Dimming film and dimming glass

Abstract

According to the dimming film and the dimming glass provided by the invention, the transparent plastic base material pre-constructed with the micropore array is introduced into the light control layer, and the micropores are filled with the light control medium, so that the visual effect of macroscopically displaying a specific pattern can be achieved; and meanwhile, the transparent plastic base material and the light control medium can be more thoroughly separated from each other microcosmically, so that the performance of the light adjusting film can be fully exerted. According to the invention, a complex wet film curing process in the prior art can be omitted, the production process of the dimming film is simplified, the problem of performance degradation of the dimming film caused by a high-temperature and high-pressure laminating process during manufacturing of the dimming glass is effectively avoided, and the working stability of the dimming glass is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of electronic light-controlling materials, and in particular to a preparation method and application of a dimming film and dimming glass. Background Art

[0002] A dimming film is an electronic light-control device that essentially places a light-control layer between two layers of transparent conductive film. When an electric field is applied, the arrangement or state of the materials in the light-control layer changes, thereby altering the device's light transmission characteristics, such as switching from low transmittance to high transmittance, or vice versa. Through the action of the electric field, rapid switching between on and off states can be achieved. Depending on the light-control mechanism of the light-control layer, dimming films can be categorized as suspended particle dimming films, polymer dispersed liquid crystal dimming films, and electrochemical reaction dimming films.

[0003] Currently, the light-controlling layer of suspended particle dimming films consists of at least three components: a polymer matrix, a suspension medium, and light-controlling particles, i.e., electrically polarized particles. The wet coating and curing process is the core step in the preparation of the dimming film. This involves the polymer matrix precursor (such as acrylate-modified polysiloxane) undergoing a cross-linking reaction initiated by light or heat to form a stable three-dimensional network structure. However, the existing wet film curing process often suffers from incomplete curing of the polymer matrix precursor, resulting in performance degradation of the dimming film during the high-temperature and high-pressure lamination process used to manufacture the dimming glass.

[0004] The present invention uses laser technology (nanosecond, femtosecond or picosecond) to etch and punch holes on a transparent plastic substrate according to a pre-designed scheme to form a microhole array, and then fills the microholes with light-controlling medium to achieve orderly distribution of the light-controlling medium through directional hole arrangement.

[0005] The present invention achieves the following technical effects: A pre-designed micropore array enables the visual display of specific patterns; micropore confinement significantly enhances the physical strength of the dimming film and fully segments the light-controlling medium. The introduction of a microporous transparent plastic substrate eliminates the complex wet film curing process commonly used in existing technologies, simplifying the production process for the dimming film. This avoids the performance degradation of the dimming film during the high-temperature, high-pressure lamination process used to manufacture the dimming glass, often caused by incomplete curing of the polymer matrix precursor and incomplete phase separation between the polymer matrix precursor and the suspending medium. Furthermore, the substrate provides a microfluidic environment for the suspending medium, liquid crystal active components, and electrochemically active components, significantly improving the dimming speed and range of the dimming film. Summary of the Invention

[0006] The inventors have proposed a dimming film and dimming glass. By setting a transparent plastic substrate in the light-control layer, presetting micropores with a specific arrangement on the transparent plastic substrate, and filling the micropores with a light-control medium, a special pattern display effect can be achieved on a macro scale and good physical strength can be achieved on a micro scale, avoiding the problem of incomplete curing of the wet film in the prior art leading to performance degradation of the dimming film during the production of dimming glass.

[0007] In a first aspect of the present invention, a dimming film is provided, comprising a first transparent substrate, a first transparent conductive layer, a light-controlling layer, a second transparent conductive layer, and a second transparent substrate stacked in sequence; wherein the light-controlling layer comprises a transparent plastic substrate with a preset micropore array and a light-controlling medium filled in the micropores.

[0008] Furthermore, the transparent plastic substrate is selected from at least one of polyester sheets, polyolefin sheets, and silicone polymer sheets.

