Variable optical property interlayer film product and method for manufacturing variable optical property interlayer film product

Abstract

A method for making a variable optical property interlayer product includes providing a variable optical property film (S10). The variable optical property film is placed on top of a first lamination interlayer film of lamination interlayer material (S30). A second lamination interlayer film of lamination interlayer material is positioned over the variable optical property film (S50), thereby forming a stack. The stack is laminated (S90) to form a polymer envelope and hermetically encapsulate the electrochromic film. This lamination forms an outer surface of the polymer envelope as a solid / gas interface. Variable optical property interlayer products and packaged variable optical property interlayer products are also disclosed.

Description

[Technical Field]

[0001] The present invention relates generally to the manufacture of laminated glass, and more particularly to an interlayer product containing a variable optical-property film and a method for making the same. [Background technology]

[0002] Glass products that exhibit various types of light-affecting effects have been manufactured for many years. Electrochromic layers, thermochromic layers, photochromic layers, PDLC films, SPD films, LCD films, etc., are applied to the outside of the glass panes or between the panes, providing the possibility to control the light transmission through the glass. This allows for many different types of light and temperature control applications. These variable optical property layers can be manufactured directly on the glass panes. Alternatively, the variable optical property layers can be manufactured as self-supporting films and then attached to or between the panes.

[0003] EP 3011388 presents an example of a highly functional electrochromic glass pane product: a polymer-based structure with a solid electrochromic layer is laminated between a first glass pane and a second glass pane, with interlayer films on both sides of the polymer-based structure with a solid electrochromic layer and between the first glass pane and the second glass pane, respectively, to form a stack.

[0004] Facilities that enable such manufacturing typically require large-area sputtering equipment and precision contacting of the polymer-based structures laminated with the solid electrochromic layer, at least for large-area products. While typical glass manufacturers today certainly have large-area lamination facilities, investments in large-area sputtering equipment and other specialized equipment for manufacturing and / or handling films with variable optical properties, such as polymer-based structures laminated with the solid electrochromic layer, are typically excessive compared to current market demands. While polymer-based structures laminated with the solid electrochromic layer can be provided as rollable films, imperfections can easily be introduced through careless transportation, handling, and / or cutting of such films. Therefore, today's processing instead occurs on-site where the polymer-based structures laminated with the solid electrochromic layer are manufactured, which requires the transportation of heavy glass sheets, first to the electrochromic film manufacturer and then to the insulating glass unit manufacturer, before being shipped to the end customer.

[0005] US Patent Application Publication No. 2022 / 072828 discloses a possible electrically controllable functional element pre-assembled with a protective film. The functional element includes a multilayer film, including a first protective film, a first carrier film, a first planar electrode, an active layer, a second planar electrode, a second carrier film, and a second protective film. The protective film is a PVB film, an EVA film, and / or a TPU film. The functional element also includes one or more sealing films attached to the multilayer film.

[0006] Therefore, there is a need to reduce the amount of heavy transport in such manufacturing chains. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] European Patent No. 3011388 [Patent Document 2] US Patent Application Publication No. 2022 / 072828 Summary of the Invention [Problem to be solved by the invention]

[0008] A general object of the present technology is to find an apparatus and method that allows for more cost-effective and reliable production of glass products that include variable optical property films. [Means for solving the problem]

[0009] The above object is achieved by a method and an apparatus as defined in the independent claims. Preferred embodiments are defined in the dependent claims.

[0010] Generally speaking, in a first aspect, a method for manufacturing a variable optical property interlayer product includes providing a variable optical property film. The variable optical property film is disposed on top of a first lamination interlayer film of a lamination interlayer material. A second lamination interlayer film of the lamination interlayer material is disposed over the variable optical property film, thereby forming a stack. The stack is laminated to form a polymer envelope. The polymer envelope hermetically encapsulates the variable optical property film. The lamination forms an outer surface of the polymer envelope as a solid / gas interface.

[0011] In a second embodiment, a variable optical property interlayer product includes a variable optical property film and a polymer envelope. The polymer envelope hermetically encloses the variable optical property film. The polymer envelope is composed of a lamination interlayer material. The outer surface of the polymer envelope is a solid / gas interface.

[0012] In a third embodiment, a packaged variable optical property interlayer product comprises a variable optical property interlayer product according to the second embodiment and a vacuum bagging film at least partially surrounding the variable optical property interlayer product. [Effects of the Invention]

[0013] One advantage of the proposed technology is that it produces an intermediate product containing the variable optical property portion of a variable optical property glass product, which product is easily transported and handled for the final glass lamination process. Other advantages will be appreciated upon reading the detailed description.

