Patent Application
20230164888
The present disclosure generally relates to a glazing having a heatable coating with differential heating regions.
Glazings, including those which may be used in a vehicle, may include a heatable coating thereon. A heatable coating may be used, for example, to defrost a glazing, including an area where a wiper sits against a windshield. In a vehicle, heatable coatings may be used on any suitable glazing, such as a windshield, rear window, sunroof, or side window. In some glazings, it may be preferable to provide a localized area of increased heating. For example, it may be preferable to heat an area of a windshield adjacent to a wiper more than other parts of the glazing. Increasing heat around such a wiper park area may allow for deicing around the wiper to allow the wiper to function. As a further example, it may be preferable to heat an area of a windshield through which an information acquisition system such as a camera or sensor collects information from outside of a vehicle. Increasing heat around such a camera opening area may allow for defogging where fogging may interfere with the collection of clear information.
Disclosed herein is a glazing including a first glass substrate and a heatable coating formed on the first glass substrate, the heatable coating including at least one heatable layer and including at least one area of partial deletion wherein the heatable coating has a thickness thinner at the partial deletion than in a non-deleted portion of the heatable coating, wherein the partial deletion of the heatable layer is formed in a differential heating area of the heatable coating.
In an embodiment of the present disclosure, the heatable coating may include a single heatable layer and the partial deletion may include a partial thickness reduction of the single heatable layer. In another embodiment, the heatable coating may include first and second heatable layers. The partial deletion may include a total or partial thickness reduction of at least one of the first and second heatable layer. The heatable layers may contain silver or a transparent conductive oxide (TCO). A dielectric layer may be provided between first and second heatable layers.
In some embodiments, the glazing may further include a second glass substrate laminated to the first glass substrate. The heatable coating may be positioned between the first glass substrate and the second glass substrate. The differential heating area may be an area for a wiper to rest upon the glazing when installed in a vehicle. The glazing may include an opaque print area in the differential heating area.
In another aspect of the present disclosure, a method of providing a glazing with a heatable coating, may include the steps of: providing a first glass substrate formed with a heatable coating thereon; and removing at least a portion of at least one heatable layer in the heatable coating to provide a partial deletion in a differential heating area for variably heating the first glass substrate, wherein at least a portion of at least one heatable layer remains in the partial deletion.
In an embodiment of the present disclosure, the portion of the heatable layer may be removed by application of a laser to the coating or by physical abrasion of the coating. The heatable coating may include a single heatable layer where the partial deletion may include a partial thickness reduction of the single heatable layer.
In another embodiment, the heatable coating may include first and second heatable layers. The partial deletion may be formed from a total or partial thickness reduction of at least one of the first and second heatable layers. The heatable coating may include a blocking layer between the first and second heatable layers. Physical abrasion of the coating may include application of a grinding wheel, wherein the grinding wheel has a lower hardness than the blocking layer. The method may further include the step of laminating the first glass substrate with a second glass substrate. The method may include a step of forming an opaque print on the first glass substrate.
In a further aspect of the present disclosure, a laminated glazing may include a first glass sheet having surfaces S1 and S2, wherein S1 faces an exterior when installed and a second glass sheet having surfaces S3 and S4, wherein S4 faces an interior when installed, an interlayer provided between the first and second glass sheets, a heatable coating formed on either of the first and second glass sheets, the heatable coating including a first heatable region and a second heatable region having a higher heating capability than that of the first heatable region; a busbar supplying power to the heatable coating, and an opaque print formed on at least one of the first and second glass sheets, the opaque print hiding the busbar and the second heatable region when viewed from an exterior side of the first glass sheet.
In an embodiment of the present disclosure, the heatable layer may include at least one heatable layer including a partial deletion wherein the heatable layer has a thickness thinner at the partial deletion than in a non-deleted portion of the heatable layer and wherein the partial deletion of the heatable layer is formed in the second heatable region. In a further embodiment, the opaque print may be formed at least provided on the surface S2, and the busbar and the heatable coating may be formed on the surface S3. In another embodiment, the opaque print may be at least provided on the surface S2, and the busbar and the heatable coating may be formed on the surface S2. In such an embodiment, the busbar and the heatable coating may be formed on the opaque print, or the opaque print may be formed on the heatable coating.
