A high-contrast dimming glass that automatically adapts to light

Abstract

The utility model provides a high-contrast dimming glass that automatically adapts to light, which is composed of a first glass, an adhesive layer, a polymer dispersed dye liquid crystal dimming element, an adhesive layer, and a second glass stacked in sequence, wherein the polymer dispersed dye liquid crystal dimming element includes a first substrate layer, a polymer dispersed dye liquid crystal layer, and a second substrate layer, and the visible light transmittance of at least one layer in the adhesive layer changes with the change of the incident light. Adding a photochromic material to the adhesive layer can make the adhesive layer present a low light transmittance when the incident light is strong, and a high light transmittance when the incident light is weak, thereby achieving the effect of automatically adapting to external light; through the joint action of the polymer dispersed dye liquid crystal dimming element and the adhesive layer, the contrast of the dimming glass is increased, the dimming glass's ability to adjust visible light is improved, and the dimming glass has a privacy function.

Description

Technical Field

[0001] The utility model relates to the field of dimming glass, in particular to a high-contrast dimming glass which can automatically adapt to light. Background Art

[0002] Dimming glass is widely used in architectural glass or transportation glass. The more mature dimming glass includes different types of dimmable films such as suspended particle (SPD), dye liquid crystal (LC), electrochromic (EC), polymer dispersed liquid crystal (PDLC). The optical performance indicators of dimmable glass mainly include: Visible light transmittance: refers to the transmittance of dimmable glass for visible light, usually refers to the proportion of light within the wavelength range of 400-700nm transmitted through the dimmable glass. The higher the visible light transmittance, the easier it is to transmit light, and the brighter the room.

[0003] When no external electric field is applied to polymer dispersed liquid crystal, the refractive index of light passing through the liquid crystal droplets and the polymer differ greatly, resulting in a strong light scattering state and an opaque film. When an external electric field is applied, the direction vector of the liquid crystal droplet is oriented in the same direction as the electric field, the long-axis refractive index of the liquid crystal matches that of the polymer, and the film is transparent. By turning the power on and off, the film can be changed between transparent and non-transparent states, thus having a privacy protection function and can also be used as a projection screen.

[0004] Existing PDLC dimming glass reduces the visible light transmittance by adding dichroic dyes to the liquid crystal material, and achieves the effect of having different visible light transmittances in the switching state. Contrast is usually used to evaluate the effect of visible light transmittance change. Due to the solubility and dielectric properties of commonly used dichroic dyes in polymer dispersed liquid crystal systems, the contrast of PDLC with dichroic dyes is usually lower than 5, which is mainly manifested in that the visible light transmittance in the switching state does not change significantly, and cannot simultaneously meet the use requirements of having low transmittance under strong light conditions and having high transmittance under weak light conditions. Therefore, a high-contrast dimming glass that automatically adapts to light is needed. Utility Model Content

[0005] The utility model provides a high-contrast dimming glass that automatically adapts to light. The glass is composed of a first glass, a first adhesive layer, a polymer disperse dye liquid crystal dimming element, a second adhesive layer, and a second glass stacked in sequence. The polymer disperse dye liquid crystal dimming element comprises a first substrate layer, a polymer disperse dye liquid crystal layer, and a second substrate layer stacked in sequence. The utility model is characterized in that the visible light transmittance of at least one of the first adhesive layer or the second adhesive layer changes with the change of the intensity of the incident light.

[0006] Furthermore, a high-contrast dimming glass that automatically adapts to light has a visible light transmittance contrast ratio greater than or equal to 10 between its brightest state and its darkest state.

[0007] Furthermore, the visible light transmittance of the first adhesive layer varies between 92% and 8%.

[0008] Furthermore, the visible light transmittance of the first adhesive layer and the second adhesive layer varies between 92% and 8%.

[0009] Furthermore, the polymer disperse dye liquid crystal dimming element layer has an on-state visible light transmittance in the range of 1 to 80%, and an off-state visible light transmittance in the range of 0.1 to 20%.

[0010] Furthermore, the first substrate layer or the second substrate layer is composed of a stack of a PET layer and a transparent conductive layer, wherein the transparent conductive layer is attached to one side of the polymer disperse dye liquid crystal layer.

[0011] Furthermore, the transparent conductive layer is a multi-layer structure.