[0014] The invention, together with its objects and advantages, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a process flow diagram of an embodiment of a method for making a variable optical property interlayer product. [Figure 2] FIG. 2 is a process flow diagram of an embodiment of a method for producing glass laminates from variable optical property interlayer products. [Figure 3] 3A-E are schematic diagrams illustrating various stages in an embodiment of a method for making a variable optical property interlayer product. [Figure 4] 4A-B show a schematic representation of the results of one embodiment of the lamination process. [Figure 5] 5A-B show a schematic representation of the results of a lamination process according to another embodiment. [Figure 6] 6A-B show schematic results of yet another embodiment of the lamination process. [Figure 7] FIG. 7 shows a schematic of the layers in one embodiment of an electrochromic film that can be used in the present technology. [Figure 8] FIG. 8 shows a schematic of one embodiment of the placement of connectors on a variable optical property film. [Figure 9] FIG. 9 shows a schematic diagram of another embodiment of the arrangement of connectors on a variable optical property film. [Figure 10]FIG. 10 is a process flow diagram of another embodiment of a method for making an interlayer film product. DETAILED DESCRIPTION OF THE INVENTION

[0016] Throughout the drawings, the same reference numbers are used for similar or corresponding elements.

[0017] To better understand the proposed technology, it may be helpful to start with a brief overview of today's manufacturing challenges.

[0018] Two basic approaches to production logistics exist today. Using electrochromic film as a model system, in the first option, the electrochromic film is manufactured at a manufacturing facility. The electrochromic film is provided in the appropriate size and shape and connected with electrical connections. Heavy glass panes are transported from a glass processing site, which may not necessarily be nearby. The electrochromic film is laminated between the panes using an interlayer material as a lamination adhesive. The glass panes are typically tempered glass, which is provided in the appropriate size and shape and typically must be ordered long in advance. Glass pane breakage and / or other processing defects can occur, requiring spare panes to be available to guarantee delivery of the final product. This leads to additional, heavier transportation and a large amount of broken and unbroken glass panes, which are then directly discarded or recycled.

[0019] In another option, the electrochromic film is provided in rolls and shipped to a glass processing facility. There, the electrochromic film is cut to the appropriate size and shape and electrical connections are made. This operation must be performed in a cleanroom environment, requiring extensive experience with these relatively expensive materials and equipment. The electrochromic film is relatively sensitive to damage and must be handled with extreme care. The electrochromic film then needs to be placed between the glass pane and the interlayer material and sealed in an appropriate manner. This is another complex operation that is far from what is typically done in glass manufacturing facilities. This approach has proven to be very difficult to implement efficiently.

[0020] However, lamination interlayer materials, such as polyvinyl butyral (PVB), have been found to have interesting properties. Lamination of glass sheets with PVB is typically carried out at temperatures between 120 and 140 °C, which allows the PVB to bond to the glass sheets, forming a strong, sealed solid / solid interface.

[0021] However, at low temperatures, adhesion to other PVB objects can still occur even when adhesion to other materials is nonexistent or at least reduced. Different PVB objects can therefore be attached to one another without forming any strong bonds with other external materials. This opens the door to creating PVB envelopes that can hermetically encase electrochromic films. The outer surface of the PVB envelope can have properties similar to those of unlaminated PVB, thereby providing a solid / gas interface that may be suitable for transportation. The PVB envelope can therefore initially serve as a transport protector for the electrochromic film. In a second step, the PVB can be used as a lamination interlayer material, depending on its originally intended role. This dual function of PVB material (first as a transport cover and then as a lamination interlayer) greatly facilitates manufacturing.

[0022] At the electrochromic film manufacturing plant, electrochromic films are produced with the desired composition, size, and shape. Contacting of the electrochromic film can be performed by any suitable method during or in conjunction with the manufacturing process. Once the electrochromic film is complete, it can be encapsulated in a lamination interlayer material, such as PVB, which serves as a shipping envelope. It can then be safely transported to the glass manufacturing site. The electrochromic film itself is typically relatively sensitive to handling, for example, prone to sharp creases. Such sharp creases can destroy or significantly affect the electrochromic function. Encapsulating the electrochromic film in an envelope significantly reduces the risk of sharp creases. At the glass manufacturing site, the PVB envelope with the encapsulated electrochromic film can be placed between glass panes and laminated. Since the electrochromic film is complete and the lamination interlayer is already in place, this can be performed using standard equipment and operations. The encapsulated electrochromic film therefore constitutes a semi-finished product and is interesting for sale as is. Similar arguments can be made for other types of variable optical property devices, including variable optical property films that are compatible with lamination processes.

