis of titanium metal-containing precursors and crystalline titanium dioxide PASC coating on the surface Maintain the surface at a temperature that promotes the formation of. The surface temperature that promotes decomposition is low Is also preferably about 400 ° C (752 ° F), more preferably at least about It is 500 ° C (932 ° F). Metal-containing precursors that comply with the CVD method include Tantetraisoprocoxide [Ti (OC)₃H₇)₄] (Hereinafter referred to as "TTIP"), Titanium Tetraethoxydo [Ti (OC)₂H₅)₄] (Hereinafter referred to as "TTEU"), tetrachloride Titanium (TiCl)₄), Or a mixture thereof. Preferred carrier gas Is nitrogen (N₂) Carrier gas. Concentration of metal-containing precursors in carrier gas , The flow rate of the carrier gas, the linear velocity of the substrate passing under the CVD coating machine, or vice versa. The rate of passage of the CVD coater over the body, the surface area covered, of the selected precursors All properties and required or desired PASC activity can be determined by this method in the oven 1 Final coating thickness and final coating of metal oxide PASC coatings formed on various surfaces of 0 It is a factor that affects morphology. The PASC coating formed by the CVD method is provisional For applications such as qualitative US patent application serial number 60 / 040,566 and Greenberg Are listed. The PASC coating is a titanium dioxide PASC coating formed by the MSVD method. If the target is made of titanium metal, about 5-50%, preferably about 20%. Argon / O with oxygen₂Sputter in atmosphere at a pressure of about 5-10 millitorls -Shape the desired thickness, generally at least about 500 Å of titanium dioxide coating To be done. To form a crystalline titanium dioxide PASC coating during the sputtering process The surface of the substrate can be heated, but in general, the substrate is taken from the MSVD coating machine. It is preferable to heat the substrate after squeezing out. Cool the substrate at about 450 ° C ~ 600 Titanium dioxide anatase formation at temperatures in the range ° C (842 ° F to 1112 ° F) Heat for a time sufficient to promote the formation of crystals to give a PASC coating. In general, Times of at least about 1 hour at those temperatures are preferred. Alternatively, crystalline dioxide Titanium PASC coating is a high energy plastic coating directly on the substrate surface in the MSVD device. By using Zuma, it can be grown without post-heat treatment. .. SIDB layers conforming to the present invention are similarly sol on various surfaces of oven 10. It can be formed by a gel method, a spray pyrolysis method, a CVD method or an MSVD method. Dib difluoride if the SIDB layer contains tin oxide and is formed by the spray pyrolysis method Chill tin, (C₄H₉)₂SnF₂And an aqueous suspension of water applied onto the substrate by spray pyrolysis To do. Aqueous suspension is 100-400 g of dibutyl tin difluoride per liter of water Is typically contained, but this ratio is thicker or thinner as needed or desired. It can be modified to give a different SIDB layer. Wetting agent as a suspension accelerator May be used. During the production of the aqueous suspension, dibutyl tin difluoride particles were ground and 1 ~ It can have an average particle size of 10 microns. Aqueous suspensions should be vigorously agitated It is preferable to give a uniform particle distribution in the suspension. Aqueous suspension is about 600-7 Heat content sprayed onto the surface of the substrate at temperatures in the range of 00 ° C (1112 ° F to 1292 ° F) Feed by solution, thereby pyrolyzing the aqueous suspension to form a tin oxide SIDB layer To do. The SIDB layer formed by the spray pyrolysis method is a provisional US patent application serial number. Applications such as No. 60 / 040,566 and Greenberg (to mention them) More incorporated herein). If the SIDB layer contains tin oxide and is formed by the CVD method, it is also in the air. Monobutyl trichloride in an air carrier gas mixed with water vapor carried The layer is deposited with a metal-containing precursor of tin (hereinafter referred to as "MBTTCL"). .. The concentration of MBTTCL and water vapor in the carrier gas is particularly the desired SIDB layer. Thickness, application rate of CVD equipment, size of coated surface, gas flow rate, substrate It depends on several factors, including the tendency to cause thorium ion transfer. MSVD A detailed description of the SIDB layer formed by law is provided in the provisional US patent application. It can be found in applications such as No. 60 / 040,566 and Greenberg. When the SIDB layer is formed by the MSVD method, the tin oxide or silicon oxide SIDB layer A tin-containing or silicon-containing cathode target, each with an atmosphere of about 5-80% oxygen. It is formed by sputtering in the air at a pressure of about 5 to 10 millitorls. If tin oxide or silicon oxide SIDB layer is formed at the same time as or after sputtering If you want to crystallize, heat the surface of the substrate