WO2024109498A1

WO2024109498A1 - Glass ceramics, preparation method therefor, and glass ceramics article

Info

Publication number: WO2024109498A1
Application number: PCT/CN2023/128827
Authority: WO
Inventors: 徐兴军; 陶武刚; 王勇; 陈发伟; 候英兰; 李要辉
Original assignee: 湖南旗滨新材料有限公司
Priority date: 2022-11-22
Filing date: 2023-10-31
Publication date: 2024-05-30
Also published as: CN118206287A; CN115716709B; CN115716709A

Abstract

Glass ceramics and a preparation method therefor. The method comprises: mixing glass raw materials to obtain a raw glass plate, then subjecting same to nucleation and crystallization treatments and a chemical strengthening treatment. The glass ceramics has a crystallinity ≥ 55% and an average particle size ≤ 50 nm, and the content of the crystal phases comprising LiAlSi4O10 and the crystal phases comprising Li2Si2O5 and LiAlSi4O10 is greater than the content of any other crystal phase, and the ratio of the content of LiAlSi4O10 to the content of Li2Si2O5 is ≥1.13; and the average transmittance of light with a wavelength of 380-780 nm is ≥ 90.5%, the b value is ≤ 0.45, the haze is ≤ 0.25, and the drop height is ≥ 1.6 m. The glass ceramics article is used for display screens, electronic intelligent terminals and photovoltaic devices.

Description

Glass-ceramic and preparation method thereof, and glass-ceramic product

This application claims priority to Chinese patent application No. 202211470006.6 filed on November 22, 2022, the entire contents of which are incorporated by reference into this application.

Technical Field

The present application relates to the field of microcrystalline glass, and in particular to a microcrystalline glass and a preparation method thereof, and microcrystalline glass products.

Background technique

With the development of display technology, glass is often used to protect display devices. Studies have shown that 70% of electronic product damage is caused by accidental drops. The cover glass used to protect electronic products on the market is generally high-aluminum silicate glass. High aluminum is conducive to the improvement of stress intensity and stress layer depth after ion exchange, but the glass has poor drop resistance.

The performance of microcrystalline glass depends on the ratio of the crystalline phase to the glass phase, the size of the crystal grains, etc. By introducing a nucleating agent into the glass formula or adjusting the oxide ratio composition in the formula, one or more crystalline phases are formed in the subsequent heat treatment process. It has both the high permeability of glass and the high strength of ceramics, which can improve the average hardness and fracture toughness of glass. The microcrystalline phase in microcrystalline glass can hinder the propagation path of microcracks, which is beneficial to the overall improvement of the glass's scratch resistance, impact resistance, and drop resistance.

technical problem

However, the weather resistance of microcrystalline glass is not ideal and it is prone to aging. Especially in high temperature and high humidity environments, the glass surface is prone to fogging, affecting its performance.

Technical Solutions

The main purpose of the present application is to provide a microcrystalline glass and a preparation method, and a microcrystalline glass product, so as to solve the technical problem in the prior art that the surface of the microcrystalline glass obtained after chemical strengthening is prone to fogging.

To achieve the above object, the present application provides a glass-ceramic, wherein the crystallinity of the glass-ceramic is ≥55%, and the crystal phase thereof comprises LiAlSi ₄ O ₁₀ and Li ₂ Si ₂ O ₅ , wherein the content of LiAlSi ₄ O ₁₀ is greater than the content of any other crystal phase.

In one embodiment, the ratio of the content of LiAlSi ₄ O ₁₀ to the content of Li ₂ Si ₂ O ₅ is ≥1.13.

In one embodiment, the crystal phase of the glass-ceramics further includes at least one of Li ₂ SiO ₃ , Li ₃ PO ₄ , and β-spodumene.

In one embodiment, the microcrystalline glass contains the following components by mass percentage:

69% to 75% SiO ₂ ;

6% to 12% Al ₂ O ₃ ;

1.7% to 3.5% P ₂ O ₅ ;

8% to 13% _Li2O ;

0.1% to 3% _Na2O ;

2% to 5% ZrO ₂ .

