A method for local coloring of a glass cover plate

Abstract

The application discloses a local coloring method of a glass cover plate, comprising the following steps: providing a glass cover plate containing alkali metal ions; according to a required identification pattern, performing a damage treatment on a lattice network in a local surface layer of the glass cover plate, so that the local surface layer of the glass cover plate forms a lattice defect area corresponding to the identification pattern, and other surface layers whose lattice network is not damaged form lattice complete areas; and immersing the glass cover plate in a molten bath salt containing coloring ions, so that the coloring ions in the molten bath salt are exchanged with the alkali metal ions in the glass cover plate, and the concentration of the coloring ions in the lattice defect area is greater than that in the lattice complete areas. The local coloring method can make the molten bath salt produce different color depths on different areas of the glass cover plate, so as to form the required identification pattern on the glass cover plate.

Description

Technical Field

[0001] This invention relates to the field of glass coloring, and more particularly to a method for partial coloring of a glass cover plate. Background Technology

[0002] Glass covers are common components used to protect the surface of electronic devices. Due to functional and personalized requirements, the surface of glass covers sometimes needs to be decorated with colored markings or patterns. Currently, the most common coloring processes are screen printing, vapor deposition, or roll coating / spraying.

[0003] Ion exchange is a glass coloring technique that involves exchanging alkali metal ions (mainly Na+) in the surface layer of a glass cover at a certain temperature. + K + ) and externally introduced coloring ions (such as Ag) + Cu + / Cu 2+ Au + The coloring ions (such as ions, etc.) exchange and diffuse into the glass structure, thus giving the glass surface a specific color. Because the coloring ions are inside the glass, the coloring layer has advantages such as being less prone to wear and peeling.

[0004] Salt fusion impregnation is a type of ion exchange method. It is suitable for large-scale production due to its advantages such as uniform coloring and easy control of color depth. However, during coloring, the glass cover plate needs to be completely immersed in molten salt bath. Since the molten salt bath cannot locally color the glass cover plate, the desired marking pattern cannot be formed on it. Summary of the Invention

[0005] To address the shortcomings of the prior art, the present invention provides a method for local coloring a glass cover plate, which allows molten bath salts to produce different color depths in different areas of the glass cover plate, thereby forming the desired marking pattern on the glass cover plate.

[0006] The technical problem to be solved by the present invention is achieved through the following technical solution: A method for local coloring a glass cover plate includes the following steps: Step S1: Provide a glass cover containing alkali metal ions; Step S2: According to the desired marking pattern, the lattice network in a local surface layer of the glass cover is disrupted so that a lattice defect region corresponding to the marking pattern is formed in the local surface layer of the glass cover, while other surface layers where the lattice network is not disrupted form a lattice complete region. Step S3: Immerse the glass cover plate in a molten bath salt containing coloring ions, so that the coloring ions in the molten bath salt exchange with the alkali metal ions in the glass cover plate, and the concentration of coloring ions in the lattice defect region is greater than that in the lattice intact region.

[0007] Furthermore, the coloring depth of the lattice defect region is greater than that of the lattice intact region.

[0008] Furthermore, the coloring depth of the lattice defect region is 5~30μm, and the coloring depth of the lattice intact region is less than 5μm.

[0009] Furthermore, in step S2, high-energy H+ is implanted using an ion implanter at a low temperature of 100~200℃. + He + Injected into a localized area of ​​the cover plate surface to bombard the O-type silicon-oxygen tetrahedra. 2- This causes the oxygen vacancy to detach from the lattice site and form an oxygen vacancy. The ion energy is 50~200keV, and the ion implantation dose is 10. 14 ~10 16 ions / cm2.

[0010] Furthermore, in step S2, the glass cover plate is heated to 50~100°C below its glass transition temperature and held at that temperature for 30~60 minutes. Then, a local area of ​​the surface layer of the cover plate is rapidly cooled by a high-speed airflow or liquid nitrogen to form a temperature gradient stress, which forces the lattice network to undergo shear deformation and generate linear dislocation defects.