on which the SIDB layer is sputtered. You may. At least about 400 ° C (752 ° F), preferably at least about 50 At a temperature of 0 ° C (932 ° F), it is preferably at least about 1 hour. "Alkali metal US Patent Application Serial No. 08/5, filed February 1, 1996, entitled "Diffusion Barrier Layer" 97,543 (which is incorporated herein by reference) is a magnetron spa. It is described that an alkali metal diffusion barrier is formed by tattering. There It has been taught that barrier layers are generally effective with a thickness of about 20 Å to about 180 Å. Therefore, the effectiveness increases as the density of the barrier increases. SIDB by MSVD method Layer formation is also provisional US patent application serial number 60 / 040,566 and Greenva It is described in applications such as-G, etc., which are incorporated herein by reference. The PASC coating described above is an oven with or without SIDB layer If present on the surface of 10, they are at the right wavelength and the right intensity of radiation. It becomes self-cleaning when exposed for a sufficient time. A place where PASC activity is generated by ultraviolet rays In that case, the UV source may be natural (ie, the sun) or artificial. Artificial Is preferable because the irradiation intensity and time can be controlled more easily. Photocatalytic self-cleaning activity when PASC coating is titanium dioxide PASC coating Radiation activated by UV rays has a wavelength in the range of about 300 to 400 nm. It is a line. Artificial UV sources include a black light source. Another light source With the "UVA-340" model code from Q-Panel, Cleveland, Ohio You can get it. The intensity of ultraviolet rays that hit the PASC coating is the desired self-cleaning activity. Select so that the degree can be obtained. Corrected by PASC coated surface, 5 ~ 100W / m²Strength within the range, preferably at least about 10 W / m², More preferably less Tomo about 20W / m²Strength is desirable. The strength is, for example, San Gabriel's U Registered by Ultraviolet Products, Inc. It seems to be sold under the model code J-221 as the brand name BLACK-RAY. It can be corrected with a simple UV meter. As shown in FIG. 1, the ultraviolet source 70 is located inside the oven 10 and in the cooking room 14. -Can be included as an integral part of Bun 10. In this aspect, in one piece The ultraviolet source 70 is a place where the door 26 or 52 is opened and closed by a mechanical or electric timer. If so, a manual on / off switch that drives the integrated UV source 70, trip switch Created in any visible way, including (but not limited to) the itch mechanism Can be moved / stopped. Oven 10 is a single internal integrated UV source 7 Has 0 or it has multiple internal integrals such as UV sources 70, 72, 74, 76 etc. It has a source and ensures uniform UV irradiation on all surfaces of the cooking room 14 of the oven 10. You can really give it. In particular, the cooking room 14 of the oven 10 is PA Has several surfaces that affect the angle of incidence of UV light on the SC coating (s) If you do, cook to ensure that all surfaces are exposed to sufficient UV radiation. Two or more integrated UV sources spaced apart around the chamber 14 are preferred. Natural if the outer surface of oven 10 has a PASC coating attached on it Uses UV light (ie, solar radiation) and / or one or more external artificial UV sources 78 The PASC coating can be photocatalytically activated. The external artificial UV source is It may be an integral part of the oven 10, or it may be the inner and outer surfaces of the oven 10. It may be a non-integral source that can move freely around. Such external ultraviolet The source may or may not be integrated, trip switch, electrical or Can be operated manually or automatically using a mechanical timer or the like. The time and intensity at which the UV source must be activated is, to name a few, Type of surface to which PASC coating is applied, thickness of PASC coating, storage on PASC coating Thickness, rate of formation, and composition of accumulated organic contaminants, exposure of UV light to the PASC coating Corners, intensity of UV source on PASC coated surface, nature of function of the device itself, desirable Or the required PASC reaction rate, the substrate and / or other coatings present on it or Including (but not limited to) the extent to which UV light is reflected or absorbed by the layer It depends on many factors. Therefore, the UV source must be activated for self-cleaning. It is not generally possible to specify a set of times and intensities that must be. But, Reliably ash most of the organic contaminants accumulated on the PASC coating for many applications At least about 20 W / m on the surface of the PASC coating²Intensity per day It is preferable to operate the UV source for at least about 1-15 hours. PA of PASC coating (s) formed on various surfaces of oven 10. It is useful to be able to measure and compare SC efficacy or activity. PA PASC coverage