71% to 74% SiO ₂ ;

7% to 10% Al ₂ O ₃ ;

2% to 3.5% P ₂ O ₅ ;

10% to 12% _Li2O ;

0.5% to 2% _Na2O ;

2.5% to 4.5% ZrO ₂ .

In one embodiment, the microcrystalline glass further comprises the following components calculated by mass percentage:

_K2O : 0-1%;

B ₂ O ₃ : 0～1%;

CaO: 0-1%;

MgO: 0-1%;

ZnO: 0-1%;

_Y2O3 : _0-1 %;

Clarifying agent: 0-1%.

In one embodiment, the average particle size of the crystals of the microcrystalline glass is ≤50nm;

And/or, the average transmittance of the microcrystalline glass at 380nm-780nm is ≥90.5%.

And/or, after the microcrystalline glass is subjected to a double 85 test, the average transmittance of light at a wavelength of 380-780 nm is ≥90.5%.

In one embodiment, the b value of the microcrystalline glass is ≤0.45, wherein the b value is the absolute value of the yellow-blue value when the thickness of the microcrystalline glass is 0.6 mm.

And/or, the haze of the microcrystalline glass is ≤0.25.

And/or, the drop height of the microcrystalline glass is ≥1.6m.

In addition, to achieve the above-mentioned purpose, the present application also provides a method for preparing microcrystalline glass, the preparation method comprising the following steps:

S10, weighing glass raw materials, mixing them, melting, clarifying, homogenizing, molding, and annealing to obtain plain glass;

S20, performing a nucleation treatment on the plain plate glass, then performing a crystallization treatment, and then cooling to obtain a basic micro-ceramic glass;

S30, chemically strengthening the basic glass-ceramics to obtain the glass-ceramics.

In one embodiment, the temperature of the nucleation treatment is 530° C. to 580° C., and the time of the nucleation treatment is 0.5 h to 1.5 h.

In one embodiment, the temperature of the crystallization treatment is 640° C. to 740° C., and the time of the crystallization treatment is 2 to 4 hours.

In one embodiment, the chemical strengthening treatment comprises a bath salt comprising 10 wt % to 40 wt % of NaNO ₃ and 59 wt % to 90 wt % of KNO ₃ ; and/or 0 wt % to 0.2 wt % of LiNO ₃ .

In one embodiment, the temperature of the chemical strengthening is 450° C. to 520° C., and the time of the chemical strengthening is 4 to 8 hours.

In addition, the present application also provides a microcrystalline glass product, which includes the microcrystalline glass as described above. The microcrystalline glass product can be applied to display screens, electronic smart terminals and photovoltaic power generation devices to play a protective role.

Beneficial Effects

Beneficial effects that this application can achieve:

Compared with the prior art, the crystallinity of the microcrystalline glass of the present application is ≥55%, and its crystal phase includes LiAlSi ₄ O ₁₀ and Li ₂ Si ₂ O _5. The content of LiAlSi ₄ O ₁₀ is greater than the content of any other crystal phase, the ratio of the content of LiAlSi ₄ O ₁₀ to the content of Li ₂ Si ₂ O ₅ is ≥1.13, the average particle size of the crystal is ≤50nm, the average transmittance of the microcrystalline glass at a wavelength of 380nm to 780nm is ≥90.5%, the b value is ≤0.45, the haze is ≤0.25, and the drop height is ≥1.6m.

By adjusting the crystal phase composition of the microcrystalline glass and controlling the difference in structure between the glass phase and the crystal phase, the formation of holes is reduced, and the problem of Na ⁺ agglomerating in the holes between the microcrystalline phase and the glass phase during chemical strengthening, which makes it difficult to form compressive stress, is avoided. At the same time, the microcrystalline glass obtained after chemical strengthening has good hardness and drop resistance, as well as excellent weather resistance, is not easy to age, the glass surface is not easy to fog, has good light transmittance, can adapt to high temperature and high humidity environments, and can be widely used in display screens, electronic smart terminals, photovoltaic power generation devices and other fields.

The preparation method of the present application has low processing difficulty and low processing cost, and can save time cost and energy for heat treatment.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

FIG1 is a schematic flow chart of a method for preparing glass-ceramics according to Example 1 of the present application.

The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings.

