CN115484330A - Glass ceramic, preparation method, glass ceramic cover plate and electronic equipment - Google Patents

Abstract

The application provides a glass ceramic, a preparation method thereof, a glass ceramic cover plate and electronic equipment. The glass ceramic comprises at least one of lithium disilicate crystals and petalite crystals and quartz crystals; the glass-ceramic contains, on an oxide basis and expressed in weight percent, materials including the following weight percent: siO2 ₂ 60～75wt％，Al ₂ O ₃ 7～13wt％，Li ₂ O 8～12wt％，P ₂ O ₅ 0～3wt％，K ₂ O 0.5～3wt％，MgO 0.5～4wt％，ZrO ₂ 0.5 to 3 weight percent. By introducing a specific content of SiO ₂ 、Al ₂ O ₃ 、Li ₂ O、P ₂ O ₅ 、K ₂ O, mgO and ZrO ₂ The glass ceramic can be prepared, the lithium disilicate crystal and the petalite crystal can provide high strength for the glass ceramic, and the quartz crystal can provide a blue light prevention effect for the glass ceramic.

Description

Glass ceramics and preparation method, glass ceramic cover plate, electronic equipment

technical field

The application relates to the field of glass materials, in particular to a glass ceramic and a preparation method, a glass ceramic cover plate, and electronic equipment.

Background technique

With the development of science and technology, electronic devices such as mobile phones are becoming more and more intelligent, and the penetration rate is also increasing. However, the blue light emitted by the screen of electronic devices will cause certain harm to the human body, mainly reflected in the harm to the eyes and the harm to the rhythm of the human body. For example, blue light exposure can cause damage to retinal cells, leading to vision loss or even loss of vision. Among them, short-wave blue light with a wavelength between 400 and 480 nm is the most harmful to the retina. Blue light can also inhibit the secretion of melatonin in the human body, thereby affect sleep quality. At present, there are two common anti-blue light technologies. One is to coat a layer of anti-blue light film on the protective film and attach the protective film to the glass screen to reduce the transmittance of blue light emitted by electronic devices. The other is to coat the surface of the glass cover of the screen with an anti-blue light film. In order to avoid problems such as wear and tear of the anti-blue light coating during use, the anti-blue light film is coated on the inner surface of the glass cover. The resulting internal stress of the film layer will lead to a decrease in glass strength, generally by 30% to 50%.

In addition, although tempered glass is mostly used as the screen protection material for the screens of electronic devices, the cracking of the glass screen cannot be completely avoided, especially when the mobile phone is dropped, the glass screen is still easy to break, and the cost of screen repair is very high. Therefore, improving the strength and drop resistance of glass screens is also one of the research directions for glass performance improvement in recent years.

Contents of the invention

The application provides a glass ceramic and a preparation method, a glass ceramic cover plate, and an electronic device. The glass ceramic has the advantages of anti-blue light and high strength.

In a first aspect, the present application provides a glass-ceramic, including at least one of lithium disilicate crystal and petalite crystal, and quartz crystal; when the glass-ceramic is based on oxide and indicated by weight percentage, it contains : SiO ₂ 60~75wt%, Al ₂ O ₃ 7~13wt%, Li ₂ O 8~12wt%, P ₂ O ₅ 0~3wt%, K ₂ O 0.5~3wt%, MgO 0.5~4wt%, ZrO ₂ 0.5~3wt%.

_The glass _ceramics provided by this application can be _prepared including _{lithium disilicate crystals} and _{lithium permeable} At least one of feldspar crystals and glass ceramics of quartz crystals, wherein lithium disilicate crystals and petalite feldspar crystals can provide high strength for glass ceramics, and quartz crystals can provide anti-blue light effects for glass ceramics, thereby The prepared glass ceramics can have the characteristics of anti-blue light and high strength.

In a possible implementation of the present application, the glass ceramics include lithium disilicate crystals and quartz crystals, wherein the weight percentage of quartz crystals in the glass ceramics is 50-90 wt%, and the lithium disilicate crystals in the glass ceramics The weight percentage in is 10-50wt%.

In a possible implementation of the present application, the glass ceramics include petalite crystals and quartz crystals, wherein the weight percentage of quartz crystals in the glass ceramics is 50-90wt%, and the petalite crystals in the glass ceramics The weight percentage in is 10-50wt%.

In a possible implementation manner of the present application, the glass ceramics include lithium disilicate crystals, petalite crystals and quartz crystals, wherein the weight percentage of quartz crystals in the glass ceramics is 40-80 wt%. The weight percentage of the lithium acid crystal in the glass ceramic is 10-30 wt%, and the weight percentage of the petalite crystal in the glass ceramic is 10-30 wt%. By limiting the ratio of the three, not only the mechanical properties of the glass ceramics can be effectively enhanced, but also the anti-blue light effect of the glass ceramics can be effectively improved.

In a possible implementation of the present application, the grain size of the quartz crystal is greater than or equal to 5nm and less than or equal to 60nm, preferably in the range of 10-60nm. On the one hand, the grain size of the quartz crystal is less than or equal to 60nm, which can effectively Improve the light transmittance of glass ceramics. On the other hand, the grain size of quartz crystals is greater than or equal to 5nm, which can effectively improve the strength of glass ceramics.

In a possible implementation of the present application, the grain size of lithium disilicate crystals is greater than or equal to 5 nm and less than or equal to 60 nm, preferably in the range of 10 to 60 nm. On the one hand, the grain size of lithium disilicate crystals is less than Or equal to 60nm, which can effectively improve the light transmittance of glass ceramics. On the other hand, the grain size of lithium disilicate crystals is greater than or equal to 5nm, which can effectively improve the strength of glass ceramics.