In another embodiment, the second heatable region may be arranged at a wiper park area. In some embodiments, the heatable coating may be removed to from a camera opening area, and the second heatable region may be formed at a peripheral area of the camera opening area. The heatable layer may contain silver or may contain a transparent conductive oxide (TCO).
The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more example aspects of the present disclosure and, together with the detailed description, serve to explain their principles and implementations.
In the following description, for purposes of explanation, specific details are set forth in order to promote a thorough understanding of one or more aspects of the disclosure. It may be evident in some or all instances, however, that many aspects described below can be practiced without adopting the specific design details described below.
Where a heatable coating is functional across an entire windshield, areas of differential heating may be formed with deleted regions separating the coating into electrically isolated portions with separate busbars for each isolated coating area. However, it may be preferable to minimize the number of busbars and electrical connections required. For example, it may be preferable to provide a heatable glazing having two busbars and differential heating across the glazing without requiring electrically isolated portions. In this specification, the terms of “top,” and “bottom” designate edges of the glazing respectively when installed in a vehicle.
Heatable coatings may include one or more heatable layers and may include dielectric layers between heatable layers where there is more than one heatable layer in the coating. In some embodiments of the present disclosure, a heatable coating may include a single heatable layer subject to thickness reduction. In another embodiment, a heatable coating may include a layer stack having at least two heatable layers where at least one heatable layer may be removed or reduced in thickness. The heatable layers may be electrically connectable and heated when powered by a power source. A heatable coating may include a metallic coating, such as an infrared reflective coating. The metallic layers may preferably be silver containing layers. The silver containing layer may have a silver content of 90 mass % or more. In particular embodiments described herein, the metallic coating may include at least two metallic layers as the heatable layers, which may be separated by dielectric layers. Example heatable coatings may comprise a sequence of layers as follows: dielectric layer/silver/dielectric layer or dielectric layer/silver/dielectric layer/silver/dielectric layer. The dielectric layers may comprise metal oxides, nitrides or oxynitrides, for example, tin oxide, zinc oxide, silicon nitride, titanium oxide, aluminum oxide or mixtures of one or more thereof. In certain embodiments, a heatable coating may include a transparent conductive oxide (TCO) coating, such as a Low-E coating. A TCO coating may include at least one TCO layer, such as Indium Tin Oxide (ITO) layer(s), as the heatable layers, which may be separated by dielectric layers. The thickness of a metallic layer may be from 1 nm to 100 nm, preferably 5 nm to 50 nm, more preferably 8 nm to 30 nm. The thickness of a dielectric layer may be 1 nm to 100 nm, preferably 5 nm to 50 nm, more preferably 8 nm to 30 nm. The thickness of a TCO layer may be from 1 nm to 200 nm, preferably 10 nm to 150 nm, more preferably 20 nm to 100 nm. The heatable coating, having any suitable heatable layers, may be provided in a laminated glazing. Preferably, the heatable coating may be on a glass surface within the laminated glazing. The visible light transparency of the glazing or the laminated glazing may be 70% or more, preferably 72% or more, to satisfy regulatory requirements. Visible light transparency may particularly be determined by ISO 3538:1997, “Road vehicles—Safety glazing materials—Test methods for optical properties.” To measure light transmission across a wavelength spectrum or at a particular wavelength, any suitable equipment complying with the ISO standard may be used, such as a UV-Vis Spectrophotometer (e.g., U4000, Hitachi High-Tech Science).
A laminated glazing may include a first glass substrate and a second glass substrate laminated together with an interlayer material therebetween. The thickness of the glass substrates is not particularly limited, but is preferably from 0.5 mm to 3.0 mm. The glass substrates may include, without limitation, soda-lime silicate glass described by ISO 16293-1:2008. In some embodiments, the first glass substrate may be an exterior glass substrate facing a vehicle exterior when the glazing is installed, and the second substrate may be an interior glass substrate facing a vehicle interior when the glazing is installed. Alternatively, the first glass substrate may be an interior glass substrate and the second glass substrate may be an exterior glass substrate, depending on the manufacturing process.
