Heatable glazing

Abstract

A heatable glazing (100) is disclosed The glazing (100) comprises a first substrate of glass (102), a first layer of conductive coating (104) disposed on a surface of the first substrate of glass (102), and a power supply line (106) connected to the conductive coating. The first layer of conductive coating (104) comprises a polymer matrix and a conductive filler uniformly dispersed in the polymer matrix. The power supply line (106) that is connected to the first layer of conductive layer (104) is configured to supply electric power to the first layer of conductive coating (104). This causes a raise in temperature of the first layer of conductive coating (104).

Description

HEATABLE GLAZINGTECHNICAL FIELD

[0001] The present disclosure relates generally to a heatable glazing, it particularly relates to a heatable glazing with a transparent defogger.BACKGROUND

[0002] Background description includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed disclosure, or that any publication specifically or implicitly referenced is prior art.

[0003] It is well known that glazing has wide range of applications in the fields of automotive, architectural, and aerospace so on and so forth. The glazing is employed for various such applications because of its ability to provide visual transparency. However, one of the persistent challenges plaguing glazing is the occurrence of fogging or mist formation over the surface of the glazing.

[0004] Fogging / mist formation occurs when moisture in the air condenses onto the cooler surface, creating a layer of water droplets that obstructs vision and reduces optical transparency. This phenomenon poses significant safety risks, especially in critical applications like vehicle windshields and aircraft windows.

[0005] Over the years, many techniques were implemented to defog or demist the glazing in automobiles. The most popular and widely used means of defogging is the use of heating grids in the glazing. The heating grid is an electrically conductive coil which operates like a heating coil when electric current is passed through it. The heating grid is embedded inside the glazing and powered ON when there is a fogformation on the glazing. The heating grid increases in temperature thereby heating the glazing and causing the fog or mist to disappear.

[0006] The existing technique of using heating grid in a glazing has a major problem associated with it. The heating grid is nothing but a network of thin electrical wires which are not optically transparent. The presence of these wires in the windshield may affect the visibility for the driver of the vehicle. Furthermore, heating grids are even more undesirable in windshields of vehicles that employ Advanced Driver- Assistance System (ADAS). The ADAS uses cameras that are placed behind the windshield for capturing image of the road or path. The presence of wires in the field of view of camera may cause light distortion and impact the images captured by the camera. This affects the performance of ADAS thereby putting the occupants of the vehicle at an extremely dangerous situation.

[0007] In view of this, there is a pressing need for a heatable glazing that comprises a heating mechanism for defogging, wherein the heating mechanism does not affect the transparency of the glazing.SUMMARY OF THE DISCLOSURE

[0008] In one embodiment, a heatable glazing is disclosed. The glazing comprises a first substrate of glass, a first layer of conductive coating disposed on a surface of the first substrate, and a power supply line connected to the conductive coating. The first layer of conductive coating comprises a polymer matrix and a conductive filler uniformly dispersed in the polymer matrix. The power supply line that is connected to the first layer of conductive layer is configured to supply electric power to the first layer of conductive coating. This causes a raise in temperature of the first layer of conductive coating.

[0009] In one embodiment, a method of manufacturing the heatable glazing is disclosed. At first step, the conductive coating is prepared by mixing conductive fillerwith the polymer matrix. At next step, the conductive coating is applied over the first substrate of glass to form the first layer of conductive coating. At next step, the first layer of conductive coating is dried. At next step, the interlayer is placed over the first layer of conductive coating such that the first layer of conductive coating is sandwiched between the first substrate of glass and the interlayer. At next step, the second substrate of glass is placed over the interlayer. Finally, the assembly is deaired and autoclaved to bind the first substrate, first layer of conductive coating, interlayer and the second substrate together to form the glazing.

[0010] In one embodiment, a system for heating the heatable glazing is disclosed. The system comprises a heatable glazing, a temperature sensor, a humidity sensor, an electronic control unit (ECU) and a powering unit. The temperature sensor and the humidity sensor are integrated to the glazing and configured to measure the temperature and humidity respectively. The ECU is connected to the temperature sensor, humidity sensor, and the powering unit, wherein the ECU is configured to operate the powering unit to supply electric power to the first layer of conductive coating.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The following briefly describes the accompanying drawings, illustrating the technical solution of the embodiments of the present invention, for assisting the understanding of a person skilled in the art to comprehend the invention. It would be apparent that the accompanying drawings in the following description merely show some embodiments of the present invention, and persons skilled in the art can derive other drawings from the accompanying drawings without deviating from the scope of the disclosure.