[0023] 1 is a flow diagram of steps of an embodiment of a method for manufacturing a variable optical property interlayer product. In step S10, a variable optical property (VOP) film is provided. In step S30, the VOP film is placed on top of a first lamination interlayer film of a lamination interlayer material.

[0024] In a preferred embodiment, in step S40, the VOP film is laterally surrounded by the lamination interlayer edge seals of the lamination interlayer material, such that the VOP film is covered from below by the first lamination interlayer film and laterally by the lamination interlayer edge seals.

[0025] In step S50, a second lamination interlayer film of a lamination interlayer material is positioned over the VOP film, thereby forming a stack. In step S90, the stack is laminated to form a polymer envelope. The polymer envelope hermetically encapsulates the VOP film. The lamination step S90 forms the outer surface of the polymer envelope as a solid / gas interface.

[0026] In a preferred embodiment, a side enclosing step S40 is arranged between the placing step S30 and the positioning step S50, and the polymer envelope is formed by a first lamination interlayer film, a second lamination interlayer film, and lamination interlayer edge sealing, where the main purpose of the lamination interlayer edge sealing is to provide thickness compensation so that the thickness of the polymer envelope is as uniform as possible across the entire VOP film area.

[0027] The variable optical property interlayer product thus formed, including the VOP film encapsulated by the polymer envelope, can be stored, shipped, and / or further used in lamination applications, etc. Figure 2 shows a process flow diagram of an embodiment of a glass lamination process using such a variable optical property interlayer product. In step S100, the polymer envelope and the VOP film encapsulated therein are placed between glass panes. In step S110, the glass panes and the envelope are laminated together. Such lamination can be performed according to glass lamination processes used in conventional laminated glass fabrication, without the use of tooling or preparation procedures specifically tailored for this particular variable optical property interlayer product.

[0028] The lamination interlayer material can be any material suitable for use as an interlayer in a lamination process. Examples of materials used in this application include polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyolefins, thermoplastic polyurethanes (TPU), and ionoplasts. Ionoplast interlayers (also called ionomer-based interlayers) are available in different compositions. The most commonly used type is SentryGlass®. Extensive testing has been done with PVB and it is currently the preferred choice. However, the other examples listed above can also be used, at least with adjustments to the lamination temperature.

[0029] Traditionally, the primary role of lamination interlayer materials is to adhere to the materials on either side of the lamination interlayer, thereby forming a strong bond between these materials, which results in a strong solid / solid interface on both sides of the lamination interlayer after lamination.

[0030] In the methods described herein, the use of lamination interlayers is expanded. First, the lamination properties of the lamination interlayer are used in part to provide a polymer envelope that encapsulates the VOP film. This is preferably achieved by exposing the lamination interlayer material to temperatures during the lamination process that induce intra-lamination between different lamination interlayer materials. In other embodiments, the polymer envelope may be formed, at least in part, by other adhesion-enhancing processes.

[0031] As mentioned above, in a typical lamination process, the lamination interlayer material forms a solid / solid interface with the surrounding material. However, in this application, it is important that the outer surface of the polymer envelope, i.e., the outer surface of the lamination interlayer material, is a solid / gas interface.

[0032] It is also important that the lamination properties of the outer surface are maintained as much as possible. When using a crosslinkable lamination interlayer, such as EVA, it is preferable to limit the lamination temperature to a range safely below the crosslinking temperature of the lamination interlayer material. A typical crosslinking temperature for EVA is about 120°C, and the lamination temperature to form the polymer envelope can be set at, for example, a maximum of 100°C.

[0033] If the lamination interlayer material does not exhibit crosslinking properties, lamination conditions can be more freely selected. However, because the lamination interlayer material is typically supplied with a specific surface structure that is advantageous in the normal lamination process, it is preferable to maintain such structure on the polymer envelope surface as much as possible. This is beneficial for the subsequent glass lamination process. To this end, in a preferred embodiment, the lamination process is carried out at a temperature that does not structurally change the outer surface of the polymer envelope.

[0034] In another embodiment, if the lamination temperature is set high enough to change the surface structure, an exterior surface having a suitable structure can be pressed against the polymer envelope during lamination to impart that structure to the outer surface of the envelope.

