A method for preparing high-alumina silicate electronic glass

Abstract

The present invention relates to the technical field of glass preparation, and in particular to a method for preparing high-aluminum silicate electronic glass. The present invention obtains a glass ribbon formed by a float process, and respectively detects the refractive index of a first surface having a tin surface and a second surface of the glass ribbon that is not a tin surface, wherein the raw material of the glass ribbon does not contain lithium elements; the glass ribbon formed by the float process is introduced into an annealing furnace, and a first spraying liquid is used in the annealing furnace to spray the second surface of the glass ribbon; the sprayed glass ribbon is annealed to obtain a lithium-containing glass ribbon after ion exchange between the first spraying liquid and the second surface; the lithium-containing glass ribbon is strengthened by a one-step low-temperature ion exchange to obtain the high-aluminum silicate electronic glass, thereby achieving the consistency of the ion exchange capacity of the first surface and the second surface, and improving the flatness of the high-aluminum silicate electronic glass.

Description

Technical Field

[0001] The invention relates to the technical field of glass preparation, and in particular to a method for preparing high-alumina silicate electronic glass. Background Art

[0002] In recent years, electronic products generally include displays with touch panels, such as tablet computers, smart phones, and car screens. The outermost layer of the touch screen display is a protective glass, also known as electronic glass. As the outer screen of the display, the electronic glass needs to have good mechanical strength, including resistance to bending, impact, drop, and flatness. At present, the float production process of electronic glass substrates is widely used in industrial production processes due to its advantages of good flatness of the original sheet and large production capacity. However, since the glass substrate produced by the float process has a tin side and a non-tin side, the warpage value of the glass will increase after chemical strengthening, affecting the fitting of the electronic glass in the application. In addition, as the size of current client products becomes larger and larger, the warpage value requirements become smaller and smaller. The problem of large warpage of the float electronic glass substrate after chemical strengthening is a technical problem that needs to be solved urgently.

[0003] For example, Chinese Patent Publication No.: CN111204989A discloses a method for manufacturing a reinforced article, including: providing an article, which includes a glass, glass ceramic or ceramic composition having a plurality of ion-exchangeable alkali metal ions, a first main surface, and a second main surface; forming a SiO2-containing film on the first main surface, wherein the SiO2-containing film includes a thickness of about 5 to about 20 nanometers; forming an anti-glare surface as a whole with the second main surface; providing a first ion exchange bath, wherein the first ion exchange bath includes a plurality of ion-exchangeable alkali metal ions, each of which has a size greater than the size of the ion-exchangeable alkali metal ions; and immersing the article in the first ion exchange bath at a first ion exchange temperature and duration to form a reinforced article. In addition, the reinforced article includes a compressive stress region extending from the first main surface and the second main surface to a first selected depth and a second selected depth, respectively.

[0004] The prior art still has the following problems:

[0005] In the prior art, when the float process is used to prepare electronic glass, it is impossible to avoid the problem of glass warping caused by the difference in ion exchange capacity between the tin-containing surface and the non-tin surface, which affects the flatness of the high-aluminosilicate electronic glass. Summary of the invention

[0006] To this end, the present invention provides a method for preparing high-alumina silicate electronic glass, which is used to overcome the problem that the electronic glass prepared by the float process in the prior art will warp after ion exchange due to the different ion exchange capacities between the tin-containing surface and the non-tin surface.

[0007] To achieve the above object, the present invention provides a method for preparing high-alumina silicate electronic glass, comprising:

[0008] Step S1, obtaining a glass ribbon formed by a float process, and detecting the refractive index of a first surface having a tin surface and a second surface having a non-tin surface of the glass ribbon, respectively, wherein the raw material of the glass ribbon does not contain lithium element;

[0009] Step S2, introducing the glass ribbon formed by float forming into an annealing furnace, and spraying the second surface of the glass ribbon with a first spraying liquid in the annealing furnace;

[0010] Step S3, annealing the sprayed glass ribbon to obtain a lithium-containing glass ribbon after ion exchange between the first sprayed liquid and the second surface;

[0011] Step S4, strengthening the lithium-containing glass ribbon by one-step low-temperature ion exchange to obtain high-alumina silicate electronic glass.

[0012] Further, in the step S2, the first spraying liquid includes a molten liquid containing a lithium salt.

[0013] Furthermore, the first spraying liquid is composed of 100% lithium nitrate, or a mixture of lithium nitrate and lithium hydroxide.

[0014] Furthermore, in the step S2, the temperature range for spraying the second surface is 400°C to 600°C.

[0015] Furthermore, in the step S2, a pulling speed of the glass ribbon for spraying the second surface is ≤15 m / min.

