A light valve and a dimming glass assembly

Abstract

The present invention provides a light valve having excellent thermal aging resistance, a dimming glass assembly prepared from the light valve, and a method for improving the thermal stability of the light valve. By introducing a polysiloxane synthesized under solvent-free conditions and forming a polymer matrix in a specific structure of the light valve through cross-linking and curing means, the finally prepared light valve exhibits better thermal stability under harsh comparison conditions. At the same time, due to the solvent-free synthesis conditions, a series of problems such as organic solvent pollution in the synthesis and production process are avoided, meeting a wide range of application requirements.

Description

Technical Field

[0001] The present invention relates to the field of electro-optical control materials, and particularly to a light valve with improved thermal aging resistance, a dimming glass assembly prepared from the light valve, and a method for improving the thermal stability of dimming glass. Background Art

[0002] A light valve is an electro-optical control device. Mainly, a light control layer is provided between two layers of transparent conductive films. When an electric field is applied, the arrangement or state of the material in the light control layer changes, thereby changing the light transmission characteristics of this device, such as changing from a low light transmittance to a high light transmittance, or from a high light transmittance to a low light transmittance. Through the action of an electric field, a rapid conversion between the on-state and the off-state can be achieved. According to different light control mechanisms of the light control layer, light valves can be divided into suspended particle light valves, polymer dispersed liquid crystal light valves, electrochemical reaction light valves, etc.

[0003] According to the different substrates of the light valve, the light valve can use a plastic sheet such as PET as the substrate, which is generally called a dimming film; or it can use glass as the substrate, which is generally called dimming glass. The assembly formed after laminating the dimming film is generally called a dimming glass assembly.

[0004] Light valves, dimming glass, and dimming glass assemblies need to withstand high-temperature pressing during the preparation process and are more exposed to the annual test of environmental temperature during use. During these processes, their dimming performance often suffers significant damage. One of the important reasons is that the mechanical properties of the dimming film are poor at high temperatures and its long-term heat resistance stability during subsequent use is poor. This causes great difficulties in the production of dimming glass assemblies and their use in automobiles and buildings. Therefore, the thermal stability of dimming films, dimming glass, and dimming glass assemblies is directly related to their production and service life, which is very important. Conventional dimming films are not ideal in terms of thermal stability, resulting in increased difficulty and cost in actual manufacturing of dimming films, and also restricting the application of dimming films, dimming glass, and dimming glass assemblies.

[0005] Therefore, for the dimming films in the prior art, it is urgently necessary to solve the problem of poor thermal stability of dimming films.

[0006] Based on providing a method for preparing a light valve, the inventors of this patent creatively introduced polysiloxane synthesized by a solvent-free method as a polymer matrix precursor. After adding an initiator, it is crosslinked and cured to obtain a polymer matrix. The finally prepared light valve exhibits better thermal stability under harsh comparison conditions. At the same time, due to the solvent-free synthesis conditions, a series of problems such as organic solvent pollution, metal catalyst residue, precise control of polymer molecular weight, and repetitive production in the synthesis production process are also solved, meeting a wide range of application requirements. Summary of the Invention

[0007] In a first aspect of the present invention, there is provided a light valve, comprising:

[0008] a first transparent substrate,

[0009] a first transparent electrode formed on the first transparent substrate,

[0010] a second transparent substrate,

[0011] a second transparent electrode formed on the second transparent substrate,

[0012] wherein the first transparent electrode and the second transparent electrode are disposed opposite to each other, and

[0013] a light control layer disposed between the first transparent electrode and the second transparent electrode; the light control layer comprises a polymer matrix; suspension medium droplets are dispersed in the polymer matrix; solid light control particles are distributed in the suspension medium droplets;

[0014] the polymer matrix is composed of at least one silicone copolymer, and the silicone copolymer is obtained by sufficient premixing and copolymerization reaction of a silicone oligomer and a crosslinkable silane coupling agent monomer under the action of an acidic catalyst and a reaction control agent, and no organic solvent is used in the synthesis process.

[0015] Further, the silicone oligomer is one or more of a hydroxyl-terminated silicone oligomer and a methoxy-terminated silicone oligomer.

[0016] Further, the silicone oligomer is one or more of a dihydroxy-terminated methylphenyl silicone oligomer, a dimethoxy-terminated methylphenyl silicone oligomer, a dihydroxy-terminated methyl silicone oligomer, and a dimethoxy-terminated methyl silicone.

