Dimming laminated glass and preparation method thereof

Abstract

The invention relates to dimming laminated glass and a preparation method thereof, the dimming laminated glass comprises a first substrate, a first adhesive layer, a dimming function layer, a second adhesive layer and a second substrate which are sequentially stacked, the maximum light transmittance TL of the dimming laminated glass is less than or equal to 15%, and the visibility of stress spots and wind spots on the dimming laminated glass is reduced. The light transmittance TL of the dimming laminated glass is controlled to be smaller than or equal to 15%, the dimming function is guaranteed, meanwhile, the transmission intensity of strong light can be weakened, then when observation is conducted at a small angle (smaller than or equal to 20 degrees) in the strong light environment, the visual visibility of stress spots and wind spots on the surface of the dimming laminated glass is remarkably reduced, and the appearance optical quality of the dimming laminated glass is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of glass technology, and in particular to a dimming laminated glass and a method for preparing dimming laminated glass. Background Technology

[0002] With the rapid development of smart doors and windows, automotive glass, and other fields, smart glass has been widely used and promoted due to its advantage of being able to flexibly switch between light transmission states. Existing smart laminated glass generally consists of two substrates, two adhesive layers, and a dimming functional film layer in the middle. The substrates are mostly made of heat-strengthened glass or semi-tempered glass. The dimming functional film layer mainly uses dye polymer dispersed liquid crystal (dye PDLC), liquid crystal film (LC), or light valve (LV) or other functional film layers with dichroic dyes. By adjusting the arrangement of molecules in the dimming functional film layer, the glass can switch between a high-transmittance state and a light-blocking state to meet the needs of different scenarios.

[0003] However, when dimming laminated glass using dye polymer dispersed liquid crystal (dye PDLC), liquid crystal film (LC), light valve (LV), or other functional films with dichroic dyes is observed at a small angle under strong light in a high-transmittance state, the surface of the dimming assembly glass will show obvious stress spots and wind spots, which greatly affect the appearance and actual application of the product. Summary of the Invention

[0004] Therefore, it is necessary to provide a dimming laminated glass and a method for preparing dimming laminated glass that can significantly reduce the visual visibility of stress spots and wind spots on the surface of dimming laminated glass and effectively improve the appearance and optical quality of dimming laminated glass.

[0005] A dimming laminated glass includes a first substrate, a first adhesive layer, a dimming functional layer, a second adhesive layer, and a second substrate stacked sequentially. The maximum light transmittance of the dimming laminated glass is TL, where TL≤15%, to reduce the visibility of stress spots and wind spots on the dimming laminated glass.

[0006] In one embodiment, the first substrate is a colored substrate, and / or the second substrate is a colored substrate.

[0007] In one embodiment, the colored substrate is a gray substrate, a green substrate, or a blue substrate.

[0008] In one embodiment, the first adhesive layer includes a colorant, and / or the second adhesive layer includes a colorant.

[0009] In one embodiment, the first adhesive layer and the second adhesive layer are gray.

[0010] In one embodiment, the thickness of the first substrate is 0.7 mm to 2.1 mm, and / or the thickness of the second substrate is 0.7 mm to 2.1 mm.

[0011] In one embodiment, the surface compressive stress of the first substrate is ≤35MPa, and / or the surface compressive stress of the second substrate is ≤35MPa.

[0012] In one embodiment, the first substrate and the second substrate are formed by gravity forming, compression molding or BT forming.

[0013] In one embodiment, the first substrate and the second substrate prepared by the self-weight forming method have a surface compressive stress ≥10MPa. Alternatively, the first substrate and the second substrate prepared by the pressing molding method have a surface compressive stress of 10MPa-35MPa. Alternatively, the first substrate and the second substrate prepared by the BT molding method have a surface compressive stress of 20MPa-35MPa.

[0014] This application also provides a method for preparing the dimming laminated glass, comprising the following steps: The first substrate and the second substrate are prepared; wherein the surface compressive stress of the first substrate and the second substrate is ≤35MPa; The first adhesive layer, the dimming functional layer, and the second adhesive layer are stacked and laminated in sequence to prepare an intermediate layer; The first substrate, the intermediate layer, and the second substrate are stacked sequentially and laminated to obtain a dimming laminated glass.

