WO2022266482A1

WO2022266482A1 - Glass product and method of producing glass product

Info

Publication number: WO2022266482A1
Application number: PCT/US2022/034056
Authority: WO
Inventors: Wladislaw BRONSTEIN; Philippe DULSKI; Markus Walter POHLEN
Original assignee: Carlex Glass America, Llc
Priority date: 2021-06-17
Filing date: 2022-06-17
Publication date: 2022-12-22

Abstract

A glass product includes a glass piece, a first adhesive layer, a switchable film having variable light transmission adhered to the glass piece via the first adhesive layer, a second adhesive layer, a protective layer adhered to the switchable film via the second adhesive layer, and an electrical connection path for electrically connecting to the switchable film on the protective layer.

Description

GLASS PRODUCT AND METHOD OF PRODUCING GLASS PRODUCT

Cross Reference to Related Application

[0001] This application claims priority to U. S. Provisional Application No. 63/211,763, filed on

June 17, 2021, entitled “GLASS PRODUCT,” the entire contents of which are incorporated by reference herein in their entirety.

Technical Field

[0002] The present disclosure is generally related to a glass product having a switchable film and a protective layer over the switchable film, and an electrical connection path for electrically connecting to the switchable film on the protective layer. The present disclosure is also generally related to a method of producing the glass product.

Background

[0003] Switchable films, functionally changing in light transmission under electrical power, may be used in automotive glazings to provide variably transparent windows. The switchable films may be laminated in a glazing between two glass sheets, which may include deairing and autoclaving the switchable film between glass sheets. The glass sheets may include a complex curvature shape.

The laminated process may be complex with a laminated functional film which may wrinkle when laminated between the glass sheets having complex curvature and may require electrical connections to be formed within the glazing. The difficulty in producing such parts may lead to unacceptable parts being produced, which may be scrapped as unusable. An alternative method for providing a switchable glazing may be needed to improve on these difficulties, among others.

Summary of the Disclosure

[0004] Disclosed herein is a glass product, including: a glass piece; a first adhesive layer; a switchable film having variable light transmission adhered to the glass piece via the first adhesive layer; a second adhesive layer; a protective layer adhered to the switchable film via the second adhesive layer; and an electrical connection path for electrically connecting to the switchable film on the protective layer.

[0005] In some embodiments of the present disclosure, the switchable film may be a liquid crystal switchable film.

[0006] In some embodiments of the present disclosure, the switchable film may include more than one segment, wherein the more than one segment may be electrically controllable independent of one another.

[0007] In some embodiments of the present disclosure, the electrical connection path may include a circuit printed onto the protective layer.

[0008] In some embodiments of the present disclosure, the electrical connection path may include a circuit printed onto a foil adhered to the protective layer.

[0009] In some embodiments of the present disclosure, the switchable film may include a busbar that is connected to the electrical connection path by a conductive adhesive.

[0010] In some embodiments of the present disclosure, the switchable film may include a busbar that is connected to the electrical connection path by a solder material.

[0011] In some embodiments of the present disclosure, the protective layer may include an area for capacitive switching of the switchable film.

[0012] In some embodiments of the present disclosure, the glass product may be a sunroof.

[0013] In some embodiments of the present disclosure, the protective layer may have a thickness of 1.0 mm or less.

[0014] In some embodiments of the present disclosure, at least one of the first and the second adhesive layers may be a coating. [0015] In some embodiments of the present disclosure, at least one of the first and the second adhesive layers may include a pressure-sensitive adhesive or a cured material of a photocurable, reaction-curable, or moisture-curable adhesive.

[0016] In some embodiments of the present disclosure, a low-emissivity functional element, which may include a coating, may be on the protective layer.

[0017] In another aspect of the present disclosure, a method of producing the glass product of the present disclosure includes: forming the electrical connection path on the protective layer; adhering the protective layer to the switchable film via the second adhesive layer; and adhering the switchable film to the glass piece via the first adhesive layer.

[0018] In some embodiments of the present disclosure, the glass piece may have a curved shape, and the switchable film with the protective layer adhered thereto may be shaped prior to adhering to the glass piece.

[0019] In some embodiments of the present disclosure, at least one of the first and the second adhesive layers may include a photocurable, reaction-curable, moisture-curable, or pressuresensitive adhesive, and the adhering at least one of the protective layer and the adhering the switchable film may be carried out at an ambient temperature.

Brief Description of the Drawings

[0020] 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.