of known and readily available organic contaminants to assess SC activity Apply over the cover, then photocatalytically activate the PASC coating, thereby organic Observe and measure the ability of the PASC coating to remove contaminants. Stearic acid, CH₃( CH₂)₁₆COOH is an organic "stain" for testing the PASC activity of PASC coatings. It is a model of "dyeing". Because stearic acid is a carbo with a long hydrocarbon chain Acids and therefore those present in common contaminants such as household oils and garbage Is a good "molecular model" for. Immersion, spray, rotary coating on PASC coating Stearic acid on the PASC coating as a thin test film by a convenient method including To apply. Generally, stearic acid test membranes in the thickness range of 10 nm to about 20 nm , Give a suitable test membrane. The stearic acid test membrane is a stearic acid / methanol solution. It may be applied as a liquid. 6 × 10^-3m / l stearic acid / methanol solution It turns out to be satisfactory. The PASC activity of the PASC coating formed on the surface of oven 10 is as described above. The PASC coating is outer-coated with a stearic acid test membrane, and the stearic acid coating / The PASC coating is irradiated with UV light from a UV source at the desired intensity for the desired time, and Stearic acid test membrane, which is generally light brown when applied over PASC coatings (Visible as a coating) disappears completely or is applied on a PASC coating, A stearic acid test compared to a portion of the stearic acid test membrane that has not been exposed to UV light. Visually examine the stearic acid / PASC coating for reduced darkness of the test membrane Therefore, it can be estimated qualitatively. The PASC activity of the PASC coating formed on the surface of oven 10 is also PASC. Carbon / hydrogen (hereinafter referred to as "CH") expansion and contraction vibration of stearic acid existing on the coating It can be measured quantitatively by measuring the integrated intensity of the absorption band. Integral strength The degree is commensurate with the amount of stearic acid test film remaining on the surface of the PASC coating. Removal of stearic acid test membrane by medium activation self-cleaning reduces CH expansion and contraction vibration band strength Is expected to bring. The CH bond present in stearic acid is infrared (this) Unlike UV light, it does not activate the PASC coating by photocatalysis. ) Is absorbed. This absorption is generally 2800-300 cm^-1Wake up with wave number, houri D. Measure using a device such as a conversion infrared spectrophotometer (hereinafter referred to as "FTIR"). Can be The FTIR spectrophotometer is a deuterated triglycine sulfate detector (hereafter Below "DTGS") or Mercury cadmium tellurate detector (hereinafter "MCT") It may be equipped with a detector such as (call). The MCT detector is a DTGS detector It is preferable because it gives a much larger signal-to-noise ratio. This means that the substrate and (Or) Other coatings outside the PASC coating give rise to an absorption spectrum. This is important when it works to absorb infrared rays used by spectrophotometers. To. If infrared rays are absorbed by the substrate and / or other coatings present, The intensity of the infrared beam through the aric acid to the detector is dramatically reduced. This and The surface of the PASC coating that produces very weak infrared absorption properties and the resulting infrared signal Combined with the low concentration of stearic acid present above, it does not become particularly strong I. Therefore, a device with an MCT detector is better than one with a DTGS detector. Gives a spectrum with a signal-to-noise ratio that is about an order of magnitude larger. PA of transparent film and substrate When measuring SC activity, infrared rays are used for stearic acid test membrane / PASC coating / group. Examine the body and / or any other existing transparent membrane and coating through it You can go to the dispenser. If the film or substrate does not allow infrared light to pass through, that infrared light A test in which the beam is directed at an angle to the surface, passes through a stearic acid test membrane, and is tested. Instead of passing through the charge, it is then reflected back into the detector. This latter method Known as reflection IR spectroscopy. The PASC reaction rate is the PASC coating when the PASC coating is exposed to UV light. The speed at which the PASC coating can remove the stearic acid test membrane present above By measuring the degree, the PASC coating can be determined. in particular, Integral intensity of CH expansion and contraction vibration characteristics (for surface coverage) by cumulative time of irradiation with ultraviolet rays The rate of decrease (in direct proportion) gives the PASC reaction rate. For example, initial PASC activity FTIR spectroscopy for the stearic acid test film present on the PASC coating Measure with a meter. Stearic acid test