阅读说明：本技术 一种玻璃基板的制备方法 (Preparation method of glass substrate ) 是由 杨国洪 曾召 王答成 孔令歆 兰静 郭静 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种玻璃基板的制备方法,属于光电显示领域。一种玻璃基板的制备方法,包括下述步骤：1)按摩尔百分比计,称量下述组分：67％-69.5％的SiO<Sub>2</Sub>、12％-14％的Al<Sub>2</Sub>O<Sub>3</Sub>、1％-2.5％的B<Sub>2</Sub>O<Sub>3</Sub>、4％-6％的MgO、7％-9％的CaO、1％-2％的SrO、2.1％-4％的BaO和0.1％-0.2％的SnO<Sub>2</Sub>；2)将上述组分混合后进行熔化、澄清,形成玻璃液；3)将所述玻璃液进行溢流下拉成型,得到成型的玻璃板；4)将所述玻璃板进行退火处理后,得到玻璃基板。(The invention discloses a preparation method of a glass substrate, and belongs to the field of photoelectric display. A method for producing a glass substrate, comprising the steps of: 1) the following components are weighed according to the molar percentage: 67% -69.5% of SiO 2 12 to 14 percent of Al 2 O 3 1% -2.5% of B 2 O 3 4 to 6 percent of MgO, 7 to 9 percent of CaO, 1 to 2 percent of SrO, 2.1 to 4 percent of BaO and 0.1 to 0.2 percent of SnO 2 (ii) a 2) Mixing the components, melting and clarifying to form molten glass; 3) performing overflow down-drawing molding on the molten glass to obtain a molded glass plate; 4) and annealing the glass plate to obtain the glass substrate.)

1. A method for manufacturing a glass substrate is characterized by comprising the following steps:

1) the following components are weighed according to the molar percentage:

67% -69.5% of SiO₂12 to 14 percent of Al₂O₃1% -2.5% of B₂O₃4 to 6 percent of MgO, 7 to 9 percent of CaO, 1 to 2 percent of SrO, 2.1 to 4 percent of BaO and 0.1 to 0.2 percent of SnO₂；

2) Mixing the components, melting and clarifying to form molten glass;

3) performing overflow down-drawing molding on the molten glass to obtain a molded glass plate;

4) and performing stress relief annealing treatment on the glass plate to obtain the glass substrate.

2. The method for producing a glass substrate according to claim 1, wherein the sum of molar percentages of MgO, CaO, SrO and BaO in step 1) is 18% or less.

3. The method according to claim 1, wherein the temperature of the molten glass is 1280 ℃ or lower when the molten glass is subjected to overflow down-draw forming in the step 3).

4. The method for manufacturing a glass substrate according to claim 1, wherein the lower limit temperature of the stress relief annealing in the step 4) is 731 to 745 ℃.

5. The method for producing a glass substrate according to claim 4, wherein the time for the stress-relief annealing treatment in the step 4) is 19.79 to 35.53 s.

Technical Field

The invention belongs to the field of photoelectric display, and particularly relates to a preparation method of a glass substrate.

Background

With the popularization of mobile interconnection such as intelligent display and tablet personal computers, new requirements on the thickness and weight of intelligent terminal products are provided, the intelligent products develop to be light, thin, flexible and intelligent, particularly the development of electronic wearable devices, bendable smart phones and curved surface display technologies with strong reality sense, and new requirements on the performance of basic materials of electronic display, such as flexibility and good flexibility, are provided.

Meanwhile, the display screen is also developed in the direction of higher resolution, high brightness and low power consumption, and the OLED display has self-luminescence and low power consumption, and compared with the conventional LCD display screen, it can be used on any shape of substrate, so that it becomes the mainstream technology of flexible display. The low-temperature polysilicon thin film transistor (LTPS TFT) can manufacture smaller and faster transistors due to the characteristic of high electron mobility, has the advantages of high brightness, high resolution, low power consumption and the like, and can meet the requirements of high-resolution display of a traditional hard screen and the requirements of flexible high-resolution display by the LTPS-OLED technology. No matter the traditional hard-screen LTPS-OLED display screen or the flexible OLED screen, the LTPS and the OLED need to be manufactured on a glass substrate, and the corresponding manufacturing process requires that the glass substrate has performance requirements of high Young modulus, low dimensional deformation, low thickness variation and the like.

In the Chinese invention with the application number of 201710585934.X, the temperature of the production process of the glass substrate compound is high, and the defects of stones in glass caused by corrosion of refractory materials in a melting furnace are more easily caused in the melting process; the temperature for conveying the molten glass to the overflow groove at the viscosity of 35,000 poises is 1280-1345 ℃, which also causes the increase of internal defects of the glass, and leads to the aggravation of creep deformation of the overflow brick at the high forming temperature, thus seriously affecting the service life.