[0012] Furthermore, the polymer dispersed dye liquid crystal dimming element comprises a plurality of polymer dispersed dye liquid crystal dimming layers, and each of the polymer dispersed dye liquid crystal dimming layers is spaced apart by a third substrate layer.

[0013] Furthermore, the third substrate layer is composed of a first transparent conductive layer, a PET layer and a second transparent conductive layer stacked in sequence.

[0014] The high-contrast dimming glass that automatically adapts to light is composed of a first glass, a first adhesive layer, a polymer dispersed dye liquid crystal dimming element, a second adhesive layer, and a second glass. The polymer dispersed dye liquid crystal dimming element includes a first substrate layer, a polymer dispersed dye liquid crystal layer, and a second substrate layer. The visible light transmittance of at least one of the first adhesive layer or the second adhesive layer changes with the intensity of the incident light.

[0015] Furthermore, the contrast ratio of visible light transmittance between the brightest state and the darkest state of the switchable glass described in the present application is greater than or equal to 10.

[0016] Furthermore, the visible light transmittance of the first adhesive layer varies between 92% and 8%.

[0017] Furthermore, the visible light transmittance of the first adhesive layer and the second adhesive layer varies between 92% and 8%.

[0018] Furthermore, the polymer disperse dye liquid crystal dimming element layer has an on-state visible light transmittance in the range of 1 to 80%, and an off-state visible light transmittance in the range of 0.1 to 20%.

[0019] Further, the first substrate layer or the second substrate layer is composed of a stack of a PET layer and a transparent conductive layer, wherein the transparent conductive layer is attached to one side of the polymer disperse dye liquid crystal layer;

[0020] Furthermore, the transparent conductive layer is a multi-layer structure.

[0021] Furthermore, the polymer disperse dye liquid crystal dimming element has two or more polymer disperse dye liquid crystal dimming layers, and the polymer disperse dye liquid crystal dimming layers are separated by a third substrate layer.

[0022] Furthermore, the third substrate layer is composed of a transparent conductive layer, a PET layer and a transparent conductive layer stacked in sequence.

[0023] In summary, the present application includes at least one of the following beneficial technical effects: adding photochromic material to the adhesive layer can make the adhesive layer present low transmittance when the incident light is strong and high transmittance when the incident light is weak, thereby achieving the effect of automatically adapting to external light; through the combined action of the polymer dispersed dye liquid crystal dimming element and the adhesive layer, the contrast of the dimming glass is increased, the ability of the dimming glass to adjust visible light is improved, and at the same time the dimming glass has a privacy function. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of the PDLC dimming film in the embodiment.

[0025] Description of reference numerals:

[0026] 100——Dimming glass;

[0027] 10 – first glass;

[0028] 20——first bonding layer;

[0029] 30——Polymer disperse dye liquid crystal dimming element;

[0030] 31 - first substrate layer;

[0031] 32 – polymer disperse dye liquid crystal layer;

[0032] 33 - second substrate layer;

[0033] 40——second adhesive layer;

[0034] 50 – second glass; DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0036] In some embodiments, the first glass and the second glass used in the dimming glass are colorless transparent glass or transparent glass with other colors, and the thickness thereof ranges from 1 to 5 mm. They can be flat glass or 3D curved glass.

[0037] In some embodiments, the first adhesive layer or the second adhesive layer is a polymer film, and its material can be one or more of PVB (polyvinyl butyral), EVA (ethylene-vinyl acetate copolymer), POE (polyolefin elastomer), SGP (ionic adhesive film), PU, ​​with a thickness between 0.1-1 mm, and the polymer film is dispersed with materials having photochromic functions, including organic photochromic materials, inorganic photochromic materials and inorganic-organic photochromic materials.

[0038] In some embodiments, the organic photochromic material may be selected from one or more of spiropyrans, spirooxazines, azobenzenes, diarylethenes, fulgides, and Schiff bases.

[0039] In some embodiments, the inorganic photochromic material can be selected from transition metal oxides, metal halides and rare earth complexes: for example, WO3, MoO3, TiO2, calcium iodide and mercuric iodide mixed crystals, copper chloride, zinc chloride, silver chloride, copper-doped ZnS nanocrystals, etc.

[0040] In some embodiments, the inorganic-organic photochromic material is compounded with an organic dye to enhance the effect of the inorganic photochromic material.