[0017] Further, the crosslinkable silane coupling agent monomer is one or more of an amino silane coupling agent monomer, a mercapto silane coupling agent monomer, an isocyanate group silane coupling agent monomer, a piperazine group silane coupling agent monomer, a vinyl silane coupling agent monomer, an epoxy silane coupling agent monomer, a methacryloxy silane coupling agent monomer, and an acryloxy silane coupling agent monomer.

[0018] Further, the crosslinkable silane coupling agent monomer is one or more of an epoxy silane coupling agent monomer, a methacryloxy silane coupling agent monomer, and an acryloxy silane coupling agent monomer.

[0019] Further, the acidic catalyst is one or more of sulfuric acid, benzenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, and fluorosulfonic acid.

[0020] Further, the acidic catalyst is one or more of benzenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, and fluorosulfonic acid.

[0021] Further, the reaction control agent is water and / or acetic acid.

[0022] Further, the mass ratio of the siloxane oligomer, the crosslinkable silane coupling agent monomer, the acidic catalyst, and the reaction control agent is 100:1 to 20:0.1 to 5:1 to 10.

[0023] Further, the copolymerization reaction temperature is 40 to 80 °C, and the reaction time is 1 to 10 h.

[0024] Further, the copolymerization reaction temperature is 50 to 60 °C, and the reaction time is 2 to 5 h.

[0025] In order to obtain a crosslinkable modified polysiloxane with higher purity, known technical means in the art such as vacuum distillation under a lower vacuum degree, extraction, and neutralization of the acidic catalyst with an alkaline substance can be used to purify the product obtained by the above method. When necessary, a small amount of solvent such as ethanol, n-heptane, toluene, etc. can also be used to further improve the purification efficiency. The alkaline substance can be selected from commonly used substances in the art such as sodium carbonate, sodium bicarbonate, calcium carbonate, etc.

[0026] Further, the first transparent substrate and the second transparent substrate are glass plates or transparent plastic sheets.

[0027] Further, the first transparent electrode and the second transparent electrode are each independently selected from an ITO conductive layer, an 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, a conductive graphene, and a nano-Cu wire conductive layer.

[0028] Further, a bonding layer is covered on the first transparent electrode and / or the second transparent electrode; the bonding layer material includes at least one of epoxy resin, polyurethane, polyimide resin, polystyrene resin, acrylic resin, modified acrylic acid, or silicone resin.

[0029] Further, the material for forming the suspension medium droplets is selected from at least one of fluorocarbon organic compounds, phthalic acid esters, trimellitic acid esters, dodecylbenzene, polybutene oil, polyacrylates, polymethacrylates, epoxy soybean oil, and epoxy linseed oil. The phthalic acid ester can be dioctyl terephthalate, bis(2-ethylhexyl) isophthalate, dibutyl phthalate, dioctyl phthalate, diisooctyl phthalate, etc.; the trimellitic acid ester can be methyl trimellitate, trioctyl trimellitate, triisodecyl trimellitate, etc.

[0030] Further, in the present invention, the solid light control particles can be optionally suitable light control particles, preferably selected from at least one of oxide nanorods, perovskite nanorods, and polyiodide nanorods.

[0031] Further, the crosslinking and curing occur under the conditions of thermal catalysis or irradiation catalysis. Preferably, a photoinitiator is added to the polymer matrix precursor to cause a polymerization reaction by irradiation. The photoinitiator can be those commonly used in the art, and can be selected from, for example, 184 (CAS No. 947-19-3), ITX (CAS No. 5495-84-1 or 83846-86-0), 819 (CAS No. 162881-26-7), 1173 (CAS No. 7473-98-5), BDK (CAS No. 24650-42-8), BP (CAS No. 119-61-9), TPO (CAS No. 75980–60–8), 369 (CAS No. 119313-12-1), 907 (CAS No. 71868-10-5), including any one of them or any combination thereof.

[0032] Further, the initiator under thermal action is selected from at least one of azobisisobutyronitrile (AIBN), azobisisoheptonitrile (ABVN), dimethyl azobisisobutyrate (AIBME), azobis(2-methylpropionamidine) dihydrochloride (AIBA), azobis(2-methyl-2-imidazoline) dihydrochloride (AIBI), tert-butyl perbenzoate (TBPB), tert-butyl peracetate, and ethyl 3,3-bis(tert-amylperoxy)butyrate.

[0033] Further, the addition amount of the initiator is 0.05% - 1% of the mass of the crosslinkable modified polysiloxane.

[0034] In the second aspect of the present invention, a dimming glass assembly is provided, which comprises

[0035] a first glass plate and a second glass plate, and

[0036] the above-mentioned light valve disposed between the first glass plate and the second glass plate.

