Light valve and dimming glass assembly with thermal stability

Abstract

The present invention provides a light valve and a dimming glass component with thermal stability. By introducing an acrylic acid ester monomer with a TEMPO nitroxide free radical structure, a macromolecular copolymer is prepared by a heating polymerization method to form a suspension medium with a nitroxide free radical structure, thereby improving the anti-aging and anti-degradation properties of the dimming film, thereby improving the thermal stability of the light valve and the dimming glass component, extending their service life, and meeting actual use requirements.

Description

Technical Field

[0001] The invention relates to the field of electronic light-controlling materials, and in particular to a light valve and a dimming glass component with thermal stability. Background Art

[0002] A light valve is an electronic light control device. It is mainly composed of a light control layer between two transparent conductive films. When the electric field is turned on, the arrangement or state of the material in the light control layer changes, thereby changing the light transmittance of the device, such as from low transmittance to high transmittance, or from high transmittance to low transmittance. Through the action of the electric field, it can achieve rapid conversion between the on state and the off state. According to the 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] Depending on the substrate of the light valve, the light valve can be based on a plastic sheet such as PET, which is generally called a dimming film; or it can be based on glass, which is generally called a dimming glass. The assembly formed by laminating the dimming film is generally called a dimming glass assembly.

[0004] Smart film, smart glass and smart glass components need to withstand high-temperature pressing during the preparation process, and must withstand the long-term test of ambient temperature during actual use. All of these put forward requirements for the heat resistance and stability of the products.

[0005] The inventor of this patent provides a method for preparing a light valve, and creatively introduces a specific type of acrylate monomer with a TEMPO nitroxide free radical structure, and prepares a specific type of macromolecular copolymer containing a TEMPO nitroxide free radical structure by means of heat polymerization, forming a suspension medium with its unique structure for use in a dimming film. The TEMPO nitroxide free radical structure can play the role of a free radical scavenger, inhibiting polymerization, anti-aging, and inhibiting thermal degradation, thereby improving the overall thermal stability of the dimming film material. After the thermal stability is improved, the dual protective effect of the suspension medium on the physical distribution state and chemical stability state of the light-controlling particles is also improved, thereby significantly improving the overall thermal stability of the dimming film, dimming glass, and dimming glass components, extending their service life, and meeting actual use needs. Summary of the invention

[0006] On the basis of proposing a light valve and a light valve preparation method, the inventor further improved the polymer composition of the suspension medium to enhance its thermal stability.

[0007] A first aspect of the present invention provides a light valve, comprising:

[0008] a first transparent substrate,

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

[0010] The second transparent substrate,

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

[0012] The first transparent electrode and the second transparent electrode are arranged opposite to each other, and

[0013] A light-controlling layer is arranged between the first transparent electrode and the second transparent electrode; the light-controlling layer comprises a polymer matrix; wherein suspension medium droplets are dispersed in the polymer matrix, solid light-controlling particles are distributed in the suspension medium droplets, and the suspension medium contains a TEMPO nitroxide free radical structure.

[0014] Furthermore, the suspension medium is obtained from at least one acrylic ester copolymer, and the acrylic ester copolymer is obtained by copolymerizing monomers containing the following units under the action of a copolymerization catalyst:

[0015] (a) selected from alkyl acrylate monomers,

[0016] (b) selected from hydroxy acrylate monomers, and

[0017] (c) an acrylate monomer having a TEMPO nitroxide free radical structure, which has the following structural formula:

[0018]

[0019] R1 is selected from a group containing at least one element of C, H, N, O, S, and P;

[0020] R2 is H or CH3.

[0021] Furthermore, the ratio of the monomers (a), (b) and (c) forming the acrylic ester copolymer is such that, based on the total mass of 100 parts, the proportion of monomer (a) is 50 to 95 parts by mass, the proportion of monomer (b) is 0 to 30 parts by mass, and the proportion of monomer (c) is 5 to 20 parts by mass.

[0022] Furthermore, the ratio of the monomers (a), (b) and (c) forming the acrylic ester copolymer is such that, based on the total mass of 100 parts, the proportion of monomer (a) is 50 to 93 parts by mass, the proportion of monomer (b) is 2 to 30 parts by mass, and the proportion of monomer (c) is 5 to 20 parts by mass.