[0041] In some embodiments, the transparent conductive layer is a transparent single-layer or multi-layer structure, selected from one or more of nano-silver conductive layer, nano-zinc aluminum oxide (AZO), indium tin oxide (ITO), zinc oxide (ZnO), aluminum gallium indium tin oxide (AlGaInSnO), aluminum zinc oxide (AZO), tin oxide (SnO2), indium oxide (In2O3), zinc tin oxide (SnZnO), and other transparent conductive oxides. The transparent conductive layer may also include an isolation layer with an isolation function, such as silicon oxide (SiO2).

[0042] Description of the status of each component in this application:

[0043] The darkest state of the smart glass refers to exposing the smart glass to strong sunlight until the smart glass no longer changes color and the smart glass is kept in a state where no electricity is supplied.

[0044] The brightest state of the dimming glass refers to the state in which the dimming glass is placed in a dark place until the dimming glass no longer changes color and the dimming glass remains powered.

[0045] The darkest state of the adhesive layer refers to a state in which the adhesive layer laminated with the colorless glass is exposed to strong sunlight until the laminated glass no longer changes color.

[0046] The brightest state of the adhesive layer refers to a state in which the adhesive layer laminated with the colorless glass is placed in a dark place until the dimming glass no longer changes color.

[0047] On-state visible light transmittance of polymer dispersed liquid crystal dimming element: refers to the visible light transmittance of the polymer dispersed liquid crystal dimming element when a current of 48V\2A is passed through it.

[0048] The off-state visible light transmittance of the polymer dispersed liquid crystal dimming element refers to the visible light transmittance of the polymer dispersed liquid crystal dimming element under no power condition.

[0049] Calculation method of contrast ratio between bonding layer and dimming glass:

[0050] Adhesive layer contrast = visible light transmittance of the adhesive layer in the brightest state / visible light transmittance in the darkest state

[0051] The contrast ratio of dimming glass = the transmittance of the dimming film glass in the brightest state / the transmittance in the darkest state.

[0052] Performance testing method:

[0053] Visible light transmittance test of the adhesive layer: Cut the first adhesive layer or the second adhesive layer material into 100×100mm sheets respectively, and hot-press and laminate them with two pieces of 100×100mm colorless glass respectively to make the samples to be tested. The visible light transmittance test was carried out respectively according to the method of GB / T2410-2008.

[0054] Visible light transmittance test of dimming glass: The first adhesive layer, polymer disperse dye liquid crystal dimming element and second adhesive layer materials are cut into 100×100mm sheets respectively, and hot-pressed and laminated with two pieces of 100×100mm colorless glass to make test samples. According to the method of GB / T2410-2008, the visible light transmittance test is carried out respectively. The power-on voltage is 48V and the current is 2A during the measurement.

[0055] The following combination Figure 1 The implementation scheme of this application is further explained.

[0056] Example 1

[0057] The structure of the dimming glass (100) described in this embodiment is as follows: Figure 1 As shown, specifically including:

[0058] The first glass (10) and the second glass (50) are float glass with a thickness of 2.1 mm and a visible light transmittance of 93%.

[0059] The first adhesive layer (20) is an EVA film with a thickness of 0.38 mm, a visible light transmittance of 92% in the brightest state and a visible light transmittance of 25% in the darkest state; the photochromic material used in the first adhesive layer is tungsten oxide doped with a transition metal.

[0060] The polymer dispersed liquid crystal dimming element (30) comprises a first substrate layer (31), a polymer dispersed liquid crystal layer (32) closely attached to one side of the first substrate layer (31), and a second substrate layer (33) attached to one side of the polymer dispersed liquid crystal layer (32). The polymer dispersed liquid crystal dimming element (30) has a visible light transmittance of 4% in an off state and a visible light transmittance of 20% in an on state; wherein the first substrate layer (31) and the second substrate layer (33) are both PET films with sputtered ITO layers, with a thickness of 200 microns; the polymer dispersed liquid crystal layer (32) has a thickness of 15 microns, and a dichroic dye is added to the polymer dispersed liquid crystal.

[0061] The second adhesive layer (40) is an EVA film with a thickness of 0.38 mm and a visible light transmittance of 92%.

[0062] The switchable glass (100) in this embodiment has a visible light transmittance of 0.8% in the darkest state and 18% in the brightest state, with a contrast ratio of 20.

[0063] Example 2

[0064] The difference between the dimming glass (100) in this embodiment and the embodiment 1 is that the first glass layer (10) and the second glass layer (50) are colorless 3D curved glass with a thickness of 2.1 mm and a visible light transmittance of 92%. The photochromic material used in the first adhesive layer is a spiropyran derivative.