[0021] FIG. 1 is a cross section illustrating a glass product, according to an exemplary embodiment of the present disclosure. [0022] FIG. 2 is a cross section illustrating a switchable film and protective layer electrically connected, according to an exemplary embodiment of the present disclosure.

[0023] FIG. 3 is a cross section illustrating a switchable film and protective layer electrically connected, according to an exemplary embodiment of the present disclosure.

[0024] FIG. 4 is a cross section illustrating a switchable film and protective layer electrically connected, according to an exemplary embodiment of the present disclosure.

[0025] FIGs. 5A, 5B. and 5C illustrate steps of producing a glass product, according to an exemplary embodiment of the present disclosure.

[0026] FIG. 6A illustrates a step of producing a glass product, according to an exemplary embodiment of the present disclosure.

[0027] FIG. 6B is a cross section illustrating a glass product, according to an exemplary embodiment of the present disclosure.

[0028] FIG. 7 illustrates a protective layer over a switchable film, according to an exemplary embodiment of the present disclosure.

Detailed Description

[0029] 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 any aspects described below can be practiced without adopting the specific design details described below.

[0030] This disclosure relates generally to a glass product, including: a glass piece; a first adhesive layer; a switchable film having variable light transmission adhered to the glass piece via the first adhesive layer; a second adhesive layer; a protective layer adhered to the switchable film via the second adhesive layer; and an electrical connection path for connecting to the switchable film on the protective layer. This disclosure also relates generally to a method of producing the glass product, including: forming the electrical connection path on the protective layer; adhering the protective layer to the switchable film via the second adhesive layer; and adhering the switchable film to the glass piece via the first adhesive layer.

[0031] Where a switchable film is laminated between interlayers in a laminated glazing, the relatively soft interlayers may allow for change in shape of the switchable film, including wrinkling of the film. Applying the film instead to a harder glass surface may allow for prevention or limitation of such wrinkling even where the glass has a complex curvature shape.

[0032] Glass products described herein may include laminated or non-laminated glazings. Such glazings may be used, for example, in automotive vehicles as windows, such as windshields, sunroofs, back windows, or side windows. The glass product includes a glass piece which may include a single glass sheet or a laminated glazing. The glass pieces may be bent to a desired shape.

A conventional laminated glazing may include a first glass sheet, an interlayer, and a second glass sheet laminated together. The glass sheets may be bent to a desired shape prior to lamination with an interlayer therebetween. Preferably, the glass sheets may be a soda-lime silica glass. Glass bending may preferably occur by heat treatment from 550°C to 700°C, more preferably from

580°C to 660°C. The interlayer may include an adhesive polymer sheet, which may include polyvinyl butyral (PVB) or ethylene vinyl acetate (EVA). An interlayer may include an ionomer sheet in some glazings. An inner glass sheet of the glazing faces a vehicle interior when installed, and an outer glass sheet faces a vehicle exterior when installed. The glass product may be a sunroof.

[0033] A switchable film as used herein includes a functional layer for changing in transparency due to a connection to an electrical power source. Switchable films may include, for example, a liquid crystal film, such as polymer dispersed liquid crystal (PDLC), polymer network liquid crystal (PNLC), or other liquid crystal films, a nanoparticle film, such as a suspended particle device (SPD), or electrochromic films. A switchable film may include, for example, a first base layer, a first electrode on the first base layer, a functional layer, a second electrode, and a second base layer. The second electrode may be formed on the second base layer. The first and second electrodes may preferably include a metal oxide, such as indium tin oxide and may be the same or different material. The first and second base layers may preferably include polymer films, such as polyethylene terephthalate (PET) and may be the same or different from each other. The first and second electrodes may be independently connected to a power source. Some switchable films may include more than one segment, and the segments may be controlled independently of each other.

Segments may be formed by creating electrically isolated portions on one or both of the first and second electrodes. The segments may each require electrical connection via a busbar. The switchable film may connect to a power source via busbars formed on the electrodes. The functional layer may include any suitable material and may include, for example, liquid crystal for

PDLC or PNLC or nanoparticles for SPD. When the switchable film is connected to an electric power source, the switchable film may switch from a dark or opaque state to a clear state, or vice versa.

[0034] As disclosed herein, a switchable film may be adhered to a glass piece, or glazing.