[0035] In tests, lamination was performed at temperatures below 70°C and showed good results in terms of both intra-adhesion between different lamination interlayer materials and preservation of the outer surface structure. The optimal temperature selection depends on the choice of lamination interlayer material. However, it should be noted that lamination at higher temperatures also produces interlayer products with variable optical properties that are advantageous in the subsequent glass lamination process, even if they do not generally improve the final result. It is currently believed that lamination temperatures can be advantageously maintained below 100°C for most lamination interlayer materials. Lower temperatures generally save energy and heating time, and in preferred embodiments, lamination temperatures are maintained below 80°C.

[0036] The lower limit for lamination also depends on the available process time. Lamination at lower temperatures generally requires longer process times. When using EVA at a lamination temperature of 50°C, long exposure times are possible.

[0037] In other words, in a preferred embodiment, the lamination step is carried out at a temperature in the range of 50°C to 100°C, more preferably at a temperature of 80°C or less, and most preferably at a temperature of 70°C or less.

[0038] 3A-3E schematically illustrate an embodiment of a method for manufacturing a variable optical property interlayer product. In FIG. 3A, a first lamination interlayer film 20 is provided. In FIG. 3B, a VOP film 10 is placed on top of the first lamination interlayer film 20. To ensure a good seal with the lamination interlayer material, a margin 21 is preferably provided between the edge of the VOP film 10 and the edge of the first lamination interlayer film 20. Thus, in a preferred embodiment, the step of placing the VOP film 10 on top of the first lamination interlayer film 20 includes placing the VOP film 10 with a margin 21 of at least 10 mm from the nearest edge of the first lamination interlayer film 20.

[0039] In FIG. 3C, lamination interlayer edge seals 22 are positioned on margin 21, thereby laterally surrounding VOP film 10. The lamination interlayer edge seals are preferably made of the same lamination interlayer material as the first lamination interlayer film. The thickness of lamination interlayer edge seal 22 is preferably comparable to the thickness of VOP film 10, preferably within 20%. The top surface of the arrangement shown in FIG. 3C is generally flat up to the outer edge of lamination interlayer edge seal 22. In this embodiment, the width of lamination interlayer edge seal 22 is equal to margin 21. However, as described below, lamination interlayer edge seal 22 can have a different width, typically smaller than margin 21.

[0040] In Figure 3D, a second lamination interlayer film 24 is placed on top of the VOP film 10 and lamination interlayer edge seal 22. A stack 2 of VOP film 10 disposed between lamination interlayer films 20, 22, and 24 is formed. The stack is subjected to a lamination process, bonding the components made of the lamination interlayer material together. As shown in Figure 3E, this lamination forms a polymer envelope 30 that encapsulates the VOP film 10. The thus-encapsulated VOP film 10 and polymer envelope 30 thereby constitute a variable optical property interlayer product 1, suitable for storage, shipping, and / or further lamination.

[0041] In other words, the variable optical property interlayer product 1 includes a VOP film 10 and a polymer envelope 30. The polymer envelope 30 hermetically encloses the VOP film. The polymer envelope 30 is composed of a lamination interlayer material. The outer surface of the polymer envelope is a solid / gas interface.

[0042] 3A-E, in a preferred embodiment, the polymer envelope 30 includes a first lamination interlayer film 20 and a second lamination interlayer film 24 disposed on opposite sides of the VOP film 10. The polymer envelope 30 further includes lamination interlayer edge seals 22 that laterally surround the VOP film 10 and connect the first lamination interlayer film 20 and the second lamination interlayer film 24.

[0043] FIG. 4A shows a portion of a stack 2 of a first lamination interlayer film 20, a VOP film 10, and a second lamination interlayer film 24, but without a lamination interlayer edge seal. During lamination, the outer edges of the lamination interlayer films 20, 24, and possibly the outer edge of the VOP film 10, deform, forming a polymer envelope. A possible result is shown schematically in FIG. 4B, forming a polymer envelope 30. This type of lamination is possible by using lamination interlayer materials that exhibit low viscosity, particularly when heated. However, lamination process conditions must be carefully controlled to minimize the risk of gas entrapment. The laminating layer 10 forms the outer surface 39 of the polymer envelope 30 as a solid / gas interface.

[0044] Figure 5A shows a stack 2 including lamination interlayer edge seals 22. Figure 5B shows a schematic of the result after lamination. Compared to the embodiment of Figure 4B, the risk of trapping gas pockets and damaging the edges of the VOP film 10 is reduced.

