Method for adjusting visible light transmittance of colored microcrystalline glass

Abstract

The invention relates to the technical field of glass ceramics, in particular to a method for adjusting the visible light transmittance width of colored glass ceramics. The method comprises the following steps: S1) crystallization process: crystallizing base glass; s2) a dimming process; the dimming process comprises the following steps: quickly heating the crystallized glass to Tmax, and then quickly cooling. The Tmax is greater than or equal to the highest temperature of crystallization. According to the dimming method, the width adjustment of the transmittance can be realized, and the key performance of the thermal expansion coefficient of the microcrystal panel is not degraded. The dimming method process provided by the invention is in a cooling section after crystallization, is close to a cold end for detection, and can realize rapid adjustment of transmittance.

Description

Technical Field

[0001] The present invention relates to the technical field of glass-ceramics, and particularly to a method for adjusting the visible light transmittance of colored glass-ceramics. Background Art

[0002] LAS glass-ceramics refer to glass-ceramics with the main crystal phase being the Li2O-Al2O3-SiO2 component system, hereinafter simply referred to as glass-ceramics. It has unique low-expansion characteristics and good impact resistance, and is widely used in kitchen stove tops, electrical appliance covers and other occasions. Under the microcrystalline cover plate, there are mainly various electronic components, such as heating wire coils, copper coils, buttons, and various light-emitting devices, such as LED indicators. In addition to providing safety protection during use, the microcrystalline cover plate should also have a visual shielding function, that is, the electronic components under the cover plate are invisible during use, while the light-emitting devices are required to be clearly visible when working. Therefore, relatively high requirements are put forward for the visible light transmittance of the glass-ceramic panel, generally limited between 0.2% and 2%. If the transmittance is lower than 0.2%, it is difficult for the light-emitting device to be clearly displayed; if the transmittance is higher than 2%, it will lead to the visibility of unwanted electronic devices. To achieve the above-mentioned light-shielding effect, the conventional method in the industry is to add colorants. Especially the addition of V element can achieve a black appearance effect. When its visible light transmittance is only 0.2% - 2%, the mid-infrared transmittance (1600nm) is still higher than 60%.

[0003] In actual operation, the required range of customers will be smaller, and the transmittance ranges of different customers may not overlap. For example, Customer A requires the transmittance of the product to be 0.35% - 0.70%, while Customer B requires the transmittance of the product to be 0.8% - 1.3%, etc. The current technology is difficult to better address the problem of adjusting the visible light transmittance of the glass-ceramic panel.

[0004] The preparation process of the glass-ceramics is roughly as follows: preparation of glass batch → high-temperature melting → rolling forming → crystallization → post-processing, and the post-processing includes but is not limited to grinding, polishing, edge grinding, chamfering, screen printing, surface treatment, etc. The base glass refers to the glass that has not been crystallized after rolling forming; the glass-ceramics generally refer to the glass that has been crystallized and formed a large number of micro-nano crystal phases. If the glass batch contains inorganic arsenic compounds, it is called an arsenic-containing plate; otherwise, it is called a non-arsenic plate.

[0005] The thermal analysis results of the base glass are as Figure 1 shown. The Tg temperature is the glass transition temperature, Tp1 is the first crystallization peak temperature, corresponding to the precipitation of the first type of crystal, and Tp2 is the second crystallization peak temperature, corresponding to the precipitation of the second type of crystal. According to the actual required crystal type and crystallinity, the crystallization temperature Tc is selected based on Tp1 or Tp2 and fluctuates up and down.

[0006] The transmittance of the glass-ceramics depends on the following factors:

[0007] 1. Colorant content. The main colorant of the glass-ceramics is vanadium pentoxide, and the secondary colorants include titanium dioxide, iron oxides, etc. Among them, titanium dioxide is introduced as the main nucleating agent, which determines the performance of the microcrystalline panel; iron elements are generally introduced as raw material impurities. Therefore, the colorant adjustment method mainly focuses on adjusting the content of vanadium pentoxide.

[0008] 2. Crystallization process. The crystallization process is the process of inducing crystal formation and growth in the glass body. The crystallization temperature often reaches 860 - 950 °C. While crystallization occurs, coloring is completed. Before crystallization, the visible light transmittance of the glass panel is 40% - 85%, and it drops rapidly to less than the required 2% after crystallization treatment. The higher the temperature or the longer the crystallization time, the lower the transmittance; but at the same time, the expansion coefficient increases and the heat resistance performance decreases.