[0012] FIG. 1 illustrates a heatable glazing 100, in accordance with an embodiment;

[0013] FIG. 2 is a cross-sectional view of the heatable glazing 100 across the plane A- A, in accordance with an embodiment;

[0014] FIG. 3 is a microscopic view of the conductive coating 104, in accordance with an embodiment;

[0015] FIG. 4 illustrates a heatable glazing 400, in accordance with an embodiment;

[0016] FIG. 5 illustrates a heatable glazing 500, in accordance with an embodiment;

[0017] FIG. 6 illustrates a cross-sectional view of the heatable glazing 500 across the plane B-B;

[0018] FIG. 7 illustrates a heatable glazing 700, in accordance with an embodiment;

[0019] FIG. 8 illustrates a heatable glazing 800, in accordance with an embodiment;

[0020] FIG. 9 illustrates a heatable glazing 900, in accordance with an embodiment;

[0021] FIG. 10 illustrates a heatable glazing 1000, in accordance with an embodiment;

[0022] FIG. 11 illustrates a heatable glazing 1100, in accordance with an embodiment;

[0023] FIG. 12 illustrates a heatable glazing 1200, in accordance with an embodiment; and

[0024] FIG. 13 illustrates a system 1300 for controlling heating of the heatable glazing, in accordance with an embodiment.

[0025] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the disclosure.DETAILED DESCRIPTION

[0026] The following detailed description includes references to the accompanying drawings, which form part of the detailed description. The drawings show illustrations in accordance with example embodiments. These example embodiments are described in enough detail to enable those skilled in the art to practice the present subject matter.However, it may be apparent to one with ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well- known methods, procedures and components have not been described in detail so as not to unnecessarily obscure aspects of the embodiments. The embodiments can be combined, other embodiments can be utilized, or structural and logical changes can be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense.

[0027] In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one. In this document, the term “or” is used to refer to a non-exclusive “or”, such that “A or B” includes “A but not B”, “B but not A”, and “A and B”, unless otherwise indicated.

[0028] FIG. 1 illustrates a heatable glazing, in accordance with an embodiment. The glazing may comprise a first substrate of glass 102, a first layer of conductive coating 104, and power supply line 106 connected to the first layer of conductive coating 104.

[0029] FIG. 2 is a cross-sectional view of the heatable glazing across the plane A- A, in accordance with an embodiment. The first layer of conductive coating 104 is coated over a first surface of the first substrate of glass 102. The first layer of conductive coating 104 comprises a polymer matrix and conductive filler uniformly dispersed in the polymer matrix. The power supply line 106 are configured to supply electric power to the first layer of conductive coating 104. This in turn results in raise in temperature of the first layer of conductive coating 104 thereby heating the glazing.

[0030] FIG. 3 is a microscopic view of the conductive coating, in accordance with an embodiment. The conductive filler is uniformly dispersed in the polymer matrix and coated over a surface of the first substrate of glass 102.

[0031] In one embodiment the polymer matrix comprises of one or more water-based biopolymer binder.

[0032] In one embodiment, the water-based biopolymer binder includes but not limited to sodium carboxymethyl cellulose (NaCMC) material. Any other material exhibiting similar properties may be used a material for polymer matrix.

[0033] In one embodiment, the conductive filler is silver nanowires. In other embodiments, the conductive filler may be nanowires or fibres of materials like copper, gold or the like.

[0034] In one embodiment, the silver nanowires are dispersed in 90% of deionized water at a concentration in the range of 0.1 mg / ml to 4 mg / ml.

[0035] In one embodiment, the diameter of the silver nanowires is in the range of 20- 100 nanometers.

[0036] In one embodiment, the length of the silver nanometers is in the range of 25- 300 micrometers.

[0037] In one embodiment, the conductive coating further comprises adhesion promoters configured to enhance adhesion of the first layer of the conductive coating with the first substrate.

[0038] In one embodiment, the adhesion promoters may be metal or organofunctional silanes.

[0039] In one embodiment, the mass concentration of silver nanowires in the first layer of conductive coating 104 may be in the range of 0.01-2.00 % (w / v).

[0040] FIG. 4 illustrates a heatable glazing 400, in accordance with an embodiment. The heatable glazing 400 comprises an encapsulation 402 disposed over the first layer of conductive coating 104. The encapsulation 402 is configured to improve the structural integrity of the coating and the glazing. In addition, the encapsulation 402 prevents a direct exposure of the first layer of conductive coating 104 to the environment.

[0041] In one embodiment, the encapsulation 402 is made using a transparent enamel. The transparent enamel may be a material that is configured to offer the required optical and thermal requirements.