[0045] FIG. 6A shows stack 2 including lamination interlayer edge seals 22, but the width 26 of the lamination interlayer edge seals 22 is smaller than the margins 21. FIG. 6B shows the result after lamination in a schematic representation. The risk of entrapped gas pockets associated with the VOP film 10 is reduced, as is the risk of damaging the edges of the VOP film 10 compared to the embodiment of FIG. 4B. The outermost edges of the lamination interlayer films 20, 24 extend beyond the edges of the lamination interlayer edge seals 22. This can be used, for example, to protect electrical connections to the VOP film 10, as described below. However, the excess polymer envelope 30 is easily trimmed to size for the final glass lamination step.

[0046] The above principles are similar for at least most variable optical property interlayer products. Electrochromic (EC) films are an obvious choice. Other film-based technologies with variable optical properties, such as liquid crystal displays (LCDs), polymer-dispersed liquid crystal films (PDLCs), and suspended particle devices (SPDs), also rely on nontrivial handling and processing of both the active film and the electrical connections. When such VOP films are provided by laminating them between or behind glass panes, the same principles can be applied. Other types of VOP films, such as thermochromic and photochromic films, can also be manufactured using similar principles.

[0047] In other words, in preferred embodiments, the VOP film comprises an electrochromic film, a thermochromic film, a photochromic film, a liquid crystal display (LCD), a PDLC, and / or an SPD.

[0048] In a most preferred embodiment, the variable optical property film comprises an electrochromic film. Such electrochromic films can be of various types known in the art. Preferably, the electrochromic film is provided on a flexible substrate, such as a polymer film. This allows the electrochromic film to be slightly bent without impairing the electrochromic function. Electrochromic films that have proven very advantageous in connection with glass lamination are types that include laminated film structures with solid electrochromic layers provided between polymer films. Such electrochromic films are described, for example, in EP 3011388 and WO 2014 / 170241.

[0049] FIG. 7 shows a schematic partial cross-sectional view of one embodiment of an electrochromic film 10′ that can be used in accordance with the present technology. The electrochromic film 10′ includes two half-cells 31 and 32. Each half-cell 31 and 32 includes a respective polymer substrate sheet 11 and 12, a respective electron-conducting layer 13 and 14, and an electrochromic layer 15 or counter electrode layer 16. In other words, one half-cell of the laminated electrochromic stack (the lower half-cell 31 in FIG. 7 ) includes a first polymer substrate sheet 11, a first electron-conducting layer 13 that at least partially covers the first substrate sheet 11, and a first electrochromic layer 15 that at least partially covers the first electron-conducting layer 13. The other half-cell of the laminated electrochromic stack (top half-cell 32 in FIG. 7 ) includes a second polymeric substrate sheet 12, a second electronically conductive layer 14 at least partially covering second substrate sheet 12, and a counter electrode layer 16 at least partially covering second electronically conductive layer 14. An electrolyte layer 17 is laminated between and at least partially covers first electrochromic layer 15 and counter electrode layer 16. In one embodiment, counter electrode layer 16 may itself be an electrochromic layer.

[0050] However, other types of electrochromic films can also be used in conjunction with the basic concepts presented here.

[0051] To operate many types of variable optical property films, a voltage or other type of electrical signal must be applied between the components of the VOP film. In the embodiment of Figure 7, the first and second electronically conductive layers 13, 14 are typically brought into contact. The process for achieving this is well known in the art and therefore will be understood by those skilled in the art, and will not be described further.

[0052] However, because this technology provides a variable optical property interlayer product intended to be accessed later, some aspects can be discussed. Typically, VOP films are provided with connectors attached to the conductive layer of the VOP film according to methods known in the prior art. FIG. 8 shows such a VOP film 10 having a first connector 18 and a second connector 19. The VOP film 10 is placed on top of a first lamination interlayer film 20 such that the ends of the connectors 18 and 19 are positioned outside the ends of the first lamination interlayer film 20 and, later, the second lamination interlayer film. During lamination, the connectors are embedded in the lamination interlayer material but remain accessible and accessible from outside the polymer envelope.

[0053] In embodiments utilizing edge seals of the lamination interlayer and in which the VOP film is provided with a connector attached to a conductive layer of the VOP film, it is preferred that the step of laterally surrounding the VOP film further includes positioning the end of the connector outside at least the edge seals of the lamination interlayer.