Embodiments of the present invention

It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

In this application, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application. Due to the high crystal content in microcrystalline glass>60%, there are structural differences between the glass phase and the crystal phase to form structural cavities. During chemical strengthening, on the one hand, Na ⁺ is easy to agglomerate in the cavities between the microcrystalline phase and the glass phase, and it is difficult to form compressive stress; on the other hand, the weather resistance of microcrystalline glass is not ideal and it is easy to age. Especially in high temperature and high humidity environments, fogging is easy to occur on the glass surface, affecting its performance.

In view of this, the present application provides a microcrystalline glass, which has high hardness, good drop resistance and excellent weather resistance, is not easy to age, the glass surface is not easy to fog, has good light transmittance, and can adapt to high temperature and high humidity environments.

The crystallinity of the glass-ceramics of the present application is ≥55%, and its crystal phases include LiAlSi ₄ O ₁₀ and Li ₂ Si ₂ O ₅ , wherein the content of LiAlSi ₄ O ₁₀ is greater than the content of any other crystal phases.

The ratio of the content of LiAlSi ₄ O ₁₀ to the content of Li ₂ Si ₂ O ₅ is ≥1.13.

The glass-ceramics of the present application includes but is not limited to the above-mentioned crystal phase types, and may also include at least one of Li ₂ SiO ₃ , Li ₃ PO ₄ , and β-spodumene.

By adjusting the crystal phase composition of the microcrystalline glass, controlling the difference in the structure between the glass phase and the crystal phase, and reducing the formation of cavities, it is avoided that during chemical strengthening, Na ⁺ agglomerates in the cavities between the microcrystalline phase and the glass phase, making it difficult to form compressive stress. It can also solve the problems of poor weather resistance of microcrystalline glass, easy aging, fogging on the glass surface, and inability to adapt to high temperature and high humidity environments. Calculated by mass percentage, the microcrystalline glass of the present application contains the following components:

69% to 75% SiO ₂ ;

6% to 12% Al ₂ O ₃ ;

1.7% to 3.5% P ₂ O ₅ ;

8% to 13% _Li2O ;

0.1% to 3% _Na2O ;

2% to 5% ZrO ₂ .

Furthermore, the microcrystalline glass of the present application contains the following components:

71% to 74% SiO ₂ ;

7% to 10% Al ₂ O ₃ ;

2% to 3.5% P ₂ O ₅ ;

10% to 12% _Li2O ;

0.5% to 2% _Na2O ;

2.5% to 4.5% ZrO ₂ .

The SiO ₂ in the glass-ceramics of the present application is a component that constitutes the glass skeleton. SiO ₂ can serve as the main body of the glass network structure, giving the basic glass and glass-ceramics better chemical stability, mechanical properties and molding properties. During the glass microcrystallization process, it provides a source of SiO ₂ for the formation of a crystalline phase. During the glass microcrystallization process, excessive SiO ₂ promotes the appearance of quartz and quartz solid solution during the glass microcrystallization process. Therefore, taking all factors into consideration, the mass percentage of SiO ₂ is 69% to 75%, and further 71% to 74%. In some embodiments, the SiO ₂ content is 69%, 70%, 71%, 72%, 73%, 74% or 75%.

The Al ₂ O ₃ in the microcrystalline glass of the present application belongs to a network intermediate oxide. Non-bridging oxygen and Al form aluminum oxide tetrahedrons, which have a larger volume than silicon oxide tetrahedrons, and produce larger gaps in the glass structure, which is conducive to ion exchange, making the chemical strengthening effect better and improving the mechanical properties of the glass. However, Al ₂ O ₃ is an extremely refractory oxide, which can quickly increase the high-temperature viscosity of the glass, making it more difficult to clarify and homogenize the glass, and greatly increasing the concentration of bubble defects in the glass; excessive Al ₂ O ₃ content can significantly increase the microcrystalline temperature of the glass, inhibit the crystallization ability of the base glass, make it difficult to form Li ₂ Si ₂ O ₅ , and promote the excessive formation of LiAlSi ₄ O ₁₀ in the crystallization process, and even form LiAlSi ₂ O ₆ crystal phase in the base glass, which reduces the glass transmittance. Therefore, taking all factors into consideration, the mass percentage of Al ₂ O ₃ is 6% to 12%, and further 7% to 10%. In some embodiments, the mass percentage of Al ₂ O ₃ is 6%, 7%, 8%, 9%, 10%, 11% or 12%.