In a possible implementation of the present application, the grain size of petalite crystals is greater than or equal to 5 nm and less than or equal to 60 nm, preferably in the range of 10 to 60 nm. On the one hand, the grain size of petalite crystals is less than Or equal to 60nm, which can effectively improve the light transmittance of glass ceramics. On the other hand, the grain size of petalite crystals is greater than or equal to 5nm, which can effectively improve the strength of glass ceramics.

In a possible implementation manner of the present application, the average transmittance of light in the wavelength range of 380-1200 nm is greater than or equal to 85%.

In a possible implementation of the present application, the average transmittance of light in the wavelength range of 400-480nm is 2-30% lower than the average transmittance of light in the wavelength range of 500-800nm. Compared with other wavelengths of light, the transmittance is lower, which can effectively improve the anti-blue light effect of glass ceramics while ensuring high light transmittance.

In a possible implementation manner of the present application, the bending strength of the glass ceramic is greater than or equal to 500 MPa.

In a possible implementation manner of the present application, the fracture toughness of the glass ceramic is greater than or equal to 1.0 MPa*m ^1/2 .

In a possible implementation of the present application, the glass ceramics includes at least one compressive stress layer, and the total depth of the at least one compressive stress layer is greater than or equal to 80 μm, which can effectively improve the strength of the glass ceramics. In the vertical direction, the closer to the glass ceramics The increase in the positional strength of the surface is more pronounced.

In a possible implementation manner of the present application, the surface compressive stress of the glass ceramic is greater than or equal to 150 MPa.

In a possible implementation manner of the present application, the compressive stress of the glass ceramic at a distance of 50 μm from the surface is greater than or equal to 60 MPa.

In a possible implementation manner of the present application, the shape of the glass ceramic is any of the following: plane 2D, 2.5D, 3D.

In the second aspect, the present application also provides a method for preparing glass ceramics in various possible embodiments of the first aspect of the present application. The glass ceramics include at least one of lithium disilicate crystals and petalite crystals, and quartz crystals, The preparation method comprises: 60-75wt% SiO ₂ , 7-13wt% Al ₂ O ₃ , 8-12wt% Li ₂ O, 0-3wt% P ₂ O ₅ , 0.5-3wt% K ₂ O, 0.5-4wt% MgO, and 0.5-3wt% ZrO ₂ are melted into block glass, and the block glass is shaped.

In this application, by introducing specific contents of SiO ₂ , Al ₂ O ₃ , Li ₂ O, P ₂ O ₅ , K ₂ O, MgO and ZrO ₂ , it is possible to prepare lithium disilicate crystals and lithium petalite crystals. At least one kind of glass ceramics and quartz crystals, wherein lithium disilicate crystals and petalite crystals can provide high strength for glass ceramics, and quartz crystals can provide anti-blue light effects for glass ceramics, so that the prepared Glass ceramics are characterized by anti-blue light and high strength.

In a possible implementation manner of the present application, the shaping treatment includes crystallization treatment. Through crystallization treatment, the grain size can be controlled to achieve the purpose of improving the optical and mechanical properties of glass ceramics.

In a possible implementation manner of the present application, the crystallization treatment specifically includes: raising the temperature to 500-650° C., keeping the temperature for 4-12 hours, and keeping the temperature at 700-750° C. for 1-10 hours.

In a possible implementation manner of the present application, after the crystallization treatment, the forming treatment further includes strengthening treatment. Through strengthening treatment, the surface strength of glass ceramics can be further improved.

In a possible implementation of the present application, the strengthening treatment includes: performing a first ion exchange process on the crystallized bulk glass, and the molten salt components used in the first ion exchange process include 5-50 wt% KNO ₃ and 50 -95 wt% NaNO3. Through the first ion exchange process, the strength of bulk glass can be improved, in which the ionic radius of potassium ions is larger than that of sodium ions, and potassium ions can increase the strength of glass ceramics, while sodium ions can diffuse to a distance from the surface At greater depths, thus, the nearer the surface of the bulk glass has a higher intensity of potassium and sodium ions.

In a possible implementation manner of the present application, the strengthening treatment may further include: performing a second ion exchange process on the bulk glass after the first ion exchange process, and the molten salt composition used in the second ion exchange process is 100%. _KNO3 . Through the second ion exchange process, the surface strength of the bulk glass can be further improved.

In a possible implementation manner of the present application, after the crystallization treatment, the shaping treatment further includes surface polishing treatment, so as to obtain light blue transparent glass ceramic flakes.

In a possible implementation manner of the present application, after the crystallization treatment, the forming treatment further includes hot bending forming treatment, so as to prepare a 3D curved glass-ceramic cover plate.

In a possible implementation manner of the present application, in the hot bending forming process, the hot bending forming temperature is 750-800° C., and the forming pressure is 0.3-0.8 MPa.

In a possible implementation of the present application, after the block glass is shaped, the above preparation method further includes: performing at least one process on the glass ceramics by silk screen printing, pad printing, yellow light, coating or film lamination. Surface decoration treatment to obtain high-value glass ceramics.

In the third aspect, the present application also provides a glass-ceramic cover plate. The material of the glass-ceramic cover plate is the glass-ceramic in each possible implementation mode of the first aspect of the application or prepared by the method of each possible implementation mode in the second aspect of the application. glass ceramics. The glass cover is anti-blue light and high strength.

In a fourth aspect, the present application further provides an electronic device, including a housing, and the housing includes the glass ceramic cover plate in the third aspect of the present application.