[0023] Furthermore, the peak molecular weight of the acrylic ester copolymer is 1,000 to 10,000.

[0024] Furthermore, the peak molecular weight of the acrylic ester copolymer is 1000-6000.

[0025] Furthermore, the copolymerization catalyst of the monomers (a), (b) and (c) for forming the acrylic copolymer is a thermally initiated free radical catalyst, preferably at least one of an azo initiator, tributyltin hydride (n-Bu3SnH) / AIBN, ammonium persulfate and an organic peroxide.

[0026] Furthermore, the azo initiator is selected from at least one of azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), dimethyl azobisisobutyrate (AIBME), azobisisobutylamidine hydrochloride (AIBA), and azobisisobutylimidazoline hydrochloride (AIBI).

[0027] Furthermore, the suspension medium also includes a non-conductive liquid, and the non-conductive liquid is selected from at least one of fluorocarbon organic compounds, phthalates, trimellitic acid esters, dodecylbenzene, polybutene oil, epoxidized soybean oil and epoxidized linseed oil.

[0028] Furthermore, the solid light-controlling particles are selected from one or more of oxide nanorods, perovskite nanorods and polyiodine compound nanorods; the particle length of the solid light-controlling particles is 50 to 800 nm; and the particle aspect ratio of the solid light-controlling particles is 2 to 30.

[0029] Furthermore, the mass ratio of the total mass of the suspension medium and the solid light-controlling particles to the polymer matrix is ​​1:(1-10); the mass ratio of the acrylic ester copolymer in the suspension medium to the total mass of the suspension medium is 1:(1-5); the mass ratio of the suspension medium to the solid light-controlling particles is 1:(0.05-0.2).

[0030] The present invention also provides an acrylate copolymer, comprising monomers of (a), (b), and (c) units; the (a) monomer is selected from alkyl acrylate monomers; the (b) monomer is selected from hydroxy acrylate monomers; and the (c) monomer is selected from acrylate monomers having a TEMPO nitroxide free radical structure. The ratio of the (a), (b), and (c) monomers forming the acrylate copolymer is, assuming the total mass is 100 parts, the proportion of the monomer (a) is 50 to 95 parts by mass, the proportion of the monomer (b) is 0 to 30 parts by mass, and the proportion of the monomer (c) is 5 to 20 parts by mass.

[0031] Furthermore, the polymer matrix is ​​a solid siloxane polymer.

[0032] Furthermore, the polymer matrix is ​​formed by cross-linking and curing an organic silicone oil polymer matrix precursor having unsaturated bonds.

[0033] Further, a photoinitiator is added to the polymer matrix precursor to induce polymerization reaction by irradiation. The photoinitiator can be those commonly used in the art, for example, it can be selected from 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 thereof or any combination thereof.

[0034] In a second aspect of the present invention, a dimming glass assembly with excellent thermal stability is provided, comprising a first glass plate and a second glass plate, and a light valve containing the TEMPO nitroxide free radical structure suspension medium disposed between the first glass plate and the second glass plate.

[0035] Further, a first interlayer is provided between the first glass plate and the light valve, and / or a second interlayer is provided between the second glass plate and the light valve.

[0036] In the present invention, there is no special restriction on the types of the first glass plate and the second glass plate. They can be transparent glass used in conventional dimming glass assemblies well known to those skilled in the art. They 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. They can also be selected from colored glass such as gray glass and brown glass.

[0037] In the present invention, there is no special restriction on the types of the first interlayer and the second interlayer, which are conventional interlayers for dimming glass components well known to those skilled in the art, and may 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., or films with certain colors, such as gray EVA films, gray TPU films, gray PVB films, etc.

[0038] In the present invention, the method for manufacturing the dimming glass assembly is not particularly limited, and can be a conventional laminating method of the dimming glass assembly in the art, such as laminating in a laminator, or laminating in an autoclave or a laminating box / furnace.

[0039] The suspension medium of the light valve in the present invention is obtained from at least one acrylate copolymer, wherein the acrylate copolymer contains a unit (c) of an acrylate monomer having a TEMPO nitroxide free radical structure. Compared with the acrylate copolymer without the unit (c), the test performance of the acrylate copolymer containing the unit (c) having a TEMPO nitroxide free radical structure in the thermal aging stability experiment is significantly improved. At the same time, the introduction of the monomer (c) having a TEMPO functional group to participate in the polymerization reaction to generate a high thermal stability suspension medium is conducive to the physical distribution state and chemical stability state of the light control particles. Finally, the working stability of the light valve and the light valve assembly under the thermal aging test conditions is significantly improved, the service life of the dimming glass is extended, and a wide range of application needs are met. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. The drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work.