In the present application's microcrystalline glass, P ₂ O ₅ , Li ₂ O and P ₂ O ₅ react to form a Li ₃ PO ₄ crystal phase, thereby inducing Li ₂ O and SiO ₂ in the glass to react to form Li ₂ SiO ₃ , and finally generating a Li ₂ Si ₂ O ₅ crystal phase; if the P ₂ O ₅ content is too high, lithium metasilicate will be precipitated during the crystallization process, resulting in too little glass phase, and insufficient Li ₂ Si ₂ O ₅ crystal phase cannot be formed, and the quartz phase will be precipitated, making it difficult to obtain a crystallized glass with high transmittance. Therefore, taking all factors into consideration, the mass percentage of P ₂ O ₅ is 1.7% to 3.5%, and further 2% to 3.5%. In some embodiments, the mass percentage of P ₂ O ₅ is 1.7%, 1.9%, 2%, 2.2%, 2.4%, 2.5%, 2.7%, 3%, 3.3% or 3.5%.

_Li2O in the microcrystalline glass of the present application is a network exo-oxide, which reduces the viscosity of the glass and promotes the melting and clarification of the glass. It promotes the formation _of _Li3PO4 in the basic microcrystallization process, and helps to form _Li2Si2O5 crystal phase and _LiAlSi4O10 _crystal phase in the crystallization process. However _, too high _Li2O will cause the viscosity of the glass to be too low, making it _difficult to obtain a chemically stable glass composition, while causing the compressive stress value to be too low during the ion strengthening process and increasing the cost of raw materials. Therefore, taking all factors into consideration, the mass percentage of _Li2O is 8% to 13%, and further 10% to 12%. In some embodiments, the mass percentage of _Li2O is 8%, 9%, 10%, 11%, 12%, 13%, 12.5%, 11.7%, 9.6% or 8.4%.

_Na2O in the microcrystalline glass of the present application can significantly reduce the viscosity of the base glass, promote the melting and clarification of the base glass, and reduce the crystallization temperature of the glass. To enable the crystallized glass to be strengthened with K ⁺ in the potassium nitrate molten salt, thereby generating high compressive stress on the glass surface to improve the strength of the glass, the glass must have enough Na ⁺ . Therefore, taking all factors into consideration, the mass percentage of _Na2O is 0.1% to 3%, and further 0.5% to 2%. In some embodiments, the mass percentage of _Na2O is 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1%, 1.4%, 1.5%, 1.8%, 2%, 2.2%, 2.6%, 2.5%, 2.8% or 3%.

The ZrO ₂ in the microcrystalline glass of the present application has a large zirconium ion potential energy, and ZrO ₂ is more inclined to promote the crystallization of petalite crystals; ZrO ₂ helps to reduce the grain size during the crystallization process, thereby improving the transmittance of the glass. Too high ZrO ₂ content leads to the presence of unmelted ZrO ₂ in the glass, which makes it impossible for the glass to crystallize uniformly. Therefore, taking all factors into consideration, the mass percentage of ZrO ₂ is 2% to 5%, and further 2.5% to 4.5%. In some embodiments, the mass percentage of ZrO ₂ is 2%, 2.2%, 2.5%, 2.6%, 2.9%, 3%, 3.2%, 3.5%, 3.9%, 4%, 4.1%, 4.5%, 4.7%, 4.9% or 5%.

The microcrystalline glass of the present application includes but is not limited to the above components, and may also include at least one of _K2O , _B2O3 _, CaO, MgO, ZnO, _Y2O3 and a _clarifier . The above components are beneficial to lowering the melting temperature of the microcrystalline glass, adjusting the properties of the glass forming material, and adjusting ion exchange, and improving the stress strength and depth of the glass after strengthening. However, excessive content will generate other impurities. Therefore, in some embodiments, the addition amount of each component is calculated by mass percentage as follows:

_K2O : 0-1%;

B ₂ O ₃ : 0～1%;

CaO: 0-1%;

MgO: 0-1%;

ZnO: 0-1%;

_Y2O3 : _0-1 %;

Clarifying agent: 0-1%.