[0054] One such embodiment is shown schematically in Figure 9. Here, bus bars 34, which electrically contact the conductive layers in the VOP film 10, are extended as connectors 18 that protrude outside the lamination interlayer edge seals 22. The connectors 18 are bent 90 degrees outside the lamination interlayer edge seals 22. Thus, as seen in cross-sectional view AA at the bottom of the figure, upon lamination, the ends of the connectors 18 are positioned in the spaces between the protruding portions of the lamination interlayer films 20, 24. For example, by providing an opening in the second lamination interlayer film 24, the connectors 18 can be secured through the holes and become available on the upper surface of the polymer envelope 30.

[0055] In other words, in one embodiment of the variable optical property interlayer product, the variable optical property interlayer product includes a connector attached to the conductive layer of the VOP film, where the connector penetrates the polymer envelope.

[0056] The actual lamination can be performed in many different ways. In one embodiment, the stack lamination process is performed by conveying the stack between heated lamination nip rolls. This is often referred to as "pre-lamination" and is often used as a pre-treatment step before a regular lamination process, e.g., in an autoclave, to help remove air between the lamination interlayer and the surrounding material. By appropriately selecting the lamination interlayer material, temperature, and conveying speed, such "pre-lamination" may be sufficient to produce a polymer envelope based on the above concept. The use of nip rolls in glass lamination involves a glass sheet between the lamination interlayer and the nip rolls, resulting in relatively slow heat transfer. When using nip rolls directly on the lamination interlayer material, the heat transferred from the rolls may be sufficient to cause the formation of a polymer envelope. However, the process conditions must be very carefully controlled.

[0057] Lamination can also be carried out in an autoclave, a vacuum laminator, or in a heated vacuum bag.

[0058] In other words, in one embodiment, the step of laminating the stack is performed as a vacuum lamination.

[0059] The use of a vacuum bag can be advantageous in several ways. Figure 10 shows a flow diagram illustrating the steps of an embodiment of a method for manufacturing a variable optical property interlayer film product using a vacuum bag. Steps common to the previous embodiment will not be discussed in detail again. In step S20, a first lamination film is placed on a polymer foil to form a vacuum bag. This foil is at least twice the size of the VOP film. A stack is then formed in the same manner as described above. In step S50, a free portion of the polymer foil is folded over the top of the stack, and in step S60, the polymer foil is sealed into a bag. This sealing can be done, for example, with butyl tape or by welding. A valve to which a vacuum pump can be connected is also attached to the bag. In step S80, a vacuum is drawn on the vacuum bag. This vacuum compresses the stack at atmospheric pressure and removes any remaining gas between the VOP film and the lamination interlayer film. The stack is then prepared for lamination by increasing the temperature.

[0060] In other words, in one embodiment, a method for manufacturing a variable optical property interlayer product includes placing a first lamination interlayer film on top of a first portion of polymer foil. After positioning a second lamination interlayer film, a second portion of polymer foil is folded over the stack. The second portion is sealed to the first portion, thereby forming a vacuum bag surrounding the stack. A vacuum is drawn on the vacuum bag. Laminating the stack includes heating the vacuum bag.

[0061] Lamination can be performed, for example, in an autoclave or oven, or simply by raising the ambient temperature in some other controllable manner. Once lamination is complete, the vacuum bag can be removed. Due to the temperature limitation, the vacuum bag is at least not completely laminated to the lamination interlayer film and is easily removed.

[0062] In this context, it may also be advantageous to leave part of the vacuum bag in place as an additional layer of protection, e.g. by removing the vacuum valve and possibly the butyl tape as well, a thin additional layer of protection is provided around the variable optical property interlayer product that is easily removed before final lamination.

[0063] In other words, in one embodiment, a packaged variable optical property interlayer product comprises a variable optical property interlayer product according to the above description and a vacuum bagging film surrounding the variable optical property interlayer product. Preferably, the vacuum bagging film comprises a polymer.

[0064] One undesirable aspect of using vacuum bags is that they introduce many processing steps that are performed in an item-by-item manner. This can be inefficient in large-scale processing sequences. Another approach is the use of reusable vacuum rubber bags. In one preferred embodiment, a protective polymer film is provided as a separate component of the vacuum bag assembly, between the rubber material and the lamination interlayer film. This typically facilitates removal of the laminated polymer envelope from the vacuum bag. This protective polymer film can also be attached to the laminated product as the vacuum bag film, providing additional protection for the laminated polymer envelope.

[0065] Yet another potentially attractive approach is where the lamination process for the stack involves processing the stack in a vacuum laminator.