[0041] Figure 1 A schematic diagram of the structure of a dimming film provided by an embodiment of the present invention, wherein 1 is a transparent electrode, 2 is a light-controlling layer, 3 is a transparent substrate, 21 is a polymer matrix, 22 is a suspension medium droplet containing solid light-controlling particles, and 23 is a solid light-controlling particle.

[0042] Figure 2 This is the GPC test result of the acrylic ester copolymer prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0043] the term

[0044] In the present invention, the following terms used have the meanings defined below.

[0045] Light valve:

[0046] A light valve is an electronic light control device, which mainly consists of a light control layer arranged between two layers of transparent conductive films. When the electric field is turned on, the arrangement or state of the material in the light control layer changes, thereby changing the light transmittance characteristics of the device, such as changing from low transmittance to high transmittance, or from high transmittance to low transmittance.

[0047] TEMPO Nitroxide Radical Structure:

[0048] Having a structure as shown in formula (B),

[0049]

[0050] Alkyl acrylate monomer:

[0051] The monomer unit (a) forming the acrylic ester copolymer has the chemical formula:

[0052] CH2=CR1COO-R1' Formula (1)

[0053] Wherein, R1 is CH3 or H; R1' is C n H 2n+1 , n is an integer from 1 to 18.

[0054] Hydroxyacrylate monomer:

[0055] The monomer unit (b) forming the acrylic ester copolymer has the chemical formula:

[0056] CH2=CR2COO-R2' Formula (2)

[0057] Wherein, R2 is CH3 or H; R2' is C q H 2q -OH, q is an integer of 1-8.

[0058] The suspension medium is sometimes also referred to herein as liquid suspension medium.

[0059] The suspension medium in the present invention is composed of at least one acrylic ester copolymer. When the suspension medium is composed of only one acrylic ester copolymer, the two terms acrylic ester copolymer and suspension medium are equivalent.

[0060] The present invention provides a light valve that can significantly improve its thermal stability. By using an acrylate monomer with a TEMPO functional group and then heating and polymerizing to form an acrylate copolymer, the suspension medium containing the acrylate copolymer can effectively solve the problem of poor thermal stability of the dimming film. In particular, the present invention can effectively achieve an improvement in thermal stability relative to materials without unit (c) by using the unit (c) of the following structural formula (A), that is, an acrylate monomer with a TEMPO nitroxide free radical structure:

[0061]

[0062] R1 is selected from a group containing at least one element of C, H, N, O, S, and P;

[0063] R2 is H or CH3.

[0064] See also Figure 1The acrylic acid ester monomer with TEMPO functional group in unit (c) contains nitrogen oxide free radicals, has the function of capturing free radicals and quenching singlet oxygen, and is not easy to degrade. After heating polymerization reaction, an acrylic acid TEMPO ester copolymer is formed, that is, the suspension medium 22. The suspension medium 22 is dispersed in the polymer matrix 21 in the form of droplets.

[0065] In order to better illustrate the present invention, the following specific examples are provided, including various preparation examples (preparation of solid light-controlling particles, preparation of polymer matrix precursors, preparation of liquid suspension media, preparation of dimming films) and thermal stability test examples.

[0066] Example 1 Preparation of solid light-controlling particles

[0067] Add 30g of isoamyl acetate solution containing 21.2wt% nitrocellulose (model SS 1 / 4sec), 6g I2, 70g isoamyl acetate and 4g anhydrous CaI2 to a 250mL three-necked round-bottomed glass flask, and heat to 42°C. After I2 is dissolved, add 6g anhydrous methanol, 0.8g distilled water and 4g 2,5-pyrazinedicarboxylic acid dihydrate to the above three-necked round-bottomed glass flask, heat and stir at 42°C for 4 hours, and then cool naturally. The resulting reaction solution is centrifuged at 1350g for 0.5h to remove large particles of product, and then the supernatant is centrifuged at 18000g for 5h, and the supernatant is discarded to obtain solid light-controlling particles. The solid light-controlling particles are fully dispersed with 250mL of isoamyl acetate.