[0009] Furthermore, the transparent plastic substrate is selected from at least one of polyethylene terephthalate (PET) sheets, polymethyl methacrylate (PMMA) sheets, amorphous copolyester (PETG) sheets, polyvinyl chloride (PVC) sheets, silicone rubber (SR) sheets, cyclic olefin copolymer (COC) sheets, polyethylene (PE) sheets, transparent polypropylene (PP) sheets, fluorinated polyethylene propylene (FEP) sheets, polystyrene methyl methacrylate (SMMA) sheets, ionomer sheets, general-purpose polystyrene (GPPS, also known as transparent polystyrene) sheets, allyl diglycol carbonate (ADCt) sheets, polysulfone (PSU) sheets, polyethylene naphthalate (PEN) sheets and colorless polyimide (PI) sheets.

[0010] Furthermore, the transparent plastic substrate is selected from at least one of polycarbonate (PC) sheets, polyethylene terephthalate (PET) sheets, polyethylene (PE) sheets, polypropylene (PP) sheets, and organosilicon polymer (PDMS) sheets.

[0011] Furthermore, the transparent plastic substrate has a thickness of 10 to 200 μm.

[0012] Furthermore, the light transmittance of the transparent plastic substrate is ≥80%.

[0013] Furthermore, the difference in room temperature refractive index between the transparent plastic substrate and the light-controlling medium is ≤0.01.

[0014] Furthermore, the difference in room temperature refractive index between the transparent plastic substrate and the light-controlling medium is ≤0.005.

[0015] Furthermore, the light-controlling medium is selected from at least one of a suspended particle light-controlling medium, a polymer dispersed liquid crystal light-controlling medium, and an electrochromic light-controlling medium.

[0016] In some possible implementations, the suspended particle light-controlling medium includes a non-conductive liquid suspension medium and solid light-controlling particles.

[0017] Furthermore, the non-conductive liquid suspension medium is selected from at least one of mineral insulating oil, synthetic insulating oil, and vegetable oil.

[0018] Furthermore, the mineral insulating oil is transformer oil.

[0019] Furthermore, the synthetic insulating oil is selected from at least one of silicone oil, fluorocarbon organic compounds, phthalic acid diester, trimellitic acid triester, dodecylbenzene, polybutene oil, polymethacrylate, and polyacrylate.

[0020] Furthermore, the vegetable oil is selected from at least one of castor oil, soybean oil and rapeseed oil.

[0021] Furthermore, the solid light-controlling particles are electrodichroic solid particles.

[0022] Furthermore, the solid light-controlling particles are polyiodine compound nanorods.

[0023] Furthermore, the solid light-controlling particles are selected from at least one of iodine-containing perovskite nanorods, iodine-quinine nanorods, and polyiodinated organic carboxylic acid complex nanorods.

[0024] In some possible implementations, the polymer dispersed liquid crystal light control medium includes a polymer matrix and a light control active component, namely, liquid crystal.

[0025] In some possible implementations, the electrochromic light-controlling medium includes a polymer matrix, an electrochromic active component, namely a polymer material such as poly (3,4-ethylenedioxythiophene) or an inorganic material such as tungsten oxide.

[0026] Furthermore, the micropores have a pore diameter of 1 to 50 μm.

[0027] Furthermore, the micropores have a pore diameter of 5 to 20 μm.

[0028] Furthermore, the microporous channel is at least one of a straight channel and a curved channel.

[0029] Furthermore, the microporous channels are at least one of penetrating the transparent plastic substrate and not penetrating the transparent plastic substrate.

[0030] Furthermore, the micropores are formed by nano-imprinting, photolithography or etching a transparent plastic sheet.

[0031] Furthermore, the nanoimprinting is to transfer the micro-nano structure on the template to the transparent plastic substrate with the assistance of photoresist, and the processing accuracy can reach 2 nanometers.

[0032] Furthermore, the mask lithography is a process in which light emitted by a photolithography machine passes through a mask with a preset pattern to expose a transparent plastic substrate coated with photoresist. The properties of the photoresist will change after being exposed to light, so that the pattern on the mask is accurately copied to the transparent plastic substrate.

[0033] Furthermore, the etching method is at least one of ion beam etching, deep silicon etching, reactive ion etching, focused ion beam etching, inductively coupled plasma etching, microwave plasma etching, laser etching or chemical etching.

[0034] Furthermore, the etching is performed by laser etching.