Particularly the switchable film may be adhered to the glass piece on an inner surface facing a vehicle interior when installed. The switchable film may be adhered by an adhesive layer which may include, or be formed by, a hot-melt, thermosetting, photocurable, reaction-curable, moisture- curable, or pressure-sensitive adhesive. The adhesive may include compounds based on acrylate, urethane, urethane acrylate, epoxy, epoxy acrylate, acryl, silicone, isocyanate, polyolefin, modified olefin, polypropylene, ethylene vinyl alcohol, vinyl chloride, chloroprene rubber, cyanoacrylate, polyamide, polyimide, polystyrene, polyvinyl butyral, ethylene vinyl acetate, or the like. The preferable adhesive may be selected for suitable workability and adhesion properties, as well as for providing suitable optical transparency.

[0035] It may be desirable to cover such a switchable film with a protective layer so as to protect it from an environment in the vehicle. The protective layer may be applied over the switchable film with an adhesive that may be the same or different from the adhesive used to adhere the switchable film to the glass piece. The protective layer may preferably have a thickness of 1.0 mm or less, more preferably 0.7 mm or less. The protective layer may include a polymer layer or a glass layer. For example, the protective layer may include a polymer film, such as a polyethylene terephthalate (PET) film, a polycarbonate film, or an acrylic film, and the polymer film may have a hard coating, such as an acrylic coating, thereon. The adhesive and protective layer may have a suitable optical appearance to be applied to a glass piece, which may preferably include a sunroof.

Where the protective layer is a glass layer, the glass layer may be thin and flexible. The glass layer may preferably have a thickness of 1.0 mm or less, more preferably 0.7 mm or less, and may be chemically strengthened. The protective layer may be larger in size than the switchable film so as to extend past the switchable film and completely cover it. Where all or part of the protective layer does not extend past the edge of the switchable film, the edges of the switchable film and the protective layer may be covered with a sealant. Where the protective layer does extend past the edge of the switchable film, the protective layer and the second adhesive may seal the edge of the switchable film or an additional sealant may be used in combination with the second adhesive. The protective layer may have flexibility to conform to the shape of the glass piece and the switchable film on the glass piece. The protective layer may further include a low-emissivity functional element. The low-emissivity functional element may include a low-emissivity coating on a surface of the protective layer facing a vehicle interior when installed. The coating may include an indium tin oxide based coating, for example.

[0036] The protective layer may have physical and chemical protective qualities. Particularly, the protective layer may have a haze value of less than 2% after the Taber test, as described in ECE

R43 (updated May 2019). Further, the protective layer may have a chemical resistance which may pass the chemical resistance test as defined in ECE R43 (updated May 2019).

[0037] The glass product 100 may further includes an electrical connection path, e.g., a circuit 70, on the protective layer 50, as shown in FIG. 1. FIG. 1 is simplified for illustration purposes. A more detailed illustration of the electrical connection between the switchable film 10 and the protective layer 50 is provided in FIG. 2. The switchable film may require connection to at least two busbars 31, 32 (one for each electrode) as shown in FIG. 3. Where there are electrically isolated segments formed in one or both of the electrodes 23, 24, each isolated segment may have a separate busbar 31, 32. As the number of connections increases, the complexity of the electrical connections increases. Even where there are only two busbars 31, 32 to connect, a simple, easy to implement connection means is desired.

[0038] The protective layer 50 may provide an electrical connection path by providing a circuit 70 for connection to the busbar 31, 32. The circuit 70 may be printed directly onto the protective layer

50 in some embodiments. The circuit 70 may be printed with a conductive material such as an ink containing silver particles or copper particles. In other embodiments, the circuit 70 may be printed onto a foil 38, as shown in FIG. 4, and the foil 38 may be adhered to the protective layer 50, when it is not easy to form the circuit 70 directly onto the protective layer 50. The foil 38 may include a polymer film such as a PET film, a polycarbonate film, an acrylic film, or a PVB film, The circuit 70 may include a portion for connecting to each busbar 31 , 32 of the switchable film 10. The circuit

70 may then be designed to reach a point for connection to a connector to reach a power source which may power the switchable film 10. The circuit 70 may overlap with the second adhesive layer 140 attaching the protective layer 50 to the switchable film 10, except for the portions of the circuit 70 for attachment to the busbar 31 in the switchable film 10, as shown in FIG. 2. In some embodiments, a conductive adhesive 75, 76 may connect the electrical connection path, i.e., the circuit 70, to the busbar 31, 32 on the switchable film 10 as shown in FIG. 2 and 3. The conductive adhesive 75, 76 may be the adhesive described above which further contains a conductive material such as silver particles or copper particles. In some other embodiments, the busbar 31, 32 may be connected to the electrical connection path by a solder material. For example, the circuit 70 may be provided with solder at the points of connection to the busbar 31, 32. During production, the protective layer 50 having solder points on the circuit 70 may be applied over the switchable film

10 and the solder points may be heated to melt the solder and connect the circuit 70 to the busbar

31, 32 of the switchable film 10. The solder points may be heated by use of a soldering iron applying heat through the protective layer 50. In some embodiments, the solder may be connected to the busbars 31, 32 with induction, heated air, ultrasonic vibration, or other methods. In some embodiments, the switchable film 10 may include a seal 33, 34 at the functional layer 25 of the switchable film 10 to protect the switchable material in the functional layer 25.