[0068] Example 2 Preparation of polymer matrix precursor

[0069] Add silicon-containing non-crosslinked oligomers: 54g hydroxyl-terminated dimethyldiphenylpolysiloxane and 190mL n-heptane to a 500mL three-necked round-bottomed glass flask. Connect a water separator to a condenser on one side of the three-necked round-bottomed glass flask, install a mechanical stirrer in the middle, and place a thermometer on the other side. Heat the reaction solution in the three-necked round-bottomed glass flask to reflux for 30 minutes, and add a solution of 0.13g stannous octoate dissolved in 10mL n-heptane. Then add a silicon-containing crosslinkable monomer: 3g hydrolyzed 3-acryloxypropylmethyldimethoxysilane dropwise for about 5 minutes. Then react under reflux for 2 hours, and then immediately add 30mL trimethylmethoxysilane as a terminator for the reaction; terminate the reaction for 2 hours, and then quickly cool to room temperature. Mix 50mL ethanol and the cooled reaction solution in a 1L beaker, and then wash the reaction bottle with 30mL heptane and pour it into the beaker. After mixing evenly, add 200mL methanol and stir for 15min. The resulting mixed solution was poured into a 1L separatory funnel and allowed to stand for several hours to separate into layers. The lower layer was taken out and then treated by a rotary evaporator at 70°C for 3 hours to remove low-boiling substances, and finally polysiloxane was obtained as a polymer matrix precursor.

[0070] Hydrolysis reaction: A three-necked round-bottomed glass flask is connected to a condenser on one side, a mechanical stirrer is installed in the middle, and a thermometer is placed on the other side. In a 250mL three-necked round-bottomed glass flask, 0.1g acetic acid, 5.5g water, 44.5g 3-acryloxypropylmethyldimethoxysilane, and 35mL anhydrous ethanol are added in sequence, and the hydrolysis reaction temperature is controlled to 65°C and the reaction is carried out for 5 hours. After the reaction is completed, a rotary evaporator is used to remove the solvent, the remaining water, and the acid to obtain a hydrolysis product.

[0071] Example 3 Preparation of a liquid suspension medium containing (c)

[0072] 24.4g dodecyl methacrylate (a), 2.0g hydroxyethyl methacrylate (b), 2.8g methacrylate TEMPO nitroxide (c), 2.3g 1-hexanethiol, and 20mL toluene were added to a 250mL three-necked round-bottom glass flask. A mechanical stirrer was installed in the middle of the three-necked round-bottom glass flask, a condenser was connected to one side, and a thermometer was placed on the other side and connected to argon. Before starting heating, argon was passed into the round-bottom glass flask for about 10 minutes to completely replace the air in the round-bottom glass flask. The flask was then heated to 60°C. At this temperature, 10mL toluene solution containing 0.2g azobisisobutyronitrile was added to the flask. The reaction temperature was maintained at 60°C for a total of 21 hours, and then the reaction temperature was increased to reflux the reaction solution for 3 hours. Stop the reaction. Then, the toluene and unreacted raw materials were removed by a rotary evaporator at 100°C for 3 hours to obtain a liquid suspension medium 3. The suspension medium material was subjected to GPC testing, and the results are shown in Figure 2 , and its molecular weight peak is 1836.

[0073] 40 g of the obtained suspension medium was added to a 250 mL round-bottom glass flask, and the isoamyl acetate dispersion of the solid light-controlling particles prepared in Example 1 was added in batches. The isoamyl acetate was removed by a rotary evaporator. Finally, the rotary evaporator was used to continue processing at 80°C for 3 hours to obtain an example of a liquid suspension medium containing solid light-controlling particles, i.e., mixture example 3.