[0009] 3. Thickness of the prepared microcrystalline panel. According to the Lambert-Beer law, the greater the optical path thickness, the stronger the absorption of visible light and the lower the transmittance. However, the thickness of the microcrystalline panel is one of the main specifications of the microcrystalline product. The thickness deviation is generally controlled within ±0.2 mm. Taking a conventional 4-mm thick microcrystalline panel as an example, the thickness requirement fluctuates in the range of 3.8 - 4.2 mm. Considering the fluctuations caused by the production process, the actual controllable thickness variation range is only 0.2 mm. Compared with the 4-mm panel thickness, 0.2 mm can only achieve a visible light change amplitude of about 0.15%, which cannot achieve the purpose of adjusting the transmittance, and the process requirements for thickness control are extremely high.

[0010] The existing processes are difficult to adapt to the rapid and large-range adjustment of visible light. First, the process of changing the colorant content is extremely long. The processes involved in the preparation of glass-ceramics include: formula adjustment, glass melting, rolling forming, and crystallization, which takes several days; and the change in colorant content is a gradual process, and the glass melting furnace requires a longer continuous production cycle to stabilize the colorant content at a new level. Second, the crystallization process is difficult to change arbitrarily. The crystallization process is mainly to achieve glass crystallization. Arbitrarily changing the crystallization parameters will cause changes in the performance of the glass-ceramics, such as insufficient impact resistance or decreased thermal shock resistance. Finally, the thickness is an index that is strictly controlled. It is difficult to obtain a wide range of transmittance changes by adjusting the thickness. At the same time, the thickness is related to the impact strength and is not suitable for arbitrary change. Summary of the Invention

[0011] In view of this, the technical problem to be solved by the present invention is to provide a method for adjusting the visible light transmittance of colored glass-ceramics, which realizes the rapid and large-range adjustment of the visible light transmittance.

[0012] The present invention provides a dimming method for colored glass-ceramics, including the following steps:

[0013] S1) Crystallization process to crystallize the glass;

[0014] S2) Light dimming process;

[0015] The light dimming process includes rapid cooling, and the cooling rate of the rapid cooling is greater than or equal to 90 °C / min to adjust the visible light transmittance of the glass-ceramics and obtain colored glass-ceramics.

[0016] Optionally, in step S2), before the rapid cooling, it further includes: a rapid heating process of rapidly heating the crystallized glass to Tmax to adjust the visible light transmittance of the glass-ceramics and obtain colored glass-ceramics. Tp2 > Tmax ≥ Tc.

[0017] Optionally, Tmax is 890 - 1100 °C.

[0018] Optionally, in step S2), the heating rate of the rapid heating is greater than or equal to 60 °C / min; the cooling rate of the rapid cooling is greater than or equal to 90 °C / min;

[0019] The higher the heat treatment temperature of the glass-ceramics, the shorter the required heat treatment time, that is, high temperature can improve the crystal precipitation efficiency. Excessive temperature or too long heat treatment time will also cause phase transformation of the crystal phase, seriously affecting the performance of the glass-ceramic panel. The inventor surprisingly found that by rapidly heating and rapidly cooling after crystallization, as long as Tmax is controlled within a certain range, it does not affect the key performance of the glass-ceramics, and the coefficient of thermal expansion remains stable. Tmax should be less than Tp2, otherwise some crystal phases in the colored glass-ceramics will transform, resulting in a rapid increase in the coefficient of thermal expansion. The above rapid heating refers to heating at a rate greater than 60 °C / min, and rapid cooling refers to cooling at a rate greater than 90 °C / min. Obviously, the higher the heating and cooling rates, the shorter the time the glass-ceramics are at high temperature; on the contrary, too low heating or cooling rates will lead to too long residence time at high temperature, resulting in phase transformation and performance deterioration.

[0020] More notably, after the rapid heating and rapid cooling treatment after crystallization, the transmittance of the glass-ceramics can be changed, thereby realizing wide-range adjustment of the transmittance of the glass-ceramics.