[0039] The protective layer 50 may further include an area for capacitive switching of the switchable film, which may be connected to the switchable film 10. For example, the protective layer 50 may have a multi-layer structure in this area which has a dielectric layer sandwiched by two conductive layers or a single layer structure. A protective layer 50 with such a structure may provide a capacitive switching, or a touch panel. An electrical connection from a power source to the capacitive switching may be formed in this area. This area may be marked to indicate the position of the capacitive switching.

[0040] FIG. 1 illustrates a glass product 100 according to an exemplary embodiment of the present disclosure, and FIG. 2 is a detailed illustration of a switchable film 10 in the glass product 100 shown in FIG. 1. The glass product 100 includes a glass piece 110; a first adhesive layer 130; a switchable film 10 having variable light transmission adhered to the glass piece 110 via the first adhesive layer 130; a second adhesive layer 140; a protective layer 50 adhered to the switchable film 10 via the second adhesive layer 140; and a circuit 70 on the protective layer 50. The switchable film 10 includes a first base layer 21 , a first electrode 23, a functional layer 25, a second electrode 24, and a second base layer 22. The first electrode 23 is electrically connected to the circuit 70 through a busbar 31 and a conductive adhesive 75 provided on the circuit 70. A seal 33 is provided at a cut out portion of the functional layer 25.

[0041] FIG. 3 is a detailed illustration of a switchable film 11 according to an exemplary embodiment of the present disclosure. The switchable film 11 includes a first base layer 21, a first electrode 23, a functional layer 25, a second electrode 24, and a second base layer 22. The first electrode 23 and the second electrode 24 are electrically connected to the circuits 70, respectively, through busbars 31, 32 and conductive adhesives 75, 76 provided on the circuits 70. Seals 33, 34 are provided at cut out portions of the functional layer 25.

[0042] FIG. 4 is a detailed illustration of a switchable film 10, according to an exemplary embodiment of the present disclosure. The switchable film 10 includes a first base layer 21, a first electrode 23, a functional layer 25, a second electrode 24, and a second base layer 22. A circuit 70 is printed on a foil 38 on a protective layer 50 adhered to the switchable film 10 via the second adhesive layer 140. The first electrode 23 is electrically connected to the circuit 70 through a busbar 31 and a conductive adhesive 75 provided on the circuit 70. A seal 33 is provided at a cut out portion of the functional layer 25.

[0043] Where a switchable film 10 is segmented, requiring multiple busbars and electrical connections, the circuit 70 may have multiple, electrically separated connections. FIG. 7 illustrates an embodiment of the present disclosure including a circuit 70 for a segmented switchable film 10.

The circuit 70 includes separate areas for connection to each segment busbar 31 as well as busbar

32 on the non-segmented electrode. In some embodiments, each electrode 23, 24 of the switchable film 10 may be segmented. The circuit 70 may extend from the area for connecting to the busbar

31, 32 to a place for connection to a connector which may reach a power source. FIG. 7 illustrates a protective layer 50 having a circuit 70 thereon for connection to the switchable film 10. The busbars 31, 32 are shown in FIG. 7 for explanation. The busbars 31, 32 may connect to the circuit

70 as described herein.

[0044] The glass product 100 may be produced by a method including: forming the electrical connection path on the protective layer 50; adhering the protective layer 50 to the switchable film

10 via the second adhesive layer 140; and adhering the switchable film 10 to the glass piece 110 via the first adhesive layer 130.