Disclosure of Invention

The invention aims to overcome the defects that the temperature of glass liquid is high in the preparation process, so that the corrosion to equipment materials is increased, the internal defects of a glass substrate are increased, and the service life of equipment is shortened.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a method for producing a glass substrate, comprising the steps of:

1) the following components are weighed according to the molar percentage:

67% -69.5% of SiO₂12 to 14 percent of Al₂O₃1% -2.5% of B₂O₃4 to 6 percent of MgO, 7 to 9 percent of CaO, 1 to 2 percent of SrO, 2.1 to 4 percent of BaO and 0.1 to 0.2 percent of SnO₂；

2) Mixing the components, melting and clarifying to form molten glass;

3) performing overflow down-drawing molding on the molten glass to obtain a molded glass plate;

4) and performing stress relief annealing treatment on the glass plate to obtain the glass substrate.

Further, in the step 1), the sum of the mole percentages of MgO, CaO, SrO and BaO is less than or equal to 18%.

Further, when the glass liquid is subjected to overflow pull-down forming in the step 3), the temperature of the glass liquid is less than or equal to 1280 ℃.

Further, the lower limit temperature of the stress relief annealing in the step 4) is 731-745 ℃.

Further, the time of the stress relief annealing treatment in the step 4) is 19.79-35.53 s.

Compared with the prior art, the invention has the following beneficial effects:

the preparation method of the glass substrate reduces the forming difficulty and improves the product performance by arranging the components, particularly, SiO₂The molar percentage of the glass is 67-69.5%, the temperature of the glass liquid in the forming process is not higher than 1280 ℃, the problem that the corrosion of refractory materials in a melting furnace is caused due to overhigh temperature, so that the defect of stones in the glass is increased is solved, and the production difficulty is reduced; meanwhile, the viscosity of the liquidus can be ensured to be higher than 10 kilopoises, which is beneficial to overflow pull-down forming and can obtain smaller density; al (Al)₂O₃The mole percentage of the glass is 12-14%, thereby avoiding the conditions that the crystallization temperature of the glass is increased, the crystallization viscosity is reduced, and the overflow pull-down is not facilitated, and simultaneously taking thermal stability, the crystallization viscosity of the glass, and the mechanical strength and hardness of the glass into consideration; b is₂O₃1 to 2.5 percent of the total amount of the antioxidant can reduce viscosityThe glass melting is promoted, the temperature of the glass production process is reduced, and the problem that the strain point temperature of the glass is rapidly reduced and the thermal stability is poor due to the over-high content of the glass is solved.

Further, the components used, in which the sum of the mole percentages of MgO, CaO, SrO and BaO is less than or equal to 18%, can reduce the overall viscosity of the molten glass while avoiding an increase in density, a decrease in strain point temperature, and deterioration in chemical durability.

Further, when the overflow downdraw forming is carried out, the temperature of the glass liquid is less than or equal to 1280 ℃, and the viscosity of the glass liquid is 35000 poise, so that the viscosity required by the overflow downdraw forming is met, and the defects in the glass substrate, such as the rise of internal defects and the shortening of the service life of equipment, caused by overhigh temperature are avoided.

Furthermore, the lower limit temperature of the stress relief annealing treatment is 731-745 ℃ and the annealing time is 19.79-35.53s, so that the problems of overhigh temperature of the production process, low yield and short service life of equipment caused by a method of increasing the material strain point temperature in order to reduce the thermal shrinkage of the glass substrate in the prior art are solved; the thermal shrinkage rate of the glass substrate formed after stress relief annealing is not more than 30ppm after the glass substrate is processed at 500 ℃ for 120 min.

Detailed Description

In order to make those skilled in the art better understand the solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the data in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not a whole embodiment. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of the present invention.

It is noted that the terms first, second and the like in the description and in the claims of the present invention are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

According to the invention, through optimized components, the glass substrate with high Young modulus and low dimensional deformation can be obtained, and the display requirement of high resolution can be met. In the present invention, SiO₂Is the main oxide forming the glass, which is composed of silicon-oxygen tetrahedron [ SiO ]₄]The structure of (a) forms an irregular continuous network, which becomes the framework of the glass. SiO 2₂Can reduce the thermal expansion coefficient and density of the glass, improve the strain point temperature of the glass, SiO₂When the content is too low, the glass with low expansion, low density and high strain point, SiO, is not easy to obtain₂When the content is too high, the high-temperature viscosity of the glass increases, making the glass difficult to melt and easily causing a stone (cristobalite) defect. Thus, the SiO of the present invention₂The total mole percentage of the glass substrate is controlled to be 67-69.5%, so that the forming temperature of the glass substrate is not higher than 1280 ℃, the service life of an overflow brick and the defects of glass are not affected, the production difficulty is reduced, and simultaneously the total mole percentage of the glass substrate is not lower than 67%, so that the liquidus viscosity can be ensured to be higher than 10 kilopoises, the overflow downdraw forming is facilitated, and a smaller density value can be obtained.