[0021] Specifically, the inventors found that the higher the Tmax, the higher the transmittance; the greater the heating rate, the higher the transmittance. At the same time, during the rapid cooling starting from Tmax, there is an "end temperature" for the cooling. Below the end temperature, the relationship between the transmittance of the microcrystalline panel and the cooling rate is not significant. For example, below the end temperature, the room temperature transmittance of the microcrystalline panel obtained by rapid cooling at 120 °C / min is almost the same as that obtained by conventional cooling at 20 °C / min. The rapid cooling between Tmax and the end temperature can effectively change the transmittance of the microcrystalline glass; during this section of cooling, as the cooling rate increases, the transmittance increases. From the end temperature to room temperature, any cooling method can be adopted, which has almost no effect on the transmittance.

[0022] The inventors found that to achieve the effects of the present invention, the rapid cooling is to rapidly cool from Tmax to the end temperature, and the end temperature is not higher than 750 °C;

[0023] Preferably, the end temperature is not higher than 700 °C.

[0024] Optionally, an annealing section is set after the dimming process to release the thermal stress generated by the rapid cooling. The annealing temperature can be the end temperature, or higher than this temperature, or lower than this temperature, etc.

[0025] Optionally, after the dimming process, a conventional cooling process is set to gradually cool the microcrystalline glass from the end temperature. The conventional cooling process does not limit the cooling rate, and the cooling steps of the current microcrystalline glass crystallization process can be referred to, such as cooling at 1-40 °C / min. The cooling can be achieved through conventional cooling processes, such as blowing air, etc.

[0026] The composition of the microcrystalline glass contains V2O5. Vanadium element is a necessary element for the present invention to achieve transmittance adjustment. Colored microcrystalline glass generally adds V2O5 to achieve the shielding effect on components after crystallization. The visible light transmittance of the base glass is generally > 40%, and after crystallization, the high-valent vanadium element is reduced, resulting in strong absorption in the visible light range. Therefore, V2O5 is necessary for the present invention.

[0027] Optionally, the mass content of V2O5 is 0.01% - 0.50%.

[0028] Preferably, the mass content of V2O5 is 0.01%, 0.02%, 0.03%, 0.04%, 0.10%, 0.20%, 0.30%, 0.40%, 0.50%.

[0029] Optionally, the glass-ceramic formulation contains TiO2. TiO2 is one of the important nucleating agents for glass-ceramics, which can promote the crystallization during the crystallization process and improve the crystallization efficiency. As a nucleating agent, the content of TiO2 is 2.0 wt% - 4.0 wt%. Specifically, the content of TiO2 is 2.0 wt%, 2.2 wt%, 2.4 wt%, 2.7 wt%, 2.9 wt%, 3.1 wt%, 3.3 wt%, 3.7 wt%, 4.0 wt%. TiO2 can enhance the coloring effect of vanadium elements after crystallization. Similarly, TiO2 is beneficial to achieving a wide transmittance adjustment range.

[0030] Optionally, in the step S2), a heat preservation process is further included between the rapid heating and the rapid cooling; the thermal conductivity of the glass-ceramic panel is very low. When the glass-ceramic is relatively thick, the temperature inside the microcrystalline panel rises more slowly than the surface. Setting a certain heat preservation time at Tmax is beneficial for the overall microcrystalline panel to reach the Tmax temperature to better achieve transmittance adjustment. To avoid crystal growth or phase transformation, the heat preservation time at Tmax is less than 10 min. The closer Tmax is to Tp2, the shorter the heat preservation time; the closer Tmax is to Tc, the heat preservation time can be appropriately extended.

[0031] Optionally, the time of the rapid heating is less than or equal to 3 min to avoid unwanted crystal growth or phase transformation.

[0032] Optionally, after the step S2), the following is further included:

[0033] S3) Cooling. Using the commonly used cooling method in the art, the glass-ceramic is further cooled from the end temperature of the dimming process. For example, it is gradually cooled at 1 °C / min - 40 °C / min.

[0034] Compared with the prior art, the method provided by the present invention can achieve a wide adjustment of the visible light transmittance of the colored glass-ceramic. Without changing the crystallization process, the transmittance of the microcrystalline panel expands from a single-point value to a controllable adjustment range of > 100%. The test results show that the dimming method provided by the present invention can significantly broaden the light transmittance from a single-point value of 0.515% to 0.465% - 1.193%, and the key performance of the thermal expansion coefficient of the microcrystalline panel will not be significantly deteriorated.