[0066] In a vacuum laminator, the items to be laminated—in this case, a stack of lamination interlayer films and VOP films—are introduced into a heated vacuum compartment by a conveyor system, e.g., a transport belt. The compartment temperature can be maintained approximately at the required lamination temperature. The compartment is sealed and a vacuum is applied. Using a high-performance pump, this procedure typically takes 30 seconds. A vacuum-sealed membrane is placed on top of the stack to be laminated, and gas, preferably heated to the lamination temperature, is introduced into the compartment above the membrane, pressing the membrane against the stack. When normal atmospheric pressure is applied, the pressure on the stack is equivalent to that achieved in a vacuum bag. If a higher pressure is required, pressurized gas can be introduced on top of the membrane. The vacuum and pressure remove any gas between the lamination interlayer film and the VOP film. Heat within the vacuum laminator then causes the lamination. This procedure typically takes from 30 seconds to several minutes, depending on the temperature and choice of lamination interlayer material.

[0067] As mentioned above, the use of high temperatures can affect the surface structure of the polymer envelope. Lamination interlayer films typically exhibit some structure within their surface, which is intended to assist in the intended subsequent lamination process. For example, when the lamination interlayer film is placed on a glass plate or the like, such structure can reduce capillary forces. It can also assist in removing air from the space between the lamination interlayer film and the surface to be laminated. The use of relatively high temperatures in the lamination of this technology can affect or even remove the surface structure of such lamination interlayer films.

[0068] In such a situation, the lamination process can additionally include the creation of a "new" surface structure. This can be easily achieved by providing a suitable structuring to the support surface that the outer surface of the envelope comes into contact with. When the lamination interlayer film softens during lamination, it takes on the same structure as the support surface.

[0069] For example, when using vacuum bags, reusable or otherwise, the material or particular structured sheet used to form the bag can be provided with the desired pattern, and the outer surface of the lamination interlayer film can be placed against these structured support surfaces, so that when the vacuum bag is evacuated, atmospheric pressure presses the surfaces together to achieve the desired structuring.

[0070] Similarly, in vacuum laminators, the stack and film conveyors can be appropriately structured, which embosses the outer surface of the polymer envelope, so that the conveyors and film act as support surfaces, similar to the vacuum bag system.

[0071] The above-described embodiments should be understood as a few illustrative examples of the present invention. Those skilled in the art will understand that various modifications, combinations, and changes can be made to the embodiments without departing from the scope of the present invention. In particular, different part solutions in different embodiments can be combined in other configurations, where technically possible. However, the scope of the present invention is defined by the appended claims.

Claims

1. A method for producing an interlayer film product (1) with variable optical properties, comprising the following steps: A step (S10) of providing a variable optical property film (10); placing the variable optical property film (10) on top of a first lamination interlayer film (20) of a lamination interlayer material (S30); Positioning (S50) a second lamination interlayer film (24) of lamination interlayer material over the variable optical property film (10) to form a stack (2); a step (S90) of laminating the stack (2) to form a polymer envelope (30) hermetically enclosing the variable optical property film (10), The laminating step (S90) forms the outer surface (39) of the polymer envelope (30) as a solid / gas interface. A manufacturing method comprising:

2. Further steps between the placing step (S30) and the positioning step (S50): laterally surrounding (S40) the variable optical property film (10) by lamination interlayer edge seals (22) of lamination interlayer material; the polymer envelope (30) is formed by the first lamination interlayer film (20), the second lamination interlayer film (24), and the lamination interlayer edge seals (22); The method of claim 1 ,

3. The lamination interlayer material is polyvinyl butyral, ethylene vinyl acetate, polyolefin, thermoplastic polyurethanes, and Ionoplast The method according to claim 1 or 2, characterized in that at least one of

4. 4. The method of claim 3, wherein the lamination interlayer material is polyvinyl butyral.

5. 5. A method according to any one of claims 1 to 4, characterized in that the laminating step is carried out at a temperature which causes an internal lamination between the lamination interlayer materials.

6. 6. The method of claim 5, wherein the laminating step is carried out at a temperature that does not structurally alter the outer surface (39) of the polymer envelope (30).

7. 7. The method according to any one of claims 1 to 6, characterized in that the laminating step (S90) is carried out at a temperature in the range of 50°C to 100°C, preferably at a temperature of 80°C or less, most preferably at a temperature of 70°C or less.

8. 8. The method according to any one of claims 1 to 7, characterized in that the step (S30) of placing the variable optical property film (10) on top of the first lamination interlayer film (20) comprises placing the variable optical property film (10) with a margin (21) of at least 10 mm relative to the nearest edge of the first lamination interlayer film.