Description of drawings

Fig. 1 is a schematic diagram of a screen glass cover plate in the prior art;

FIG. 2 is a schematic diagram of another screen glass cover plate in the prior art;

Fig. 3 is a flow chart of a preparation method for preparing glass-ceramic provided by the embodiment of the present application;

Fig. 4 is a schematic diagram of the process of the 3D curved glass cover plate in Example 1 of the present application;

Fig. 5 is the X-ray diffraction figure of the glass-ceramic that the application embodiment 1 provides;

FIG. 6 is a comparison chart of transmittance spectra between glass ceramics provided in Example 1 of the present application and Corning Gorilla Glass;

Figure 7 is the reflectance spectrum of the glass ceramics and Corning Gorilla Glass provided in Example 1 of the present application;

Figure 8 is a schematic diagram of the four-bar bending stress before and after strengthening the glass-ceramics provided in Example 1 of the present application;

Fig. 9 is the stress curve after chemical strengthening of the glass-ceramic cover plate provided by Example 1 of the present application;

FIG. 10 is a schematic diagram of the preparation process of the 2D glass-ceramics provided in Example 1 of the present application.

detailed description

In order to make the purpose, technical solution and advantages of the application clearer, the application will be further described in detail below in conjunction with the accompanying drawings.

The terms used in the following examples are for the purpose of describing particular examples only, and are not intended to limit the application. As used in the specification and appended claims of this application, the singular expressions "a", "an", "", "above", "the" and "this" are intended to also include for example The expression "one or more" is used unless the context clearly indicates otherwise.

Reference to "one embodiment" or "some embodiments" or the like in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in other embodiments," etc. in various places in this specification are not necessarily All refer to the same embodiment, but mean "one or more but not all embodiments" unless specifically stated otherwise. The terms "including", "comprising", "having" and variations thereof mean "including but not limited to", unless specifically stated otherwise.

There are mainly two technological schemes for the screen anti-blue light technology of the existing electronic equipment, and the specific schemes are as follows:

The first solution, as shown in Figure 1, is to coat a layer of anti-blue light coating on the protective film, and then use glue to bond the side of the protective film coated with the anti-blue light coating to the glass cover. Due to the low hardness of the protective film, it is very easy to scratch during daily use, and the scratched protective film has a great impact on the display effect and appearance.

The second solution, as shown in Figure 2, is to coat the surface of the screen glass cover with an anti-blue light film. In order to avoid problems such as wear and scratches of the anti-blue light coating during use, the anti-blue light coating is generally made on the glass cover. However, since the coating layer is on the inner surface of the glass, the internal stress of the coating layer will lead to a decrease in the strength of the glass. The decrease in the strength of the coating is related to the thickness of the coating layer. Generally, the decrease in the strength of the glass 30% to 50%, resulting in easy cracking of the glass cover.

In addition, although tempered glass is mostly used as the screen protection material for the screens of electronic devices, the cracking of the glass screen cannot be completely avoided, especially when the mobile phone is dropped, the glass screen is still easy to break, and the cost of screen repair is very high. .

In order to solve the above technical problems, an embodiment of the present application provides a glass ceramic, the glass ceramic includes at least one of lithium disilicate crystal and petalite crystal, and a quartz crystal, the glass ceramic is based on oxide And when marked by weight percentage, it contains: SiO ₂ 60-75wt%, Al ₂ O ₃ 7-13wt%, Li ₂ O 8-12wt%, P ₂ O ₅ 0-3wt%, K ₂ O 0.5-3wt%, MgO 0.5-4wt%, ZrO ₂ 0.5-3wt%.

_The glass ceramics provided in the _{examples of} the present application can be _{prepared including lithium disilicate crystals} and At least one of petalite crystals and glass ceramics of quartz crystals, wherein lithium disilicate crystals and petalite crystals can provide high strength for glass ceramics, and quartz crystals can provide anti-blue light effects for glass ceramics , so that the prepared glass ceramics have the characteristics of anti-blue light and high strength.

In addition, it should be noted that the glass ceramics provided in the examples of the present application may include some unavoidable impurities in addition to the above-mentioned components.

In the glass ceramics of the embodiments of the present application, the mass percentage of SiO ₂ can be 60-75%, specifically, the mass percentage of SiO ₂ can be 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, or 75%.

In the glass ceramics of the embodiments of the present application, the mass percentage of Al ₂ O ₃ can be 7-13%, specifically, the mass percentage of Al ₂ O ₃ can be 7%, 8%, 9% in a typical but non-limiting example , 10%, 11%, 12% or 13%.

In the glass ceramics of the embodiments of the present application, the mass percentage of Li ₂ O can be 8-12%, specifically, the mass percentage of Li ₂ O can be 8%, 9%, 10%, 11 % or 12%.

In the glass ceramics of the embodiments of the present application, the mass percentage of P ₂ O ₅ can be 0 to 3%, specifically, the mass percentage of P ₂ O ₅ can be 0%, 0.5%, 1% for example but not limitatively , 1.5%, 2%, 2.5% or 3%.

In the glass ceramics of the embodiments of the present application, the mass percentage of K ₂ O can be 0.5-3%. Specifically, the mass percentage of K ₂ O can be 0.5%, 1%, 1.5%, 2 %, 2.5% or 3%.

In the glass-ceramic of the embodiment of the present application, the mass percentage of MgO can be 0.5-4%, specifically, the mass percentage of MgO can be 0.5%, 1%, 1.5%, 2%, 2.5% in typical but non-limiting examples , 3%, 3.5% or 4%.

In the glass ceramics of the embodiments of the present application, the mass percentage of ZrO2 can be 0.5-3%. Specifically, the mass percentage of ZrO2 can be 0.5%, ₁ %, 1.5%, ₂ %, or 0.5%, but not limitatively. 2.5% or 3%.

In the embodiment of the present application, the composition of glass ceramics may include any of the following possible implementations:

In a possible implementation manner, the glass ceramics include lithium disilicate crystals and quartz crystals, wherein the weight percentage of quartz crystals in the glass ceramics is 50-90wt%, and the weight percentage of lithium disilicate crystals in the glass ceramics is The weight percentage is 10-50wt%. By limiting the ratio of lithium disilicate crystals and quartz crystals, not only the mechanical properties of the glass ceramics can be effectively enhanced, but also the anti-blue light effect of the glass ceramics can be effectively improved.