[0035] Moreover, the process change of the dimming process provided by the present invention is in the cooling section of the original crystallization process. The adjustment process takes a short time, only about ten minutes away from the cold-end detection. By detecting the transmittance of the microcrystalline panel at the cold end and changing the process parameters of the dimming process, rapid transmittance adjustment can be achieved. Even if the formulation is changed, during the gradual change of the coloring agent content, based on the method of the present invention, the transmittance of the microcrystalline panel can be quickly adjusted to maintain the stability of the transmittance of the microcrystalline panel produced during the change of the coloring agent or formulation. Description of the Drawings

[0036] Figure 1 Thermal analysis curve of the base glass;

[0037] Figure 2 Dilatation curves of the glass-ceramics prepared in Examples 1-2 and Comparative Example 1. Detailed implementation mode

[0038] The present invention provides a method for adjusting the light of colored glass-ceramics, comprising the following steps:

[0039] S1) Crystallization process to crystallize the glass;

[0040] S2) Light adjustment process;

[0041] The light adjustment process includes rapid cooling, and the cooling rate of the rapid cooling is greater than or equal to 90 °C / min to adjust the visible light transmittance of the glass-ceramics to obtain colored glass-ceramics.

[0042] The present invention is applicable to glass-ceramics containing V2O5.

[0043] The V2O5 is a colorant of the glass-ceramics, and the mass content of the V2O5 is 0.01% to 0.5%, and can be 0.01%, 0.02%, 0.03%, 0.04%, 0.10%, 0.20%, 0.30%, 0.40%, 0.50%.

[0044] The mass content of the V2O5 is preferably 0.015% to 0.35%.

[0045] Among them, when the glass is an arsenic-free plate, the mass content of the V2O5 is preferably 0.015% to 0.04%; when the glass is an arsenic-containing plate, the mass content of the V2O5 is preferably 0.2% to 0.35%.

[0046] The present invention is applicable to glass-ceramics containing TiO2. TiO2 can enhance the coloring effect of vanadium after crystallization.

[0047] Among them, the TiO2 is a nucleating agent of the glass-ceramics, and the mass content of the TiO2 is 2% to 4%, and can be 2.0%, 2.2%, 2.5%, 2.8%, 3.0%, 3.2%, 3.5%, 3.8%, 4.0%.

[0048] The mass content of the TiO2 is preferably 2.7% to 3.2%.

[0049] In the present invention, the components of the glass further include conventional aids such as clarifying agents, fluxes and batch materials of glass cullet.

[0050] The present invention does not specifically limit the specific types and contents of the clarifying agent, flux, glass cullet batch and other additives, which can be the types well-known to those skilled in the art, and the contents of each additive can be adjusted by themselves according to requirements.

[0051] In some specific embodiments of the present invention, the glass-ceramics include:

[0052] V2O5, As2O3, TiO2, ZrO2, Li2O, Al2O3, SiO2, flux and inevitable impurities.

[0053] In some specific embodiments of the present invention, the glass-ceramics include:

[0054] V2O5, SnO2, TiO2, ZrO2, Li2O, Al2O3, SiO2, flux and inevitable impurities.

[0055] In some embodiments of the present invention, first, the main components of the glass and each additive are mixed, and then melted at high temperature to melt the glass batch into a uniform and bubble-free high-temperature glass melt. The temperature of the high-temperature melting can be 1600-1800 °C.

[0056] Then calendering is carried out to roll into a base glass plate with a specified thickness by a calender roll.

[0057] In some embodiments of the present invention, the thickness of the glass plate is 3-5 mm, including but not limited to 3 mm, 3.5 mm, 3.8 mm, 4.2 mm or 5 mm, and the visible light transmittance of the base glass plate can be higher than 40%.

[0058] Then subsequent heat treatment is carried out to induce crystallization of the base glass by heating and holding to form glass-ceramics.