[0015] In the above solution, this application controls the light transmittance TL of the dimming laminated glass to ≤15%, which can reduce the transmission intensity of strong light while ensuring the dimming function. Thus, when observed at a small angle (≤20°) in a strong light environment, the visual visibility of stress spots and wind spots on the surface of the dimming laminated glass is significantly reduced, effectively improving the appearance and optical quality of the dimming laminated glass. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a dimming laminated glass according to an embodiment of this application.

[0019] Figure 2 This is a schematic diagram of the dimming functional layer (single-cell LC) shown in one embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: 10. Dimming laminated glass; 100. First substrate; 200. First adhesive layer; 300. Dimming functional layer; 310. Polarizing film; 320. Adhesive layer; 330. First conductive layer; 340. Liquid crystal layer; 350. Second conductive layer; 360. Sealing layer; 400. Second adhesive layer; 500. Second substrate; 600. Supporting adhesive layer; 700. Conductor. Detailed Implementation

[0021] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0022] In the description of this application, it should be understood that if terms such as "thickness", "upper", "lower", etc. appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0025] With the rapid development of smart doors and windows, automotive glass, and other fields, smart glass has been widely used and promoted due to its advantage of being able to flexibly switch between light transmission states. Existing smart laminated glass generally consists of two substrates, two adhesive layers, and a dimming functional film layer in the middle. The substrates are mostly made of heat-strengthened glass or semi-tempered glass. The dimming functional film layer mainly uses dye polymer dispersed liquid crystal (dye PDLC), liquid crystal film (LC), or light valve (LV) or other functional film layers with dichroic dyes. By adjusting the arrangement of molecules in the dimming functional film layer, the glass can switch between a high-transmittance state and a light-blocking state to meet the needs of different scenarios.

[0026] However, when dimming laminated glass using dye polymer dispersed liquid crystal (dye PDLC), liquid crystal film (LC), light valve (LV), or other functional films with dichroic dyes is observed at a small angle under strong light in a high-transmittance state, the surface of the dimming assembly glass will show obvious stress spots and wind spots, which greatly affect the appearance and actual application of the product.

[0027] The generation mechanism of the aforementioned stress spots is as follows: Dichroism is an inherent optical anisotropy characteristic of dye molecules, meaning that dye molecules have different absorption capabilities for light with different polarization directions. When unpolarized light (including light with all vibration directions) irradiates a film composed of highly ordered dichroic dye molecules (such as dye polymer dispersed liquid crystal (dye PDLC), liquid crystal film (LC), or light valve (LV) dimming film), the light component whose vibration direction is parallel to the absorption axis of the dye molecules will be strongly absorbed, while the light component whose vibration direction is perpendicular to the absorption axis of the dye molecules will be absorbed less and most of it can be transmitted smoothly.

[0028] See Figure 1 and Figure 2 To address the aforementioned issues, embodiments of this application relate to a dimming laminated glass 10, comprising a first substrate 100, a first adhesive layer 200, a dimming functional layer 300, a second adhesive layer 400, and a second substrate 500, which are sequentially stacked. The first substrate 100 generally faces the surface directly exposed to sunlight.

[0029] The size of the dimming functional layer 300 is smaller than that of the first substrate 100, the first adhesive layer 200, the second adhesive layer 400, and the second substrate 500. A supporting adhesive layer 600 is provided around the dimming functional layer 300, and the thickness of the supporting adhesive layer 600 is equal to or slightly greater than that of the dimming functional layer 300. Specifically, the dimming functional layer 300 is also connected to a wire 700.

[0030] It should be noted that the first substrate 100 and the second substrate 500 can be glass or transparent plastic. The glass can include, but is not limited to, ordinary soda-lime silicate glass, borosilicate glass, aluminosilicate glass, heat-strengthened glass, semi-tempered glass, fully tempered glass, ultra-thin glass, and high-transparency optical glass. Suitable transparent plastics can include, but are not limited to, transparent polycarbonate, polyethylene terephthalate (PET), polyamide, acrylics, cycloolefins, polyethylene (PEN), metallocene polyethylene (mPE), silicone resin, polyurethane, and various polymer materials.