[0011] Furthermore, in step S2, a mask is first used to partially cover the surface of the cover plate, exposing the local area to be processed. Then, a low-concentration hydrofluoric acid solution is used to etch the local area of ​​the cover plate surface for 10 to 30 minutes, so that the silicon-oxygen tetrahedra in the local area are preferentially dissolved and a layered etched surface is formed. Finally, the mask is removed.

[0012] Furthermore, in step S2, a nanosecond laser is used, and the laser beam is split into multiple parallel beams by a beam splitter to irradiate and scan a local area of ​​the cover plate surface. The power is 50~150W, the scanning speed is 50~300mm / s, and the repetition frequency is 50~200kHz, so as to utilize the thermal effect and optical breakdown effect of the laser to form parallel microcrack surfaces.

[0013] Furthermore, in step S2, a high-pressure airflow is used to drive alumina or silicon carbide abrasive with a particle size of 50~200μm to impact a local area of ​​the cover plate surface, so as to tear the lattice network through mechanical impact force and form a porous three-dimensional defect area.

[0014] Furthermore, the lattice defect region has a rough surface with an uneven microstructure, while the corresponding lattice intact region has a smooth surface.

[0015] Furthermore, the depth of the uneven microstructure is 10~100μm, the width is 50~200μm, and the width-to-depth ratio is 3:1~5:1.

[0016] The present invention has the following beneficial effects: The local coloring method of the present invention first destroys the lattice network in a local surface layer of the glass cover plate to form lattice defect regions and lattice intact regions on the surface layer of the cover plate, and then uses the different diffusion rates of the lattice defect regions and lattice intact regions to form different color depths in the molten bath salts in the lattice defect regions and lattice intact regions, and then uses the color difference between the lattice defect regions and lattice intact regions to form the desired marking pattern; The local coloring method of the present invention increases the effective specific surface area of ​​the lattice defect region by forming a rough surface with an uneven microstructure on the lattice defect region of the glass cover plate. During ion exchange, the different contact areas between the lattice defect region and the lattice intact region and the molten bath salt further increase the color difference between the lattice defect region and the lattice intact region. In addition to increasing the color difference, the rough surface of the lattice defect region can also produce diffuse reflection of incident external light, which has a completely different visual effect from the parallel reflection formed by the smooth surface of the lattice intact region, and can further improve the recognizability of the marking pattern. Attached Figure Description

[0017] Figure 1 A flowchart illustrating the steps of the local coloring method provided by the present invention. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and embodiments, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0019] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this invention, "multiple" means two or more, unless otherwise explicitly specified.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," and "setting," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the connection within two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] Example 1 like Figure 1 As shown, a method for local coloring a glass cover plate includes the following steps: Step S1: Provide a glass cover containing alkali metal ions.

[0023] Specifically, the alkali metal ions contained in the glass cover are mainly Na. + K + Li + 、Rb + and Cs + One or more of the following; the glass cover plate may be, but is not limited to, sodium-calcium silicate glass, potassium silicate glass, lithium aluminum silicate glass, sodium borosilicate glass, sodium aluminum silicate glass, lithium borosilicate glass or rubidium / cesium silicate glass, etc., with a thickness of 0.4~1.2mm and a surface roughness Ra≤0.5μm.

[0024] The main component of the glass cover is SiO2, and the Si within it... 4+ and O 2-The silicon-oxygen tetrahedra are connected by covalent bonds to form a regular tetrahedral configuration. Unlike the long-range ordered lattice structure in crystalline materials, the silicon-oxygen tetrahedra of the glass cover plate form an amorphous lattice network with short-range order and long-range disorder, containing a large number of interstitial channels of uneven size. The alkali metal ions are dispersed in the interstitial channels of the lattice network composed of silicon-oxygen tetrahedra in an interstitial form.