In another possible implementation, the glass ceramics include petalite crystals and quartz crystals, wherein the weight percentage of quartz crystals in the glass ceramics is 50-90 wt%, and the petalite crystals in the glass ceramics The percentage by weight is 10-50wt%. By restricting the proportioning relationship between petalite crystals and quartz crystals, not only the mechanical properties of glass ceramics can be effectively enhanced, but also the anti-blue light effect of glass ceramics can be effectively improved.

In yet another possible implementation, the glass ceramics include lithium disilicate crystals, petalite crystals and quartz crystals, wherein the weight percentage of quartz crystals in the glass ceramics is 40-80 wt%, and lithium disilicate The weight percentage of the crystal in the glass ceramic is 10-30 wt%, and the weight percentage of the petalite crystal in the glass ceramic is 10-30 wt%. By limiting the ratio of the three, not only the mechanical properties of the glass ceramics can be effectively enhanced, but also the anti-blue light effect of the glass ceramics can be effectively improved.

Nanocrystals in transparent glass ceramics are like dust in the sky. Due to the Rayleigh scattering effect, the intensity of scattered light is inversely proportional to the fourth power of the wavelength, so the blue-violet scattering with shorter wavelengths in the natural spectrum is more obvious. By controlling the size of nanocrystals, such as 10nm-60nm, under the scattering effect of nanocrystals, blue-violet light is scattered more, while the reflection of visible light of other colors is basically not obvious, and finally the effect of reflecting blue-ultraviolet light is obtained.

In one embodiment of the present application, the grain size of the quartz crystal is greater than or equal to 5nm and less than or equal to 60nm, preferably in the range of 10-60nm. On the one hand, the grain size of the quartz crystal is less than or equal to 60nm, which can effectively improve the glass The light transmittance of ceramics, on the other hand, the grain size of quartz crystals is greater than or equal to 5nm, which can effectively improve the strength of glass ceramics.

In one embodiment of the present application, the grain size of lithium disilicate crystals is greater than or equal to 5 nm and less than or equal to 60 nm, preferably in the range of 10 to 60 nm. On the one hand, the grain size of lithium disilicate crystals is less than or equal to 60nm, which can effectively improve the light transmittance of glass ceramics. On the other hand, the grain size of lithium disilicate crystals is greater than or equal to 5nm, which can effectively improve the strength of glass ceramics.

In one embodiment of the present application, the grain size of petalite feldspar crystals is greater than or equal to 5 nm and less than or equal to 60 nm, preferably in the range of 10 to 60 nm. On the one hand, the grain size of petalite feldspar crystals is less than or equal to 60nm, which can effectively improve the light transmittance of glass ceramics. On the other hand, the grain size of petalite crystals is greater than or equal to 5nm, which can effectively improve the strength of glass ceramics.

In one embodiment of the present application, the average light transmittance of the glass ceramics within the wavelength range of 380-1200 nm is greater than or equal to 85%.

In one embodiment of the present application, the average transmittance of glass ceramics in the wavelength range of 400-480nm is 2-30% lower than the average transmittance of light in the wavelength range of 500-800nm. Compared with other wavelengths of light, the transmittance is lower, which can effectively improve the anti-blue light effect of glass ceramics while ensuring high light transmittance.

In one embodiment of the present application, the bending strength of the glass ceramic is greater than or equal to 500 MPa.

In one embodiment of the present application, the fracture toughness of the glass ceramic is greater than or equal to 1.0 MPa*m ^1/2 .

In one embodiment of the present application, the glass ceramics includes at least one compressive stress layer, and the total depth of the at least one compressive stress layer is greater than or equal to 80 μm, which can effectively improve the strength of the glass ceramics. In the vertical direction, the closer to the surface of the glass ceramics The increase in positional strength is more pronounced.

In one embodiment of the present application, the surface compressive stress of the glass ceramic is greater than or equal to 150 MPa.

In one embodiment of the present application, the compressive stress of the glass ceramic at a distance of 50 μm from the surface is greater than or equal to 60 MPa.

In an embodiment of the present application, the shape of the glass ceramic is any of the following: plane 2D, 2.5D, 3D.

Based on the same technical idea, the embodiment of the present application also provides a method for preparing the above-mentioned glass ceramics, wherein the glass ceramics include at least one of lithium disilicate crystals and petalite crystals, and quartz crystals, as shown in 3, the preparation method comprises the following steps:

S301, the weight percentage is 60-75wt% SiO ₂ , 7-13wt% Al ₂ O ₃ , 8-12wt% Li ₂ O, 0-3wt% P ₂ O ₅ , 0.5-3wt% K ₂ O, 0.5-4wt% of MgO, and _0.5-3wt % of ZrO2 are melted into block glass.

S302, performing forming treatment on the bulk glass.

In the preparation method provided in the examples of the present application, by introducing specific contents of SiO ₂ , Al ₂ O ₃ , Li ₂ O, P ₂ O ₅ , K ₂ O, MgO and ZrO ₂ , lithium disilicate crystals including And at least one of petalite crystals and glass ceramics of quartz crystals, wherein lithium disilicate crystals and petalite crystals can provide high strength for glass ceramics, and quartz crystals can provide anti-blue light for glass ceramics effect, so that the prepared glass ceramics have the characteristics of anti-blue light and high strength.

In an embodiment of the present application, the shaping treatment in S302 includes crystallization treatment. Through crystallization treatment, the grain size can be controlled to achieve the purpose of improving the optical and mechanical properties of glass ceramics.

In one embodiment of the present application, the above-mentioned crystallization treatment specifically includes: raising the temperature to 500-650° C. for 4-12 hours, and keeping the temperature at 700-750° C. for 1-10 hours.