[0059] The crystallization of glass-ceramics is common knowledge in the field of glass-ceramics. The crystallization process can be to hold for a certain time after heating to Tc (crystallization temperature); it can also be to directly enter the cooling process after heating to Tc (crystallization temperature). It is well-known to those skilled in the art that a low-temperature holding process or a slow heating process can also be inserted during the above heating process to achieve "nucleation".

[0060] A typical two-stage crystallization process is as follows:

[0061] First, a nucleation process is carried out to nucleate the glass.

[0062] The temperature of the nucleation process is preferably 690 - 780 °C, the heat preservation time of the nucleation process is preferably 3 - 60 min, and the heating rate before nucleation, i.e., the primary heating rate, is 2 - 30 °C / min. The nucleation temperature can be 690 °C, 715 °C, 725 °C, 735 °C, 740 °C, 745 °C, 750 °C or 780 °C; the heat preservation time can be 3 min, 10 min, 15 min, 20 min, 25 min, 35 min, 45 min, 55 min or 60 min; the heating rate can be 2 °C / min, 5 °C / min, 10 °C / min, 15 °C / min, 20 °C / min or 30 °C / min.

[0063] As is well known to those skilled in the art, the nucleation process does not require isothermal heat preservation and can also be replaced by a heating section.

[0064] After the glass is nucleated, it is heated for the second time to crystallize the glass to complete crystal growth and preliminary coloring.

[0065] The temperature of the crystallization process is preferably 840 - 980 °C, the heating rate of the crystallization process is preferably 2 - 30 °C / min, and the heat preservation time of the crystallization process is preferably < 120 min.

[0066] The nucleated base glass is heated to the crystallization temperature Tc at a rate of 2 - 30 °C / min, preferably at a heating rate of 4 - 15 °C / min, more preferably 5 - 10 °C / min. The crystallization temperature is generally in the range of -20 to +120 °C near the Tp1 temperature (referring to a decrease of 20 °C or an increase of 120 °C based on the Tp1 temperature), generally 840 - 980 °C. The preferred crystallization temperature range is 870 - 930 °C. Among them, the Tp1 temperature is the first exothermic peak of the base glass and can be measured by DSC or DTA. The crystallization heat preservation time is generally < 120 min, preferably 25 - 45 min. The crystallization process completes the precipitation of the crystals of the glass-ceramics, and at the same time, the transmittance decreases from 40% - 85% of the base glass to less than 2%.

[0067] In some embodiments of the present invention, the temperature of the crystallization process is 890 °C, the heating rate of the crystallization process is 5 - 6 °C / min, and the heat preservation time of the crystallization process is 40 min.

[0068] The present invention sets a dimming process after the crystallization process to realize online rapid and large-range adjustment of the transmittance of the crystallized glass-ceramics. The dimming process includes rapid heating and rapid cooling.

[0069] The heating rate of the rapid heating is preferably greater than or equal to 60 °C / min, more preferably greater than or equal to 80 °C / min. In some specific embodiments of the present invention, the heating rate of the rapid heating is 70-150 °C / min, preferably 80-120 °C / min, and specifically can be 80, 90, 100, 110 or 120 °C / min.

[0070] In the present invention, the crystallized glass is rapidly heated to Tmax. To obtain a large adjustment range of light transmittance, Tmax should be as high as possible, but should be lower than the temperature of Tp2. Tp2 is the crystallization peak of hydrothermal quartz. Approaching the temperature of Tp2 will cause significant precipitation of hydrothermal quartz and deterioration of the thermal expansion coefficient. Preferably, the Tmax is 890-1100 °C, and specifically can be 890, 900, 950, 980, 1000, 1010, 1050, 1060, 1080, 1100 °C.

[0071] It should be noted here that when Tmax is equal to the highest temperature of crystallization, that is, rapid cooling is directly carried out without rapid heating.

[0072] The cooling rate of the rapid cooling is preferably greater than or equal to 90 °C / min; more preferably greater than or equal to 120 °C / min. In some specific embodiments of the present invention, the cooling rate of the rapid cooling is 90-200 °C / min, and specifically can be 95, 100, 110, 120, 130, 140 °C / min.

[0073] The rapid cooling preferably rapidly cools to the end temperature, and the end temperature is below 750 °C.

[0074] Further preferably, the rapid cooling cools to below 700 °C.