[0025] Step S2: According to the desired marking pattern, the lattice network in a local surface layer of the glass cover is disrupted so that a lattice defect region corresponding to the marking pattern is formed in the local surface layer of the glass cover, while other surface layers where the lattice network is not disrupted form a lattice complete region.

[0026] Specifically, one side of the glass cover along the thickness direction is the surface, which is the side that allows external light to enter during use, and the other side opposite the surface is the bottom surface. The part of the glass cover inside that is close to the surface is the top layer, and the part that is close to the bottom surface is the bottom layer.

[0027] When the crystal network is not disrupted, the crystal network of the entire surface layer of the glass cover is intact. That is, the number and size of the void channels within the crystal network of the entire surface layer of the glass cover can be considered to be exactly the same.

[0028] By employing a specific process, the integrity of the crystal lattice network in a localized area of ​​the glass cover's surface is disrupted to increase the number and aperture of the void channels within that area, thus forming a lattice defect region. Meanwhile, the integrity of the crystal lattice network in other areas of the glass cover's surface is preserved, maintaining the original number and aperture of the void channels within those areas, thereby forming a complete lattice region. In other words, the number and aperture of the void channels in the lattice defect region are greater than those in the complete lattice region.

[0029] The disruption of the crystal network includes both the structural disruption of the silicon-oxygen tetrahedra and the disruption of the connections between individual silicon-oxygen tetrahedra. In general, the lattice defects in the glass cover are typically classified into the following four categories: Point defects: atomic-scale defects, such as vacancies (the absence of Si in a silicon-oxygen tetrahedron). 4+ Or O 2- Interstitial ions (alkali metal ions entering non-lattice sites) are the basic channels for ion exchange; Line defects: One-dimensional defects, such as dislocations (linear distortions in the lattice arrangement), are commonly found in stress concentration areas of glass; Surface defects: Two-dimensional defects, such as grain boundaries, phase boundaries, and crack surfaces of microcracks—the glass structures on both sides of the crack are completely separated, forming a large area of ​​structural discontinuity. Volumetric defects: Three-dimensional defects, such as bubbles and inclusions, can also be classified as volumetric defects if microcracks extend into the interior of the glass to form a three-dimensional network of gaps.

[0030] Point defects in the lattice network can be addressed using low-temperature ion implantation. Specifically, at a low temperature of 100-200°C, a high-energy H+ ion implanter is used to implant H+ ions. + He + Injected into a localized area of ​​the cover plate surface to bombard the O-type silicon-oxygen tetrahedra. 2- This causes the oxygen vacancy to detach from the lattice site and form an oxygen vacancy. The ion energy is 50~200keV, and the ion implantation dose is 10. 14 ~10 16 ions / cm 2 .

[0031] Linear defects in the lattice network can be addressed using a thermal stress hardening method. Specifically, the glass cover plate is heated to 50-100°C below its glass transition temperature (Tg), held at that temperature for 30-60 minutes, and then rapidly cooled in a localized area of ​​the cover plate surface using a high-speed gas flow or liquid nitrogen to create a temperature gradient stress. This forces the lattice network to undergo shear deformation, generating linear dislocation defects.

[0032] The planar defects in the lattice network can be addressed using chemical etching or laser engraving. Specifically, First, a mask is used to partially cover the surface of the cover plate, exposing the local area to be processed. Then, a low-concentration hydrofluoric acid solution (HF:NH4F=1:5~1:10) is used to etch the local area of ​​the cover plate surface for 10~30 minutes, so that the silicon-oxygen tetrahedra in the local area are preferentially dissolved and a layered etched surface (stack fault defect) is formed. Finally, the mask is removed. Alternatively, a nanosecond laser (wavelength 1064nm) can be used, and the laser beam can be split into multiple parallel beams by a beam splitter to irradiate and scan a local area of ​​the cover plate surface. The power is 50~150W, the scanning speed is 50~300mm / s, and the repetition frequency is 50~200kHz, so as to utilize the thermal effect and optical breakdown effect of the laser to form parallel microcrack surfaces (surface defects).