[0037] Further, a first interlayer is disposed between the first glass plate and the light valve, and / or a second interlayer is disposed between the second glass plate and the light valve.

[0038] In the present invention, the types of the first glass plate and the second glass plate are not particularly limited, and can be conventional transparent glasses for dimming glass assemblies well-known to those skilled in the art, which can be ordinary glasses such as inorganic glass and organic glass, or can be functional glasses such as UV-blocking glass, IR-blocking glass, Low-E glass, tempered glass, or antibacterial glass, etc., and can also be selected from colored glasses such as gray glass and brown glass.

[0039] In the present invention, there are no special restrictions on the types of the first interlayer and the second interlayer, which are interlayers for conventional dimming glass components well-known to those skilled in the art. They can be EVA films, TPU films, PVB films, or functional films, such as UV-blocking EVA films, UV-blocking TPU films, UV-blocking PVB films, etc. They can also be films with a certain color, such as gray EVA films, gray TPU films, gray PVB films, etc.

[0040] In the present invention, there are no special restrictions on the method of manufacturing the dimming glass component, and any conventional laminating method for dimming glass components in the art can be used, such as laminating in a laminator, or laminating in an autoclave or a laminating box / furnace, etc.

[0041] In the third aspect of the present invention, a method for improving the thermal stability of a light valve is provided, including:

[0042] Providing a light control layer matrix emulsion;

[0043] Coating the light control layer matrix emulsion on the first transparent electrode to form a wet light control layer film;

[0044] Covering the second transparent electrode on the wet light control layer film; and

[0045] Crosslinking and curing the wet light control layer film to obtain the above-mentioned light valve,

[0046] wherein

[0047] the light control layer matrix emulsion contains a polymer matrix precursor; suspension medium droplets are dispersed in the polymer matrix precursor; solid light control particles are distributed in the suspension medium droplets; the polymer matrix precursor is composed of at least one siloxane copolymer, and the siloxane copolymer is obtained by sufficient premixing and copolymerization reaction of a siloxane oligomer and a crosslinkable silane coupling agent monomer under the action of an acidic catalyst and a reaction control agent, and no organic solvent is used in the synthesis process.

[0048] Furthermore, the light control layer matrix emulsion is obtained by the following steps:

[0049] Providing a mixture of a suspension medium containing solid light control particles;

[0050] Providing a polymer matrix precursor; and

[0051] Mixing an initiator for crosslinking and curing the polymer matrix precursor, the mixture of the suspension medium containing solid light control particles, and the polymer matrix precursor.

[0052] In the method for improving the thermal aging stability of the light valve according to the present invention, the light control layer matrix emulsion and the polymer matrix precursor contained therein are in a liquid state. In the light valve of the present invention, the polymer matrix is in a solid state after cross-linking and curing of the polymer matrix precursor.

[0053] The light valve, dimming glass, and dimming glass assembly prepared by the present invention adopt a new solvent-free polymer matrix, and their heat resistance stability is significantly improved. At the same time, a completely solvent-free reaction system is used in the synthesis process of the polymer matrix precursor, avoiding the generation of organic waste liquid and the introduction of organic impurities, which is beneficial to environmental protection and cost reduction. In addition, an acidic catalyst is used in the synthesis process of the polymer matrix precursor, avoiding the residue of metal catalysts, which also plays an important role in improving the heat resistance stability of the light valve. Detailed Embodiments

[0054] Terms

[0055] In the present invention, the following terms used have the meanings defined as follows.

[0056] Light valve:

[0057] A light valve is an electronically controlled light device, mainly with a light control layer disposed between two transparent electrodes. When an electric field is applied, the arrangement or state of the material in the light control layer changes, thereby changing the light transmission characteristics of the device, such as from a low light transmittance to a high light transmittance, or from a high light transmittance to a low light transmittance. Copolymerization:

[0058] Copolymerization is a polymerization reaction between silanol groups, siloxy groups, and between silanol groups and siloxy groups in monomers containing silicon units.

[0059] Cross-linking:

[0060] Cross-linking refers to the polymerization reaction of active groups on the side chains of monomer units in polysiloxane. The side chain refers to the structure covalently connected to the silicon atom other than silanol groups and siloxy groups. In this article, cross-linking is sometimes also referred to as cross-linking and curing or curing, which occurs under thermal catalysis or irradiation catalysis conditions. For example, a photoinitiator is added to polysiloxane to cause a polymerization reaction through irradiation.

[0061] Cross-linkable silane coupling agent monomer:

[0062] A monomer unit with active groups on the side chain that forms polysiloxane and can participate in cross-linking reactions. The side chain refers to the structure covalently connected to the silicon atom other than silanol groups and siloxy groups.