The bulk crystallization method is a traditional and still widely used method for preparing glass ceramics. Its process includes glass preparation and molding, and then uses a controllable heat treatment process to nucleate and crystallize the glass. Generally, in the process of glass preparation and molding, the glass cannot be crystallized, and then through the strictly controlled crystallization process, the required crystal types and proportions are precipitated in the glass to achieve the required physical and chemical properties. The 3D glass cover makes the smart phone look beautiful and full of technology, and can avoid shielding the communication signal of the mobile phone. 3D curved glass has gradually become the mainstream configuration of many high-end flagship models. When the glass-ceramic is to be formed into a curved 3D shape through hot bending, the glass-ceramic will be heated and cooled during the thermoforming process, and the nanocrystals in the glass-ceramic will undergo nucleation and nucleation growth again. In order to ensure the production efficiency of hot bending forming, the hot bending forming time needs to be controlled within a short time range, so the thermal field in the hot bending forming process is not enough to support the glass ceramics from the initial glass state to the final required glass ceramics. Therefore, we split the crystallization process of curved 3D glass ceramics into two crystallization processes, one is crystallization after glass forming, and the other is crystallization during hot bending. In order to obtain the crystal types, proportions and physical and chemical properties we ultimately need, we need to precisely control the two-stage crystallization process. In order to facilitate production control, the crystallization process of these two stages can be controlled through the transmittance and the b value of the color difference Lab. For the crystallization of glass molding, we fix the crystallization parameters, control the b value in the range of ≥-1.0, and the transmittance at 400nm is ≥88%. For the crystallization of hot bending, we can adjust different bending temperatures and times to obtain different b values and transmittances. The higher the temperature and the longer the time, the larger the b value and the lower the transmittance. Generally, the b value after hot bending is distributed in the range of -10.0≤b≤-1.2, and the 400nm transmittance is distributed in the range of 60%≤T≤88%.

In one embodiment of the present application, the above-mentioned strengthening treatment includes: performing a first ion exchange process on the crystallized bulk glass, and the molten salt components used in the first ion exchange process include 5-50 wt% KNO ₃ and 50-50 wt % 95wt% NaNO3, the molten salt temperature is 420-480°C, and the first ion exchange time is 4-15h. Through the first ion exchange process, the strength of bulk glass can be improved, in which the ionic radius of potassium ions is larger than that of sodium ions, and potassium ions can increase the strength of glass ceramics, while sodium ions can diffuse to a distance from the surface At greater depths, thus, the nearer the surface of the bulk glass has a higher intensity of potassium and sodium ions.

Wherein, the molten salt temperature of the first ion exchange process is typically but not limited to 420°C, 430°C, 440°C, 450°C, 460°C, 470°C or 480°C, and the first ion exchange time is typically but not limited The ground is 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h, 11h, 12h, 13h, 14h or 15h.

In an embodiment of the present application, the above strengthening treatment may also include: performing a second ion exchange process on the block glass after the first ion exchange process, and the molten salt used in the second ion exchange process is 100% KNO _3. The molten salt temperature is 420-480°C, and the ion exchange time is 0.5-2h. Through the second ion exchange process, the surface strength of the bulk glass can be further improved.

Wherein, the molten salt temperature of the second ion exchange process is typically but not limited to 420°C, 430°C, 440°C, 450°C, 460°C, 470°C or 480°C, and the first ion exchange time is typically but not limited The ground is 0.5h, 1h, 1.5h or 2h.

In one embodiment of the present application, after the crystallization treatment, the shaping treatment further includes surface polishing treatment, so as to obtain light blue transparent glass ceramic flakes.

In one embodiment of the present application, after the crystallization treatment, the forming treatment further includes hot bending forming treatment, so as to prepare a 3D curved glass-ceramic cover plate.

In one embodiment of the present application, after the crystallization treatment, the forming treatment further includes strengthening treatment. Through strengthening treatment, the surface strength of glass ceramics can be further improved.

In one embodiment of the present application, in the above-mentioned hot bending forming process, the hot bending forming temperature is 750-800° C., and the forming pressure is 0.3-0.8 MPa.

In one embodiment of the present application, after the bulk glass is shaped, the above preparation method further includes: performing surface decoration on the glass ceramics by at least one process of silk screen printing, pad printing, yellow light, coating or film lamination treatment to obtain high-value glass ceramics.

The preparation process of the glass-ceramics of the present application will be described below in conjunction with different embodiments.

Embodiment one

In one embodiment of the present application, as shown in Figure 4, taking the preparation of a 3D curved glass cover as an example, the preparation process of glass ceramics is as follows:

S11, melting and block forming.

The raw materials with the ratio of SiO2 75%, Al2O3 9%, Li2O 10%, P2O5 1%, K2O 1.5%, MgO 2%, ZrO 22% are melted at 1600°C and formed into blocks.

S12, cutting the sheet.

Through the cutting process, the block material is cut into sheets of 0.7-1.0mm.

S13, performing crystallization treatment on the sheet.

The conditions of crystallization heat treatment are: 500°C for 8 hours, 500°C to 640°C with a heating rate of 40°C/h, 640°C for 8 hours, 640°C to 720°C with a heating rate of 40°C/h, and 720°C for 4 hours. Cool down to room temperature.

S14, shape processing and polishing.

Through the shape CNC processing and polishing, the crystallized sheet is polished to a transparent sheet of 0.55-0.75mm.

S15, 3D molding.

In this embodiment, the crystallization process of 3D molding is considered, and the b value of the crystallized sheet at this stage is controlled at -0.41.0, and the transmittance at 400nm is controlled at 86% to 88%. Then, at 780°C, 0.7MPa Under hot bending forming conditions, the flat glass ceramics are molded into curved glass ceramic cover plates.

S16, performing ion exchange strengthening on the formed 3D glass-ceramic cover plate twice.

