Preparation method of curved-surface electrochromic glass

Abstract

The invention provides a preparation method of curved-surface electrochromic glass. The preparation method comprises the following steps: depositing an electrochromic functional layer on a glass substrate, depositing a buffer layer on at least one side of the electrochromic functional layer to obtain coated glass, and carrying out cold roll forming on the coated glass to obtain the curved-surface electrochromic glass. The preparation method disclosed by the invention adopts a process of first coating and then cold roll forming, so that the thickness and performance uniformity of the functional layer during coating can be guaranteed, the problems of large thickness deviation during coating of the curved glass and difficulty in adaptation of curvature, size and equipment are solved, the performance stability of the device is guaranteed, secondary processing such as cutting and punching is easy to realize, and the production cost is reduced. And the flexibility of product design can be improved.

Description

A method for preparing curved electrochromic glass Technical Field

[0001] This invention belongs to the field of electrochromic technology, specifically relating to a method for preparing curved electrochromic glass. Background Technology

[0002] Electrochromic glass has achieved large-scale application in fields such as architecture, automobiles, and smart displays due to its excellent dynamic dimming capabilities, low power consumption, and visual comfort. With the diversification of product forms and the development of consumer demands, the market's demand for electrochromic glass has transcended traditional planar structures and shifted to an urgent need for high-performance, curved electrochromic glass.

[0003] Currently, the mainstream process for preparing curved electrochromic glass in the industry is to first heat-bend and then coat the glass. The specific process is as follows: First, the flat glass substrate is heated to the softening point temperature of 600-700℃ and then heat-bent to obtain a curved glass substrate with a predetermined curvature. Then, using a specially designed roll-to-roll magnetron sputtering coating equipment, functional films including a conductive layer, an electrochromic layer, and an ion storage layer are sequentially deposited on the surface of the curved glass to finally obtain curved electrochromic glass.

[0004] However, this approach has certain inherent drawbacks. First, curved surface coating requires customized roll-to-roll coating equipment for specific curvatures and dimensions, which is extremely expensive. Second, the glass substrate needs to be tempered after the hot bending process, making subsequent secondary machining such as cutting and irregular grinding extremely difficult, and it is hard to adapt to customized, small-batch design requirements. Third, the variation in different positions of the curved surface makes it difficult to precisely control the uniformity of film deposition, and the film thickness deviation in different areas can typically reach ±20% or more, affecting the final performance of the device. At the same time, the impact of the curved surface on the ion incidence of the target material also leads to a significant reduction in the utilization rate of the target material.

[0005] Therefore, based on the problems existing in the current process, it is necessary to develop a process for preparing curved electrochromic glass. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for preparing curved electrochromic glass, optimize the preparation process of curved electrochromic glass, and improve the performance and product adaptability of curved electrochromic glass.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] The present invention provides a method for preparing curved electrochromic glass, the method comprising the following steps: depositing an electrochromic functional layer on a glass substrate, depositing a buffer layer on at least one side of the electrochromic functional layer to obtain coated glass, and cold bending the coated glass to obtain the curved electrochromic glass.

[0009] The method for preparing curved glass provided by this invention employs a process of first coating and then cold bending. Preparing the functional layer in a flat glass state ensures the uniformity of the functional layer's thickness and performance during coating, solving the problems of large thickness deviations and difficulty in adapting curvature and dimensions to equipment during curved glass coating. Cold bending is then used after coating, avoiding damage to the functional layer from high temperatures and ensuring device performance stability. After cold bending, the glass is easier to cut, drill, and perform secondary processing, improving product design flexibility. The buffer layer addresses film stress issues during cold bending, ensuring the film's performance after bending.

[0010] Preferably, the thickness of the glass substrate is 0.5-1.0 mm, for example, it can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1.0 mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0011] By controlling the thickness of the glass substrate, the bending performance of the glass is improved, ensuring that the glass can be directly bent into shape.

[0012] Preferably, the glass substrate is selected from soda-lime glass and / or borosilicate glass.

[0013] Preferably, the material of the buffer layer includes silicon oxide (SiOx) and / or silicon nitride (SiNx).

[0014] Preferably, the thickness of the buffer layer is 50-100nm, for example, it can be 50nm, 60nm, 70nm, 80nm, 90nm or 100nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0015] By setting a buffer layer of specific materials and thickness, the stress problem of the film layer during the cold bending process can be improved, the impact of the cold bending process on the electrochromic functional layer can be avoided, and the device performance can be guaranteed.

[0016] Preferably, the total thickness of the electrochromic functional layer is ≤2μm, for example, it can be 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm or 2μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, and it is further preferred to be 1.2-1.8μm.