[0016] Further, in the step S2, the sodium content of the first surface of the glass ribbon after the spraying is greater than the sodium content of the second surface of the glass ribbon, and the difference between the sodium content of the first surface and the sodium content of the second surface is greater than or equal to 0.27wt%.

[0017] Furthermore, the step S4 includes:

[0018] Step S41, preheating the lithium-containing glass ribbon to a temperature of molten salt, wherein the temperature ranges from 300° C. to 450° C.;

[0019] Step S42, at a preset ion exchange temperature, placing the lithium-containing glass ribbon into the molten salt for ion exchange for a preset exchange time, replacing sodium ions in the lithium-containing glass ribbon with potassium ions in the molten salt, wherein the ion exchange temperature ranges from 370° C. to 500° C., the exchange time ranges from 60 min to 600 min, and the composition of the molten salt is potassium nitrate or a mixture of potassium nitrate and potassium salt;

[0020] Step S43, taking the lithium-containing glass ribbon out of the molten salt, and keeping it warm at a preset salt dropping temperature for a preset time, wherein the salt dropping temperature ranges from 280° C. to 420° C., and the preset insulation time ranges from 3 min to 10 min;

[0021] Step S44, cooling the lithium-containing glass ribbon from the salt dropping temperature to room temperature within a cooling time, wherein the cooling time ranges from 1 min to 60 min.

[0022] Furthermore, in the step S1, it also includes:

[0023] Step S11, dividing the second surface of the glass ribbon into a plurality of surface sub-regions based on the size of the glass ribbon;

[0024] Step S12, determining whether a surface sub-region is a surface abnormality characterization region based on a difference between a sub-region refractive index of each surface sub-region and a first refractive index of the first surface of the glass ribbon;

[0025] Step S13, obtaining the number of surface abnormality characterization areas to determine the degree of surface difference of the second surface;

[0026] If the surface difference degree of the second surface is a weak representation degree of the surface difference, adjusting the spraying amount of each surface abnormality representation area;

[0027] If the surface difference degree of the second surface is a strong characterization degree of the surface difference, the position distribution of the surface abnormality characterization area is obtained to select an adjustment method for the spraying, including:

[0028] adjusting the overall spraying temperature of the glass ribbon based on the variance of the sub-region refractive index of each surface sub-region and the first refractive index;

[0029] Alternatively, the pulling speed of each surface abnormality characterization region is adjusted based on the average value of the refractive index of the sub-region corresponding to each surface abnormality characterization region.

[0030] Furthermore, in the step S13, determining the surface difference degree of the second surface includes:

[0031] Comparing the number of surface anomaly characterization areas with a preset number threshold;

[0032] If the number is less than or equal to the number threshold, determining that the surface difference degree of the second surface is a surface difference weak representation degree;

[0033] If the number is greater than the number threshold, it is determined that the surface difference degree of the second surface is a surface difference strong representation degree.

[0034] Furthermore, in step S13, the adjustment method of the spraying is selected, including:

[0035] Obtaining the position distribution of the surface anomaly characterization area to determine the aggregation category of the surface anomaly characterization area, including a surface difference dispersion category and a surface difference concentration category;

[0036] The corresponding spraying adjustment method is selected based on the clustering category of the surface abnormality characterization area, wherein:

[0037] If the aggregation category of the surface anomaly characterization area is the surface difference dispersion category, adjusting the overall spraying temperature of the glass ribbon based on the variance of the sub-region refractive index of each surface sub-region and the first refractive index;

[0038] If the aggregation category of the surface anomaly characterization regions is the surface difference concentration category, the pulling speed of each surface anomaly characterization region is adjusted based on the average value of the refractive index of the sub-region corresponding to each surface anomaly characterization region.

[0039] Compared with the prior art, the beneficial effect of the present invention lies in that, by obtaining a glass ribbon formed by float process, the refractive index of a first surface having a tin surface and a second surface not having a tin surface of the glass ribbon are detected respectively, wherein the raw material of the glass ribbon does not contain lithium element; the glass ribbon formed by float process is introduced into an annealing furnace, and the second surface of the glass ribbon is sprayed with a first spraying liquid in the annealing furnace; the glass ribbon after spraying is annealed to obtain a lithium-containing glass ribbon after ion exchange between the first spraying liquid and the second surface; the lithium-containing glass ribbon is strengthened by a one-step low-temperature ion exchange to obtain a high-aluminum silicate electronic glass, thereby achieving consistency in the ion exchange capacity of the first surface and the second surface, and improving the flatness of the high-aluminum silicate electronic glass.