[0074] Example 4 Preparation of a liquid suspension medium containing (c)

[0075] 24.4g of dodecyl acrylate (a), 2.0g of hydroxyethyl acrylate (b), 2.8g of methyl methacrylate TEMPO nitroxide (c) shown in Table 1, 2.3g of 1-hexanethiol, and 20mL of n-heptane were added to a 250mL three-necked round-bottomed glass flask. A mechanical stirrer was installed in the middle of the three-necked round-bottomed glass flask, a condenser was connected to one side, and a thermometer was placed on the other side and connected to argon. Before starting heating, argon was passed through the round-bottomed glass flask for about 10 minutes to completely replace the air in the round-bottomed glass flask. The flask was then heated to 60°C. At this temperature, 10mL of n-heptane solution containing 0.2g of azobisisobutyronitrile was added to the flask. The reaction temperature was maintained at 60°C for a total of 21 hours, and the reaction temperature was then increased to reflux the reaction solution for 3 hours. The reaction was stopped. Then, the mixture was treated at 100°C for 3 hours by a rotary evaporator to remove toluene and unreacted raw materials to obtain a liquid suspension medium 4.

[0076] 40 g of the obtained suspension medium was added to a 250 mL round-bottom glass flask, and the isoamyl acetate dispersion of the solid light-controlling particles prepared in Example 1 was added in batches. The isoamyl acetate was removed by a rotary evaporator, and finally the rotary evaporator was used to continue processing at 80°C for 3 hours to obtain an example of a liquid suspension medium containing solid light-controlling particles, i.e., mixture example 4.

[0077] Example 5 Preparation of a liquid suspension medium containing (c)

[0078] The same as Example 3, except that the unit monomer (c) containing TEMPO nitroxide free radical is replaced with the material with the molecular structure shown in Table 1, to obtain liquid suspension medium 5 and an example of a liquid suspension medium containing solid light-controlling particles, namely, mixture Example 5.

[0079] Example 6 Preparation of a liquid suspension medium containing (c)

[0080] The same as Example 3, except that the unit monomer (c) containing TEMPO nitroxide free radical is replaced with the material with the molecular structure shown in Table 1, to obtain liquid suspension medium 6 and an example of a liquid suspension medium containing solid light-controlling particles, namely, mixture Example 6.

[0081] Example 7 Preparation of a liquid suspension medium containing (c)

[0082] The same as Example 3, except that the unit monomer (c) containing TEMPO nitroxide free radical is replaced with the material with the molecular structure shown in Table 1, to obtain liquid suspension medium 7 and an example of a liquid suspension medium containing solid light-controlling particles, namely, mixture Example 7.

[0083] Example 8 Preparation of a liquid suspension medium containing (c)

[0084] The same as Example 3, except that the unit monomer (c) containing TEMPO nitroxide free radical is replaced with the material with the molecular structure shown in Table 1, to obtain liquid suspension medium 8 and an example of a liquid suspension medium containing solid light-controlling particles, namely, mixture example 8.

[0085] Example 9 Preparation of a liquid suspension medium containing (c)

[0086] The same as Example 3, except that the unit monomer (c) containing TEMPO nitroxide free radical is replaced with the material with the molecular structure shown in Table 1, to obtain liquid suspension medium 9 and an example of a liquid suspension medium containing solid light-controlling particles, namely, mixture example 9.

[0087] Example 10 Preparation of a liquid suspension medium containing (c)

[0088] The same as Example 4, except that the unit monomer (c) containing TEMPO nitroxide free radical is replaced with the material with the molecular structure shown in Table 1, to obtain a liquid suspension medium 10 and an example of a liquid suspension medium containing solid light-controlling particles, namely, mixture Example 10.

[0089] Example 11 Preparation of a liquid suspension medium containing (c)

[0090] The same as Example 4, except that the unit monomer (c) containing TEMPO nitroxide free radical is replaced with the material with the molecular structure shown in Table 1, to obtain a liquid suspension medium 11 and an example of a liquid suspension medium containing solid light-controlling particles, namely, mixture Example 11.

[0091] Example 12 Preparation of a liquid suspension medium containing (c)

[0092] The same as Example 4, except that the unit monomer (c) containing TEMPO nitroxide free radical is replaced with the material with the molecular structure shown in Table 1, to obtain a liquid suspension medium 12 and an example of a liquid suspension medium containing solid light-controlling particles, i.e., mixture Example 12.

