Chemically strengthened glass, float glass raw sheet, preparation method and production line thereofTechnical Field
The invention relates to the field of glass, in particular to chemically strengthened glass, a float glass raw sheet, a preparation method and a production line thereof.
Background
In recent years, the technology of the present invention has been developedElectronic information products such as tablet computers, smart phones, vehicle-mounted screens and the like are basically displays with touch panels, and a layer of protective glass, also called cover glass, is arranged on the outermost layer of the display. At present, the method for improving the mechanical property of cover glass mainly adopts a low-temperature ion exchange chemical strengthening method, and the principle is as follows: alkali ions (such as Na) having an ionic radius ratio to the surface layer of the glass in a temperature region lower than the strain point of the glass+) Also large monovalent cations (e.g. K)+) With alkali ions (e.g. Na) on the surface of the glass+) Exchanging cations having large ionic radii (e.g. K)+) Entering the glass surface layer to form certain stress strength and stress depth on the glass surface layer.
In the float glass, one surface of the glass is in contact with air, namely an air surface, and the other surface of the glass is in contact with molten tin, namely a molten tin surface, and the air surface and the molten tin surface have certain differences in chemical components and structures, so that the ion exchange is asymmetric in the chemical strengthening process, and large warping is generated. Since tin atoms permeate into the tin surface during molding and ion exchange is difficult to perform compared with the air surface, the air surface is more likely to be ion exchanged and the tin surface is less likely to be ion exchanged under the same conditions. After chemical strengthening, the stress intensity of the air surface is large, and the stress intensity of the tin liquid surface is small, so that the glass is warped.
At present, there are many methods for adjusting the chemically strengthened warpage, and there are mainly added processes, such as: carrying out flat grinding after glass strengthening; or optimizing the strengthening process, mainly by adjusting the cooling rate of the air level and the tin level in the glass annealing process. The glass is subjected to flat grinding after being strengthened, so that the production cost is increased, more polishing waste liquid is generated, and the environment is not protected; the cooling rate of the air level and tin level of the glass during annealing is adjusted by air blast, and the adjustment capability is limited due to insufficient precision.
Disclosure of Invention
The invention mainly aims to provide a method for preparing a float glass sheet, and the float glass sheet prepared by the method can not warp or has small warping degree after being chemically strengthened.
In order to achieve the above object, the present invention provides a method for manufacturing a float glass raw sheet, comprising:
(1) preparing sol for coating;
(2) atomizing the coating sol into aerosol by an atomizing device;
(3) mixing the aerosol with clean compressed air in a mixer to obtain mixed gas;
(4) introducing the mixed gas into a coating device, wherein the coating device sprays the mixed gas on the air surface of float glass; the coating device is positioned on an annealing kiln of a float glass production line;
(5) and annealing, cooling, cutting and the like to obtain the coated float glass sheet.
Optionally, the sol for coating includes one or more of aluminum hydroxide sol, silica sol and the like.
Optionally, the solid content of the sol for coating is less than 15 wt%, and the particle size of the particles is below 0.1 μm.
Optionally, the gas molar ratio of compressed air to aerosol in the mixed gas is greater than 5: 1.
optionally, the temperature of the area where the coating device is located is 500-1000 ℃.
Optionally, the aerosol and the clean compressed air are mixed in the mixer for more than 1 hour, and the mixing temperature is 180-220 ℃.
The invention also provides a float glass raw sheet prepared by the preparation method of the float glass raw sheet.
The invention also provides chemically strengthened glass, which is obtained by chemically strengthening the float glass raw sheet.
The invention also provides a float glass sheet production line which comprises a production line main body, an atomization device, a mixer and a coating device, wherein the coating device is positioned on the annealing kiln of the production line main body.
The float glass raw sheet prepared by the preparation method of the invention increases the difficulty of ion exchange of the air surface and reduces the ion exchange capacity of the air surface because the air surface is plated with the inorganic oxide film, so that the ion exchange capacity of the air surface is consistent with that of the tin liquid surface.
Detailed Description
The technical solution and the technical effect achieved by the present invention will be described below with reference to the embodiments of the present invention. In the following examples and comparative examples, each material used was commercially available unless otherwise specified, and the method used was a conventional method in the art unless otherwise specified.
In one aspect of the invention, a method of making a float glass sheet is provided.
The preparation method of the float glass sheet comprises the following steps:
(1) preparing sol for coating;
(2) atomizing the coating sol into aerosol by an atomizing device;
(3) mixing the aerosol with clean compressed air in a mixer to obtain mixed gas;
(4) introducing the mixed gas into a coating device, wherein the coating device sprays the mixed gas on the air surface of float glass; the coating device is positioned on an annealing kiln of a float glass production line;
(5) and annealing, cooling, cutting and the like to obtain the coated float glass sheet.
Collosol for coating is prepared according to the actual production requirement. The sol for coating comprises one or more of aluminum hydroxide sol, silica sol and the like. The solid content of the sol for coating is less than 15 wt%, and the particle size of the particles is less than 0.1 mu m, so that the atomizing device can conveniently atomize the sol for coating into aerosol.