[0042] FIG. 5 illustrates a heatable glazing 500, in accordance with an embodiment. The instant embodiment relates to a laminated glazing. FIG. 6 illustrates a cross- sectional view of the heatable glazing 500 across the plane B-B. Referring to FIGs. 5 and 6, the glazing comprises the first substrate of glass 102, the first layer of conductive coating 104 coated on a surface of the first substrate of glass 102, an interlayer 602 disposed over the first layer of conductive coating 104, a second layer of conductive coating 606 disposed over the interlayer 602, and a second substrate of glass 604 positioned over the second layer of conductive coating 606.

[0043] In an embodiment, the first layer of conductive coating 104 and the second layer of conductive coating 606 may comprise dedicated power supply line 106 and can be operated independent of each other.

[0044] In one embodiment, the interlayer 602 may be made of a polymeric material such as polyvinyl butyral.

[0045] In one embodiment, a method of manufacturing the heatable glazing is disclosed. At first step, the conductive coating is prepared by mixing conductive filler with the polymer matrix. As mentioned earlier, in one embodiment, the conductive filler may be silver nanowires and the polymer matrix may be sodium carboxymethyl cellulose (NaCMC).

[0046] At next step, the conductive coating is applied over the first substrate of glass 102 to form the first layer of conductive coating 104. The different methods of applying the first layer of conductive coating 104 may include but not limited to screen printing, spray printing or mayer rod printing.

[0047] At next step, the first layer of conductive coating 104 is dried. In one embodiment, the drying process is performed in atmospheric conditions.

[0048] At next step, the interlayer 602 is placed over the first layer of conductive coating 104 such that the first layer of conductive coating 104 is sandwiched between the first substrate of glass 102 and the interlayer 602.

[0049] At next step, the second substrate of glass 604 is placed over the interlayer 602.

[0050] Finally, the assembly is deaired and autoclaved to bind the first substrate, first layer of conductive coating 104, interlayer 602 and the second substrate together to form the glazing.

[0051] FIG. 7 illustrates a heatable glazing 700, in accordance with an embodiment. The first layer of conductive coating 104 comprises an interior region 704 and edges 702. The concentration of the silver nanowires is higher on the edges 702 than the interior region 704. This enables accelerated heating on the edges 702 as compared to the heating in the interior region 704.

[0052] FIG. 8 illustrates a heatable glazing 800, in accordance with an embodiment. The glazing comprises multiple layers of conductive coating (104, 804) formed on a same plane of the glazing 800. In one embodiment, the layers of conductive coating (104, 804) are concentrically formed over each other.

[0053] In one embodiment, each of the layers of the conductive coating (104, 804) are connected with a dedicated power supply line 106 and configured to be operated independently.

[0054] FIG. 9 illustrates a heatable glazing 900, in accordance with an embodiment. The first layer of conductive coating 104 is configured in a manner that the concentration of the silver nano wires follows a gradient. The concentration of the silver nano wires is high at the center 904 of the first layer of conductive coating 104 and gradually decreases towards the periphery 902 of the first layer of conductive coating 104.

[0055] FIG. 10 illustrates a heatable glazing 1000, in accordance with an embodiment. The glazing 1000 comprises multiple layers of conductive coating (104a, 104b, 104c),wherein the layers of conductive coating (104a, 104b, 104c) are stacked over each other. Further, concentration of silver nanowires in each of the layer of conductive coating may be different from each other.

[0056] In one embodiment, the inner most layer disposed towards the first substrate of glass 102 may comprise higher concentration of silver nanowires and the concentration of silver nanowires decreases across the layers disposed away from the first substrate of glass 102.

[0057] As an example, the concentration of silver nanowires in conductive coating 104a is higher than the concentration of silver nanowires in conductive coating 104b. Further, the concentration of silver nanowires in conductive coating 104b is higher than the concentration of silver nano wires in conductive coating 104c.

[0058] FIG. 11 illustrates a heatable glazing 1100, in accordance with an embodiment. The heatable glazing 1100 comprises a plurality of silver nano wire layers (1102a, 1102b) and multiple first layer of conductive coating (104a, 104b, 104c). Each of the silver nano wire layers (1102a, 1102b) is alternatively arranged over each of the first layer conductive coating (104a, 104b, 104c).

[0059] As an example, one layer of conductive coating 104a is disposed over the first substrate further one layer of silver nanowires 1102a is disposed over the layer of conductive coating. Further, another layer of conductive coating 104b is disposed over the layer of silver nanowire 1102b so on and so forth.