[0035] Laser etching is to focus a low-power laser with high beam quality (usually ultraviolet laser, fiber laser) on a very small light spot, forming a high power density at the light spot, and making the light spot located on the transparent plastic substrate, so that the transparent plastic substrate at the light spot is instantly heated, while the transparent plastic substrate outside the light spot is not heated, so that the transparent plastic substrate at the light spot peels off and forms micropores.

[0036] Furthermore, the first transparent conductive layer and / or the second transparent conductive layer is selected from at least one of an ITO conductive layer, a FZO conductive layer, an IZO conductive layer, a GZO conductive layer, an AZO conductive layer, a PEDOT conductive layer, a nano-Ag wire conductive layer, conductive graphene and a nano-Cu wire conductive layer.

[0037] Furthermore, the first transparent substrate and the second transparent substrate are transparent plastic plates.

[0038] Furthermore, the light-controlling medium is injected into the micropores of the transparent plastic substrate by dipping.

[0039] Furthermore, the transparent plastic substrate is subjected to a vacuum operation before the dipping process.

[0040] Furthermore, the pressure of the vacuum operation is 0.1-500 Pa.

[0041] The second aspect of the present invention provides a switchable glass, characterized in that it comprises

[0042] a first glass sheet and a second glass sheet, and

[0043] The dimming film is arranged between the first glass plate and the second glass plate.

[0044] In the present invention, the type of the glass plate is not particularly limited. It can be any transparent glass used for conventional dimming glass well known to those skilled in the art. It can be ordinary glass such as inorganic glass and organic glass, or functional glass such as UV blocking glass, IR blocking glass, Low-E glass, tempered glass or antibacterial glass, etc. It can also be selected from colored glass such as gray glass and brown glass.

[0045] Furthermore, a first interlayer is provided between the first glass plate and the dimming film, and / or a second interlayer is provided between the second glass plate and the dimming film.

[0046] Furthermore, the first interlayer and the second interlayer are selected from at least one of PVB, EVA and TPU.

[0047] In the present invention, the first interlayer and the second interlayer can be EVA film, TPU film, PVB film, or functional film, such as UV-blocking EVA film, UV-blocking TPU film, UV-blocking PVB film, etc., or can be films with a certain color, such as gray EVA film, gray TPU film, gray PVB film, etc.

[0048] According to the structure of the dimming glass, the layers are stacked and placed, and then laminated to obtain the dimming glass.

[0049] Furthermore, the temperature of the lamination treatment is 90-140° C., and the pressure is 0.1-1.5 MPa.

[0050] Furthermore, the laminating equipment may be a laminator, an autoclave, or a laminating box / furnace.

[0051] A third aspect of the present invention relates to an application of the above-mentioned dimming film or the above-mentioned dimming glass in vehicle window glass, skylight glass and glass curtain wall.

[0052] The dimming film and dimming glass of the present invention can effectively control the distribution of the light-controlling medium by arranging a transparent plastic substrate with a preset micropore array in the light-controlling layer, omitting the complex wet film curing process in the prior art and avoiding partial miscibility between the polymer matrix precursor and the suspension medium. The above dual effects can ensure that the dimming performance of the dimming film is fully exerted and long-term stable.

[0053] The dimming film and dimming glass of the present invention can be applied to vehicles and buildings that require dimming, and can also be applied to scenes that require special visual display effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. The drawings described below are merely embodiments of the present invention. Those skilled in the art can also derive other drawings based on the provided drawings without inventive effort.

[0055] Figure 1 Schematic diagram of a cross section of the dimming film of the present invention;

[0056] Figure 2 Schematic diagram of a cross section of the switchable glass of the present invention;

[0057] Among them, 1 is the first transparent substrate, 2 is the first transparent conductive layer, 3 is the light control layer, 4 is the second transparent conductive layer, 5 is the second transparent substrate; 6 is the first glass plate, 7 is the second glass plate, 8 is the first interlayer, and 9 is the second interlayer. DETAILED DESCRIPTION

[0058] In the present invention, the concepts of the first transparent substrate, the second transparent substrate, the first transparent conductive layer, the second transparent conductive layer, the first glass plate, the second glass plate, the first interlayer, and the second interlayer merely indicate the relative relationship between them and are not restrictive conditions. They do not necessarily need to be in a first-second relationship, but may also be in an up-down relationship, or a front-back, left-right, or other directional relationship.