[0031] In this embodiment, both the first substrate 100 and the second substrate 500 are heat-strengthened glass or semi-tempered glass. In another embodiment, one of the first substrate 100 and the second substrate 500 is heat-strengthened glass or semi-tempered glass, and the other of the first substrate 100 and the second substrate 500 is ordinary soda-lime silica glass.

[0032] The materials used for the first adhesive layer 200 and the second adhesive layer 400 are polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), and thermoplastic polyurethane elastomer (TPU). PVB is classified into ordinary PVB, sound-insulating PVB, and high UV-blocking PVB. EVA is classified into ordinary EVA and high UV-blocking EVA. The first adhesive layer 200 and the second adhesive layer 400 must have a UV cutoff wavelength ≥390nm. Preferably, the first adhesive layer 200 and the second adhesive layer 400 must have a UV cutoff wavelength ≥400nm.

[0033] The maximum transmittance of the dimming laminated glass 10 is TL, where TL ≤ 15%, to reduce the visibility of stress spots and wind spots on the dimming laminated glass. Preferably, the transmittance TL of the dimming laminated glass 10 is ≤ 12%. It should be noted that the maximum transmittance is defined as the highest transmittance value that the dimming laminated glass 10 can achieve in all its operating states (including low transmittance state, high transmittance state, and any adjustable intermediate transmittance state). In this application, the maximum transmittance refers to the transmittance of the dimming laminated glass 10 in the high transmittance state, and the transmittance in the low transmittance state is lower than this maximum value, thus meeting the requirement of TL ≤ 15% overall.

[0034] This application controls the light transmittance TL of the dimming laminated glass 10 to ≤15%, which, while ensuring the dimming function, reduces the intensity of strong light transmission. Consequently, when observed at a small angle (≤20°) in strong light environments, the visual visibility of stress spots and wind spots on the surface of the dimming laminated glass 10 is significantly reduced, effectively improving the appearance and optical quality of the dimming laminated glass 10. It should be noted that: a small angle (≤20°) refers to the angle between the observer's line of sight and the normal to the surface of the dimming laminated glass 10 being ≤20°.

[0035] See Figure 1 and Figure 2 According to some embodiments of this application, optionally, the first substrate 100 is a colored substrate. The second substrate 500 is a colored substrate.

[0036] By setting the first substrate 100 and the second substrate 500 as colored substrates, the light transmittance of the first substrate 100 and the second substrate 500 can be reduced, thereby reducing the light transmittance of the dimming laminated glass 10 to achieve the light transmittance requirement of TL ≤ 15%. This can suppress the visibility of stress spots and wind spots, and improve the consistency of product appearance. It should be noted that the darker the color, the less likely stress spots and wind spots are to be seen.

[0037] Specifically, the colored substrates are gray substrates, green substrates, and blue substrates. For example, gray substrates are generally categorized as light gray, medium gray, and dark gray. Green substrates are generally categorized as light green, emerald green, and dark green. Blue substrates are generally categorized as light blue and deep ocean blue. The appropriate colored substrate can be selected based on different application scenarios.

[0038] See Figure 1 and Figure 2 According to some embodiments of this application, optionally, the first adhesive layer 200 includes a colorant and an adhesive. The second adhesive layer 400 includes a colorant and an adhesive. Both the first adhesive layer 200 and the second adhesive layer 400 are gray. After a curing process, the colorant makes the first adhesive layer 200 and the second adhesive layer 400 appear gray (or other dark colors), effectively reducing the light transmittance of the first adhesive layer 200 and the second adhesive layer 400. It should be noted that the darker the color of the first adhesive layer 200 and the second adhesive layer 400, the less likely stress spots and wind spots are to be observed.