[0040] In particular, the present invention uses a molten liquid containing a lithium salt as the first spraying liquid to spray-plate the second surface. Those skilled in the art can understand that by spraying the molten liquid containing a lithium salt, lithium ions can be introduced into the non-tin surface of the glass. The introduction of lithium ions can change the ion composition of the glass. The radius of lithium ions is small and can form a stronger bond with the oxygen ions in the glass, thereby increasing the structural stability of the glass. Furthermore, the ion exchange capacity of the non-tin surface is adjusted to make it closer to the tin surface, thereby improving the flatness of the electronic glass.

[0041] In particular, the present invention selects 100% lithium nitrate, or a mixture of lithium nitrate and lithium hydroxide as a component of the first spraying liquid. It can be understood by those skilled in the art that the glass ribbon needs to be at least 400°C to ensure the ion exchange efficiency. In the lithium-containing mixture, in order to produce the ion exchange effect, the sprayed lithium salt needs to be in a molten state when the melting temperature is ≤400°C. The melting point of lithium nitrate is 264°C, which can maintain a stable molten state under the required temperature conditions of the glass ribbon and provide the required lithium ions for ion exchange. Adding a small amount of lithium hydroxide to lithium nitrate can adjust the pH value of the spraying liquid. During the spraying process, the appropriate pH value can affect the rate and degree of ion exchange, thereby enhancing the Li-Na ion exchange capacity, adjusting the ion exchange capacity of the non-tin surface to make it closer to the tin surface, and improving the flatness of the electronic glass.

[0042] In particular, the temperature range for spraying the second surface of the present invention is 400°C to 600°C. It can be understood by those skilled in the art that when the spraying temperature is ≥400°C, the ion exchange efficiency is relatively high. As the temperature increases, the thermal motion of ions in the glass intensifies, which accelerates the diffusion rate of lithium ions and sodium ions, thereby promoting the Li-Na ion exchange reaction. If the temperature is lower than 400°C, the ion exchange efficiency will slow down, and the Li-Na exchange amount will be less within a certain period of time. It takes a longer time to achieve the same exchange amount, which reduces the production efficiency. The decomposition temperature of lithium nitrate is 600°C. If the spraying temperature exceeds 600°C, the lithium nitrate will decompose into substances such as lithium oxide and nitrogen dioxide. These products will affect the effect of ion exchange. Therefore, in order to ensure the stability of lithium nitrate during the spraying process, it is necessary to control the temperature range for spraying the second surface to be 400°C to 600°C. Furthermore, the ion exchange capacity of the non-tin surface is adjusted to make it closer to the tin surface, thereby improving the flatness of the electronic glass.

[0043] In particular, the pulling speed of the glass ribbon for spraying the second surface of the present invention is ≤15m / min. Those skilled in the art can understand that when the glass passes through the spraying area of ​​the molten liquid containing lithium salt, there needs to be enough time for the lithium ions to exchange with the sodium ions in the glass. The faster the pulling speed, the shorter the time the glass stays in the spraying area, and the less sufficient the ion exchange. Therefore, it is necessary to control the pulling speed of the glass ribbon for spraying to be within 15m / min, thereby achieving sufficient exchange between ions, ensuring the ion exchange amount, adjusting the ion exchange capacity of the non-tin surface to make it closer to the tin surface, and improving the flatness of the electronic glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A step diagram of a method for preparing high-alumina silicate electronic glass according to an embodiment of the present invention;

[0045] Figure 2 A diagram showing the steps of a one-step low-temperature ion exchange according to an embodiment of the present invention;

[0046] Figure 3 A step diagram of an adjustment method for selecting spraying on a second surface according to an embodiment of the present invention;

[0047] Figure 4 The present invention is a logic flow chart for determining the degree of surface difference of the second surface according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0050] It should be noted that, in the description of the present invention, terms such as "upper", "lower", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0051] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] It can be understood that the float process referred to in this embodiment is a production process of electronic glass substrates, and the main process steps include high-temperature melting, tin bath floating and annealing.

[0053] See also Figure 1 As shown, it is a step diagram of a method for preparing high-aluminum silicate electronic glass according to an embodiment of the present invention. The embodiment of the present invention provides a method for preparing high-aluminum silicate electronic glass, comprising:

[0054] Step S1, obtaining a glass ribbon formed by a float process, and detecting the refractive index of a first surface having a tin surface and a second surface which is not a tin surface of the glass ribbon, respectively, wherein the raw material of the glass ribbon does not contain lithium element; specifically, the first surface is a glass surface in direct contact with the tin liquid, and the second surface is a glass surface away from the tin liquid. It can be understood that during the float process, tin atoms will diffuse to the first surface of the glass, change the microstructure and composition of the first surface, thereby affecting the refractive index of the first surface. The first surface and the second surface exposed to the air are subjected to different surface tensions. This difference in surface tension will cause changes in the molecular arrangement and structure of the glass surface. The first surface is subjected to the surface tension of the tin liquid, which will make the molecular arrangement of the glass surface different from that of the second surface, thereby affecting the refractive index;

[0055] Step S2, introducing the glass ribbon formed by float forming into an annealing furnace, and spraying the second surface of the glass ribbon with a first spraying liquid in the annealing furnace;

[0056] Step S3, annealing the sprayed glass ribbon to obtain a lithium-containing glass ribbon after ion exchange between the first sprayed liquid and the second surface;

[0057] Step S4, strengthening the lithium-containing glass ribbon by one-step low-temperature ion exchange to obtain high-alumina silicate electronic glass.