The strengthening conditions are as follows: the first strengthening molten salt composition is 10% KNO3 and 90% NaNO3, the exchange temperature is 450°C, and the exchange time is 700 minutes; the second strengthening molten salt composition is 100% KNO3, the exchange temperature is 390°C, and the exchange time is 60 minutes. The surface compressive stress of the strengthened glass ceramics is 280MPa, the compressive stress at a distance of 50 microns from the surface is 120MPa, and the depth of the compressive stress layer is 108μm.

S17, surface appearance treatment.

The appearance decoration treatment of the processed curved glass ceramic cover plate is carried out by pad printing ink and anti-fingerprint coating.

Fig. 5 is the X-ray diffraction pattern (XRD) of the glass ceramics that example 1 of the present application provides, the XRD peak as shown in Fig. 5, the diffraction peaks of 26.1 ° and 20.2 ° correspond to quartz crystals, and the diffraction peaks of 24.9 ° are lithium penetration For feldspar crystal, the diffraction peak at 23.9° is the diffraction peak of lithium disilicate crystal, and the diffraction peak at 24.4° is the common diffraction peak of lithium petalite and lithium disilicate crystal.

In the glass ceramics provided in Example 1 of the present application, the refractive index (for example, the refractive index of 1.48 to 1.54) of the three crystals of lithium disilicate crystal, lithium petalite crystal and quartz crystal is the same as that of the glass matrix (refractive index of 1.51). The refractive index is very close, showing high transmittance.

FIG. 6 is a comparative graph of transmittance spectra between glass ceramics provided in Example 1 of the present application and Corning Gorilla Glass. As shown in Figure 6, the glass-ceramic of the present application has better transmittance than Corning Gorilla Glass, especially in the blue light wavelength range compared to Corning Gorilla Glass, the advantage of light transmittance more obvious. The glass-ceramic cover plate of the present application has an average transmittance of 90.5% in the wavelength range of 380nm-1200nm, an average transmittance of 88.0% in the wavelength of blue light of 400-480nm, and the transmittance of the wavelength of blue light of 400-480nm is higher than other The visible light band is reduced by 2.5%, which can effectively prevent blue light.

Figure 7 is the reflectance spectrum of the glass ceramics and Corning Gorilla Glass provided in Example 1 of the present application. As can be seen from Figure 7, the reflectance of the glass ceramics provided in the embodiments of the present application at the blue-violet light wavelength (360-480nm) Higher than Corning Gorilla Glass, the shorter the wavelength, the higher the reflectivity.

Fig. 8 shows the four-bar bending stress before and after strengthening the glass-ceramic provided in Example 1 of the present application. As shown in Fig. 8, the bending stress of the glass-ceramic after strengthening is significantly increased, greater than 600 MPa.

Fig. 9 is the stress curve after the chemical strengthening of the glass-ceramic cover plate provided by the embodiment 1 of the present application. The surface layer compressive stress of the glass-ceramic provided by the embodiment of the present application is 267MPa, and the compressive stress at 50 microns away from the surface layer is 162MPa. With a depth of 131 μm, the strengthened glass-ceramic has higher bending and drop resistance than unstrengthened transparent glass-ceramic.

In addition, the prepared curved glass-ceramic cover plate is assembled on a 180g mobile phone, which can fall through a 1.5m marble drop and a 180-grit sandpaper ground drop, and the drop resistance effect is better than that of various commercial cover glass currently on the market.

Embodiment two

In one embodiment of the present application, as shown in FIG. 10 , taking the preparation of a flat 2D glass cover plate as an example, the preparation process of glass ceramics is as follows:

S11, melting and block forming.

The raw materials with the ratio of SiO2 75%, Al2O3 9%, Li2O 10%, P2O5 1%, K2O 1.5%, MgO 2%, ZrO 22% were melted at 1600°C and formed into blocks.

S12, cutting the sheet.

Through the cutting process, the block material is cut into sheets of 0.9-1.1mm.

S13, performing crystallization treatment on the sheet.

The conditions of crystallization heat treatment are: 500°C for 8h, 500°C-640°C, heating rate 40°C/h, 640°C for 8h, 640°C-720°C, heating rate 40°C/h, 720°C for 8h, and finally furnace Cool down to room temperature.

S14, shape processing and polishing.

The crystallized sheet is polished to a transparent sheet of 0.7-0.9mm through contour CNC machining and polishing.

S15, performing twice ion exchange strengthening on the processed glass-ceramic cover plate.

The strengthening conditions are as follows: the first strengthening molten salt composition is 40% KNO3 and 60% NaNO3, the exchange temperature is 450°C, and the exchange time is 12h; the second strengthening molten salt composition is 100% KNO3, the exchange temperature is 420°C, and the exchange time is 30min. The surface compressive stress of the strengthened glass-ceramic is 240MPa, the compressive stress at a distance of 50 microns from the surface is 108MPa, and the depth of the compressive stress layer is 126μm.

S16, surface appearance treatment.

The appearance of the processed curved glass-ceramic cover plate is treated with silk screen printing ink and anti-fingerprint coating.

In the 380nm-1200nm wavelength range, the average transmittance of the planar glass-ceramic cover plate prepared by the above-mentioned embodiment 2 is 88%, the average transmittance at the blue light 400-480nm wavelength is 78%, and the blue light 400-480nm wavelength The transmittance is 10% lower than other visible light bands, which can effectively prevent blue light.

In addition, the prepared planar glass-ceramic cover plate is assembled on a 180g mobile phone, and it can fall through a 1.5m marble drop and a 180-grit sandpaper ground drop, and the anti-drop effect is better than various cover glass commercially available on the market.

Embodiment Three

In one embodiment of the present application, taking the preparation of a 3D curved glass cover plate as an example, the preparation process of glass ceramics can refer to Figure 4, as follows:

S11, melting and block forming.

The raw materials with the ratio of SiO2 75%, Al2O3 10%, Li2O 9%, P2O5 2%, K2O 1.5%, MgO 2%, ZrO21% were melted at 1550°C and formed into blocks.