Particularly, an interlayer may be a polymer adhesive, such as polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) or an ionomer. A heatable coating may be formed on a glass substrate prior to lamination. In the laminated glazing, the heatable coating may be protected from corrosion from exposure to external elements. In some embodiments, the coating may be deleted around an edge of the glass substrate. The heatable coating may be connected to a power source via busbars formed on the coating. Preferably, the coating includes two busbars formed opposite each other, such that electrical current may pass across the coating between the busbars. The busbars may be made, for example, by printing a conductive paste on a coating formed on a glass substrate, in particular by the screen-printing method, which may be fired, for example, during bending of the glass substrate. The busbars may, for example, be implemented as strip-shaped or band-shaped electrodes. The busbars may include a thin, narrow metal foil strip of copper or aluminum, for instance, that include a conductive adhesive layer, applied with electrical contact to the heatable coating. The adhesive foil strip may be attached over a conductive paste material formed on the heatable coating.
Where it is preferable to variably heat the coating, such as for a wiper park area, the coating according to the present disclosure may include partial deletions. The partial deletions, or partially removed areas of the heatable layer(s), may locally increase resistance in the coating such that the amount of heat generated by ohmic resistance heating increases to enable faster deicing and/or defogging. The electric current may be locally forced through narrow and/or long stretches due to the partial deletions which may locally increase the electrical resistance. The increased resistance may cause the coating to locally heat more than areas of the coating with no partial deletions. The partial deletions may be in the uppermost layer of the heatable coating and the partial deletion may be made by application of laser abrasion or any other means of physical deletion from an exposed surface of the heatable coating on the workpiece, such as by the use of physical abrasion. The partial deletions may be formed in any suitable shape, such as straight, zigzag, or curved lines. For example without limitation, partial deletion may be formed with multiple deleted lines of 0.1 mm width with intervals of 0.5 mm. Shape, width, length, and/or interval may be varied depending on a purpose/location of heating. The partial deletions may be produced as lines perpendicular to a substrate edge or hatching lines, or also from parallel or random patterns.
The area of a coating having partial deletions may be any suitable shape and size. In some embodiments, an area having partial deletions may extend across all or part of a bottom portion of a glazing. The area having partial deletions may include multiple areas of deleted coating. For example, a vehicle may include two wipers positioned on a windshield and a windshield coating may preferably heat areas of the windshield corresponding to each wiper position. Through application of a supplied voltage on the two busbars, the heatable coating areas with partial deletions and without partial deletions may be heated simultaneously. The coating area with partial deletions may heat more than the coating area without partial deletions. For example, the heatable coating area without partial deletions may be configured such that with impingement by an on-board voltage of 12 to 48 V, a specific heating output of 3 to 6 watts/dm2 is obtained and the heatable coating area with partial deletions may be configured such that with impingement by an onboard voltage of 12 to 48V, a specific heating output of 5 to 20 watts/dm2 is obtained. Deletions may be controlled by width, length, and depth. By controlling depth and relative positioning of the deletions, one area of partial deletions, or an area of differential heating, may have a local variation in resistance. Where a differential heating area desirably has a gradually changing heat profile, such deletion control may be used to provide a gradual differential heating area.
It may be preferable, in some embodiments, for a glazing to include a heatable coating having multiple conductive layers. For example, a coating may include two or three conductive metallic or TCO layers. The partial deletions may preferably not extend through all of the conductive layers. Thus, a full or partial conductive layer of the heatable coating may remain intact even where there are partial deletions extending partially through the coating. Where there are three conductive layers, there may remain one or two conductive layers without deletions. Where the deletions would be formed through the entire coating, the portion of the coating at the deletion would have no heatable materials. According to the present disclosure, the coating maintains a heatable material across the entire coated area. Thus, there may not be an interruption in heating. The coating may be entirely deleted in some areas, which are not part of the coated area, including around a periphery of a glazing substrate or in an area for a sensor or camera. By preventing the interruption in heating, heat may be relatively more evenly distributed across the area of the coating having partial deletions. Further, the design of the partial deletions may be flexible. For example, the partial deletions may be wider, compared to a full deletion, as the coating retains conductivity across the entire coating area.