After the sol for coating is prepared, atomizing the sol for coating into aerosol through an atomizing device, wherein the atomizing device is common equipment in the field, and the specific structure of the atomizing device is not described herein again.
After the sol for coating is atomized into aerosol by an atomizing device, the aerosol is mixed with clean compressed air in a mixer to obtain mixed gas, the mixing time in the mixing process is more than 1h, the mixing temperature is 180-220 ℃, the mixing time is too short, and the mixing temperature is too low, so that the uniform mixing of the aerosol and the compressed air is not facilitated. The mixer is also a common device in the art, and the specific structure thereof is not described herein. After being mixed by the mixer, the gas molar ratio of the compressed air to the aerosol in the obtained mixed gas is more than 5: 1, so as to reduce the agglomeration and coagulation of aerosol in the mixed gas and avoid blocking a pipeline and a spray head of a coating device.
Introducing the obtained mixed gas into a coating device, wherein the coating device sprays the mixed gas on the air surface of float glass; the coating device is positioned on an annealing kiln of a float glass production line, the temperature of the area where the coating device is positioned is 500-1000 ℃, and the decomposition of aerosol and the deposition on the surface of glass are facilitated.
The front-end production steps of float glass, such as mixing, melting, forming, etc., are common float glass production processes and are not described herein again. After the front-end production step, the float glass enters an annealing kiln, a coating device on the annealing kiln sprays the mixed gas on the air surface of the float glass, and a layer of inorganic oxide film is coated on the air surface of the float glass. Finally, annealing, cooling, cutting and the like are carried out to obtain the coated float glass sheet.
The float glass raw sheet prepared by the preparation method of the invention increases the difficulty of ion exchange of the air surface and reduces the ion exchange capacity of the air surface because the air surface is plated with the inorganic oxide film, so that the ion exchange capacity of the air surface is consistent with that of the tin liquid surface.
In another aspect of the present invention, a float glass raw sheet is provided, and the process for manufacturing the float glass raw sheet is described in reference to the method for manufacturing the float glass raw sheet, and thus, the detailed description is omitted.
In still another aspect of the present invention, a chemically strengthened glass is provided, wherein the float glass raw sheet prepared by the above-described preparation method is chemically strengthened to obtain the chemically strengthened glass.
In another aspect of the present invention, a float glass sheet production line is provided, which includes a production line main body, an atomization device, a mixer, and a coating device, where the production line main body is a float glass production apparatus well known in the art, and includes a material distributor, a material feeder, a melting furnace, a tin bath, a transition roller, an annealing furnace, a cutting machine, and details thereof are not repeated. The coating device is positioned on the annealing kiln of the production line main body.
The present invention will be described in further detail with reference to specific examples.
Example 1:
atomizing the aluminum hydroxide sol with the solid content of 13 wt% by an atomizing device to obtain aerosol. Pressing and air compressing: mixing the aerosol in a mixer at a gas molar ratio of 6:1 for more than 1h at 200 ℃, introducing the mixed gas into a coating device in an annealing kiln at a certain flow rate, spraying the mixed gas onto the air surface of the float glass by the coating device, staying the float glass at the coating device for 5s at a temperature of 600 ℃, and annealing, cooling, cutting and the like to obtain a coated float glass raw sheet.
Processing a float glass raw sheet into 5.5-inch 2D cover glass, cleaning, and then carrying out chemical strengthening, wherein the chemical strengthening process comprises the following steps: raising the temperature from room temperature to 380 ℃ within 1h, keeping the temperature for 15min, keeping the ion exchange temperature at 420 ℃, keeping the ion exchange time at 5h, keeping the annealing initial temperature at 380 ℃, and cooling and annealing along with the furnace. After chemical strengthening, the product has the air surface CS of 824MPa, the DoL of 42.3 μm, the tin liquid surface CS: 851MPa, DOL 41.8 μm, and warping degree 0.08 mm.
Example 2:
atomizing the aluminum hydroxide sol with the solid content of 14 wt% by an atomizing device to obtain aerosol. Pressing and air compressing: mixing the aerosol in a mixer at a ratio of 8:1 (gas molar ratio) for more than 1h at a mixing temperature of 200 ℃, introducing the mixed gas into a coating device in an annealing kiln at a certain flow rate, spraying the mixed gas onto the air surface of the float glass by the coating device, staying the float glass at the coating device for 5s at a temperature of 600 ℃, and annealing, cooling, cutting and the like to obtain a coated float glass raw sheet.
Processing a float glass raw sheet into 5.5-inch 2D cover glass, cleaning, and then carrying out chemical strengthening, wherein the chemical strengthening process comprises the following steps: raising the temperature from room temperature to 380 ℃ within 1h, keeping the temperature for 15min, keeping the ion exchange temperature at 420 ℃, keeping the ion exchange time at 5h, keeping the annealing initial temperature at 380 ℃, and cooling and annealing along with the furnace. After chemical strengthening, the product has CS of the air surface of 828MPa, DoL of 42.3 μm, CS of the tin liquid surface: 851MPa, DOL 41.7 μm, and warping degree 0.09 mm.