[0017] The flexibility of glass devices can be improved by controlling the thickness of the electrochromic functional layer.

[0018] Preferably, the temperature for cold bending is 120-150℃, for example, it can be 120℃, 125℃, 130℃, 135℃, 140℃, 145℃ or 150℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0019] Preferably, the bending time for cold bending is 90-150s, for example, it can be 90s, 100s, 110s, 120s, 130s, 140s or 150s, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0020] Preferably, the bending angle of the cold bending forming is ≤18°, for example, it can be 18°, 15°, 12°, 10°, 8°, 5° or 1°, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0021] Preferably, the bending radius of the cold bending forming is ≥5cm, for example, it can be 5cm, 8cm, 10cm, 12cm, 15cm, 20cm or 30cm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0022] Preferably, the pressure for cold bending is 0.5-2 MPa, for example, it can be 0.5 MPa, 0.8 MPa, 1 MPa, 1.2 MPa, 1.5 MPa, 1.8 MPa or 2 MPa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0023] Preferably, the holding time for cold bending is 30-60 minutes, for example, it can be 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes or 60 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0024] Preferably, the buffer layer and / or electrochromic functional layer are prepared by magnetron sputtering.

[0025] Preferably, the sputtering power of the magnetron sputtering is 5-45kW, for example, it can be 5kW, 10kW, 20kW, 30kW, 40kW or 45kW, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0026] Preferably, the deposition rate of the magnetron sputtering is 0.2-1 nm / s, for example, it can be 0.2 nm / s, 0.5 nm / s, 0.8 nm / s or 1 nm / s, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0027] Preferably, the electrochromic functional layer comprises a first transparent conductive layer, an ion storage layer, an electrochromic layer, an encapsulation layer, and a second transparent conductive layer stacked sequentially.

[0028] Preferably, the material of the first transparent conductive layer includes indium tin oxide (ITO) and / or indium zinc oxide (IZO).

[0029] Preferably, the thickness of the first transparent conductive layer is 300-400nm, for example, it can be 300nm, 320nm, 350nm, 380nm or 400nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0030] Preferably, the material of the ion storage layer includes nickel tungsten oxide (NiWOx).

[0031] Preferably, the thickness of the ion storage layer is 200-300 nm, for example, it can be 200 nm, 220 nm, 250 nm, 280 nm or 300 nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0032] Preferably, the material of the electrochromic layer includes tungsten trioxide (WO3).

[0033] Preferably, the thickness of the electrochromic layer is 300-400nm, for example, it can be 300nm, 320nm, 350nm, 380nm or 400nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0034] Preferably, the material of the encapsulation layer includes titanium oxide (TiOx).

[0035] Preferably, the thickness of the encapsulation layer is 40-55nm, for example, it can be 40nm, 42nm, 45nm, 48nm, 50nm, 52nm or 55nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0036] Preferably, the material of the second transparent conductive layer includes indium tin oxide (ITO) and / or indium zinc oxide (IZO).

[0037] Preferably, the thickness of the second transparent conductive layer is 300-400nm, for example, it can be 300nm, 320nm, 350nm, 380nm or 400nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] Preferably, the glass substrate is pretreated before deposition.

[0039] Preferably, the surface pretreatment includes sequential cleaning and plasma treatment.

[0040] Preferably, the power of the plasma treatment is 100-200W, for example, it can be 100W, 120W, 150W, 180W or 200W, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0041] Preferably, the plasma treatment time is 3-5 minutes, for example, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes or 5 minutes, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0043] (1) The curved electrochromic glass prepared by the present invention can effectively control the thickness deviation of the film layer by coating in a flat state, and ensure the uniformity of the film layer thickness and performance. The cold bending process can avoid high temperature damage to the film layer and ensure the performance stability of the electrochromic glass.

[0044] (2) Compared with the existing hot bending + roll coating process, the cold bending process makes it easier for curved glass to be processed in the future, which can improve the flexibility of product design; solves the problem that the glass curvature and size are not easy to match with the equipment in the roll coating; increases the utilization rate of target material in film deposition from 30%-40% in the roll coating to 70%-80%, and reduces the production cycle of a single batch of products from 12-16h in the roll coating to 6-8h, which significantly improves the production efficiency of products. Detailed Implementation

[0045] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0046] Example 1

[0047] This embodiment provides a method for preparing curved electrochromic glass, the method comprising the following steps:

[0048] (1) Soda-lime glass with a thickness of 1.0 mm was used as the glass substrate with a size of 1 m × 1.2 m. The glass substrate was ultrasonically cleaned with deionized water and alcohol in sequence, and then plasma treated with 150 W power for 4 min.