[0060] FIG. 12 illustrates a heatable glazing, in accordance with an embodiment. The glazing comprises a first layer of conductive coating 104 disposed over the first substrate of glass 102. Further, a first layer of polymer material 1202 is disposed over the first layer of conductive coating 104. Similarly, a second layer of conductive coating 606 is disposed over the second substrate of glass 604. Further, a second layer of polymer material 1204 is disposed over the second layer of conductive coating 606.

[0061] The first layer of conductive coating 104 and the first layer of polymer material 1202 may be joined together to form a patch before disposing it within the glazing. The patch may then be disposed within the glazing.

[0062] FIG. 13 illustrates a system 1300 for controlling heating the heatable glazing, in accordance with an embodiment. The system 1300 comprises a heatable glazing 500 comprising a first layer of conductive coating 104, a temperature sensor 1302, a humidity sensor 1304, an electronic control unit (ECU) 1306, and a powering unit 1308. The temperature sensor 1302 and the humidity sensor 1304 are embedded in the glazing 500 and configured to measure the temperature of the glazing and relative humidity of the atmosphere respectively. The ECU 1306 may further be connected to the temperature sensor 1302, humidity sensor 1304 and the powering unit 1308.

[0063] The ECU 1306 may be configured to receive the temperature and humidity data measured by the temperature sensor and the humidity sensor respectively. The ECU 1306 may further determine the fog or mist formation on the surface of the glazing and operate the powering unit 1308 to supply electric power to the first layer of conductive coating 104. Thus, the fog or mist is removed from the surface of the glazing 500 automatically.

[0064] In an alternate embodiment, the system includes a feedback-based heating level control. In such system, the heating level is controlled based on at least glazing condition sensing, heating layer / material properties, heating rate settings from monitoring of temperature & power parameters. The system may further comprise an Artificial Intelligence (Al) or Machine Learning (ML) model configured to record historical heating control information and take corrective action based on the historical data.ADVANTAGES

[0065] As mentioned earlier, the conductive coating is water-based and hence applying the conductive coating over the first substrate is easier. Further, the drying time required by the first layer of conductive coating is also less.

[0066] The polymer matrix used in some embodiments is NaCMC which enables in adhesion of ink to the first substrate of glass without flaking or peeling.

[0067] The conductive coating composition is formulated in a manner that the conductive coating is optically transparent and hence suitable for windshield applications. The conductive coating may be disposed in a region in the field of view of camera. Thus, the conductive coating may find its application in windshields suitable for ADAS applications.

[0068] In one embodiment, the optical transparency of the conductive coating is greater than 95% and offers low haze.

[0069] The conductive coating enables controlled heating of the glazing. As an example, to reach a maximum temperature of 60 or 70° C the system may take 10-20 minutes.

[0070] Although embodiments have been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the system and method described herein. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

[0071] Many alterations and modifications of the present invention will no doubt become apparent to a person of ordinary skill in the art after having read the foregoing description. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. It is to be understood that the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the personally preferred embodiments of this invention. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents rather than by the examples given.List of reference numerals100, 400, 500, 700, 800, 900, 1000, 1100, 1200 - Heatable glazing102 - First substrate of glass 104 - First layer of conductive coating106 - Power supply line402 - Encapsulation602 - Interlayer604 - Second substrate of glass 606 - Second layer of conductive coating1102a, 1102b - Silver nano wire layer1202, 1204 - Layer of polymeric material1302 - Temperature sensor1304 - Humidity sensor 1306 - ECU1308 - Powering unit

Claims

CLAIMS1. A heatable glazing (100), wherein the glazing (100) comprises: a first substrate (102) of glass; a first layer of conductive coating (104) disposed on a surface of the first substrate (102), wherein the first layer of conductive coating (104) comprises: a polymer matrix; and a conductive filler uniformly dispersed in the polymer matrix; and power supply line (106) connected to the first layer of conductive coating (104), wherein the power supply line (106) is configured to supply electric power to the first layer of conductive coating (104) thereby causing a raise in temperature of the first layer of conductive coating (104).

2. The glazing (100) as claimed in claim 1, wherein the polymer matrix comprises of one or more water-based biopolymer binder.

3. The glazing (100) as claimed in claim 1, wherein the water-based biopolymer binder is sodium carboxymethyl cellulose (NaCMC) material.

4. The glazing (100) as claimed in claim 1, wherein the conductive filler is silver nano wires.

5. The glazing (100) as claimed in claim 4, wherein the silver nano wires are dispersed in a concentration in the range of 0.1 mg / ml to 4 mg / ml in 90% of deionized water.