[0075] The heat conduction performance of the glass-ceramics is poor. When the glass-ceramic panel is relatively thick, in order to make the internal temperature of the glass-ceramic panel also close to Tmax, a heat preservation process can be set between the rapid heating and the rapid cooling. However, increasing the heat preservation time will bring the risk of deterioration of the performance of the glass-ceramic panel. Specifically, during the heat preservation process at Tmax, a crystal phase transformation occurs and the linear thermal expansion coefficient increases, thereby resulting in damage to the thermal shock resistance.

[0076] Preferably, the time of the rapid heating is less than or equal to 3 min.

[0077] The heat preservation time is preferably <10 min.

[0078] Preferably, the total time of the rapid heating and the heat preservation process is less than or equal to 10 min; for a higher Tmax, such as 1010 °C, an appropriate heat preservation time is given, which is beneficial to the overall heating of the microcrystalline panel to Tmax, thereby obtaining a larger transmittance adjustment range. An excessively long heat preservation time, especially for a higher Tmax, will lead to crystal phase transformation and deterioration of panel performance.

[0079] The temperature change rate of the above rapid heating and rapid cooling should be as large as possible to obtain as large a transmittance adjustment range as possible; however, an excessively large temperature change rate will cause the aggregation of thermal stress caused by volume change to exceed the bearing capacity of the microcrystalline panel body and result in cracking. Preferably, the closer the thermal expansion coefficient of the microcrystalline glass body after the crystallization process is to 0, the larger the temperature change rate it can withstand.

[0080] Preferably, after the step S2), the following is further included:

[0081] S3) Cooling.

[0082] The cooling rate can be 1 - 40 °C / min and can be achieved by conventional cooling processes such as blowing air, etc.

[0083] The present invention has no special limitation on the conventional cooling method and the cooling rate, and natural cooling or blowing air cooling, etc. can be used.

[0084] After cooling to room temperature, conventional post-treatments such as cutting and post-processing can also be included.

[0085] The post-processing includes but is not limited to grinding, polishing, screen printing, surface treatment, etc.

[0086] The visible light transmittance herein is measured by Hunterlab ColorQuest XE, and the visible light range refers to a wavelength of 400 - 700 nm.

[0087] In order to further illustrate the present invention, the following will be described in detail with reference to embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.

[0088] For all raw materials of the present invention, there is no special limitation on their sources, and they can be purchased on the market or prepared by conventional methods well-known to those skilled in the art.

[0089] In Examples 1 to 4 and Comparative Example 1, the microcrystalline glass used is an arsenic-containing plate, and the components are as follows, by mass percentage:

[0090] V2O5 0.3%, As2O3 0.8%, TiO2 2.9%, ZrO2 1.6%, Li2O 3.9%, Al2O3 21%, SiO2 64%, and the remaining components 5.3%.

[0091] Example 1

[0092] Crystallization process: 1. Nucleation: Heat from room temperature to 735°C at a rate of 10°C / min and hold for 15 minutes to complete the nucleation process; 2. Crystallization: Heat to the crystallization temperature of 890°C at a rate of 5°C / min and hold for 40 min to complete crystal growth and preliminary coloring.

[0093] Dimming process: Heat to 1010°C at a rate of 120°C / min in about 1 min without holding, and then cool to 700°C at a rate of 130°C / min;

[0094] Conventional cooling: Cool to 400°C at a rate of 25°C / min in 12 min, and then further cool to room temperature to obtain colored glass-ceramics.

[0095] Test the transmittance and thermal expansion coefficient (DIL) of the glass-ceramic panel. The results are shown in Table 1.

[0096] Examples 2 - 4

[0097] Crystallization process: 1. Nucleation: Heat from room temperature to 735°C at a rate of 10°C / min and hold for 15 minutes to complete the nucleation process; 2. Crystallization: Heat to the crystallization temperature of 890°C at a rate of 5°C / min and hold for 40 min to complete crystal growth and preliminary coloring.

[0098] Dimming process: The parameters of the temperature adjustment process are shown in Table 1.

[0099] Conventional cooling: The parameters of the cooling process are shown in Table 1, and then further cool to room temperature to obtain colored glass-ceramics.

[0100] Test the transmittance and DIL of the glass-ceramic panel. The results are shown in Table 1.