[0039] By introducing a colorant into the first adhesive layer 200 and the second adhesive layer 400, the colorant can reduce the light transmittance of the first adhesive layer 200 and the second adhesive layer 400, thereby enabling the dimming laminated glass 10 to achieve the overall light transmittance requirement of TL≤15%.

[0040] See Figure 1 and Figure 2According to some embodiments of this application, optionally, the thickness of the first substrate 100 is 0.7mm-2.1mm. The thickness of the second substrate 500 is 0.7mm-2.1mm. It should be noted that this application does not specifically limit the thickness of the first substrate 100 and the second substrate 500, and can be set according to actual usage requirements. It should also be noted that the smaller the thickness of the first substrate 100 and the second substrate 500, the less likely the stress spots and wind spots of the dimming laminated glass 10 are to be observed. For example, the thickness of the first substrate 100 and the second substrate 500 is 1.8mm or 2.1mm.

[0041] It should also be noted that this application does not specifically limit the thickness of the first adhesive layer 200 and the second adhesive layer 400, which can be set according to actual usage requirements. For example, the thickness of the first adhesive layer 200 and the second adhesive layer 400 is 0.76mm or 0.38mm.

[0042] See Figure 1 and Figure 2 According to some embodiments of this application, optionally, the surface compressive stress of the first substrate 100 is ≤35MPa. The surface compressive stress of the second substrate 500 is ≤35MPa.

[0043] By setting the surface compressive stress of the first substrate 100 and the second substrate 500 to ≤35MPa, the internal stress concentration of the first substrate 100 and the second substrate 500 can be reduced, and the generation of stress spots and wind spots inside the dimming laminated glass 10 can be significantly reduced.

[0044] See Figure 1 and Figure 2 According to some embodiments of this application, optionally, the first substrate 100 and the second substrate 500 are formed by gravity forming, compression molding, or BT forming. By using gravity forming, compression molding, or BT forming, the surface compressive stress of the first substrate 100 and the second substrate 500 can be stably controlled at ≤35MPa, which can fundamentally reduce the internal stress gradient and stress concentration of the first substrate 100 and the second substrate 500, and reduce the probability of stress spots and wind spots.

[0045] Self-weight forming method: The glass is formed by its own weight, without the need for external pressure or forced cooling air. During the forming process, the glass is subjected to uniform stress and the temperature gradient is gentle, which has a significant inhibitory effect on the generation of stress spots and wind spots.

[0046] Compression molding method: This is a type of thermo-strengthened molding. It achieves glass molding by applying external pressure, and can precisely control the curvature and thickness tolerance of the glass surface.

[0047] BT molding method: Also a type of heat-strengthened molding, combining heating and molding processes, the molded glass possesses both curved shape and tempered strength, exhibiting excellent impact resistance. For example, the first substrate 100 and the second substrate 500 for automotive sunroofs can be manufactured using gravity molding and compression molding methods; the first substrate 100 and the second substrate 500 for automotive side windows can be manufactured using the BT molding method.

[0048] See Figure 1 and Figure 2 According to some embodiments of this application, optionally, the first substrate 100 and the second substrate 500 prepared by gravity forming have a surface compressive stress ≥10MPa. The first substrate 100 and the second substrate 500 prepared by compression molding have a surface compressive stress of 10MPa-35MPa. The first substrate 100 and the second substrate 500 prepared by BT molding have a surface compressive stress of 20MPa-35MPa.

[0049] It should be noted that the magnitude of the surface compressive stress of the first substrate 100 and the second substrate 500 is directly related to the molding method. The process characteristics (stress mode, cooling rate, temperature gradient) of different molding methods determine the generation and distribution of internal stress of the first substrate 100 and the second substrate 500, and different molding methods correspond to specific ranges of surface compressive stress.

[0050] Among them, the self-weight molding does not require external pressure and forced rapid cooling. During the molding process, the first substrate 100 and the second substrate 500 are subjected to uniform force and the temperature gradient is gentle. The surface compressive stress of the first substrate 100 and the second substrate 500 prepared by it is ≥10MPa, and the surface compressive stress can be controlled at ≤35MPa most easily.