[0093] Table 1 Structural formula of unit (c) for preparing suspension medium in Examples 3 to 12

[0094]

[0095]

[0096]

[0097] Comparative Example 1 Preparation of a liquid suspension medium without (c)

[0098] 24.4g of dodecyl methacrylate (a), 2.0g of hydroxyethyl methacrylate (b), 2.3g of 1-hexanethiol and 20mL of toluene were added to a 250mL three-necked round-bottomed glass flask. A mechanical stirrer was installed in the middle of the three-necked round-bottomed glass flask, a condenser was connected to one side, and a thermometer was placed on the other side and connected to argon. Before starting heating, argon was passed through the round-bottomed glass flask for about 10 minutes to completely replace the air in the round-bottomed glass flask. The flask was then heated to 60°C. At this temperature, 10mL of toluene solution containing 0.2g of azobisisobutyronitrile was added to the flask. The reaction temperature was maintained at 60°C for a total of 21 hours, and the reaction temperature was then increased to reflux the reaction solution for 3 hours. The reaction was stopped. Then the toluene and unreacted raw materials were removed by a rotary evaporator at 100°C for 3 hours to obtain a liquid suspension medium comparative example 1.

[0099] 40 g of the obtained suspension medium was added to a 250 mL round-bottom glass flask, and the isoamyl acetate dispersion of the solid light-controlling particles prepared in Example 1 was added in batches. The isoamyl acetate was removed by a rotary evaporator. Finally, the rotary evaporator was used to continue processing at 80°C for 3 hours to obtain a comparative example of a liquid suspension medium containing solid light-controlling particles, i.e., mixture comparative example 1.

[0100] Comparative Example 2 Preparation of a liquid suspension medium without (c)

[0101] 24.4g of dodecyl acrylate (a), 2.0g of hydroxyethyl acrylate (b), 2.3g of 1-hexanethiol, and 20mL of n-heptane were added to a 250mL three-necked round-bottomed glass flask. A mechanical stirrer was installed in the middle of the three-necked round-bottomed glass flask, a condenser was connected to one side, and a thermometer was placed on the other side and connected to argon. Before starting heating, argon was passed through the round-bottomed glass flask for about 10 minutes to completely replace the air in the round-bottomed glass flask. The flask was then heated to 60°C. At this temperature, 10mL of n-heptane solution containing 0.2g of azobisisobutyronitrile was added to the flask. The reaction temperature was maintained at 60°C for a total of 21 hours, and the reaction temperature was then increased to reflux the reaction solution for 3 hours. The reaction was stopped. Then the toluene and unreacted raw materials were removed by a rotary evaporator at 100°C for 3 hours to obtain a liquid suspension medium comparative example 2.

[0102] 40 g of the obtained suspension medium was added to a 250 mL round-bottom glass flask, and the isoamyl acetate dispersion of the solid light-controlling particles prepared in Example 1 was added in batches. The isoamyl acetate was removed by a rotary evaporator. Finally, the rotary evaporator was used to continue processing at 80°C for 3 hours to obtain a comparative example of a liquid suspension medium containing solid light-controlling particles, i.e., mixture comparative example 2.

[0103] Example 13 Preparation of dimming film

[0104] The initiator for initiating crosslinking and curing of the polymer matrix precursor, the mixture of the suspension medium containing solid light-controlling particles and the polymer matrix precursor are uniformly mixed, and the obtained mixture is called the light-controlling layer matrix emulsion.

[0105] 0.03 g of photoinitiator 819, 7.0 g of the polymer matrix precursor prepared in Example 2 and 3.0 g of the mixture of the liquid suspension medium containing solid light-controlling particles prepared in Examples 3 to 12 and Comparative Examples 1 to 2 were mixed evenly to obtain a light-controlling layer matrix emulsion.

[0106] The light-controlling layer matrix emulsion was coated on the ITO / PET transparent conductive film with a doctor blade type automatic coating machine (MSK-AFA-III, MTI Corporation) to a thickness of 80 μm, and another layer of ITO / PET transparent conductive film was covered on the light-controlling layer matrix emulsion wet film to obtain a light-controlling layer wet film. Then, the film was cured for 1 minute using an X200-150 UV curing machine produced by Aventk under a nitrogen atmosphere, with a UV power of 700 W / m 2 , that is, dimming films are obtained, which are respectively recorded as Examples 13 to 22 and Comparative Examples 3 to 4.

[0107] In an embodiment, a transparent conductive film (transparent electrode) is formed on a substrate of a plastic sheet.

[0108] The polymer matrix precursor is cross-linked and cured to form a polymer matrix.