[0058] Specifically, in step S2, the first spraying liquid includes a molten liquid containing a lithium salt.

[0059] Specifically, the present invention uses a molten liquid containing a lithium salt as the first spraying liquid to spray the second surface. Those skilled in the art can understand that by spraying the molten liquid containing a lithium salt, lithium ions can be introduced into the non-tin surface of the glass. The introduction of lithium ions can change the ion composition of the glass. The radius of lithium ions is small and can form a stronger bond with the oxygen ions in the glass, thereby increasing the structural stability of the glass, thereby adjusting the ion exchange capacity of the non-tin surface to make it closer to the tin surface.

[0060] Specifically, the first spraying liquid is composed of 100% lithium nitrate, or a mixture of lithium nitrate and lithium hydroxide.

[0061] Specifically, the present invention selects 100% lithium nitrate, or a mixture of lithium nitrate and lithium hydroxide as a component of the first spraying liquid. Those skilled in the art will understand that the glass ribbon needs to be at least 400°C to ensure the ion exchange efficiency. In the lithium-containing mixture, in order to produce the ion exchange effect, the sprayed lithium salt needs to be in a molten state when the melting temperature is ≤400°C. The melting point of lithium nitrate is 264°C, which can maintain a stable molten state under the required temperature conditions of the glass ribbon, thereby providing the required lithium ions for ion exchange.

[0062] Specifically, adding a small amount of lithium hydroxide to lithium nitrate can adjust the pH value of the spraying liquid. During the spraying process, the appropriate pH value can affect the rate and degree of ion exchange. By adding a small amount of lithium hydroxide, the spraying liquid can achieve the best spraying conditions. At the same time, the lithium ions in the lithium hydroxide can also participate in the ion exchange reaction. Compared with adding lithium nitrate alone, the lithium ions in lithium hydroxide are easier to exchange with sodium ions because of the higher solubility of lithium hydroxide in water. Therefore, mixing lithium nitrate and lithium hydroxide can enhance the ion exchange capacity of the spraying liquid and play a synergistic role in the spraying process. Lithium nitrate mainly provides a stable lithium ion source to promote ion exchange and form a compressive stress layer, while lithium hydroxide can adjust the pH value and enhance the ion exchange capacity. The mixed use of the two can combine their respective advantages to achieve better spraying effects.

[0063] Specifically, in step S2, the temperature range for spraying the second surface is 400°C to 600°C.

[0064] Specifically, the temperature range for spraying the second surface of the present invention is 400°C to 600°C. It can be understood by those skilled in the art that when the spraying temperature is ≥400°C, the ion exchange efficiency is relatively high. As the temperature increases, the thermal motion of ions in the glass intensifies, which accelerates the diffusion rate of lithium ions and sodium ions, thereby promoting the Li-Na ion exchange reaction. If the temperature is lower than 400°C, the ion exchange efficiency will slow down, and the Li-Na exchange amount will be less within a certain period of time. It takes a longer time to achieve the same exchange amount, which reduces the production efficiency. The decomposition temperature of lithium nitrate is 600°C. If the spraying temperature exceeds 600°C, the lithium nitrate will decompose into substances such as lithium oxide and nitrogen dioxide. These products will affect the effect of ion exchange. Therefore, in order to ensure the stability of lithium nitrate during the spraying process, it is necessary to control the temperature range for spraying the second surface to be 400°C to 600°C.

[0065] Specifically, in the step S2, the pulling speed of the glass ribbon for spraying the second surface is ≤15 m / min.

[0066] Specifically, the pulling speed of the glass ribbon for spraying the second surface of the present invention is ≤15m / min. Those skilled in the art can understand that when the glass passes through the spraying area of ​​the molten liquid containing lithium salt, there needs to be enough time for the lithium ions to exchange with the sodium ions in the glass. The faster the pulling speed, the shorter the time the glass stays in the spraying area, and the less sufficient the ion exchange. Therefore, it is necessary to control the pulling speed of the glass ribbon for spraying within 15m / min, thereby achieving sufficient exchange between ions and ensuring the ion exchange amount.