Al₂O₃Also a glass former, Al₂O₃Is an intermediate oxide, when the glass has insufficient O, Al has a coordination number of 6, is in a network gap, and forms [ AlO ] with O₆]An octahedron; when there is excess O in the glass, the coordination number of Al is 4, enters the glass network, and forms [ AlO ] with O₄]Tetrahedron for supplementing network, increasing glass stability, and reducing glass expansion coefficient, and [ AlO ]₄]The tetrahedron has a large volume, which can reduce the density of the glass. Al (Al)₂O₃Can obviously improve the strain point and the elastic modulus of the glass and increase the chemical stability of the glass, but Al₂O₃When the content is too large, the glass is easily devitrified. Al (Al)₂O₃Mole percent ofThe specific content is preferably 12-14%, which not only avoids the crystallization temperature rise and crystallization viscosity reduction of the glass and is not beneficial to overflow downdraw forming, but also considers high thermal stability, Young modulus and hardness.

B₂O₃Is a glass forming agent and a flux, which is composed of a boron-oxygen trigonal [ BO ]₃]And boron-oxygen tetrahedron [ BO₄]Is a structural component, and is a silicon-oxygen tetrahedron [ SiO ]₄]Together forming a structural network, B₂O₃Can reduce the density of the glass and improve the BHF resistance of the glass, B₂O₃Lowering the viscosity of the glass at high temperatures and increasing the viscosity at low temperatures, B₂O₃Also acts as a fluxing agent, accelerates the fining of the glass and reduces the crystallization capacity of the glass when B₂O₃When the amount of incorporation is too high, the strain point temperature of the glass decreases, the Young's modulus decreases, and the acid resistance of the glass decreases, so that in the embodiment, B₂O₃The content of (A) is maintained between 1% and 2.5%. If B is present₂O₃If the content of (B) is less than 1%, the effect as a flux is insufficient and B is simply lowered₂O₃The content may in turn cause other problems including deterioration of melting ability and increase of bubbles. On the other hand, higher B₂O₃The content tends to decrease the acid resistance, and at the same time, the strain point of the glass decreases, so that the thermal stability decreases.

The alkaline earth metal oxides CaO, MgO, SrO and BaO belong to the external oxides of the glass network, and the alkaline earth metal cation R²⁺Move relatively freely at high temperature and have O^2-The polarization weakens the effect of silicon-oxygen bonds, and the viscosity of the glass liquid is reduced; but when the temperature is lowered, the cation R²⁺The mobility of the glass is weakened, and the glass is possibly in certain silicon-oxygen tetrahedron groups according to a certain coordination relationship, and the small silicon-oxygen tetrahedron is combined into a large silicon-oxygen tetrahedron group, so that the viscosity of the glass liquid is increased to some extent. Therefore, alkaline earth metal oxides can be beneficial to clarifying molten glass at high temperature and beneficial to forming molten glass at low temperature, but the density is increased, the strain point temperature is reduced, and the chemical durability is improved when the content of the alkaline earth metal oxides is too highThe deterioration and the increase in the thermal expansion coefficient. The mixed oxide of the alkaline earth metal can reduce the liquidus temperature and increase the liquidus viscosity, thereby being beneficial to overflow pull-down production.

Ca²⁺The coordination number of (A) is generally 6, the mobility of which in the glass network structure is small and which is generally not easily precipitated from the glass, but the mobility is large at high temperatures, Ca²⁺The effect of polarizing oxygen and weakening silicon-oxygen bonds is exhibited, and when the content of CaO in the glass is too large, the glass generally becomes short in terms of glass cullability, which is disadvantageous in terms of molding, and the tendency of devitrification of the glass increases, and in other embodiments, the content of CaO is maintained between 7% and 9%. If the content of CaO is more than 9%, the glass has a large tendency to devitrify, and MgO is used to replace part of CaO, whereby the glass is reduced in the tendency to devitrify and the glass is adjusted in the glass behavior,

SrO, which is similarly affected by BaO, is a component that not only improves the chemical resistance of the glass but also its devitrification tendency. In other embodiments, the SrO content is maintained between 1% and 2%. If the SrO content is more than 2%, the density of the glass is undesirably increased; the content of BaO is maintained at 2.1-4%. If the content of BaO is more than 4 percent, the density is greatly increased, and if the content of BaO is less than 2.1 percent, the crystallization viscosity is lower than 10 ten thousand poise, so that the method cannot adapt to overflow down-draw method production.

Tables 1-7 provide examples 1-35 of the present invention, which are specific components of the glass composition and performance parameters of the resulting glass substrates, respectively.

Table 1 examples 1 to 5 of the present invention

Table 2 example 6-example 10 of the invention

Table 3 examples 11 to 15 of the present invention

Table 4 examples 16 to 20 of the present invention

TABLE 5 examples 21 to 25 of the present invention

TABLE 6 examples 26 to 27 of the present invention

TABLE 7 examples 31 to 35 of the present invention

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.