[0063] Polysiloxane:

[0064] A liquid substance obtained by copolymerizing monomers containing siloxane units is called polysiloxane. In this article, polysiloxane is sometimes also referred to as cross-linkable modified polysiloxane or siloxane copolymer.

[0065] The polymer matrix precursor in the present invention is composed of at least one silicone copolymer. When the polymer matrix precursor is composed of only one silicone copolymer, the two terms of silicone copolymer and polymer matrix precursor are equivalent.

[0066] To better illustrate the present invention, the following specific examples are provided, including the preparation of the polymer matrix precursor, the preparation of solid light control particles, the preparation of the liquid suspension medium, the preparation of the dimming film, and the thermal aging test examples.

[0067] Comparative Example 1 Polymer Matrix Precursor Comparative Sample, Existing Synthesis Method

[0068] Add 500 g of hydroxyl-terminated dimethyldiphenyl polysiloxane and 1000 ml of n-heptane to a 2000 ml three-necked flask. Connect a water separator to a condenser on one side of the three-necked flask, add a mechanical stirrer in the middle, and place a thermometer on the other side. Heat the solution in the flask to reflux for 30 minutes. When a small amount of water appears in the water separator, add a catalyst stannous octoate solution (1.3 g dissolved in 100 ml of n-heptane). Then add 30 g of acryloxypropyltrimethoxysilane dropwise over about 5 minutes. The condensation reaction takes about 5 hours. Immediately after that, add 30 ml of trimethylmethoxysilane as a reaction terminator. The termination reaction lasts for 2 hours, and then it is quickly cooled to room temperature.

[0069] Mix and stir 250 ml of ethanol and the cooled reaction solution in a 5000 ml beaker. Then wash the reaction flask with 30 ml of n-heptane and pour it into the beaker. After mixing evenly, add 1000 ml of methanol and stir for 15 min. Pour the resulting mixture into a 5000 ml separating funnel and let it stand for several hours until it layers. Take out the lower layer liquid, pour it into a 2000 ml round-bottom flask, and rotary evaporate it at 70 °C and 10 mbar for 2 h to finally obtain the polymer matrix precursor, i.e., the comparative sample, with a yield of 530 g.

[0070] Example 1 Polymer Matrix Precursor Sample 1, Solvent-Free Synthesis Method

[0071] Add 500 g of hydroxyl-terminated dimethyldiphenyl polysiloxane and 30 g of acryloxypropyl dimethoxysilane to a 1000 ml three-necked flask. Add 0.6 g of methanesulfonic acid and 40 g of water. Connect a water separator to a condenser on one side of the three-necked flask, add a mechanical stirrer in the middle, and place a thermometer on the other side. After stirring well for 1 h, heat the mixture to 55 °C and keep the reaction temperature for 2 h. After the reaction ends, let it cool naturally to room temperature. Pour the reaction solution into a 1000 ml round-bottom flask and rotary evaporate it at 70 °C and 10 mbar for 2 h to finally obtain the polymer matrix precursor, i.e., Sample 1, with a yield of 522 g, a molecular weight Mw = 43000, and a viscosity of 11000 cp.

[0072] Example 2 Polymer Matrix Precursor Sample 2, Solvent-Free Synthesis Method

[0073] Add 500 g of hydroxyl-terminated dimethyldiphenyl polysiloxane, 60 g of acryloxypropyl dimethoxysilane, 0.6 g of trifluoromethanesulfonic acid, and 40 g of water into a 1000 ml three-necked flask. Connect a water separator to one side of the three-necked flask and then connect a condenser. Add a mechanical stirrer in the middle and place a thermometer on the other side. After stirring thoroughly for 1 h, heat the mixture to 55 °C and maintain the reaction temperature for 2 h. After the reaction is completed, let it cool naturally to room temperature. Pour the reaction solution into a 1000 ml round-bottom flask and rotary evaporate it at 70 °C and 10 mbar for 2 h. Finally, obtain the polymer matrix precursor, namely Sample 2, with a yield of 545 g, a molecular weight Mw = 45000, and a viscosity of 11900 cp.