[0051] The BT molding process uses line blowing for uniform cooling, resulting in a relatively uniform stress distribution. The surface compressive stress of the first substrate 100 and the second substrate 500 prepared by the process is 20MPa-35MPa, which can be precisely matched by adjusting the process parameters.

[0052] Due to the external pressure applied during compression molding and the use of multiple cooling points, stress distribution is prone to unevenness. The surface compressive stress of the first substrate 100 and the second substrate 500 produced by compression molding ranges from 10MPa to 35MPa. Precise control of parameters such as molding pressure and cooling rate is required to ensure that the surface compressive stress remains stable within this range. The three molding methods can be flexibly selected according to the actual scenario, such as the curvature requirements of the first substrate 100 and the second substrate 500 and production efficiency, to achieve the target surface compressive stress.

[0053] By rationally selecting the molding method and controlling the process, the surface compressive stress of the first substrate 100 and the second substrate 500 prepared by different molding methods can be stabilized within a range of no more than 35 MPa. This can fundamentally reduce the internal stress gradient and stress concentration of the first substrate 100 and the second substrate 500, and reduce the probability of stress spots and wind spots.

[0054] See Figure 1 and Figure 2 According to some embodiments of this application, optionally, the dimming functional layer 300 includes dye polymer dispersed liquid crystal (dye PDLC), liquid crystal film (LC), light valve (LV), and other functional film layers with dichroic dyes. The liquid crystal film (LC) includes dual-cell LC and single-cell LC.

[0055] The single-cell LC includes, from bottom to top, a polarizing film 310, an adhesive layer 320, a first conductive layer 330, a liquid crystal layer 340, and a second conductive layer 350, stacked sequentially. The size of the dimming layer is smaller than the sizes of the first conductive layer 330 and the second conductive layer 350, and a sealant layer 360 is disposed around the periphery of the dimming layer. Specifically, the width of the sealant layer 360 is 2mm-8mm. Preferably, the sealant layer 360 is a transparent adhesive layer.

[0056] The transparent adhesive layer is made of polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), and thermoplastic polyurethane elastomer (TPU). Polyvinyl butyral (PVB) is divided into ordinary PVB, sound-insulating PVB, and high UV-blocking PVB. Ethylene-vinyl acetate copolymer (EVA) is divided into ordinary EVA and high UV-blocking EVA.

[0057] The periphery of the dye polymer dispersed liquid crystal (dye PDLC) is sealed, which can be done by dispensing or by using polyethylene terephthalate (PET).

[0058] This application also discloses a method for preparing a dimming laminated glass 10, comprising the following steps: S1: Prepare a first substrate 100 and a second substrate 500. The surface compressive stress of the first substrate 100 and the second substrate 500 is ≤35MPa. The first substrate 100 and the second substrate 500 can be prepared by gravity forming, compression molding, or BT molding to ensure that the surface compressive stress of the prepared first substrate 100 and the second substrate 500 meets the requirement of ≤35MPa.

[0059] For example, the first substrate 100 and the second substrate 500 for automotive sunroofs can be manufactured by gravity molding and compression molding; the first substrate 100 and the second substrate 500 for automotive side windows can be manufactured by BT molding. The first substrate 100 and the second substrate 500 can be colored substrates.

[0060] S2: The first adhesive layer 200, the dimming functional layer 300, and the second adhesive layer 400 are sequentially stacked and laminated to prepare an intermediate layer. Specifically, a supporting adhesive layer 600 is provided around the dimming functional layer 300, and the thickness of the supporting adhesive layer 600 is equal to or equivalent to the thickness of the dimming functional layer 300. Exemplarily, the first adhesive layer 200 and the second adhesive layer 400 include a colorant.

[0061] This step specifically includes the following steps: S201: Cut the support adhesive layer 600 according to the set dimensions. It should be noted that the size of the support adhesive layer 600 must be larger than the size of the first substrate 100 and the second substrate 500 to prevent the support adhesive layer 600 from shrinking. Specifically, the size of the support adhesive layer 600 is 3mm-5mm larger than the size of the first substrate 100 and the second substrate 500.