S12, cutting the sheet.

Through the cutting process, the block material is cut into sheets of 0.7-1.0mm.

S13, performing crystallization treatment on the sheet.

The conditions for crystallization heat treatment are: 500°C for 8 hours, 500°C-650°C for 40°C/h, 650°C for 10 hours, 650°C-730°C for 40°C/h, 730°C for 5h, and finally Cool down to room temperature.

S14, shape processing and polishing.

The crystallized sheet is polished to a transparent sheet of 0.55-0.75mm through contour CNC machining and polishing.

S15, 3D molding.

This embodiment considers the crystallization process of 3D molding. We control the b value of the crystallized sheet at this stage at -0.6~-1.2, and the transmittance at 400nm at 84%~86%. Then, at 770°C, 0.6 Under the hot-bending forming condition of MPa, the flat glass-ceramic is molded into a curved glass-ceramic cover plate.

S16, performing ion exchange strengthening on the formed 3D glass-ceramic cover plate twice.

The strengthening conditions are as follows: the first strengthening molten salt composition is 20% KNO3 and 80% NaNO3, the exchange temperature is 450°C, and the exchange time is 10h; the second strengthening molten salt composition is 100% KNO3, the exchange temperature is 400°C, and the exchange time is 1.5h. The surface compressive stress of the strengthened glass-ceramic is 275MPa, the compressive stress at a distance of 50 microns from the surface is 114MPa, and the depth of the compressive stress layer is 115μm.

S17, surface appearance treatment.

The appearance decoration treatment of the processed curved glass ceramic cover plate is carried out by pad printing ink and anti-fingerprint coating.

In the 380nm-1200nm wavelength range, the curved glass-ceramic cover plate prepared by the above-mentioned embodiment 3 has an average transmittance of 90%, an average transmittance of 85% at the wavelength of blue light of 400-480nm, and an average transmittance of 85% at the wavelength of blue light of 400-480nm. The transmittance is 5% lower than other visible light bands, which can effectively prevent blue light.

In addition, the prepared curved glass-ceramic cover plate is assembled on a 180g mobile phone, which can pass through a 1.5m marble drop and a 180-grit sandpaper drop.

Embodiment Four

In one embodiment of the present application, taking the preparation of a flat 2D glass cover plate as an example, the preparation process of glass ceramics can be seen in Figure 10, as follows:

S11, melting and block forming.

The raw materials with the ratio of SiO2 75%, Al2O3 10%, Li2O 9%, P2O5 2%, K2O 1.5%, MgO 2%, ZrO21% were melted at 1550°C and formed into blocks.

S12, cutting the sheet.

Through the cutting process, the block material is cut into sheets of 0.9-1.1mm.

S13, performing crystallization treatment on the sheet.

The conditions of crystallization heat treatment are: 500°C for 8 hours, 500°C-650°C for 40°C/h, 650°C for 10 hours, 650°C-730°C for 40°C/h, 730°C for 10h, and finally Cool down to room temperature.

S14, shape processing and polishing.

The crystallized sheet is polished to a transparent sheet of 0.7-0.9mm through contour CNC machining and polishing.

S15, performing twice ion exchange strengthening on the processed glass-ceramic cover plate.

The strengthening conditions are as follows: the first strengthening molten salt composition is 30% KNO3 and 70% NaNO3, the exchange temperature is 450°C, and the exchange time is 10h; the second strengthening molten salt composition is 100% KNO3, the exchange temperature is 400°C, and the exchange time is 2h. The surface compressive stress of the strengthened glass ceramics is 255MPa, the compressive stress at a distance of 50 microns from the surface is 116MPa, and the depth of the compressive stress layer is 120μm.

S16, surface appearance treatment.

The appearance decoration treatment of the processed curved glass ceramic cover plate is carried out by pad printing ink and anti-fingerprint coating.

The planar glass-ceramic cover plate prepared by the above-mentioned embodiment 2 has an average transmittance of 86% in the wavelength range of 380nm-1200nm, an average transmittance of 74% in the blue light of 400-480nm wavelength, and an average transmittance of 74% in the blue light of 400-480nm wavelength. The transmittance is 12% lower than other visible light bands, which can effectively prevent blue light.

In addition, the prepared curved glass-ceramic cover plate is assembled on a 180g mobile phone, and it can fall through a 1.8m marble drop and a 180-grit sandpaper ground drop.

Based on the same technical idea, the embodiment of the present application also provides a glass-ceramic cover plate. The material of the glass-ceramic cover plate is the above-mentioned glass-ceramic of the present application or the glass-ceramic prepared by the above-mentioned method of the present application. The glass cover is anti-blue light and high strength.

Based on the same technical idea, an embodiment of the present application further provides an electronic device, which includes a casing, and the casing includes the above-mentioned glass-ceramic cover plate.

It should be noted that in this application, unless otherwise specified, all the implementation modes and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution. In this application, if there is no special description, all the technical features and preferred features mentioned herein can be combined with each other to form a new technical solution. In the present application, unless otherwise specified, percentage (%) or part refers to percentage by weight or part by weight relative to the composition. In this application, unless otherwise specified, the various components involved or their preferred components can be combined with each other to form a new technical solution. In the present application, unless otherwise stated, the numerical range "a~b" represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6-22" indicates that all real numbers between "60-75" have been listed in this article, and "6-22" is just an abbreviated representation of the combination of these values. A "range" disclosed in this application takes the form of a lower limit and an upper limit, and may refer to one or more lower limits, and one or more upper limits, respectively. In this application, unless otherwise stated, each reaction or operation step can be carried out sequentially or in sequence. Preferably, the reaction processes herein are performed sequentially.