[0074] Example 3 Polymer Matrix Precursor Sample 3, Solvent-Free Synthesis Method

[0075] Add 500 g of hydroxyl-terminated dimethyldiphenyl polysiloxane, 100 g of methacryloxypropyl dimethoxysilane, 0.9 g of benzenesulfonic acid, and 40 g of water into a 1000 ml three-necked flask. Connect a water separator to one side of the three-necked flask and then connect a condenser. Add a mechanical stirrer in the middle and place a thermometer on the other side. After stirring thoroughly for 1 h, heat the mixture to 55 °C and maintain the reaction temperature for 2 h. After the reaction is completed, let it cool naturally to room temperature. Pour the reaction solution into a 1000 ml round-bottom flask and rotary evaporate it at 70 °C and 10 mbar for 2 h. Finally, obtain the polymer matrix precursor, namely Sample 3, with a yield of 590 g, a molecular weight Mw = 44000, and a viscosity of 11300 cp.

[0076] Example 4 Polymer Matrix Precursor Sample 4, Solvent-Free Synthesis Method

[0077] Add 500 g of hydroxyl-terminated dimethyldiphenyl polysiloxane, 10 g of methacryloxypropyl trimethoxysilane, 0.6 g of methanesulfonic acid, and 40 g of water into a 1000 ml three-necked flask. Connect a water separator to one side of the three-necked flask and then connect a condenser. Add a mechanical stirrer in the middle and place a thermometer on the other side. After stirring thoroughly for 1 h, heat the mixture to 55 °C and maintain the reaction temperature for 2 h. After the reaction is completed, let it cool naturally to room temperature. Pour the mixture into a 1000 ml round-bottom flask, add 100 ml of ethanol and 10 g of sodium carbonate into the round-bottom flask, stir thoroughly, then perform vacuum filtration. Pour the reaction solution into a 1000 ml round-bottom flask and rotary evaporate it at 70 °C and 10 mbar for 2 h. Finally, obtain the polymer matrix precursor, namely Sample 4, with a yield of 501 g, a molecular weight Mw = 51000, and a viscosity of 13000 cp.

[0078] Example 5 Polymer Matrix Precursor Sample 5, Solvent-Free Synthesis Method

[0079] Add 500 g of hydroxyl-terminated dimethyldiphenyl polysiloxane, 40 g of methacryloxypropyl dimethoxysilane, 0.6 g of methanesulfonic acid, and 70 g of acetic acid to a 1000 ml three-necked flask. Connect a water separator to one side of the three-necked flask and then connect a condenser. Add a mechanical stirrer in the middle and a thermometer on the other side. After stirring well for 1 h, heat the mixture to 55 °C and maintain the reaction temperature for 2 h. After the reaction is completed, let it cool naturally to room temperature. Pour the mixture into a 1000 ml round-bottom flask, add 100 ml of ethanol and 10 g of calcium carbonate to the round-bottom flask, stir well, and then perform vacuum filtration. Pour the reaction solution into a 1000 ml round-bottom flask and rotary evaporate it at 70 °C and 10 mbar for 2 h. Finally, obtain the polymer matrix precursor, i.e., sample 5, with a yield of 532 g, a molecular weight Mw = 42000, and a viscosity of 10900 cp.

[0080] Example 6 Polymer Matrix Precursor Sample 6, Solvent-Free Synthesis Method

[0081] Add 500 g of hydroxyl-terminated dimethyldiphenyl polysiloxane, 40 g of methacryloxypropyl dimethoxysilane, 0.6 g of methanesulfonic acid, and 60 g of acetic acid to a 1000 ml three-necked flask. Connect a water separator to one side of the three-necked flask and then connect a condenser. Add a mechanical stirrer in the middle and a thermometer on the other side. After stirring well for 1 h, heat the mixture to 55 °C and maintain the reaction temperature for 2 h. After the reaction is completed, let it cool naturally to room temperature. Pour the reaction solution into a 1000 ml round-bottom flask and rotary evaporate it at 70 °C and 10 mbar for 2 h. Finally, obtain the polymer matrix precursor, i.e., sample 6, with a yield of 534 g, a molecular weight Mw = 35000, and a viscosity of 10300 cp.

[0082] Example 7 Polymer Matrix Precursor Sample 7, Solvent-Free Synthesis Method

[0083] Add 500 g of hydroxyl-terminated dimethyldiphenyl polysiloxane, 40 g of methacryloxypropyl dimethoxysilane, 0.6 g of methanesulfonic acid, and 50 g of acetic acid to a 1000 ml three-necked flask. Connect a water separator to one side of the three-necked flask and then connect a condenser. Add a mechanical stirrer in the middle and a thermometer on the other side. After stirring well for 1 h, heat the mixture to 55 °C and maintain the reaction temperature for 2 h. After the reaction is completed, let it cool naturally to room temperature. Pour the reaction solution into a 1000 ml round-bottom flask and rotary evaporate it at 70 °C and 10 mbar for 2 h. Finally, obtain the polymer matrix precursor, i.e., sample 7, with a yield of 532 g, a molecular weight Mw = 29000, and a viscosity of 9500 cp.