[0062] S202: The first adhesive layer 200, the dimming functional layer 300, and the second adhesive layer 400 are sequentially stacked, and two supporting adhesive layers 600 are respectively arranged on both sides of the dimming functional layer 300 to form a stacked structure. The dimensions of the first adhesive layer 200 and the second adhesive layer 400 are 3mm-5mm larger than the dimensions of the first substrate 100 and the second substrate 500. The dimming functional layer 300 includes dye polymer dispersed liquid crystal (dye PDLC), liquid crystal film (LC), or a liquid crystal light valve (LV) with a polarizing structure.

[0063] S203: The stacked structure is fed into a pre-composite equipment and composited into one unit by means of vacuuming, heating and pressurizing.

[0064] S3: The first substrate 100, the intermediate layer and the second substrate 500 are stacked in sequence and then laminated to obtain the dimming laminated glass 10.

[0065] This step specifically includes the following steps: S301: The first substrate 100, the intermediate layer, and the second substrate 500 are sequentially stacked to form a laminated structure. Positioning can be performed according to the positioning lines to calibrate stacking discrepancies and ensure accurate stacking positions.

[0066] S302: A vacuum ring is fitted around the periphery of the laminated structure, and a cold-pull process is performed.

[0067] S303: The laminated structure that has undergone cold drawing is subjected to initial pressing and high-pressure treatment in sequence to obtain the dimming laminated glass 10.

[0068] This application provides embodiments and comparative examples, as shown below: Example 1: The dimming laminated glass 10 comprises a gray substrate, a first adhesive layer 200, a dye-polymer dispersed liquid crystal (Dye-PDLC), a second adhesive layer 400, and the gray substrate stacked sequentially. Both the first adhesive layer 200 and the second adhesive layer 400 are transparent, and the surface compressive stress of the gray substrate is 20 MPa. The light transmittance (TL) of the dimming laminated glass 10 is 5%. Testing showed that the stress spots and wind spots of the dimming laminated glass 10 prepared in Example 1 were invisible in both low-transmittance and high-transmittance operating states.

[0069] Example 2: The difference from Example 1 is that this example uses a white substrate, and both the first adhesive layer 200 and the second adhesive layer 400 are gray. The surface compressive stress of the white substrate is 20 MPa. The light transmittance TL of the dimming laminated glass 10 is 4%. Testing showed that the stress spots and wind spots of the dimming laminated glass 10 prepared in Example 2 were invisible in both low-transmittance and high-transmittance operating states.

[0070] Comparative Example 1: The difference from Example 2 is that the surface compressive stress of the white substrate is 40 MPa. Both the first adhesive layer 200 and the second adhesive layer 400 are transparent. The light transmittance TL of the dimming laminated glass 10 is 20%. Testing showed that the stress spots and wind spots of the dimming laminated glass 10 prepared in Comparative Example 1 were visible in both low-transmittance and high-transmittance operating states.

[0071] Example 3: The dimming laminated glass 10 comprises a gray substrate, a first adhesive layer 200, a single-cell LC, a second adhesive layer 400, and the gray substrate stacked sequentially. Both the first adhesive layer 200 and the second adhesive layer 400 are transparent, and the surface compressive stress of the gray substrate is 30 MPa. The light transmittance (TL) of the dimming laminated glass 10 is 7%. Testing showed that the stress spots and wind spots of the dimming laminated glass 10 prepared in Example 3 were invisible in both low-transmittance and high-transmittance operating states.

[0072] Example 4: The difference from Example 3 is that this example uses a white substrate, and both the first adhesive layer 200 and the second adhesive layer 400 are gray. The surface compressive stress of the white substrate is 30 MPa. The light transmittance TL of the dimming laminated glass 10 is 6%. Testing showed that the dimming laminated glass 10 prepared in Example 4 exhibited invisible stress spots and wind spots in both low-transmittance and high-transmittance operating states.