[0059] The present invention provides a transparent plastic substrate with a preset micropore array, which is used in the light-control layer of a dimming film as a carrier of a light-control medium. The substrate realizes the display of a preset pattern through the confining effect of the micropores, and can effectively improve the dimming performance of the dimming film and extend the life of the dimming film.

[0060] In order to better illustrate the present invention, the following specific examples are provided.

[0061] Example 1: dimming film

[0062] A polycarbonate (PC) sheet with a thickness of 60 μm was selected as the transparent plastic substrate.

[0063] Nanosecond laser pulses with a wavelength of 355 nm and a frequency of 50 kHz were used to etch through microholes with a diameter of 5 μm and a spacing of 1 μm on the transparent plastic sheet.

[0064] Preparation of suspended particle light-controlling medium:

[0065] To a 250 mL three-necked round-bottom glass flask, add 30 g of an isoamyl acetate solution containing 21.2 wt% nitrocellulose (SS1 / 4sec), 6 g of I2, 70 g of isoamyl acetate, 4 g of anhydrous CaI2, and 4 g of titanium dioxide (P25) and heat to 42°C. After the I2 has dissolved, add 6 g of anhydrous methanol, 0.8 g of distilled water, and 4 g of 2,5-pyrazinedicarboxylic acid dihydrate to the flask. Heat and stir at 42°C for 4 hours, then cool naturally. The resulting reaction solution is centrifuged at 1350 g for 0.5 h to remove large particles. The supernatant is then centrifuged at 18,000 g for 5 h and discarded to obtain light-controllable particles. 3.0 g of the light-controllable particles and 26.9 g of transformer oil are mixed to obtain a suspended particle light-control medium.

[0066] The punched transparent plastic substrate was vacuumed at a pressure of 100 Pa for 2 hours, and then the suspended particle light-controlling medium was injected into the vacuumed transparent plastic substrate and immersed for 0.5 hours.

[0067] The impregnated transparent plastic substrate is covered on the ITO transparent conductive film, and then another layer of ITO transparent conductive film is covered on the transparent plastic substrate to obtain the following: Figure 1 The dimming performance of the suspended particle dimming film 1 is shown in Table 1.

[0068] Example 2: dimming film

[0069] A polyethylene terephthalate (PET) sheet with a thickness of 100 μm was selected as the transparent plastic substrate.

[0070] Using the nanoimprint method, through micropores with a pore size of 10 μm and a spacing of 0.5 μm are etched on the above transparent plastic sheet, and these micropores together form a wavy shape.

[0071] Preparation of polymer dispersed liquid crystal light control medium:

[0072] Trimethylolpropane triacrylate, small molecule nematic liquid crystal 76G9700 (n0 = 1.49, Δn = 0.15, T n-1 =122°C, a low-melting mixture of biphenyl cyanide and terphenyl cyanide), a polymer liquid crystal mixed liquid was prepared by mixing in a mass ratio of 53.0:45.3, and stirred evenly to obtain a polymer dispersed liquid crystal light control medium.

[0073] The punched transparent plastic substrate was vacuumed at a pressure of 200 Pa for 1.5 hours, and then the polymer dispersed liquid crystal light control medium was injected into the vacuumed transparent plastic substrate and immersed for 1 hour.

[0074] The impregnated transparent plastic substrate is covered on the FZO transparent conductive film, and then another layer of FZO transparent conductive film is covered on the transparent plastic substrate to obtain the following: Figure 1 The dimming performance of the polymer dispersed liquid crystal dimming film 2 is shown in Table 1.

[0075] Example 3: dimming film

[0076] A polyethylene (PE) sheet with a thickness of 40 μm was selected as the transparent plastic substrate.

[0077] Using mask lithography, micropores with a diameter of 16 μm and a pitch of 0.5 μm were etched into the transparent plastic sheet. These micropores formed a floral pattern. The punctured transparent plastic substrate was vacuumed at a pressure of 400 Pa for 1 hour. The suspended particle light-control medium prepared in Example 1 was then injected into the vacuumed transparent plastic substrate and allowed to soak for 1 hour.