[0084] Example 8 Polymer Matrix Precursor Sample 8, Solvent-Free Synthesis Method

[0085] Add 500 g of hydroxyl-terminated dimethyl diphenyl polysiloxane, 40 g of methacryloxypropyl dimethoxysilane, 0.6 g of methanesulfonic acid, and 80 g of acetic acid into a 1000 ml three-necked flask. Connect a water separator to one side of the three-necked flask and then connect a condenser. Add a mechanical stirrer in the middle and place a thermometer on the other side. After stirring thoroughly for 1 h, heat the mixture to 55 °C and maintain the reaction temperature for 2 h. After the reaction is completed, let it cool naturally to room temperature. Pour the reaction solution into a 1000 ml round-bottom flask and rotary evaporate it at 70 °C under 10 mbar for 2 h. Finally, obtain the polymer matrix precursor, namely sample 8, with a yield of 530 g, a molecular weight Mw = 53000, and a viscosity of 13200 cp.

[0086] Preparation of Solid Light-Controlling Particles

[0087] Add 30 g of an isopentyl acetate solution containing 21.2 wt% nitrocellulose (model SS 1 / 4 sec), 6 g of I2, 70 g of isopentyl acetate, and 4 g of anhydrous CaI2 into a 250 mL three-necked round-bottom glass flask, and heat to 42 °C. After the I2 dissolves, add 6 g of anhydrous methanol, 0.8 g of distilled water, and 4 g of 2,5-pyrazinedicarboxylic acid dihydrate into the above three-necked round-bottom glass flask, and heat and stir the reaction at 42 °C for 4 h, then let it cool naturally. Centrifuge the obtained reaction solution at 1350 g for 0.5 h to remove large particle products, and then centrifuge the supernatant at 18000 g for 5 h. Discard the supernatant to obtain solid light-control particles. Disperse these solid light-control particles thoroughly with 250 mL of isopentyl acetate.

[0088] Preparation of Suspension Medium

[0089] Add 24.4 g of dodecyl methacrylate, 2.0 g of 2-hydroxyethyl methacrylate, 2.3 g of 1-hexanethiol, and 20 mL of toluene into a 250 mL three-necked round-bottom glass flask respectively. Install a mechanical stirrer in the middle of the three-necked round-bottom glass flask, connect a condenser to one side, and place a thermometer on the other side and connect it to argon gas. Before starting to heat, pass argon gas into the round-bottom glass flask for about 10 min to completely displace the air in the round-bottom glass flask. Then heat the flask to 60 °C. At this temperature, add a 10 mL toluene solution containing 0.20 g of azobisisobutyronitrile into the flask. Maintain the reaction temperature at 60 °C for a total of 21 h, then raise the reaction temperature to make the reaction solution reflux for about 3 h. Stop the reaction. Then treat it with a rotary evaporator at 100 °C for 3 h to remove toluene and unreacted raw materials, and obtain the suspension medium.

[0090] Mixture of Suspension Medium Containing Solid Light-Controlling Particles

[0091] Add 40 g of the obtained suspension medium into a 250 mL round-bottom glass flask, and add the isopentyl acetate dispersion of the prepared solid light-control particles in batches. Remove the isopentyl acetate by a rotary evaporator, and finally continue to treat for 3 h at 80 °C using the rotary evaporator to obtain a mixture of the suspension medium containing solid light-control particles.

[0092] Preparation of Light-Controlling Layer Matrix Emulsion

[0093] Mix evenly the initiator for crosslinking and curing the polymer matrix precursor, the mixture of the suspension medium containing solid light-control particles, and the polymer matrix precursor. The obtained mixture is called the light-control layer matrix emulsion.

[0094] Mix evenly 0.03 g of photoinitiator 819, 3.0 g of the prepared mixture of the suspension medium containing solid light-control particles, and 7.0 g of the polymer matrix precursors prepared in Examples 1-10 and Comparative Example 1 respectively to obtain Examples of light-control layer matrix emulsions 1-10, and the comparative example light-control layer matrix emulsion.

[0095] Preparation of Light-Adjusting Film

[0096] Apply the above Examples of light-control layer matrix emulsions 1-10 and the comparative example light-control layer matrix emulsion respectively on the ITO / PET transparent conductive film with a doctor blade type automatic film coater (Model MSK-AFA-III, MTI Corporation) to a thickness of 80 microns. Cover another layer of ITO / PET transparent conductive film on the wet film of the light-control layer matrix emulsion to obtain a wet film containing the light-control layer. Then, under a nitrogen atmosphere, cure for 1 minute using an X200-150 ultraviolet curing machine produced by Aventk Corporation, and the UV power is 700 W / m 2 , thus obtaining Examples of light-adjusting films 1-10 and the comparative example light-adjusting film.