membrane is about this initial PASC activity measurement May or may not be exposed to UV light. Next, stearic acid coating PASC coating Was exposed to UV light for a measured period of time, after which a second PAS C activity is measured using an FTIR spectrophotometer. CH expansion and contraction vibration in the second measurement The integrated intensity of is that a part of the stearic acid test film is removed by ultraviolet irradiation. As a result, it is expected to be lower than the first one. These two measurements From the constant value, it is possible to plot the curve of the integrated intensity of CH stretching vibration with respect to time The PASC reaction rate can be obtained from the slope. At two points to give a curve Sufficient, but some during the PASC activity measurement period to give a more accurate curve It is preferable to make some FTIR measurements. The time of exposure to UV light between measurement points Keep it constant or fluctuate to accumulate exposure time to UV light and curve it May be used for lots, but intensity and direction, i.e. UV irradiation of the sample Whether it is on the coating side or the substrate side is the total taken when determining the PASC reaction rate. It should be constant for all PASC measurements. PASC reaction rate is cm^-1Minutes^-1Can be reported in units of, and the value is large It shows that the PASC activity is high. PASC coating is acceptable level of P Whether or not it has ASC activity is selected in relation to the purpose of using the device and that purpose. PASC coatings are "acceptable" or "acceptable" as they are largely determined by the performance criteria. There is no absolute speed to make it "unacceptable". In general, the PASC reaction rate is possible Larger is desirable. Preferably the PASC reaction rate is formed on the PASC coating. For most applications of stearic acid test membranes, F with an MCT detector Approximately 20 on the coated surface when irradiated from the coated side of the substrate as measured by a TIR spectrophotometer W / m²At least about 2x10 when exposed to intense UV light^-3cm^-1Minutes^-1Is Is preferable. More preferably, the PASC reaction rate is measured with those same parameters. At least about 5x10^-3cm^-1Minutes^-1Is. PASC cover to significantly determine and compare PASC activity of PASC coating It is also useful to measure the thickness of the cover. Because the thickness of the PASC coating is a photocatalyst This is because it affects activity (for example, a thick PASC coating has a large PAS. Tends to give C reaction rate). PASC coating thickness [and / or), if present SIDB layer if present] is referred to as variable angle spectroscopic ellipsometry (hereinafter referred to as "VASE"). ) Or, as is known in the art, the profile of the disappearing edge of the measured membrane. Measured by profilometer measurements or also known in the art As you can see, it can be estimated from the interference color. The PASC coating of the present invention and, if present, the SIDB layer is its PAS. C coating and / or SIDB layer is given to the operating parameters of the equipment inside. Those skilled in the art will recognize that they must be able to endure. Therefore, for most purposes On the way, they must be able to withstand normal wiping and abrasion forces, for example. For example, it must be able to withstand the operating temperatures of equipment such as ovens, refrigerators, and refrigerators. Absent. They are, for example, when the equipment is a clothes washing machine or a dishwasher. Must be able to withstand exposure to water and detergents. If the device is an oven, the present invention cleans the oven as described above. Currently requires unusually high temperatures [ie about 648.9 ° C (1200 ° F)] Approved by those skilled in the art to give special advantages over available self-cleaning ovens Will be found. PA on those surfaces of the oven, which should be self-cleaning The self-cleaning ovens of the present invention with SC coatings are used to clean such surfaces. Such high temperatures are unnecessary. Therefore, the self-cleaning oven of the present invention is currently available. Designed and manufactured to withstand the excessive temperatures associated with available high temperature self-cleaning ovens No need to build, resulting in significantly reduced manufacturing costs and significantly longer operating life become. In addition, the "burning" required in currently available high temperature self-cleaning ovens There is no need to remove organic waste. This is because the organic waste of the present invention is mainly carbon dioxide. This is because it is incinerated into element and water vapor. The above disclosure is not limited to the present invention and is provided for the purpose of understanding the present invention. It will be acknowledged that it has been done. The scope of the present invention is defined by the following claims. It is to be determined.