[0078] The impregnated transparent plastic substrate is covered on the AZO transparent conductive film, and then another layer of AZO transparent conductive film is covered on the transparent plastic substrate to obtain the following: Figure 1 The dimming performance of the suspended particle dimming film 3 shown is shown in Table 1.

[0079] Example 4: Smart Glass

[0080] The first transparent substrate, the first interlayer, the suspended particle dimming film 1 prepared in Example 1, the second interlayer and the second transparent substrate were stacked in sequence and placed in an autoclave, and interlayered at 130° C. and 1.1 MPa to obtain the following: Figure 2 The dimming performance of the dimming glass 4 is shown in Table 1. The first transparent substrate and the second transparent substrate are selected from ordinary white glass, and the first interlayer and the second interlayer are selected from EVA film.

[0081] Example 5: Smart Glass

[0082] The first transparent substrate, the first interlayer, the polymer dispersed liquid crystal dimming film 2 prepared in Example 2, the second interlayer and the second transparent substrate were stacked in sequence and placed in an autoclave, and interlayered at 130° C. and 1.5 MPa to obtain the following: Figure 2 The dimming performance of the dimming glass 5 is shown in Table 1. The first transparent substrate and the second transparent substrate are selected from tempered glass, and the first interlayer and the second interlayer are selected from TPU film.

[0083] Example 6: Smart Glass

[0084] The first transparent substrate, the first interlayer, the suspended particle dimming film 3 prepared in Example 3, the second interlayer and the second transparent substrate were stacked in sequence and placed in an autoclave, and interlayered at 130° C. and 1.5 MPa to obtain the following: Figure 2 The dimming performance of the dimming glass is shown in Table 1. The first transparent substrate and the second transparent substrate are selected from UV-blocking glass, and the first interlayer and the second interlayer are selected from EVA film.

[0085] Comparative Example 1: Smart Glass

[0086] The same as Example 4 was used except that a conventional suspended particle dimming film was used instead of the suspended particle dimming film 1 prepared in Example 1 to obtain the dimming glass of Comparative Example 1. The dimming performance of the dimming glass is shown in Table 1.

[0087] Comparative Example 2: Smart Glass

[0088] The same as Example 5, except that a conventional polymer dispersed liquid crystal dimming film was used instead of the polymer dispersed liquid crystal dimming film 2 prepared in Example 2, to obtain the dimming glass of Comparative Example 2. The dimming performance of the dimming glass is shown in Table 1.

[0089] Table 1 Dimming membrane / Dimming properties of glass

[0090] Examples Toff Ton Example 1 1.0％ 58.5％ Example 2 2.1％ 60.5％ Example 3 1.0％ 59.3％ Example 4 1.0％ 58.3％ Example 5 2.0％ 60.0％ Example 6 1.0％ 58.9％ Comparative Example 1 1.5％ 38.2％ Comparative Example 2 2.8％ 49.8％ Conventional suspended particle dimming film 1.0％ 60.1％ Conventional polymer dispersed liquid crystal dimming film 2.0％ 60.3％

[0091] In Table 1, Toff represents the dark-state transmittance of the switchable film or switchable glass, and Ton represents the bright-state transmittance of the switchable film or switchable glass. Comparing Comparative Example 1 with Examples 4 and 6 shows that the suspended particle switchable film prepared by the present invention exhibits no significant degradation in dimming performance during the lamination process for making switchable glass. For example, Ton slightly decreases from 60.1% to 58.3% and 58.9% respectively. In contrast, the conventional suspended particle switchable film used in Comparative Example 1 exhibits a significant degradation in Ton from 60.1% to 38.2% during the lamination process. Similarly, comparing Comparative Example 2 with Example 5 shows that the polymer-dispersed liquid crystal switchable film prepared by the present invention exhibits no significant degradation in dimming performance during the lamination process for making switchable glass. For example, Ton slightly decreases from 60.3% to 60.0%. In contrast, the conventional polymer-dispersed liquid crystal switchable film used in Comparative Example 2 exhibits a significant degradation in Ton from 60.3% to 49.8% during the lamination process.