[0097] Transmittance Test of Light-Adjusting Film

[0098] Measure the light transmittance of the light-adjusting film with an LS116 light transmittance meter (Shenzhen Linshang Technology Co., Ltd.). When no voltage is applied (off state), the light transmittance of the light-adjusting film is marked as Toff = %; when 220 V alternating current at 60 Hz is applied (on state), the total light transmittance of the light-adjusting film is marked as Ton = %.

[0099] Thermal Aging Test

[0100] Carry out thermal aging on the test samples in a common oven at 90 °C for 500 h.

[0101] The light modulation performances of the light modulation films prepared from the polymer matrix precursors of the comparative examples and the examples were tested separately, and the results are listed in Table 1. It can be seen therefrom that the light modulation films prepared by the solvent-free method can fully achieve the light modulation performances of the light modulation films prepared by the solvent-based system of the comparative examples. The light modulation ranges of all samples are between 0.7% and 60.5%, and the light valve haze is less than 3.5%.

[0102] Table 1 Light modulation performances of light modulation films with different polymer matrix precursors

[0103] Polymer Matrix Precursor Light-Adjusting Film Toff Ton Haze Comparative Example Comparative Example 0.8％ 60.5％ 2.95％ Example 1 Example 1 0.8％ 60.3％ 2.54％ Example 2 Example 2 0.7％ 59.9％ 2.18％ Example 3 Example 3 0.8％ 60.2％ 2.65％ Example 4 Example 4 0.8％ 60.4％ 2.56％ Example 5 Example 5 0.7％ 60.0％ 2.76％ Example 6 Example 6 0.8％ 60.5％ 2.43％ Example 7 Example 7 0.8％ 60.4％ 2.21％ Example 8 Example 8 0.8％ 60.4％ 2.25％

[0104] The light modulation films of the examples and the comparative examples were subjected to thermal aging treatment in a common oven under the condition of 90 °C for 500 h. Then, the light modulation performances of the aged light modulation films were tested, and the results are listed in Table 2. It can be seen therefrom that after thermal aging, compared with the light modulation film samples 1-10 of the examples and the light modulation film samples of the comparative examples, the light transmission effect in the dark state is similar, while the performance in the bright state is more stable. After the aging treatment, the bright state light transmittance of the light modulation film of the comparative example decreased from 60.5% before the treatment to 57.9%, while the bright state light transmittance of the light modulation film prepared by the examples was basically maintained at 60%. It can be confirmed therefrom that the light modulation film prepared from the polymer matrix precursor prepared by the solvent-free method can achieve a more stable thermal aging effect compared with the products prepared by the prior art, while maintaining the initial performance unchanged.

[0105] Table 2 Influence of different polymer matrix precursors on the aging performance of light modulation films

[0106] Polymer Matrix Precursor Light-Adjusting Film Initial Performance Performance after Aging at 90°C for 500 h Comparative Example 1 Comparative Example 1 0.8％-60.5％ 0.9％-57.9％ Example 1 Example 1 0.8％-60.3％ 1.1％-60.8％ Example 2 Example 2 0.7％-59.9％ 1.0％-60.5％ Example 3 Example 3 0.8％-60.2％ 0.9％-59.8％ Example 4 Example 4 0.8％-60.4％ 0.9％-60.1％ Example 5 Example 5 0.7％-60.0％ 0.8％-59.7％ Example 6 Example 6 0.8％-60.5％ 0.9％-60.0％ Example 7 Example 7 0.8％-60.4％ 0.9％-60.1％ Example 8 Example 8 0.8％-60.4％ 0.9％-60.1％

[0107] The above examples described the present invention by taking the test results of the light modulation films as representatives. Obviously, the idea of the present invention is also fully applicable to light modulation glasses and light modulation glass assemblies.