[0101] Comparative Example 1

[0102] Comparative Example 1 is a typical crystallization process for arsenic-containing glass-ceramic panels.

[0103] Crystallization process: 1. Nucleation: Heat from room temperature to 735°C at a rate of 10°C / min and hold for 15 minutes to complete the nucleation process; 2. Crystallization: Heat to the crystallization temperature of 890°C at a rate of 5°C / min and hold for 40 min to complete crystal growth and preliminary coloring; 3. Cooling: The parameters of the cooling process are shown in Table 1, and then further cool to room temperature to obtain colored glass-ceramics.

[0104] Test the transmittance and DIL of the glass-ceramic panel. The results are shown in Table 1.

[0105] Table 1 Crystallization processes and test results of Examples 1 - 4 and Comparative Example 1

[0106]

[0107] Figure 2 It is the expansion curve graph of the glass-ceramics prepared in Example 1-2 and Comparative Example 1. Generally speaking, when the linear thermal expansion coefficient of the microcrystalline panel line < 0.5 ppm / °C, it can withstand thermal shock above 800 °C. From Figure 2 It can be seen that after being processed by the method described in the present invention, the linear thermal expansion coefficients of the glass-ceramics are all < 0.2 ppm / °C, and the performance has not changed significantly. However, the visible light transmittance has expanded from a single point value of 0.515% to a controllable adjustment range of 0.465 - 1.193% with an amplitude exceeding 100%, and the overall time required does not increase.

[0108] Examples 5-7, and Comparative Examples 2-3 are arsenic-free plates, and the components are as follows, in mass percentage:

[0109] V2O5 0.03%, SnO2 0.3%, TiO2 2.9%, ZrO2 1.6%, Li2O 3.9%, Al2O3 21%, SiO2 64%, and the remaining components 6.27%.

[0110] Example 5

[0111] Crystallization process: 1. Nucleation: Heat from room temperature to 735 °C at a rate of 10 °C / min and hold for 15 minutes to complete the nucleation process; 2. Crystallization: Heat to the crystallization temperature of 890 °C at a rate of 5 °C / min and hold for 40 min to complete crystal growth and preliminary coloring.

[0112] Light regulation: Heat to 980 °C at a rate of 120 °C / min in 45 s, hold for 5 min, and then cool to 700 °C at a rate of 120 °C / min.

[0113] Conventional cooling: Cool to 400 °C at a rate of 25 °C / min in 12 min, and further cool to room temperature to obtain colored glass-ceramics.

[0114] Test the transmittance and DIL of the microcrystalline panel. The results are shown in Table 2.

[0115] Examples 6-7

[0116] Crystallization process: 1. Nucleation: Heat from room temperature to 735 °C at a rate of 10 °C / min and hold for 15 minutes to complete the nucleation process; 2. Crystallization: Heat to the crystallization temperature of 890 °C at a rate of 5 °C / min and hold for 40 min to complete crystal growth and preliminary coloring.

[0117] Light regulation process: The parameters of the temperature regulation process are shown in Table 2.

[0118] Conventional cooling: The parameters of the cooling process are shown in Table 2. It is further cooled to room temperature to obtain the colored glass-ceramics.

[0119] Measure the transmittance and DIL of the microcrystalline panel. The results are shown in Table 2.

[0120] Comparative Example 2

[0121] The holding time of Tmax in Comparative Example 2 is relatively long, 10 min.

[0122] Crystallization process: 1. Nucleation: Heat from room temperature to 735 °C at a rate of 10 °C / min and hold for 15 minutes to complete the nucleation process; 2. Crystallization: Heat to the crystallization temperature of 890 °C at a rate of 5 °C / min and hold for 40 min to complete crystal growth and preliminary coloring.

[0123] Dimming process: Heat to 980 °C at a rate of 120 °C / min in 45 s, hold for 10 min, and then cool to 700 °C at a rate of 120 °C / min.

[0124] Conventional cooling: Cool to 400 °C at a rate of 25 °C / min in 12 min, and further cool to room temperature to obtain the colored glass-ceramics.

[0125] Comparative Example 3

[0126] Comparative Example 3 is a typical crystallization process for arsenic-free microcrystalline panels.