[0067] Specifically, in step S2, the sodium content of the first surface of the glass ribbon after the spraying is greater than the sodium content of the second surface of the glass ribbon. Preferably, the difference between the sodium content of the first surface and the sodium content of the second surface is greater than or equal to 0.27wt%.

[0068] Specifically, see Figure 2 The above is a step diagram of a one-step low-temperature ion exchange according to an embodiment of the present invention, wherein step S4 includes:

[0069] Step S41, preheating the lithium-containing glass ribbon to a temperature of molten salt, wherein the temperature ranges from 300° C. to 450° C.;

[0070] Step S42, at a preset ion exchange temperature, placing the lithium-containing glass ribbon into the molten salt for ion exchange for a preset exchange time, replacing sodium ions in the lithium-containing glass ribbon with potassium ions in the molten salt, wherein the ion exchange temperature ranges from 370° C. to 500° C., the exchange time ranges from 60 min to 600 min, and the composition of the molten salt is potassium nitrate or a mixture of potassium nitrate and potassium salt;

[0071] Step S43, taking the lithium-containing glass ribbon out of the molten salt, and keeping it warm at a preset salt dropping temperature for a preset time, wherein the salt dropping temperature ranges from 280° C. to 420° C., and the preset insulation time ranges from 3 min to 10 min;

[0072] Step S44, cooling the lithium-containing glass ribbon from the salt dropping temperature to room temperature within a cooling time, wherein the cooling time ranges from 1 min to 60 min.

[0073] Specifically, see Figure 3 As shown, it is a step diagram of an adjustment method for selectively spraying on the second surface according to an embodiment of the present invention. In the step S1, it also includes:

[0074] Step S11, dividing the second surface of the glass ribbon into a plurality of surface sub-regions based on the size of the glass ribbon;

[0075] Specifically, the non-tin surface can be divided into surface sub-regions according to the length of the glass ribbon. Preferably, the glass ribbon can be divided into several regions at the same interval in the length direction. The interval value range can be [10, 20], and the interval unit is m.

[0076] Step S12, determining whether a surface sub-region is a surface abnormality characterization region based on a difference between a sub-region refractive index of each surface sub-region and a first refractive index of the first surface of the glass ribbon;

[0077] Specifically, in step S12, the process of determining whether the surface sub-region is a surface abnormality characterization region includes:

[0078] Step S121, obtaining a difference between a sub-region refractive index of each surface sub-region and a first refractive index of a first surface of the glass ribbon;

[0079] Step S122, comparing the difference with the refractive index difference reference range, wherein:

[0080] If the difference falls within the refractive index difference reference range, the surface sub-region corresponding to the difference is determined to be a surface abnormality characterization region;

[0081] If the difference does not fall within the refractive index difference reference range, it is determined that the surface sub-region corresponding to the difference is not a surface abnormality characterization region.

[0082] Specifically, the reference range of the refractive index difference may be within the refractive index extreme values ​​of various regions of several glass surfaces that have passed the warpage detection. Preferably, the reference range of the refractive index difference may be [0.05, 0.1].

[0083] It is understandable that the sub-region refractive index of each surface sub-region and the first refractive index of the first surface can be determined by measuring the propagation angle and speed change of light in the glass through an optical sensor.

[0084] Specifically, in step S13, the number of surface abnormality characterization areas is obtained to determine the degree of surface difference of the second surface;

[0085] If the surface difference degree of the second surface is a weak representation degree of the surface difference, adjusting the spraying amount of each surface abnormality representation area;

[0086] If the surface difference degree of the second surface is a strong characterization degree of the surface difference, the position distribution of the surface abnormality characterization area is obtained to select an adjustment method for the spraying, and the adjustment method includes:

[0087] A first adjustment method: adjusting the overall spraying temperature of the glass ribbon based on the variance between the sub-region refractive index of each surface sub-region and the first refractive index;

[0088] The second adjustment method: adjusting the pulling speed of each surface abnormality characterization area based on the average value of the refractive index of the sub-area corresponding to each surface abnormality characterization area.

[0089] Specifically, the pulling speed of each surface anomaly characterization area is negatively correlated with the average refractive index of the sub-area corresponding to each surface anomaly characterization area. The larger the average refractive index of the sub-area corresponding to each surface anomaly characterization area, the smaller the pulling speed of the surface anomaly characterization area, so that the surface anomaly characterization area can fully carry out Li-Na ion exchange.

[0090] In a specific embodiment, the adjustment amount of the pulling speed of each surface anomaly characterization area can be determined by the difference between the reference pulling speed and the current pulling speed. The reference pulling speed is calculated based on the average value of the refractive index of the sub-region corresponding to each surface anomaly characterization area and the pulling coefficient, wherein the pulling coefficient can be calculated by substituting the pulling speed of the glass ribbon that has passed the spraying test in several historical tests and the refractive index of the corresponding sub-region into a polynomial. Preferably, the pulling coefficient can be determined using the least squares method.