9. 9. The method according to any one of claims 1 to 8, characterized in that the variable optical property film (10) is provided with connectors (18, 19) attached to conductive layers (13, 14) of the variable optical property film (10), and the step (S30) of placing the variable optical property film (10) on top of the first lamination interlayer film (20) further comprises placing ends of the connectors (18, 19) outside the first lamination interlayer film (20) and the second lamination interlayer film (24).

10. 9. The method according to claim 2, or any one of claims 3 to 8 when dependent on claim 2, wherein the variable optical property film (10) is provided with connectors (18, 19) attached to conductive layers (13, 14) of the variable optical property film (10), and wherein the step (S40) of laterally surrounding the variable optical property film (10) further comprises locating ends of the connectors (18, 19) outside the lamination interlayer edge seals (22).

11. 11. The method according to any one of claims 1 to 10, characterized in that the step (S90) of laminating the stack is performed as a vacuum lamination.

12. placing the first lamination interlayer film (20) on top of a first portion of polymer foil (S10); After the step (S50) of positioning the second lamination interlayer film (24), a step (S60) of folding a second portion of the polymer foil onto the stack (2); a step (S70) of sealing the second part to the first part to form a vacuum bag surrounding the stack (2); and A step (S80) of drawing a vacuum in the vacuum bag; 12. The method of claim 11, further comprising: wherein the step (S90) of laminating the stack (2) comprises heating the vacuum bag.

13. 12. The method of claim 11, wherein the step (S90) of laminating the stack (2) comprises processing the stack (2) in a vacuum laminator.

14. 10. The method according to any one of claims 1 to 9, characterized in that the step (S90) of laminating the stack (2) is performed by conveying the stack (2) between heated lamination rolls.

15. The variable optical property film (10) Electrochromic film, Thermochromic film, Photochromic film, LCD display, Polymer dispersed liquid crystal film, and Suspended Particle Device The method according to any one of claims 1 to 14, characterized in that it comprises at least one of the following.

16. 16. The method of claim 15, wherein the variable optical property film (10) comprises an electrochromic film.

17. 17. The method of claim 16, wherein the electrochromic film comprises a laminated film structure of a solid electrochromic layer disposed between polymer films (11, 12).

18. A variable optical property interlayer film product (1), comprising: a variable optical property film (10), and a polymer envelope (30) hermetically enclosing said variable optical property film (10); Including, said polymer envelope (30) being made of a lamination interlayer material; The variable optical property interlayer product, wherein the outer surface (39) of said polymer envelope (30) is a solid / gas interface.

19. 20. The variable optical property interlayer product of claim 18, wherein the polymer envelope (30) comprises a first lamination interlayer film (20) and a second lamination interlayer film (24) disposed on either side of the variable optical property film (10), and the polymer envelope (30) further comprises lamination interlayer edge seals (22) laterally surrounding the variable optical property film (10) and connecting the first lamination interlayer film (20) and the second lamination interlayer film (24).

20. The lamination interlayer material is polyvinyl butyral, ethylene vinyl acetate, polyolefin, thermoplastic polyurethanes, and Ionoplast 20. The variable optical property interlayer film product of claim 18 or 19, characterized in that it is selected as at least one of:

21. 21. The variable optical property interlayer product of claim 20, wherein the lamination interlayer material is polyvinyl butyral.

22. The variable optical property film (10) Electrochromic film, Thermochromic film, Photochromic film, LCD display, Polymer dispersed liquid crystal film, and Suspended Particle Device The variable optical property interlayer film product according to any one of claims 18 to 21, characterized in that it comprises at least one of:

23. 23. The method of claim 22, wherein the variable optical property film (10) comprises an electrochromic film.

24. 24. The variable optical property interlayer product according to claim 23, characterized in that the electrochromic film (10) comprises a laminated film structure of a solid electrochromic layer disposed between polymer films (11, 12).

25. 25. The variable optical property interlayer product of any one of claims 18 to 24, comprising connectors (18, 19) attached to conductive layers (13, 14) of the variable optical property film (10), said connectors (18, 19) passing through the polymer envelope (30).

26. 1. A packaged variable optical property interlayer product comprising: A variable optical property interlayer film product (1) according to any one of claims 18 to 25, and A vacuum bag film at least partially enclosing said variable optical property interlayer product (1).

1. A packaged variable optical property interlayer product comprising:

27. 27. The packaged variable optical property interlayer product of claim 26, wherein the vacuum bagging film comprises a polymer.

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