[0127] Crystallization process: 1. Nucleation: Heat from room temperature to 735 °C at a rate of 10 °C / min and hold for 15 minutes to complete the nucleation process; 2. Crystallization: Heat to the crystallization temperature of 890 °C at a rate of 5 °C / min and hold for 40 min to complete crystal growth and preliminary coloring; 3. Cooling: The parameters of the cooling process are shown in Table 2. It is further cooled to room temperature to obtain the colored glass-ceramics.

[0128] Measure the transmittance and DIL of the microcrystalline panel. The results are shown in Table 2.

[0129] Table 2 Crystallization processes and test results of Examples 5-7 and Comparative Examples 2-3

[0130]

[0131] The results of Examples 1 to 4 and Comparative Example 1 show that the method provided by the present invention can significantly broaden the light transmittance from a single-point value of 0.515% to 0.465% - 1.193%, the visible light adjustment range reaches 156%, and the key performance of the thermal expansion coefficient of the microcrystalline panel will not deteriorate. Therefore, the present invention realizes a wide-range adjustment of the transmittance of microcrystalline glass by adding a dimming process during the preparation of colored microcrystalline glass and adjusting different heating rates, heating times, Tmax temperatures, holding times, cooling rates, and cooling times, which can meet the different transmittance requirements of different customers for different products, and the adjustment method is simple and fast.

[0132] Examples 5 to 6 and Comparative Examples 2 to 3 show that although the adjustment of the transmittance can be achieved by holding at Tmax for a certain time, there are side effects, which will cause an increase in the linear thermal expansion coefficient. Especially the holding at a higher temperature will cause the DIL to increase to more than 0.5 ppm / °C, resulting in a significant decrease in the thermal shock resistance performance.

[0133] Based on the above findings, the present invention realizes a rapid and large-range adjustment of the visible light transmittance without changing the current crystallization process and without increasing the production time.

[0134] The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for adjusting the visible light transmittance of colored glass-ceramics, comprising the following steps: S1) Crystallization process to crystallize the glass; S2) Light modulation process; The light modulation process includes rapid cooling, and the cooling rate of the rapid cooling is greater than or equal to 90 °C / min to adjust the visible light transmittance of the glass-ceramics and obtain colored glass-ceramics.

2. The method for adjusting the visible light transmittance of the colored glass-ceramics according to claim 1, characterized in that, In step S2), before the rapid cooling, it further includes a rapid heating process of rapidly heating the crystallized glass to Tmax to adjust the visible light transmittance of the glass-ceramics and obtain colored glass-ceramics. The heating rate of the rapid heating is greater than or equal to 60 °C / min.

3. The method for adjusting the visible light transmittance of the colored glass-ceramics according to claim 2, characterized in that, The Tmax ≥ crystallization temperature and is less than Tp2.

4. The method for adjusting the visible light transmittance of the colored glass-ceramics according to claim 2, wherein, The Tmax is 890 - 1100 °C.

5. The method for adjusting the visible light transmittance of the colored glass-ceramics according to claim 1 or claim 2, characterized in that, In step S2), the rapid cooling is to rapidly cool to below 750 °C.

6. The method for adjusting the visible light transmittance of the colored glass-ceramics according to claim 1 or claim 2, characterized in that, The components of the glass include V2O5, and the mass content of V2O5 is 0.01% - 0.5%.

7. The method for adjusting the visible light transmittance of the colored glass-ceramics according to claim 2, characterized in that, In step S2), there is also an insulation process between the rapid heating and the rapid cooling; the time of the rapid heating is less than or equal to 3 min; the insulation time is less than 10 min.

8. The method for adjusting the visible light transmittance of the colored glass-ceramics according to claim 1, wherein After step S2), it further includes: S3) Cooling.

9. The dimming method of the colored glass-ceramics according to claim 1, characterized in that, In step S1), the temperature of the crystallization process is 840 - 980 °C, the heating rate of the crystallization process is 2 - 30 °C / min, and the holding time of the crystallization process is less than 120 min.

10. The method for adjusting the visible light transmittance of the colored glass-ceramics according to claim 9, characterized in that, In step S1), it also includes a nucleation process. The temperature of the nucleation process is 690 - 780 °C, and the holding time of the nucleation process is 3 - 60 min.

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