[0049] (2) A first buffer layer is deposited on a glass substrate by magnetron sputtering. The first buffer layer is a silicon oxide layer (SiO2) with a thickness of 80 nm.

[0050] (3) An electrochromic functional layer is deposited on the first buffer layer, wherein the electrochromic functional layer comprises, in sequence, a first transparent conductive layer, an ion storage layer, an electrochromic layer, an encapsulation layer, and a second transparent conductive layer.

[0051] The materials, thicknesses, and sputtering parameters of each layer are as follows: First transparent conductive layer: ITO layer, 400 nm thick, sputtered in an argon and oxygen atmosphere (volume ratio 100:1), sputtering power 9 kW, deposition rate 0.2 nm / s; Ion storage layer: Nickel-tungsten oxide layer (NiWOx, x 3.5-4.5), 300 nm thick, sputtered in an argon atmosphere, sputtering power 35 kW, deposition rate 1 nm / s; Electrochromic layer: WO3 layer, 4 nm thick. The first layer is a titanium oxide layer (TiOx, x in 1.5-2.0) with a thickness of 50 nm. It is sputtered in an argon atmosphere with a sputtering power of 44 kW and a deposition rate of 1 nm / s. The second transparent conductive layer is an ITO layer with a thickness of 350 nm. It is sputtered in an argon atmosphere with a sputtering power of 9 kW and a deposition rate of 1 nm / s. The total thickness of the electrochromic functional layer is controlled to be 1.5 μm.

[0052] (4) A second buffer layer is deposited on the electrochromic functional layer. The second buffer layer is a silicon nitride layer (SiNx, x is 1.0-1.4) with a thickness of 80 nm to obtain the coated glass.

[0053] (5) The coated glass is subjected to pressure cold bending at 140°C. The bending radius is 5cm, the bending angle is 18°, the bending time is 120s, the bending pressure is 1MPa, and the holding time is 45min. After the bending is completed, the curved electrochromic glass is obtained.

[0054] Example 2

[0055] This embodiment provides a method for preparing curved electrochromic glass, the method comprising the following steps:

[0056] (1) Soda-lime glass with a thickness of 1.0 mm was used as the glass substrate with a size of 1 m × 1.2 m. The glass substrate was ultrasonically cleaned with deionized water and alcohol in sequence, and then plasma treated with 100 W power for 5 min.

[0057] (2) A first buffer layer is deposited on a glass substrate by magnetron sputtering. The first buffer layer is a silicon nitride layer (SiNx, x is 1.0-1.4) with a thickness of 100 nm.

[0058] (3) An electrochromic functional layer is deposited on the first buffer layer, wherein the electrochromic functional layer comprises, in sequence, a first transparent conductive layer, an ion storage layer, an electrochromic layer, an encapsulation layer, and a second transparent conductive layer.

[0059] The materials, thicknesses, and sputtering parameters of each layer are as follows: First transparent conductive layer: ITO layer, 400 nm thick, sputtered in an argon and oxygen atmosphere (volume ratio 100:1), sputtering power 9 kW, deposition rate 0.2 nm / s; Ion storage layer: Nickel-tungsten oxide layer (NiWOx, x 3.5-4.5), 300 nm thick, sputtered in an argon atmosphere, sputtering power 35 kW, deposition rate 1 nm / s; Electrochromic layer: WO3 layer, 4 nm thick. The first layer is a titanium oxide layer (TiOx, x in 1.5-2.0) with a thickness of 50 nm. It is sputtered in an argon atmosphere with a sputtering power of 44 kW and a deposition rate of 1 nm / s. The second transparent conductive layer is an ITO layer with a thickness of 350 nm. It is sputtered in an argon atmosphere with a sputtering power of 9 kW and a deposition rate of 1 nm / s. The total thickness of the electrochromic functional layer is controlled to be 1.5 μm.

[0060] (4) A second buffer layer is deposited on the electrochromic functional layer. The second buffer layer is a silicon oxide layer (SiO2) with a thickness of 50 nm to obtain the coated glass.

[0061] (5) The coated glass is subjected to pressure cold bending at 150°C. The bending radius is 5cm, the bending angle is 18°, the bending time is 90s, the bending pressure is 2MPa, and the holding time is 30min. After the bending is completed, the curved electrochromic glass is obtained.