The clarifier may be any of the types known to the public. In some embodiments, the clarifier includes at least one of SnO ₂ and CeO ₂ .

In some embodiments, the glass-ceramic includes, by mass percentage, 74% SiO ₂ , 9.4% Al ₂ O ₃ , 2% P ₂ O ₅ , 8.8% Li ₂ O, 2.8% Na ₂ O, and 3% ZrO ₂ .

In some embodiments, the glass-ceramic includes, by mass percentage, 72.5% SiO ₂ , 9.1% Al ₂ O ₃ , 2.1% P ₂ O ₅ , 9.5% Li ₂ O, 2.9% Na ₂ O, 2.9% ZrO ₂ and 1% B ₂ O ₃ .

In some embodiments, the glass-ceramic includes, by mass percentage, 73.6% SiO ₂ , 8.2% Al ₂ O ₃ , 2.5% P ₂ O ₅ , 8.5% Li ₂ O, 1.4% Na ₂ O, 3.9% ZrO ₂ , 0.8% K ₂ O, 0.3% B ₂ O ₃ and 0.8% Y ₂ O ₃ .

By adjusting the ratio of the above components, the obtained microcrystalline glass has the following properties:

The average particle size of the crystals is ≤50nm;

The average transmittance at 380nm～780nm is ≥90.5%;

After the double 85 test, the average transmittance of the micro-ceramic glass at the wavelength of 380-780nm is ≥90.5%;

b value ≤ 0.45, where b value is the absolute value of the yellow-blue value when the thickness of the microcrystalline glass is 0.6 mm;

Haze ≤ 0.25;

Drop height ≥1.6m.

The present application also provides a method for preparing the above-mentioned microcrystalline glass, comprising the following steps:

In step S10, the plain glass plate can also be cut according to the size requirements. In addition, the glass raw materials can be prepared according to the component ratio of the microcrystalline glass of the present application.

This step does not limit the method of forming the plain glass plate, and can be carried out by methods well known to those skilled in the art, such as float forming, overflow forming, calendering, slit draw-down or frit casting.

In some embodiments, the plain glass obtained by the above process has a thickness of 0.3 to 2 mm.

In step S20, the temperature of the nucleation treatment is 530°C to 580°C, and the nucleation treatment time is 0.5h to 1.5h. Specifically, in some embodiments, the nucleation treatment temperature may be 530°C, 540°C, 550°C, 560°C, 570°C, 580°C, 555°C, 565°C, or 575°C; and the nucleation treatment time may be 0.5h, 0.8h, 1.0h, 1.2h, 1.3h, or 1.5h.

The crystallization temperature is 640°C to 740°C. The crystallization time is 2 to 4 hours. Specifically, in some embodiments, the crystallization temperature may be 640°C, 650°C, 670°C, 690°C, 700°C, 710°C, 720°C, 730°C, 740°C, 705°C, 715°C, 725°C or 695°C; the crystallization time may be 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 2.8 hours or 3.8 hours.

The nucleation treatment and crystallization treatment under the above conditions can be adjusted so that the content of LiAlSi ₄ O ₁₀ in the microcrystalline glass phase is greater than the content of any other crystal phase.

In some embodiments, the content of LiAlSi ₄ O ₁₀ is greater than the content of Li ₂ Si ₂ O ₅ .

In some embodiments, the ratio of the content of LiAlSi ₄ O ₁₀ to the content of Li ₂ Si ₂ O ₅ is ≥1.13.

In step S20, the basic glass-ceramics may be trimmed, processed by CNC machine tools, roughly ground or polished.

In step S30, before chemical strengthening, the basic microcrystalline glass may be pretreated, and the specific operation is as follows: the basic microcrystalline glass is kept at 350-400°C for 20-40 minutes. Specifically, in some embodiments, the holding temperature may be 350°C, 370°C, 380°C, 390°C or 400°C; the holding time may be 20 minutes, 25 minutes, 28 minutes, 30 minutes, 35 minutes, 38 minutes or 40 minutes.