[0108] The description of the above examples is only used to help understand the method and its core idea of the present invention. Various modifications to these examples will be obvious to those skilled in the art. The general principles defined herein can be implemented in other examples without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these examples shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A light valve, comprising: a first transparent substrate, a first transparent electrode formed on a first transparent substrate, The second transparent substrate, a second transparent electrode formed on a second transparent substrate, The first transparent electrode and the second transparent electrode are arranged opposite to each other, and A light control layer is disposed between the first transparent electrode and the second transparent electrode; the light control layer comprises a polymer matrix; droplets of a suspension medium are dispersed in the polymer matrix; solid light control particles are distributed in the droplets of the suspension medium; The polymer matrix is ​​composed of at least one siloxane copolymer, characterized in that the siloxane copolymer is obtained by fully premixing and copolymerizing siloxane oligomers and crosslinkable silane coupling agent monomers under the action of an acidic catalyst and a reaction control agent, and no organic solvent is used in the synthesis process; The siloxane oligomer is one or more of a hydroxyl-terminated siloxane oligomer and a methoxy-terminated siloxane oligomer; The cross-linkable silane coupling agent monomer is one or more of an amino silane coupling agent monomer, a mercapto silane coupling agent monomer, an isocyanate silane coupling agent monomer, a piperazine silane coupling agent monomer, a vinyl silane coupling agent monomer, an epoxy silane coupling agent monomer, a methacryloxy silane coupling agent monomer, and an acryloxy silane coupling agent monomer; The acidic catalyst is one or more of sulfuric acid, benzenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, and fluorosulfonic acid; The reaction control agent is water and / or acetic acid; The mass ratio of the siloxane oligomer, the cross-linkable silane coupling agent monomer, the acid catalyst and the reaction control agent is 100:1-20:0.1-5:1-10.

2. The liquid crystal light valve according to claim 1, wherein The copolymerization reaction temperature is 40-80° C., and the reaction time is 1-10 hours.

3. A light valve according to claim 1, characterized in that, The first transparent substrate and the second transparent substrate are glass plates or transparent plastic sheets.

4. A light valve according to claim 1, characterized in that, The first transparent electrode and the second transparent electrode are each independently selected from 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.

5. A light valve according to claim 1, characterized in that, The first transparent electrode and / or the second transparent electrode is covered with an adhesive layer; The material of the bonding layer includes at least one of epoxy resin, polyurethane, polyimide resin, polystyrene resin, acrylic resin, modified acrylic resin or silicone resin.

6. A light valve according to claim 1, wherein, The material forming the suspension medium droplets is selected from at least one of fluorocarbon organic compounds, phthalates, trimellitates, dodecylbenzene, polybutene oil, polyacrylate, polymethacrylate, epoxidized soybean oil, and epoxidized linseed oil.

7. A light valve according to claim 1, characterized in that, The solid light-controlling particles are selected from at least one of oxide nanorods, perovskite nanorods, and polyiodine compound nanorods.

8. A light valve according to claim 1, characterized in that, The polymer matrix is ​​obtained by crosslinking and curing at least one siloxane copolymer, and the crosslinking and curing occurs under the conditions of thermal catalysis or radiation catalysis; the radiation catalysis is to add a photoinitiator to the siloxane copolymer to induce a polymerization reaction by radiation.

9. A light valve according to claim 8, characterized in that, The photoinitiator is selected from at least one of 184, ITX, 819, 1173, BDK, BP, TPO, 369, and 907.

10. A dimming glass component, characterized in that, Include The first glass plate and the second glass plate, and A light valve as claimed in any one of claims 1 to 9 disposed between the first glass plate and the second glass plate.

11. A dimming glass component according to claim 10, characterized in that, A first interlayer is disposed between the first glass plate and the light valve, and / or a second interlayer is disposed between the second glass plate and the light valve.

12. A method for improving the thermal stability of a light valve, comprising: Providing a light control layer matrix emulsion; Coating the light control layer matrix emulsion on a first transparent electrode to form a wet film of the light control layer; Covering the wet film of the light control layer with a second transparent electrode; And Crosslinking and curing the wet film of the light control layer to obtain a light valve as claimed in any one of claims 1 to 9, wherein The light control layer matrix emulsion contains a polymer matrix precursor; suspension medium droplets are dispersed in the polymer matrix precursor; solid light control particles are distributed in the suspension medium droplets; the polymer matrix precursor is composed of at least one silicone copolymer, characterized in that the silicone copolymer is obtained by sufficient premixing and copolymerization reaction of a silicone oligomer and a crosslinkable silane coupling agent monomer under the action of an acidic catalyst and a reaction control agent, and no organic solvent is used in the synthesis process.

13. A method for improving the thermal stability of an optical valve according to claim 12, characterized in that, The light control layer matrix emulsion is obtained by the following steps: Providing a mixture of a suspension medium containing solid light control particles; Providing a polymer matrix precursor; and Mixing an initiator for crosslinking and curing the polymer matrix precursor, the mixture of the suspension medium containing solid light control particles, and the polymer matrix precursor.