[0062] Example 3

[0063] This embodiment provides a method for preparing curved electrochromic glass, the method comprising the following steps:

[0064] (1) Use 1.0 mm thick soda-lime glass as the glass substrate with a size of 1 m × 1.2 m. Clean the glass substrate with deionized water and alcohol in sequence using ultrasonic cleaning, and then use 200 W power to perform plasma treatment for 3 min.

[0065] (2) A first buffer layer is deposited on a glass substrate by magnetron sputtering. The first buffer layer is a silicon nitride layer (SiNx, x is 1.0-1.4) with a thickness of 50 nm.

[0066] (3) An electrochromic functional layer is deposited on the first buffer layer, wherein the electrochromic functional layer comprises, in sequence, a first transparent conductive layer, an ion storage layer, an electrochromic layer, an encapsulation layer, and a second transparent conductive layer.

[0067] The materials, thicknesses, and sputtering parameters of each layer are as follows: First transparent conductive layer: ITO layer, 300 nm thick, sputtered in an argon and oxygen atmosphere (volume ratio 100:1), sputtering power 9 kW, deposition rate 0.2 nm / s; Ion storage layer: Nickel tungsten oxide layer (NiWOx, x 3.5-4.5), 200 nm thick, sputtered in an argon atmosphere, sputtering power 35 kW, deposition rate 1 nm / s; Electrochromic layer: WO3 layer, 3 nm thick. The first layer is a titanium oxide layer (TiOx, x in 1.5-2.0) with a thickness of 50 nm. It is sputtered in an argon atmosphere with a sputtering power of 44 kW and a deposition rate of 1 nm / s. The second transparent conductive layer is an ITO layer with a thickness of 300 nm. It is sputtered in an argon atmosphere with a sputtering power of 9 kW and a deposition rate of 1 nm / s. The total thickness of the electrochromic functional layer is controlled to be 1.1 μm.

[0068] (4) A second buffer layer is deposited on the electrochromic functional layer. The second buffer layer is a silicon oxide layer (SiO2) with a thickness of 100 nm to obtain coated glass.

[0069] (5) The coated glass is subjected to pressure cold bending at 120°C. The bending radius is 5cm, the bending angle is 18°, the bending time is 150s, the bending pressure is 0.5MPa, and the holding time is 60min. After the bending is completed, the curved electrochromic glass is obtained.

[0070] Example 4

[0071] This embodiment provides a method for preparing curved electrochromic glass. Compared with Embodiment 1, only the first buffer layer is deposited, and the second buffer layer is not deposited. All other aspects are the same as in Embodiment 1.

[0072] Example 5

[0073] This embodiment provides a method for preparing curved electrochromic glass. Compared with Embodiment 1, the thickness of the second buffer layer is set to 30 nm, and the rest is the same as in Embodiment 1.

[0074] Example 6

[0075] This embodiment provides a method for preparing curved electrochromic glass. Compared with Embodiment 1, the thickness of the second buffer layer is set to 130 nm, and the rest is the same as in Embodiment 1.

[0076] Comparative Example 1

[0077] This comparative example provides a method for preparing curved electrochromic glass. Compared with Example 1, the first and second buffer layers are not deposited, but all other aspects are the same as in Example 1.

[0078] Performance testing

[0079] The curved electrochromic glasses prepared in the examples and comparative examples were tested. The results are shown in Table 1.

[0080] ① Test film thickness deviation: Take multiple measurement points distributed in a dispersed manner on the glass surface, measure their thickness and average value, and calculate the standard deviation of the thickness at each measurement point.

[0081] ② Test dimming performance:

[0082] Bleaching voltage and coloring voltage were applied to the glass in sequence, and the transmittance of visible light (380-780nm) in the bleached and colored states was measured. The response time from bleaching to coloring was recorded, that is, the time required from the application of the coloring voltage until the change in the transmittance of the device reaches 90% of its total change.

[0083] ③ Cyclic stability: The glass was subjected to bleaching-coloring cycles 1000 times. The range of light transmittance adjustment before and after the cycles was tested, and the dimming amplitude attenuation rate before and after the cycles was calculated.

[0084] ④ Bending reliability test: The glass was repeatedly bent 1000 times (bending angle 18°, each bend held for 10s) to test the range of light transmittance adjustment before and after bending, and to calculate the light adjustment amplitude attenuation rate before and after bending; and the adhesion of the film layer was measured by using the cross-cut test.

[0085] ⑤ Environmental stability test: Place the glass at 60℃ and 90% relative humidity for 1000 hours, test the range of light transmittance adjustment before and after placement, and calculate the attenuation rate of light adjustment amplitude before and after placement.