The chemical strengthening treatment in this step includes a bath salt. Specifically, the base glass-ceramics is placed in the bath salt for chemical strengthening treatment.

In some embodiments, the temperature and time of chemical strengthening are 450° C. to 520° C. and 4 to 8 hours. Specifically, the temperature of the chemical strengthening may be 450° C., 460° C., 470° C., 480° C., 490° C., 500° C., 510° C. or 520° C., and the time of the chemical strengthening may be 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours or 8 hours.

In some embodiments, the bath salt comprises 10 wt% to 40 wt% NaNO ₃ and 59 wt% to 90 wt% KNO ₃ ; and/or 0 wt% to 0.2 wt% LiNO _3. It is understood that in some embodiments, the bath salt comprises 10 wt% to 40 wt% NaNO ₃ and 59 wt% to 90 wt% KNO ₃ ; in some embodiments, the bath salt comprises 10 wt% to 40 wt% NaNO ₃ and 59 wt% to 90 wt% KNO ₃ and 0 wt% to 0.2 wt% LiNO ₃ .

The microcrystalline glass obtained after the above-mentioned chemical strengthening treatment has high hardness and good drop resistance, compressive stress and weather resistance. The glass surface is not easy to fog, can adapt to high temperature and high humidity environment, and maintain good light transmittance.

In some embodiments, after the chemical strengthening treatment is completed, the glass-ceramics may be cleaned and dried to prevent residual contaminants from affecting the strengthening effect.

The microcrystalline glass obtained by the technical solution of the present application has excellent physical and chemical properties and mechanical properties. The microcrystalline glass products containing the microcrystalline glass as described above have the same beneficial effects and can be widely used in the fields of display screens, electronic smart terminals and photovoltaic power generation devices to play a protective role.

The technical solution of the present application is further described in detail below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to explain the present application but not to limit the present application.

Example 1

1 , the method for preparing the microcrystalline glass of the present application comprises the following steps:

S10, weighing glass raw materials, mixing them, melting them at 1380° C., clarifying, homogenizing, molding, annealing, and finally cutting them to obtain plain glass with a thickness of 0.6 mm.

S20, performing a nucleation treatment on the plain glass of step S10 at 530°C for 0.5h, then performing a crystallization treatment at 640°C for 2h, and then cooling to room temperature to obtain a basic microcrystalline glass.

S30, pre-treating the base glass-ceramics of step S20 at 370°C for 30 minutes, and then immersing the base glass-ceramics in a salt bath at 450°C for 4 hours for chemical strengthening. The salt used in the salt bath includes

0.2 wt% LiNO ₃ + 40 wt% NaNO ₃ + 59.8 wt% KNO ₃ .

Example 2

Glass raw materials are weighed according to the proportion of the microcrystalline glass component of component 1 in Example 1 in Table 1, and plain glass is obtained according to the preparation method of step S10 in Example 1. Then, 8 groups of basic microcrystalline glasses are prepared according to the conditions of Example 2 in step S20 in Table 2. The properties of the obtained basic microcrystalline glasses are shown in Table 2.

Example 3

Weigh glass raw materials according to the proportion of microcrystalline glass components of component 1 in Example 1 in Table 1, obtain plain glass according to the preparation method of step S10 in Example 1, prepare basic microcrystalline glass according to condition 1 of Example 2 in step S20 of Table 2, and prepare 5 groups of microcrystalline glasses according to the conditions in step S30 of Table 3. The properties of the 5 groups of microcrystalline glasses are shown in Table 3.

Comparative Example 1

Glass raw materials were weighed according to the proportion of the glass-ceramics components of comparative component 1 in Table 1, and glass-ceramics were prepared according to the preparation method of steps S10 to S30 in Example 1. The properties of the glass-ceramics are shown in Table 1.

Comparative Example 2

Glass raw materials are weighed according to the proportion of the microcrystalline glass components of component 1 in Example 1 in Table 1, and plain glass is obtained according to the preparation method of step S10 in Example 1. Basic microcrystalline glass is prepared according to the conditions of comparative example 2 in step S20 in Table 2. The properties of the basic microcrystalline glass are shown in Table 2.