In some embodiments, the partial deletions may be formed using a laser. The laser may be absorbed by the coating and locally decompose said coating without affecting the underlying material. The laser may be configured to locally vaporize a part of the coating. For the present description, the laser may be focused, with a suitable shape and size, on some coating layers without deleting the lower coating layers. Particularly, a laser may be configured such that the laser strength deletes at least one or part of a heatable layer of the coating without deleting the entire coating such that at least part of a heatable layer remains intact at the partial deletion. The preferable power and/or focus of a laser may be determined based on the coating materials and the number and thickness of layers to be deleted by the laser.
Laser power sources known in the art for laser deletion for an automotive glazing for electric sensor installation may be used. For example, equipment producing a pulsed green laser with a wavelength of 532 nm and frequency of 10 kHz may be used. In some embodiments, a continuous or pulsed infrared laser with a wavelength of 1059-1065 nm may be used. Moreover, power, pulsation and/or frequency may be periodically or non-periodically varied or scanned. Variation of laser focus during scanning with or without a Galvano scanner may be also used. For another example, laser processing technology with spatial phase modulator or holographic optics may be used. The laser processing may include interfering laser beams to create the partial deletion. Interfering lasers may provide a stable, energy efficient system over a focused laser beam. An axicon lens may be used to create the deleted openings described herein with interfering laser beams. Further, the interfering beams may be focused on the coating such that openings may be reliably formed on a three-dimensionally bent glass substrate.
In some further embodiments, a partial deletion may be formed by physical abrasion. For example, a grinding wheel may be applied to the coating to provide partial deletions through part of the coating. Where a coating includes at least two heatable layers, a blocking layer may be provided between the heatable layers. Preferably, a blocking layer may be harder than an abrasion tool, such as a grinding wheel. Where the blocking layer is harder than such a grinding wheel, the wheel may be used to remove layers of the coating above the blocking layer. The blocking layer may include, without limitation, oxide, nitride or oxynitride of silicon (Si), titanium (Ti), aluminum (Al), zirconium (Zr) or tungsten (W), or combinations thereof, depending on a hardness of the desired physical abrasion tool. The heatable layer positioned below the blocking layer may remain intact, protected by the blocking layer and partial deletions may be formed in the heatable layer of the coating above the blocking layer.
For various uses, including for automotive glazings, glass substrates may be thermally treated, including bending and/or tempering. Where the heatable coating is applied to a glass substrate prior to thermal treatment, the partial deletions may be formed before or after the thermal treatment.
Where the glazing is a laminated glazing such as a windshield, the first glass substrate may be laminated with a second glass and an interlayer therebetween. Preferably, the heatable coating may be positioned between the first and second glass substrates in such a laminated construction.
The exterior glass substrate 40 and the interior glass substrate 20 may be laminated as shown in
Producing the glazing thus formed with a heatable coating may include the following steps. First, a first glass substrate may be prepared with a heatable coating thereon.
After forming a heatable coating, at least a portion of at least one heatable layer in the heatable coating is removed to form a partial deletion in the heatable coating. The removal may be achieved by using a laser abrasion or a physical abrasion process.
The opaque print may be formed on a first or second glass substrate. If the opaque print is made on the first glass substrate, the opaque print may be made before or after the formation of the heatable coating.
After forming the partial deletions and opaque print, an interlayer film may be arranged between the first and second glass substrates, which may then be deaired and autoclaved to provide a laminated glazing with the heatable coating having the differential heating area.
The above description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the common principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Further, the above description in connection with the drawings describes examples and does not represent the only examples that may be implemented or that are within the scope of the claims.
Furthermore, although elements of the described aspects and/or embodiments may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect and/or embodiment may be utilized with all or a portion of any other aspect and/or embodiment, unless stated otherwise. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
This application claims priority to U.S. Provisional Application No. 63/007,752 filed on Apr. 9, 2020, entitled “Coated Glazing” the entire contents of which are incorporated by reference herein in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/026605 | 4/9/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63007752 | Apr 2020 | US |