[0092] The above embodiments are intended only to facilitate understanding of the methods and core concepts of the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but is intended to be construed in the widest manner consistent with the principles and novel features disclosed herein.

Claims

1. A dimming film, characterized in that: It includes a first transparent substrate, a first transparent conductive layer, a light-controlling layer, a second transparent conductive layer, and a second transparent substrate stacked in sequence; wherein the light-controlling layer includes a transparent plastic substrate with a preset micropore array and a light-controlling medium filled in the micropores.

2. The dimming film according to claim 1, wherein: The transparent plastic substrate is selected from at least one of polyester sheets, polyolefin sheets, and silicone polymer sheets.

3. The dimming film according to claim 1, wherein: The transparent plastic substrate is selected from at least one of polycarbonate sheets, polyethylene terephthalate sheets, polyethylene sheets, polypropylene sheets, and silicone polymer sheets.

4. The dimming film according to claim 1, wherein: The difference in room temperature refractive index between the transparent plastic substrate and the light-controlling medium is ≤0.

01.

5. The dimming film according to claim 1, wherein: The difference in room temperature refractive index between the transparent plastic substrate and the light-controlling medium is ≤0.

005.

6. The dimming film according to claim 1, wherein: The light-controlling medium is selected from at least one of a suspended particle light-controlling medium, a polymer dispersed liquid crystal light-controlling medium, and an electrochromic light-controlling medium.

7. The dimming film according to claim 6, wherein: The suspended particle light-controlling medium includes a non-conductive liquid suspended medium and solid light-controlling particles.

8. The dimming film according to claim 7, characterized in that: The non-conductive liquid suspension medium is selected from at least one of mineral insulating oil, synthetic insulating oil, and vegetable oil.

9. The dimming film according to claim 8, characterized in that: The mineral insulating oil is transformer oil.

10. The dimming film according to claim 8, characterized in that: The synthetic insulating oil is selected from at least one of silicone oil, fluorocarbon organic compounds, phthalic acid diester, trimellitic acid triester, dodecylbenzene, polybutene oil, polymethacrylate, and polyacrylate.

11. The dimming film according to claim 8, characterized in that: The vegetable oil is selected from at least one of castor oil, soybean oil and rapeseed oil.

12. The dimming film according to claim 7, wherein: The solid light-controlling particles are electrodichroic solid particles.

13. The dimming film according to claim 7, characterized in that: The solid light-controlling particles are polyiodine compound nanorods.

14. The dimming film according to claim 7, characterized in that: The solid light-controlling particles are selected from at least one of iodine-containing perovskite nanorods, iodine-quinine nanorods, and polyiodine organic carboxylic acid complex nanorods.

15. The dimming film according to claim 1, characterized in that: The micropore diameter is 1 to 50 μm.

16. The dimming film according to claim 1, wherein: The micropore channel is at least one of a straight channel and a curved channel.

17. The dimming film according to claim 1, wherein: The microporous channels are at least one of penetrating the transparent plastic substrate and not penetrating the transparent plastic substrate.

18. The dimming film according to claim 1, wherein: The micropores are formed by nano-imprinting, photolithography or etching a transparent plastic substrate.

19. The dimming film according to claim 1, wherein: The first transparent conductive layer and / or the second transparent conductive layer is selected from at least one of an ITO conductive layer, a FZO conductive layer, an IZO conductive layer, a GZO conductive layer, an AZO conductive layer, a PEDOT conductive layer, a nano-Ag wire conductive layer, conductive graphene and a nano-Cu wire conductive layer.

20. The dimming film according to claim 1, wherein: The first transparent substrate and the second transparent substrate are transparent plastic plates.

21. A dimming glass, characterized in that: Include a first glass sheet and a second glass sheet, and The dimming film according to any one of claims 1 to 20 is disposed between the first glass plate and the second glass plate.

22. The switchable glass according to claim 21, characterized in that: A first interlayer is provided between the first glass plate and the dimming film, and / or a second interlayer is provided between the second glass plate and the dimming film.

23. Use of the smart film according to any one of claims 1 to 20 or the smart glass according to any one of claims 21 to 22 in vehicle window glass, skylight glass and glass curtain wall.

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