[0091] Specifically, a specific method for calculating the pulling speed is given, where the pulling speed is the ratio of the length of the surface sub-region to the moving time, wherein the moving time is the time required for the surface sub-region to move the length of the surface sub-region.

[0092] Those skilled in the art will appreciate that a logic component may be used to obtain the number and location distribution of surface anomaly characterization areas. The logic component may be a field programmable logic component, a microprocessor, a processor used in a computer, and the like.

[0093] Specifically, see Figure 4 As shown, it is a logic flow chart of determining the surface difference degree of the second surface according to an embodiment of the present invention. In the step S13, determining the surface difference degree of the second surface includes:

[0094] Step S1311, comparing the number of surface abnormality characterization areas with a preset number threshold;

[0095] Step S1312, determining the surface difference degree of the second surface according to the comparison result, wherein:

[0096] If the number is less than or equal to the number threshold, determining that the surface difference degree of the second surface is a surface difference weak representation degree;

[0097] If the number is greater than the number threshold, it is determined that the surface difference degree of the second surface is a surface difference strong representation degree.

[0098] Specifically, the reference range of the quantity threshold can be set by technicians in this field based on historical data of several glass surfaces that have passed several tests on the degree of warping. Preferably, the value range of the preset quantity threshold can be [20, 35].

[0099] Specifically, in step S13, the adjustment method of the spraying is selected, including:

[0100] Step S1321, obtaining the position distribution of the surface anomaly characterization area to determine the aggregation category of the surface anomaly characterization area, including the surface difference dispersion category and the surface difference concentration category;

[0101] Step S1322, selecting a corresponding spraying adjustment method based on the clustering category of the surface abnormality characterization area, wherein:

[0102] If the aggregation category of the surface anomaly characterization area is the surface difference dispersion category, adjusting the overall spraying temperature of the glass ribbon based on the variance of the sub-region refractive index of each surface sub-region and the first refractive index;

[0103] Specifically, the overall spraying temperature of the glass ribbon is positively correlated with the variance of the sub-region refractive index of each surface sub-region and the first refractive index. The larger the variance is, the greater the density difference between the second surface and the first surface is, and the second surface requires a higher spraying temperature to increase the exchange amount of Li-Na ions on the second surface, so that the K-Na ion exchange capacity of the first surface and the second surface tend to be consistent.

[0104] In a specific embodiment, the adjustment amount of the spraying temperature can be determined by the difference between the reference spraying temperature and the current spraying temperature, and the reference spraying temperature is calculated according to the variance of the sub-region refractive index and the first refractive index and the temperature coefficient, wherein the spraying temperature coefficient can be calculated by substituting the temperature values ​​of glass ribbons that have passed spraying in several historical tests and the corresponding sub-region refractive index and the first refractive index into a polynomial. Preferably, the spraying temperature coefficient can be determined using the least squares method.

[0105] Specifically, a specific method for calculating the variance of the sub-region refractive index of each surface sub-region and the first refractive index is given, the refractive index of each sub-region is obtained, the difference between the refractive index of each sub-region and the first refractive index is calculated, each difference is squared, and the average of the squares of all sub-region differences is calculated, which is the variance of the sub-region refractive index of each surface sub-region and the first refractive index.

[0106] If the aggregation category of the surface anomaly characterization regions is the surface difference concentration category, the pulling speed of each surface anomaly characterization region is adjusted based on the average value of the refractive index of the sub-region corresponding to each surface anomaly characterization region.

[0107] Specifically, the pulling speed of each surface anomaly characterization area is negatively correlated with the average refractive index of the sub-area corresponding to each surface anomaly characterization area. The larger the average refractive index of the sub-area, the slower the pulling speed of each surface anomaly characterization area, so that the surface anomaly characterization area can fully carry out Li-Na ion exchange.

[0108] Example 1: As shown in Table 1, the glass ribbon formed by float forming is not sprayed, but directly annealed. At this time, the pulling speed of the glass ribbon is 8.6 m / min, the sodium difference is 0.21 wt%, the Li content in the glass ribbon is 3 ppm, and the glass information is thickness: 0.6 mm, 150.9 mm*75.7 mm. The chemical strengthening process is preheating for 40 min to 60 min, heating from room temperature to 380°C, and taking a salt bath for 5 hours in a molten salt composition of pure potassium nitrate. The temperature of the salt bath is 420°C, and salt is dripped for 5 min at 380°C, and cooled to room temperature for 40 min.