[0065] Example 3

[0066] The difference between this embodiment and embodiment 1 is that the second adhesive layer (40) and the first adhesive layer (20) are both EVA films with a thickness of 0.38 mm, a visible light transmittance of 90% in the brightest state, and a visible light transmittance of 20% in the darkest state; the photochromic material used in the first adhesive layer is copper-doped ZnS nanocrystals, and the photochromic material used in the second adhesive layer is a spirooxazine derivative.

[0067] The visible light transmittance of the switchable glass (100) in this embodiment is 0.2% in the darkest state, 19% in the brightest state, and the contrast ratio is 95.

[0068] Example 4

[0069] The difference between this embodiment and embodiment 1 is that the first adhesive layer (20) is an EVA film with a thickness of 0.38 mm, a visible light transmittance of 80% in the brightest state and 8% in the darkest state; and the photochromic material used in the first adhesive layer is an azobenzene derivative.

[0070] The polymer dispersed liquid crystal dimming element (30) has an off-state visible light transmittance of 5% and an on-state visible light transmittance of 35%.

[0071] The visible light transmittance of the switchable glass (100) in this embodiment is 0.4% in the darkest state, 28% in the brightest state, and has a contrast ratio of 70.

[0072] Example 5

[0073] The difference between this embodiment and embodiment 4 is that the first glass layer (10) and the second glass layer (50) are colorless 3D curved glass with a thickness of 2.1 mm and a visible light transmittance of 92%. The photochromic material used in the first adhesive layer is a fulgide derivative.

[0074] Example 6

[0075] The difference between this embodiment and embodiment 1 is that the polymer dispersed dye liquid crystal dimming element (30) comprises two polymer dispersed dye liquid crystal layers. The photochromic material used in the first adhesive layer is a diarylethene derivative.

[0076] The dimming glass (100) in this embodiment has a visible light transmittance of less than 0.1% in the darkest state, a visible light transmittance of 4% in the brightest state, and a contrast ratio of greater than 100.

Claims

1. A high-contrast dimming glass that automatically adapts to light, comprising a first glass, a first adhesive layer, a polymer dispersed dye liquid crystal dimming element, a second adhesive layer, and a second glass stacked in sequence, wherein the polymer dispersed dye liquid crystal dimming element comprises a first substrate layer, a polymer dispersed dye liquid crystal layer, and a second substrate layer stacked in sequence, characterized in that: The visible light transmittance of at least one of the first adhesive layer or the second adhesive layer varies with the intensity of incident light.

2. The high-contrast dimming glass that automatically adapts to light according to claim 1, characterized in that: The contrast ratio of visible light transmittance between the brightest state and the darkest state is greater than or equal to 10.

3. The high-contrast dimming glass that automatically adapts to light according to claim 1, characterized in that: The visible light transmittance of the first adhesive layer varies between 92% and 8%.

4. The high-contrast dimming glass that automatically adapts to light according to claim 1, characterized in that: The visible light transmittance of the first adhesive layer and the second adhesive layer varies between 92% and 8%.

5. The high-contrast dimming glass that automatically adapts to light according to claim 1, characterized in that: The polymer disperse dye liquid crystal dimming element layer has an on-state visible light transmittance in the range of 1 to 80%, and an off-state visible light transmittance in the range of 0.1 to 20%.

6. The high-contrast dimming glass that automatically adapts to light according to claim 1, characterized in that: The first substrate layer or the second substrate layer is composed of a stacked PET layer and a transparent conductive layer, wherein the transparent conductive layer is attached to one side of the polymer disperse dye liquid crystal layer.

7. The high-contrast dimming glass that automatically adapts to light according to claim 6, characterized in that: The transparent conductive layer is a multi-layer structure.

8. The high-contrast dimming glass capable of automatically adapting to light according to claim 1, characterized in that: The polymer dispersed dye liquid crystal dimming element comprises a plurality of polymer dispersed dye liquid crystal dimming layers, and each of the polymer dispersed dye liquid crystal dimming layers is separated by a third substrate layer.

9. The high-contrast dimming glass capable of automatically adapting to light according to claim 8, characterized in that: The third substrate layer is composed of a first transparent conductive layer, a PET layer and a second transparent conductive layer stacked in sequence.

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