Comparative Example 3

The basic microcrystalline glass obtained in Comparative Example 2 was used to prepare 5 groups of microcrystalline glass according to the preparation conditions of step S30 in Table 3.

Performance Testing

The performance tests were carried out on the products of the embodiments and comparative examples, and the results are shown in Tables 1 to 2. Unless otherwise specified, the detection methods of each detection item are conventional methods in the art. The details are as follows:

(1) Crystalline phase and crystallinity: The crystal phase is determined by comparing the XRD diffraction peak with the database spectrum, and the crystallinity is calculated by the Rietveld method to calculate the proportion of the crystalline phase diffraction intensity in the overall spectrum intensity.

(2) Average grain size: measured using a scanning electron microscope (SEM). The glass-ceramics was surface treated in HF acid and then chrome-plated. The surface was scanned under a SEM scanning electron microscope to observe the diameter of the particles. The average diameter of all grain cross-sections was added up and divided by the number of grains in the SEM image.

(3) Use Datacolor 650 ultra-high precision desktop spectrophotometer to test the color b value.

(4) Visible light transmittance test was performed using a spectrophotometer in accordance with standard ISO13468-1:1996.

(5) Double 85 test: The test temperature of the double 85 test is set at 85°C and the humidity is set at 85%. The reliability test is carried out on the test samples for 1000 hours.

(6) Sandpaper drop performance of the whole device: measured by a mobile phone controlled drop test machine. The specific test conditions are: 80-grit sandpaper, 195g total weight, 60cm base height, 10cm increment, 1 time per height, until broken.

In this article, unless otherwise stated, the products of each embodiment and comparative example after ion exchange were tested using a Japanese Orihara FSM-6000LE+SLP1000 surface stress meter, wherein CS refers to the compressive stress value on the surface of the strengthened glass; CS-30 refers to the compressive stress value at a depth of 30 microns after the strengthened glass sample is strengthened by mixed salt; and DOC refers to the ion exchange depth of the compressive stress layer of the strengthened glass.

Table 1 Component ratios and properties of glass-ceramics of Example 1 and Comparative Example 1

Table 2 Preparation conditions of step S20 of Example 2 and Comparative Example 2 and properties of their basic microcrystalline glass

Table 3 Preparation conditions and glass-ceramic properties of step S30 in Example 3

Table 4 Preparation conditions and glass-ceramic properties of step S30 in comparative example 3

As can be seen from the above table, the crystallinity of the microcrystalline glass obtained by the technical solution of the present application in the embodiment of the present application is ≥55%, the average particle size of the crystal is ≤50nm, the content of the crystalline phase LiAlSi ₄ O ₁₀ is greater than that of Li ₂ Si ₂ O ₅ , and the ratio of the content of the crystalline phase LiAlSi ₄ O ₁₀ to the content of Li ₂ Si ₂ O ₅ is ≥1.13, the b value is ≤0.45, the average transmittance at 380nm~780nm is ≥90.5%, and the haze is ≤0.25. Moreover, after completing the chemical strengthening treatment, the surface of the microcrystalline glass is clean after the double 85 test, it is not easy to fog, maintains good transmittance, has good weather resistance, is not easy to age, can resist high temperature and high humidity environment, and also has high hardness, excellent compressive stress and drop resistance.

In Comparative Example 1, the amount of P ₂ O ₅ added to the microcrystalline glass is too much, reaching 4%, resulting in the content of LiAlSi ₄ O ₁₀ being less than the content of Li ₂ Si ₂ O _5. The b value and haze of the microcrystalline glass are both relatively large, 0.75 and 0.55% respectively. The transmittance of 0.6mm microcrystalline glass at 560nm is only 89.2%. After the double 85 test, the glass surface is fogged, and the transmittance of 0.6mm microcrystalline glass at 560nm is only 65.3%. In Comparative Example 2, the nucleation time is too long, which does not meet the preparation requirements of the microcrystalline glass of this application. Before chemical strengthening, the content of LiAlSi ₄ O ₁₀ in the crystal phase of the basic microcrystalline glass is equal to the content of Li ₂ Si ₂ O ₅ .