[0109] Example 14: Transmittance test of dimming film

[0110] The light transmittance of the dimming film was measured using a LS116 light transmittance meter (Shenzhen Linshang Technology Co., Ltd.). When no voltage was applied (off state), the light transmittance of the dimming film was marked as Toff = %; when 60 Hz 220V AC was applied (on state), the total light transmittance of the dimming film was marked as Ton = %.

[0111] Example 15 Heat Aging Test

[0112] The test samples were thermally aged in a conventional oven at 90°C for 600 h.

[0113] The dimming films of the embodiment and the comparative example were subjected to heat aging treatment at 90°C for 600 hours in a common oven, and then the dimming performance of the dimming films after aging was tested, and the results are listed in Table 2. It can be seen that after heat aging, the dimming film samples 13 to 22 of the embodiment and the dimming film samples of the comparative examples 3 to 4 have similar light transmittance effects in the dark state, while the performance in the bright state is more stable. After aging treatment, the bright state transmittance of the dimming film of the comparative example 3 decreased from 60.2% before treatment to 52.4%, and the bright state transmittance of the dimming film of the comparative example 4 decreased from 60.3% before treatment to 51.1%, while the bright state transmittance of the dimming film prepared in the embodiment was basically maintained, still above 59.0%. It can be confirmed that the dimming film prepared by introducing the suspension medium prepared by the acrylic acid ester monomer containing the TEMPO structure can achieve a more stable heat aging effect than the product prepared by the prior art, that is, it has a longer working time, while keeping the initial performance unchanged.

[0114] Table 2 Effect of different suspension media on thermal aging performance of dimming film

[0115]

[0116] The present invention is described above by taking a light valve with a transparent plastic sheet as a substrate, namely a dimming film, as an example. Obviously, the concept of the present invention is also fully applicable to a light valve with a glass substrate, namely a dimming glass.

[0117] The description of the above embodiments is only used to help understand the method of the present invention and its core idea. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest range 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 disposed between the first transparent electrode and the second transparent electrode; the light control layer comprises a polymer matrix; wherein the polymer matrix is ​​dispersed with suspension medium droplets, and solid light control particles are distributed in the suspension medium droplets, characterized in that the suspension medium is obtained from at least one acrylic ester copolymer, and the acrylic ester copolymer is obtained by copolymerizing monomers comprising the following units under the action of a copolymerization catalyst: (a) selected from alkyl acrylate monomers, (b) hydroxy acrylate monomer, and (c) an acrylate monomer having a TEMPO nitroxide free radical structure, which has the following structural formula: R1 is selected from a group containing at least one element of C, H, N, O, S, and P; R2 is H or CH3; The ratio of the monomers (a), (b) and (c) is such that, based on the total mass of 100 parts, the proportion of the monomer (a) is 50 to 95 parts by mass, the proportion of the monomer (b) is 0 to 30 parts by mass, and the proportion of the monomer (c) is 5 to 20 parts by mass; The peak molecular weight of the acrylic ester copolymer is 1,000 to 10,000.

2. A light valve according to claim 1, characterized in that: The monomer copolymerization catalyst (a), (b) and (c) for forming the acrylic ester copolymer is a thermally initiated free radical catalyst.

3. A light valve according to claim 1, characterized in that: The suspension medium also includes a non-conductive liquid; the non-conductive liquid is selected from at least one of fluorocarbon organic compounds, phthalates, trimellitates, dodecylbenzene, polybutene oil, epoxidized soybean oil and epoxidized linseed oil.

4. A light valve according to claim 1, characterized in that: The solid light-controlling particles are selected from one or more of oxide nanorods, perovskite nanorods and polyiodine compound nanorods; the particle length of the solid light-controlling particles is 50 to 800 nm; and the particle aspect ratio of the solid light-controlling particles is 2 to 30.

5. A light valve according to claim 1, characterized in that: The polymer matrix is ​​a solid siloxane polymer.

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

7. 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.

8. 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, and the adhesive layer material includes at least one of epoxy resin, polyurethane, polyimide resin, polystyrene resin, acrylic resin, modified acrylic resin and silicone resin.

9. A thermally stable dimming glass assembly, characterized in that: Include a first glass sheet and a second glass sheet, and The light valve according to any one of claims 1 to 8 is arranged between the first glass plate and the second glass plate.

10. The thermally stable dimming glass assembly according to claim 9, 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.

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