[0109] Example 2: As described in Table 2, the difference from Example 1 is that 100% lithium nitrate is used to spray the glass ribbon formed by float forming, the spraying area temperature is 400°C, the spraying amount is 8L / min, the sodium difference is 0.28wt%, and the Li content in the glass ribbon is 21ppm.

[0110] Example 3: As described in Table 3, the difference between Example 3 and Example 2 is that a mixed liquid of 99% lithium nitrate and 1% lithium hydroxide is used to spray the glass ribbon formed by float forming.

[0111] Example 4: As shown in Table 4, the difference between Example 4 and Example 3 is that the temperature for spraying the glass ribbon formed by the float process is 600°C.

[0112] Example 5: As shown in Table 5, the difference between Example 5 and Example 4 is that the pulling speed for spraying the glass ribbon formed by float forming is 15 m / min.

[0113] Example 6: As shown in Table 6, the difference between Example 6 and Example 4 is that the temperature for spraying the glass ribbon formed by the float process is 500°C.

[0114] Example 7: As shown in Table 7, the difference between Example 7 and Example 4 is that the spraying amount of the glass ribbon formed by float molding is 16 L / min.

[0115] Example 8: As shown in Table 8, the difference between Example 8 and Example 5 is that the spraying amount of the glass ribbon formed by float molding is 4 L / min.

[0116] Table 1

[0117]

[0118]

[0119] Table 2

[0120]

[0121] Table 3

[0122]

[0123]

[0124] Table 4

[0125]

[0126]

[0127] Table 5

[0128]

[0129]

[0130] Table 6

[0131]

[0132]

[0133] Table 7

[0134]

[0135] Table 8

[0136]

[0137]

[0138] It can be seen from the data in the above table that according to the experimental results of Example 1 and Example 2 of the present invention, when the glass ribbon formed by float forming is sprayed at a spraying temperature of 400° C., the average value of the strengthening warpage is reduced from 0.26 to 0.21;

[0139] According to the experimental results of Examples 2 and 3 of the present invention, it can be obtained that the composition of the sprayed molten salt is changed from 100% lithium nitrate to 99% lithium nitrate and 1% lithium hydroxide, and the average value of the strengthening warpage is reduced from 0.21 to 0.20;

[0140] According to the experimental results of Examples 3 and 4 of the present invention, it can be obtained that the temperature for spraying the glass ribbon formed by float forming is adjusted to 600°C, the pulling speed is 8.6m / min, the spraying amount is 8L / min, and the average value of strengthening warpage is reduced from 0.20 to 0.09;

[0141] According to the experimental results of Examples 4 and 5 of the present invention, it can be obtained that the pulling speed of the glass ribbon formed by float forming is adjusted to 15m / min, and the pulling speed is increased, and the average value of the strengthening warpage is increased from 0.09 to 0.20;

[0142] According to the experimental results of Examples 4 and 6 of the present invention, it can be obtained that when the temperature for spraying the glass ribbon formed by float forming is adjusted to 500° C., the average value of strengthening warpage increases from 0.09 to 0.15;

[0143] According to the experimental results of Examples 4 and 7 of the present invention, it can be obtained that when the spraying amount of the glass ribbon formed by float forming is adjusted to 16 L / min, the average value of the strengthening warpage is reduced from 0.09 to 0.07;

[0144] According to the experimental results of Examples 5 and 8 of the present invention, it can be obtained that when the spraying amount of the glass ribbon formed by float forming is adjusted to 4 L / min, the average value of the strengthening warpage increases from 0.20 to 0.21;

[0145] It is obvious that spraying the glass ribbon formed by float molding can effectively reduce the glass warping value, improve the glass warping phenomenon caused by the difference in ion exchange capacity between the tin-containing surface and the non-tin surface, and improve the flatness of the high-aluminosilicate electronic glass. Adding a small amount of lithium hydroxide to the sprayed lithium nitrate can reduce the glass warping value and improve the flatness of the high-aluminosilicate electronic glass. Properly increasing the spraying temperature can reduce the glass warping value and improve the flatness of the high-aluminosilicate electronic glass. Properly reducing the pulling speed can reduce the glass warping value and improve the flatness of the high-aluminosilicate electronic glass. Properly increasing the spraying amount can reduce the glass warping value and improve the flatness of the high-aluminosilicate electronic glass.