6. The glazing (100) as claimed in claim 5, wherein:the diameter of the silver nanowires is in the range of 20-100 nanometres; and the length of the silver nano wires is in the range of 25-300 micrometres.

7. The glazing (100) as claimed in claim 1, wherein the first layer of conductive coating (104) further comprises adhesion promoters configured to enhance adhesion of the first layer of conductive coating (104) with the first substrate (102).

8. The glazing (100) as claimed in claim 7, wherein the adhesion promoters are metal or organofunctional silanes.

9. The glazing (100) as claimed in claim 1 , wherein the mass concentration of silver nanowires in the first layer of conductive coating (104) is 0.01-2.00 % (w / v).

10. The glazing (100) as claimed in claim 1, wherein the glazing further comprises: an encapsulation (402) disposed over the first layer of conductive coating (104) to improve the structural integrity of the coating and glazing.

11. The glazing (100) as claimed in claim 10, wherein the encapsulation (402) is made using a transparent enamel that is configured to offer the required optical and thermal requirements.

12. The glazing (500) as claimed in claim 1, wherein the glazing (500) further comprises: an interlayer (602) made of a polymeric material disposed over the first layer of conductive coating (104); and a second substrate (604) of glass disposed over the interlayer (602).

13. The glazing (500) as claimed in claim 12, wherein the glazing (500) further comprises: a second layer of conductive coating (606) disposed between the interlayer (602) and the second substrate (604) of glass, wherein the second layer of conductive coating (606) is connected to another power supply line (106) and is operated independently of the first layer of conductive coating (104).

14. The glazing (700) as claimed in claim 1, wherein the concentration of the silver nanowires is higher on the edges (702) than the interior region (704) of the first layer of conductive coating (104).

15. The glazing (800) as claimed in claim 1, wherein the glazing (800) comprises multiple layers of conductive coating (104, 804) concentrically formed on a same plane of the glazing (800).

16. The glazing (1000) as claimed in claim 12, wherein: the glazing (1000) comprises multiple layers of conductive coating (104a, 104b, 104c) stacked one over the other; and the concentration of silver nanowires is different for each of the layers of conductive coating (104a, 104b, 104c).

17. The glazing (1100) as claimed in claim 1, wherein the glazing (1100) further comprises: a plurality of silver nano wire layers (1102a, 1102b) and multiple first layer of conductive coating (104a, 104b, 104c), wherein each of the silver nano wire layers (1102a, 1102b) are alternatively disposed over each of the first layer of conductive coatings (104a, 104b, 104c).

18. The glazing (900) as claimed in claim 1, wherein the concentration of the silver nano wires in the first layer of conductive coating (104) is higher at the centre (904) of the conductive coating and gradually decreases towards the periphery (902) of the conductive coating.

19. The glazing (100) as claimed in claim 1, wherein the first layer of conductive coating (104) is formed on a region on the glazing (100) where a camera is positioned behind the glazing.

20. The glazing (100) as claimed in claim 12, wherein the glazing (100) comprises: a heating grid disposed around the periphery of the first layer of conductive coating (104) to enhance the heating.

21. A method of manufacturing the heatable glazing (500) as claimed in claim 12, wherein the method comprises the steps of: preparing the conductive coating by mixing conductive filler with the polymer matrix; applying the conductive coating on the surface of the first substrate (102) of glass to form the first layer of conductive coating (104); drying the first layer of conductive coating (104); placing the interlayer (602) over the first layer of conductive coating (104); placing the second substrate (604) of glass over the interlayer (602); and deairing and autoclaving the glazing to bind the first substrate (102), first layer of conductive coating (104), interlayer (602) and second substrate (604) together.

22. A system (1300) for heating the heatable glazing (500) as claimed in claim 12, wherein the system (1300) comprises:a temperature sensor (1302) integrated to the glazing (500) and configured to measure the temperature of the glazing (500); a humidity sensor (1304) integrated to the glazing and configured to measure the relative humidity of the atmosphere; an electronic control unit (ECU) (1306) connected to the temperature sensor (1302) and the humidity sensor (1304); and a powering unit (1308) connected to the power supply line (106) and configured to supply electric power to the first layer of conductive coating (104).

23. The system (1300) as claimed in claim 21, wherein the ECU is configured to: receive the temperature and humidity values from the temperature and humidity sensors (1302, 1304); determine the fog or mist formation on the surface of the glazing (500); and operate the powering unit (1308) to supply electric power to the first layer of conductive coating (104) to heat the glazing (500).

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