Comparative Example 3 is a microcrystalline glass obtained by chemically strengthening the basic microcrystalline glass obtained in Comparative Example 2. After the double 85 test, the obtained microcrystalline glass showed fogging on the glass surface, and the 560nm transmittance of 0.6mm microcrystalline glass was less than 70%. The weather resistance of the microcrystalline glass is poor, it is easy to age, and it is not suitable for high temperature and high humidity environments.

The above are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

A glass-ceramic, wherein the crystallinity of the glass-ceramic is ≥55%, and the crystal phase thereof comprises LiAlSi 4 O 10 and Li 2 Si 2 O 5 , wherein the content of the LiAlSi 4 O 10 is greater than the content of any other crystal phase.
The glass-ceramics according to claim 1, wherein the ratio of the content of LiAlSi 4 O 10 to the content of Li 2 Si 2 O 5 is ≥ 1.13.
The microcrystalline glass according to claim 1, wherein the crystal phase of the microcrystalline glass further comprises at least one of Li 2 SiO 3 , Li 3 PO 4 , and β-spodumene.
The glass-ceramic according to claim 1, wherein the glass-ceramic contains the following components, calculated by mass percentage:

69% to 75% SiO 2 ;

6% to 12% Al 2 O 3 ;

1.7% to 3.5% P 2 O 5 ;

8% to 13% Li2O ;

0.1% to 3% Na2O ;

2% to 5% ZrO 2 .
The glass-ceramic according to claim 1, wherein the glass-ceramic contains the following components, calculated by mass percentage:

71% to 74% SiO 2 ;

7% to 10% Al 2 O 3 ;

2% to 3.5% P 2 O 5 ;

10% to 12% Li2O ;

0.5% to 2% Na2O ;

2.5% to 4.5% ZrO 2 .
The glass-ceramics according to claim 4 or 5, wherein the glass-ceramics further comprises the following components, calculated by mass percentage:

K2O : 0-1%;

B 2 O 3 : 0～1%;

CaO: 0-1%;

MgO: 0-1%;

ZnO: 0-1%;

Y2O3 : 0-1 %;

Clarifying agent: 0-1%.
The microcrystalline glass according to claim 1, wherein the average particle size of the crystals of the microcrystalline glass is ≤50 nm;

And/or, the average transmittance of the glass-ceramics at 380nm to 780nm is ≥ 90.5%;

And/or, after the microcrystalline glass is subjected to a double 85 test, the average transmittance of light at a wavelength of 380-780 nm is ≥90.5%.
The microcrystalline glass according to claim 1, wherein the b value of the microcrystalline glass is ≤ 0.45, wherein the b value is the absolute value of the yellow-blue value when the thickness of the microcrystalline glass is 0.6 mm;

And/or, the haze of the glass-ceramics is ≤0.25;

And/or, the drop height of the microcrystalline glass is ≥1.6m.
A method for preparing glass-ceramics according to any one of claims 1 to 8, wherein the method comprises the following steps:

Weighing glass raw materials, mixing them, melting, clarifying, homogenizing, molding, and annealing to obtain plain glass;

The plain plate glass is subjected to a nucleation treatment, a crystallization treatment, and then cooled to obtain a basic micro-ceramic glass;

The basic microcrystalline glass is chemically strengthened to obtain the microcrystalline glass.
The method for preparing glass-ceramics according to claim 9, wherein the temperature of the nucleation treatment is 530° C. to 580° C. The nucleation treatment time is 0.5h to 1.5h;

And/or, the temperature of the crystallization treatment is 640° C. to 740° C., and the time of the crystallization treatment is 2 to 4 hours.
The method for preparing glass-ceramics according to claim 9, wherein the chemical strengthening treatment comprises a bath salt comprising 10wt% to 40wt% NaNO 3 and 59wt% to 90wt% KNO 3 ; and/or 0wt% to 0.2wt% LiNO 3 .
The method for preparing microcrystalline glass according to claim 9, wherein the temperature of chemical strengthening is 450°C to 520°C, and the time of chemical strengthening is 4 to 8 hours.
A glass-ceramic product, wherein the glass-ceramic product comprises the glass-ceramic described in any one of claims 1 to 8, and the glass-ceramic product is applied to the fields of display screens, electronic intelligent terminals or photovoltaic power generation devices.