[0146] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0147] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing high aluminosilicate electronic glass, characterized in that: include: Step S1, obtaining a glass ribbon formed by a float process, and detecting the refractive index of a first surface having a tin surface and a second surface having a non-tin surface of the glass ribbon, respectively, wherein the raw material of the glass ribbon does not contain lithium element, Wherein, in step S11, the second surface of the glass ribbon is divided into a plurality of surface sub-regions based on the size of the glass ribbon; Step S12, determining whether a surface sub-region is a surface abnormality characterization region based on a difference between a sub-region refractive index of each surface sub-region and a first refractive index of the first surface of the glass ribbon; Step S13, obtaining the number of surface abnormality characterization areas to determine the degree of surface difference of the second surface; If the surface difference degree of the second surface is a weak representation degree of the surface difference, adjusting the spraying amount of each surface abnormality representation area; If the surface difference degree of the second surface is a strong characterization degree of the surface difference, the position distribution of the surface abnormality characterization area is obtained to select an adjustment method for the spraying, including: Adjusting the overall spraying temperature of the glass ribbon based on the variance of the sub-region refractive index of each surface sub-region and the first refractive index, or adjusting the pulling speed of each surface abnormality characterization region based on the average value of the sub-region refractive index corresponding to each surface abnormality characterization region; Step S2, introducing the glass ribbon formed by float forming into an annealing furnace, and spraying the second surface of the glass ribbon with a first spraying liquid in the annealing furnace; Step S3, annealing the sprayed glass ribbon to obtain a lithium-containing glass ribbon after ion exchange between the first sprayed liquid and the second surface; Step S4, strengthening the lithium-containing glass ribbon by one-step low-temperature ion exchange to obtain high-alumina silicate electronic glass.

2. The method for preparing high aluminosilicate electronic glass according to claim 1, characterized in that: In the step S2, the first spraying liquid includes a molten liquid containing a lithium salt.

3. The method for preparing high aluminosilicate electronic glass according to claim 1 or 2, characterized in that: The first spraying liquid is composed of 100% lithium nitrate or a mixture of lithium nitrate and lithium hydroxide.

4. The method for preparing high aluminosilicate electronic glass according to claim 1 or 2, characterized in that: In the step S2, the temperature range for spraying the second surface is 400°C to 600°C.

5. The method for preparing high aluminosilicate electronic glass according to claim 1 or 2, characterized in that: In the step S2, the drawing speed of the glass ribbon for spraying the second surface is ≤15 m / min.

6. The method for preparing high aluminosilicate electronic glass according to claim 5, characterized in that: In the step S2, the sodium content of the first surface of the glass ribbon after the spraying is greater than the sodium content of the second surface of the glass ribbon, and the difference between the sodium content of the first surface and the sodium content of the second surface is greater than or equal to 0.27wt%.

7. The method for preparing high aluminosilicate electronic glass according to claim 1, characterized in that: The step S4 includes: Step S41, preheating the lithium-containing glass ribbon to a temperature of molten salt, wherein the temperature ranges from 300° C. to 450° C.; Step S42, at a preset ion exchange temperature, placing the lithium-containing glass ribbon into the molten salt for ion exchange for a preset exchange time, replacing sodium ions in the lithium-containing glass ribbon with potassium ions in the molten salt, wherein the ion exchange temperature ranges from 370° C. to 500° C., the exchange time ranges from 60 min to 600 min, and the composition of the molten salt is potassium nitrate or a mixture of potassium nitrate and potassium salt; Step S43, taking the lithium-containing glass ribbon out of the molten salt, and keeping it warm at a preset salt dropping temperature for a preset time, wherein the salt dropping temperature ranges from 280° C. to 420° C., and the preset insulation time ranges from 3 min to 10 min; Step S44, cooling the lithium-containing glass ribbon from the salt dropping temperature to room temperature within a cooling time, wherein the cooling time ranges from 1 min to 60 min.

8. The method for preparing high aluminosilicate electronic glass according to claim 1, characterized in that: In the step S13, determining the surface difference degree of the second surface includes: Comparing the number of surface anomaly characterization areas with a preset number threshold; If the number is less than or equal to the number threshold, determining that the surface difference degree of the second surface is a surface difference weak representation degree; If the number is greater than the number threshold, it is determined that the surface difference degree of the second surface is a surface difference strong representation degree.

9. The method for preparing high aluminosilicate electronic glass according to claim 8, characterized in that: In step S13, a method for adjusting the spraying is selected, including: Obtaining the position distribution of the surface anomaly characterization area to determine the aggregation category of the surface anomaly characterization area, including a surface difference dispersion category and a surface difference concentration category; The corresponding spraying adjustment method is selected based on the clustering category of the surface abnormality characterization area, wherein: If the aggregation category of the surface anomaly characterization area is the surface difference dispersion category, adjusting the overall spraying temperature of the glass ribbon based on the variance of the sub-region refractive index of each surface sub-region and the first refractive index; If the aggregation category of the surface anomaly characterization regions is the surface difference concentration category, the pulling speed of each surface anomaly characterization region is adjusted based on the average value of the refractive index of the sub-region corresponding to each surface anomaly characterization region.

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