The above is only the specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the application, and should cover Within the protection scope of this application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (27)

1. A glass-ceramic, characterized in that at least comprising at least one of lithium disilicate crystals and petalite crystals, and quartz crystals; when said glass-ceramic is based on oxide and expressed in weight percent, contain: SiO ₂ 60~75wt%, Al ₂ O ₃ 7~13wt%, Li ₂ O 8~12wt%, P ₂ O ₅ 0~3wt%, K ₂ O 0.5~3wt%, MgO 0.5~4wt%, ZrO ₂ 0.5~3wt%. 2. The glass-ceramic according to claim 1, characterized in that, the glass-ceramic comprises lithium disilicate crystals and quartz crystals, wherein the weight percentage of the quartz crystals in the glass-ceramics is 50-50%. 90%, the weight percentage of the lithium disilicate crystal in the glass ceramic is 10-50wt%. 3. glass-ceramic according to claim 1, is characterized in that, described glass-ceramic comprises petalite crystal and quartz crystal, and wherein, the percentage by weight that described petalite crystal accounts for in described glass-ceramic It is 50-90 wt%, and the weight percentage of the quartz crystal in the glass ceramic is 10-50 wt%. 4. The glass-ceramic according to claim 1, characterized in that, the glass-ceramic comprises lithium disilicate crystals, petalite crystals and quartz crystals, wherein the quartz crystal occupies The weight percentage of the lithium disilicate crystal is 40 to 80 wt%, the weight percentage of the lithium disilicate crystal in the glass ceramic is 10 to 30 wt%, and the weight percentage of the petalite crystal in the glass ceramic is The percentage is 10-30wt%. 5. The glass-ceramic according to any one of claims 1 to 4, characterized in that the grain size of the quartz crystal is greater than or equal to 5 nm and less than or equal to 60 nm. 6. The glass ceramic according to any one of claims 1 to 5, characterized in that the grain size of the lithium disilicate crystal is greater than or equal to 5 nm and less than or equal to 60 nm. 7. The glass-ceramic according to any one of claims 1 to 6, characterized in that the grain size of the petalite crystal is greater than or equal to 5 nm and less than or equal to 60 nm. 8. The glass ceramic according to any one of claims 1 to 7, characterized in that the average transmittance of light in the wavelength range of 380-1200 nm is greater than or equal to 85%. 9. The glass-ceramic according to any one of claims 1 to 8, characterized in that, the average transmittance of light in the wavelength range of 400 to 480 nm is 2 to 50% lower than the average transmittance of light in the wavelength range of 500 to 800 nm. 30%. 10. The glass ceramic according to any one of claims 1 to 9, characterized in that the bending strength of the glass ceramic is greater than or equal to 500 MPa. 11. The glass ceramic according to any one of claims 1 to 10, characterized in that the fracture toughness of the glass ceramic is greater than or equal to 1.0 MPa*m ^1/2 . 12. The glass-ceramic according to any one of claims 1-11, characterized in that the glass-ceramic comprises at least one compressive stress layer, and the total depth of the at least one compressive stress layer is greater than or equal to 80 μm. 13. The glass ceramic according to any one of claims 1 to 12, characterized in that the surface compressive stress of the glass ceramic is greater than or equal to 150 MPa. 14. The glass-ceramic according to any one of claims 1-13, characterized in that, the compressive stress of the glass-ceramic at a distance of 50 μm from the surface is greater than or equal to 60 MPa. 15. The glass-ceramic according to any one of claims 1-14, characterized in that the shape of the glass-ceramic is any of the following: plane 2D, 2.5D, 3D. 16. A method for preparing the glass-ceramic according to any one of claims 1 to 15, wherein the glass-ceramic comprises at least one of lithium disilicate crystals and petalite crystals, and quartz crystals; the method comprising: The weight percentage is 60-75wt% of _SiO2 , 7-13wt% of _Al2O3 , _8-12wt % of _Li2O , _0-3wt % of _P2O5 , _0.5-3wt % of K2O, 0.5-4wt% MgO, and _0.5-3wt % ZrO2 are melted into block glass; The bulk glass is subjected to shaping treatment. 17. The method of claim 16, wherein the shaping treatment comprises a crystallization treatment. 18. The method according to claim 17, wherein the crystallization treatment is specifically: Raise the temperature to 500°C-650°C for 4-12 hours, and 700-750°C for 1-10 hours. 19. The method according to claim 17 or 18, characterized in that, after the crystallization treatment, the shaping treatment further includes strengthening treatment. 20. The method of claim 19, wherein the strengthening treatment comprises: The first ion exchange process is performed on the crystallized bulk glass, and the molten salt components used in the first ion exchange process include 5-50 wt% _KNO3 and 50-95 wt% NaNO3. 21. The method according to claim 20, wherein the strengthening process further comprises: A second ion exchange process is performed on the bulk glass treated by the first ion exchange process, and the molten salt composition used in the second ion exchange process is 100% KNO ₃ . 22. The method according to any one of claims 16-21, characterized in that, after the crystallization treatment, the shaping treatment further includes surface polishing treatment. 23. The method according to any one of claims 16 to 22, characterized in that, after the crystallization treatment, the forming treatment further comprises hot bending forming treatment. 24. The method according to any one of claims 16 to 23, characterized in that, in the hot bending forming process, the hot bending forming temperature is 750-800° C., and the forming pressure is 0.3-0.8 MPa. 25. The method according to any one of claims 16 to 24, characterized in that, after the bulk glass is shaped, the method further comprises: The surface decoration treatment of the glass ceramics is carried out by silk screen printing, pad printing, yellow light, coating or membrane laminating technology. 26. A glass-ceramic cover plate, characterized in that, the material of the glass-ceramic cover plate is the glass-ceramic as claimed in any one of claims 1-15 or utilizes the glass-ceramic as described in any one of claims 16-25 The glass ceramics prepared by the method. 27. An electronic device, characterized by comprising a casing, the casing comprising the glass-ceramic cover plate according to claim 26.

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