[0086] Table 1

[0087]

[0088] As can be seen from the test results in Table 1, the preparation method of this invention adopts a pre-coating followed by cold bending process and sets a buffer layer. The thickness deviation of the resulting film is only ±1.0%~±2.1%, which is far better than the ±20% of traditional curved surface coating. At the same time, it ensures that the device has good dimming performance and stability, with a bleached state transmittance of 82%~87% and a colored state transmittance of 5%~9%. The dimming attenuation rate after cycling, bending, and placement is ≤4.8%, and the bending adhesion reaches level 2 or below. In contrast, in Comparative Example 1, no buffer layer was set, and the film stress could not be released, resulting in increased thickness deviation, decreased transmittance, prolonged response time, and a significant increase in the attenuation rate of cycling / bending / environmental stability (all exceeding 8%). The bending adhesion is only level 3, and the film is easy to fall off. This shows that the design of the buffer layer ensures the performance of the film after cold bending.

[0089] Furthermore, compared to other embodiments, Embodiments 1-3 exhibit superior performance. Embodiment 4, with only a single buffer layer, shows a slight decrease in device performance, indicating a more comprehensive mitigation of cold bending stress. In Embodiments 5-6, when the buffer layer thickness deviates from the preferred range of 50-100 μm, the stress buffering effect weakens; a reasonable stress buffer layer thickness can further improve device performance.

[0090] In summary, the preparation process of this invention can ensure the uniformity of the thickness and performance of the functional layer during coating, solve the problem of large thickness deviation when coating curved glass, and the problem of difficulty in adapting curvature, size and equipment, ensure the stability of device performance, facilitate secondary processing such as cutting and drilling, and improve the flexibility of product design.

[0091] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing curved electrochromic glass, characterized in that, The preparation method includes the following steps: depositing an electrochromic functional layer on a glass substrate, depositing a buffer layer on at least one side of the electrochromic functional layer to obtain coated glass, and cold bending the coated glass to obtain the curved electrochromic glass.

2. The preparation method according to claim 1, characterized in that, The thickness of the glass substrate is 0.5-1.0 mm; preferably, the glass substrate is selected from soda-lime glass and / or borosilicate glass.

3. The preparation method according to claim 1 or 2, characterized in that, The total thickness of the electrochromic functional layer is ≤2μm, preferably 1.2-1.8μm.

4. The preparation method according to any one of claims 1-3, characterized in that, The material of the buffer layer includes silicon oxide and / or silicon nitride; preferably, the thickness of the buffer layer is 50-100 nm.

5. The preparation method according to any one of claims 1-4, characterized in that, The temperature for cold bending is 120-150℃.

6. The preparation method according to any one of claims 1-5, characterized in that, The bending time for the cold bending forming is 90-150 seconds.

7. The preparation method according to any one of claims 1-6, characterized in that, The bending angle of the cold bending forming is ≤18°; preferably, the bending radius of the cold bending forming is ≥5cm.

8. The preparation method according to any one of claims 1-7, characterized in that, The pressure for cold bending is 0.5-2 MPa; preferably, the holding time for cold bending is 30-60 min.

9. The preparation method according to any one of claims 1-8, characterized in that, The buffer layer and / or electrochromic functional layer are prepared by magnetron sputtering; preferably, the sputtering power of the magnetron sputtering is 5-45kW; preferably, the deposition rate of the magnetron sputtering is 0.2-1nm / s.

10. The preparation method according to any one of claims 1-9, characterized in that, The electrochromic functional layer comprises a first transparent conductive layer, an ion storage layer, an electrochromic layer, an encapsulation layer, and a second transparent conductive layer stacked sequentially. Preferably, the first transparent conductive layer is made of indium tin oxide and / or indium zinc oxide. Preferably, the thickness of the first transparent conductive layer is 300-400 nm. Preferably, the ion storage layer is made of nickel tungsten oxide. Preferably, the thickness of the ion storage layer is 200-300 nm. Preferably, the electrochromic layer is made of tungsten trioxide. Preferably, the thickness of the electrochromic layer is 300-400 nm. Preferably, the encapsulation layer is made of titanium oxide. Preferably, the thickness of the encapsulation layer is 40-55 nm. Preferably, the second transparent conductive layer is made of indium tin oxide and / or indium zinc oxide. Preferably, the thickness of the second transparent conductive layer is 300-400 nm. Preferably, the glass substrate is pretreated before deposition; preferably, the surface pretreatment includes sequential cleaning and plasma treatment; preferably, the power of the plasma treatment is 100-200W; preferably, the plasma treatment time is 3-5 minutes.

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