[0045] FIGs. 5 A, 5B and 5C illustrate steps of producing the glass product 100, according to an exemplary embodiment of the present disclosure. A circuit 70 may be printed on a protective layer

50 as shown in FIG. 5A. As shown in FIG. 5B, the protective layer 50 with the circuit 70 may then be adhered to a switchable film 10 which includes a busbar 31 and a conductive adhesive 75 via a second adhesive layer 140 so that the busbar 31 and the circuit 70 are connected via the conductive adhesive 75. The switchable film 10 with the protective layer 50 may then be adhered to a glass piece 110 via a first adhesive layer 130 as shown in FIG. 5C. [0046] As shown in FIG. 6A, the glass piece 111 may have a curved shape. After adhering the protective layer 50 to the switchable film 10 via the second adhesive layer 140, the switchable film

10 may be shaped or curved prior to adhering to the glass piece 111.

[0047] FIG. 6A illustrates a step of producing the glass product 103 shown in FIG. 6B, according to an exemplary embodiment of the present disclosure. When a glass piece 111 has a curved shape, the switchable film 10 with the protective layer 50 may be shaped or curved to complement the glass piece 111 shape prior to adhering to the glass piece 111.

[0048] Adhering the switchable film 10 with the protective layer 50 to the glass piece 110, 111 may be carried out by laminating the switchable film 10 and the glass piece 110, 111 with the first adhesive layer 130 therebetween, which may include adhering them via a vacuum, such as a vacuum bag degassing, or physically pressing them with a roller. The adhering may preferably be processed in a vacuum or double-vacuum thermoforming process such that the first contact of adhesive layer 130 and the glass piece 110, 111 will be under vacuum which may avoid air bubbles in the interface between the glass piece 110, 111 and the adhesive layer 130.

[0049] At least one of the first and the second adhesive layers 130, 140 may be a coating. In other words, at least one of these adhesive layers 130, 140 may be formed by coating an adhesive. The adhering may be carried out at an ambient temperature, i.e., about 10 to 40°C, when the first and the second adhesive layers 130, 140 include, or are formed by, a photocurable, reaction-curable, moisture-curable, or pressure-sensitive adhesive. Adhering at an ambient temperature may be preferable since it can avoid a damage of the switchable film 10 caused by heating.

[0050] 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.

[0051] 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.

Claims

1. A glass product, comprising: a glass piece; a first adhesive layer; a switchable film having variable light transmission adhered to the glass piece via the first adhesive layer; a second adhesive layer; a protective layer adhered to the switchable film via the second adhesive layer; and an electrical connection path for electrically connecting to the switchable film on the protective layer.

2. The glass product according to claim 1, wherein the switchable film is a liquid crystal switchable film.

3. The glass product according to claim 1 or 2, wherein the switchable film includes more than one segment, wherein the more than one segments are electrically controllable independent of one another.

4. The glass product according to any one of claims 1 to 3, wherein the electrical connection path includes a circuit printed onto the protective layer.

5. The glass product according to any one of claims 1 to 3, wherein the electrical connection path includes a circuit printed onto a foil adhered to the protective layer.

6. The glass product according to any one of claims 1 to 5, wherein the switchable film includes a busbar that is connected to the electrical connection path by a conductive adhesive.

7. The glass product according to any one of claims 1 to 5, wherein the switchable film includes a busbar that is connected to the electrical connection path by a solder material.

8. The glass product according to any one of claims 1 to 7, wherein the protective layer includes an area for capacitive switching of the switchable film.

9. The glass product according to any one of claims 1 to 8, wherein the glass product is a sunroof.

10. The glass product according to any one of claims 1 to 9, wherein the protective layer has a thickness of 1.0 mm or less.

11. The glass product according to any one of claims 1 to 10, wherein at least one of the first and the second adhesive layers is a coating.

12. The glass product according to any one of claims 1 to 11, wherein at least one of the first and the second adhesive layers includes a pressure-sensitive adhesive or a cured material of a photocurable. reaction-curable, or moisture-curable adhesive.

13. The glass product according to any one of claims 1 to 12, further comprising a low- emissivity functional element on the protective layer.

14. The glass product according to claim 13, wherein the low-emissivity functional element includes a coating on the protective layer.

15. A method of producing the glass product according to any one of claims 1 to 14, the method comprising: forming the electrical connection path on the protective layer; adhering the protective layer to the switchable film via the second adhesive layer; and adhering the switchable film to the glass piece via the first adhesive layer.

16. The method according to claim 15, wherein the glass piece has a curved shape, and the switchable film with the protective layer adhered thereto is shaped prior to adhering to the glass piece.

17. The method according to claim 15 or 16, wherein at least one of the first and the second adhesive layers includes a photocurable, reaction-curable, moisture-curable, or pressure-sensitive adhesive, and at least one of the adhering the protective layer and the adhering the switchable film is carried out at an ambient temperature.