[0073] Comparative Example 2: The difference from Example 4 is that the surface compressive stress of the white substrate is 40 MPa. Both the first adhesive layer 200 and the second adhesive layer 400 are transparent. The light transmittance TL of the dimming laminated glass 10 is 25%. Testing showed that the stress spots and wind spots of the dimming laminated glass 10 prepared in Comparative Example 1 were visible in both low-transmittance and high-transmittance operating states.

[0074] Example 5: The difference from Example 3 is that this example uses a green substrate with a surface compressive stress of 10 MPa. The transmittance TL of the dimming laminated glass 10 is 14%. Testing showed that the stress spots and wind spots of the dimming laminated glass 10 prepared in Example 3 were invisible in both low-transmittance and high-transmittance operating states.

[0075] To more clearly demonstrate the structural parameters and performance test results of the dimming laminated glass in the above embodiments and comparative examples, the key parameters, transmittance, and visibility of stress spots and wind spots of each experimental group are summarized in the table below.

[0076]

[0077] As can be seen from Examples 1-5 and Comparative Examples 1-2, the light transmittance of the dimming laminated glass 10 can be adjusted to meet the requirement of ≤15% by adjusting the color of the substrate and / or adhesive layer. This ensures that stress spots and wind spots are invisible in both low-transmittance and high-transmittance operating states of the dimming laminated glass 10. Furthermore, if the compressive stress on the substrate surface is too high, stress spots and wind spots will be visible in both low-transmittance and high-transmittance operating states of the dimming laminated glass 10. Therefore, the compressive stress on the substrate surface must meet the requirement of ≤35MPa to effectively avoid the generation of stress spots and wind spots.

[0078] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A dimming laminated glass (10), characterized in that, The first substrate (100), the first adhesive layer (200), the dimming functional layer (300), the second adhesive layer (400) and the second substrate (500) are stacked in sequence. The maximum light transmittance of the dimming laminated glass (10) is TL, where TL≤15%, in order to reduce the visibility of stress spots and wind spots on the dimming laminated glass.

2. The dimming laminated glass (10) according to claim 1, characterized in that, The first substrate (100) is a colored substrate, and / or the second substrate (500) is a colored substrate.

3. The dimming laminated glass (10) according to claim 2, characterized in that, The colored substrate is a gray substrate, a green substrate, or a blue substrate.

4. The dimming laminated glass (10) according to claim 1, characterized in that, The first adhesive layer (200) includes a colorant, and / or the second adhesive layer (400) includes a colorant.

5. The dimming laminated glass (10) according to claim 1, characterized in that, The first adhesive layer (200) and the second adhesive layer (400) are gray.

6. The dimming laminated glass (10) according to claim 1, characterized in that, The thickness of the first substrate (100) is 0.7 mm to 2.1 mm, and / or the thickness of the second substrate (500) is 0.7 mm to 2.1 mm.

7. The dimming laminated glass (10) according to claim 1, characterized in that, The surface compressive stress of the first substrate (100) is ≤35MPa, and / or the surface compressive stress of the second substrate (500) is ≤35MPa.

8. The dimming laminated glass (10) according to claim 7, characterized in that, The molding methods of the first substrate (100) and the second substrate (500) include gravity molding, compression molding or BT molding.

9. The dimming laminated glass (10) according to claim 8, characterized in that, The first substrate (100) and the second substrate (500) prepared by the self-weight forming method have a surface compressive stress ≥10MPa; Alternatively, the first substrate (100) and the second substrate (500) prepared by the pressing molding method have a surface compressive stress of 10MPa-35MPa. Alternatively, the first substrate (100) and the second substrate (500) prepared by the BT molding method have a surface compressive stress of 20MPa-35MPa.

10. A method for preparing the dimming laminated glass (10) according to any one of claims 7-9, comprising the following steps: The first substrate (100) and the second substrate (500) are prepared; wherein, The surface compressive stress of the first substrate (100) and the second substrate (500) is ≤35MPa; The first adhesive layer (200), the dimming functional layer (300), and the second adhesive layer (400) are stacked and laminated in sequence to prepare an intermediate layer; The first substrate (100), the intermediate layer and the second substrate (500) are stacked in sequence and laminated to obtain a dimming laminated glass (10).

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