Example 3:
atomizing the aluminum hydroxide sol with the solid content of 14.5 wt% by an atomizing device to obtain aerosol. Pressing and air compressing: mixing the aerosol in a mixer at a gas molar ratio of 10:1 for more than 1h at 200 ℃, introducing the mixed gas into a coating device in an annealing kiln at a certain flow rate, spraying the mixed gas onto the air surface of the float glass by the coating device, staying the float glass at the coating device for 5s at a temperature of 600 ℃, and annealing, cooling, cutting and the like to obtain a coated float glass raw sheet.
Processing a float glass raw sheet into 5.5-inch 2D cover glass, cleaning, and then carrying out chemical strengthening, wherein the chemical strengthening process comprises the following steps: raising the temperature from room temperature to 380 ℃ within 1h, keeping the temperature for 15min, keeping the ion exchange temperature at 420 ℃, keeping the ion exchange time at 5h, keeping the annealing initial temperature at 380 ℃, and cooling and annealing along with the furnace. After chemical strengthening, the product has CS of the air surface of 825MPa, DoL of 42.4 μm, CS of the tin liquid surface: 852MPa, DOL 42.0 μm, and warping degree 0.10 mm.
Example 4:
atomizing the aluminum hydroxide sol with the solid content of 13 wt% by an atomizing device to obtain aerosol. Pressing and air compressing: mixing the aerosol in a mixer at a gas molar ratio of 6:1 for more than 1h at 200 ℃, introducing the mixed gas into a coating device in an annealing kiln at a certain flow rate, spraying the mixed gas onto the air surface of the float glass by the coating device, staying the float glass at the coating device for 5s at a temperature of 650 ℃, and annealing, cooling, cutting and the like to obtain a coated float glass raw sheet.
Processing a float glass raw sheet into 5.5-inch 2D cover glass, cleaning, and then carrying out chemical strengthening, wherein the chemical strengthening process comprises the following steps: raising the temperature from room temperature to 380 ℃ within 1h, keeping the temperature for 15min, keeping the ion exchange temperature at 420 ℃, keeping the ion exchange time at 5h, keeping the annealing initial temperature at 380 ℃, and cooling and annealing along with the furnace. After chemical strengthening, the air surface CS of the product is 823MPa, the DoL is 42.6 μm, the tin liquid surface CS is: 852MPa, DOL 41.9 μm, and warping degree 0.09 mm.
Example 5:
atomizing the aluminum hydroxide sol with the solid content of 13 wt% by an atomizing device to obtain aerosol. Pressing and air compressing: mixing the aerosol in a mixer at a gas molar ratio of 6:1 for more than 1h at 200 ℃, introducing the mixed gas into a coating device in an annealing kiln at a certain flow rate, spraying the mixed gas onto the air surface of the float glass by the coating device, staying the float glass at the coating device for 5s at a temperature of 700 ℃, and annealing, cooling, cutting and the like to obtain a coated float glass raw sheet.
Processing a float glass raw sheet into 5.5-inch 2D cover glass, cleaning, and then carrying out chemical strengthening, wherein the chemical strengthening process comprises the following steps: raising the temperature from room temperature to 380 ℃ within 1h, keeping the temperature for 15min, keeping the ion exchange temperature at 420 ℃, keeping the ion exchange time at 5h, keeping the annealing initial temperature at 380 ℃, and cooling and annealing along with the furnace. After chemical strengthening, the ratio of CS to 826MPa of the air surface of the product, 42.5 μm of DoL, CS to the tin liquid surface: 850MPa, DOL 41.7 μm, and warping degree 0.09 mm.
Example 6:
atomizing the aluminum hydroxide sol with the solid content of 13 wt% by an atomizing device to obtain aerosol. Pressing and air compressing: mixing the aerosol in a mixer at a gas molar ratio of 6:1 for more than 1h at 200 ℃, introducing the mixed gas into a coating device in an annealing kiln at a certain flow rate, spraying the mixed gas onto the air surface of the float glass by the coating device, staying the float glass at the coating device for 5s at a temperature of 750 ℃, and annealing, cooling, cutting and the like to obtain a coated float glass raw sheet.
Processing a float glass raw sheet into 5.5-inch 2D cover glass, cleaning, and then carrying out chemical strengthening, wherein the chemical strengthening process comprises the following steps: raising the temperature from room temperature to 380 ℃ within 1h, keeping the temperature for 15min, keeping the ion exchange temperature at 420 ℃, keeping the ion exchange time at 5h, keeping the annealing initial temperature at 380 ℃, and cooling and annealing along with the furnace. After chemical strengthening, the product has CS of the air surface of 825MPa, DoL of 42.0 μm, CS of the tin liquid surface: 853MPa, DOL 41.7 μm, and warping degree 0.10 mm.
In the above examples, CS represents the compressive stress intensity of the glass surface, and DoL represents the ion exchange depth of the glass surface.
It can be known from the above embodiments that the float glass raw sheet prepared by the preparation method of the present invention increases the difficulty of ion exchange of the air surface due to the fact that the air surface is plated with the inorganic oxide film, reduces the ion exchange capacity of the air surface, and enables the ion exchange capacity of the air surface to be consistent with that of the tin liquid surface.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.