[0033] The bulk defects in the lattice network can be addressed by mechanical grinding. Specifically, a high-pressure airflow (0.2~0.5MPa) is used to drive alumina or silicon carbide abrasive particles with a particle size of 50~200μm to impact a local area on the surface of the cover plate, thereby tearing the lattice network through mechanical impact force to form a porous, three-dimensional defect region.

[0034] Step S3: Immerse the glass cover plate in a molten bath salt containing coloring ions, so that the coloring ions in the molten bath salt exchange with the alkali metal ions in the glass cover plate, and the concentration of coloring ions in the lattice defect region is greater than that in the lattice intact region.

[0035] Specifically, the coloring ions contained in the molten bath salt mainly include one or two of transition metal ions and rare earth ions, wherein the transition metal ions mainly include Fe. 3+ Cu 2+ Co 2+ One or more of the rare earth ions, wherein the rare earth ions mainly include Nd 3+ Er 3+ One or more of the following. The composition of the molten bath salt may include one or more of CoCl2, CoSO4, NiCl2, NiSO4, CuSO4, CuCl2, CrCl3, and Cr2(SO4)3, with a salt bath temperature of 400-550℃ and a salt bath time of 60-180 minutes.

[0036] The specific composition of the molten bath salt and the molar ratio between the components depend on the alkali metal ions contained in the glass substrate and the required color of the marking pattern. For example, soda-lime-silicon glass commonly uses molten bath salts containing KNO3, NaNO3, and LiNO3 in a molar ratio of 4:1:1; potassium-silicon glass commonly uses molten bath salts containing RbNO3, AgNO3, and KCl in a molar ratio of 28:1:16; and lithium-aluminum-silicon glass commonly uses molten bath salts containing NaNO3, AgNO3, LiCl, and Na2SO4 in a molar ratio of 131:1:24:3. These are not all listed here.

[0037] When the coloring ions undergo electronic energy level transitions, they absorb light of a specific wavelength, thus exhibiting the corresponding color. Assuming the external light is white light, Fe... 3+ The glass cover can absorb the blue light band in white light, thus giving it a yellow color, for example, Cu. 2+ It can absorb the yellow light band in white light, thus making the glass cover appear blue. Other examples are not listed here.

[0038] During ion exchange, the void channels within the lattice network also constitute diffusion channels for the coloring ions. Therefore, the coloring ions in the molten bath salt can exchange with the alkali metal ions in these void channels and diffuse along these void channels inside the glass cover plate.

[0039] When the colored ions diffuse inside the glass cover, if the ion radius does not match the channel aperture, they will collide with the coordinating atoms of the silicon-oxygen tetrahedra, creating mechanical resistance. This is the main source of resistance when the colored ions diffuse inside the glass cover, and it has a significant impact on their diffusion rate.

[0040] Because the number and diameter of void channels in the lattice defect region are greater than those in the intact lattice region, the diffusion rate of coloring ions in the lattice defect region is also greater than that in the intact lattice region. Under the same salt bath temperature and time, the concentration of coloring ions in the lattice defect region is greater than that in the intact lattice region, resulting in a greater color depth in the lattice defect region than in the intact lattice region. Therefore, using the lighter color of the intact lattice region as the background color, the darker color of the lattice defect region can present the desired marking pattern.

[0041] The local coloring method of the present invention first disrupts the lattice network in a local surface layer of the glass cover plate to form lattice defect regions and lattice intact regions on the surface layer of the cover plate, and then uses the different diffusion rates of the lattice defect regions and lattice intact regions to form different color depths in the molten bath salts in the lattice defect regions and lattice intact regions, and then uses the color difference between the lattice defect regions and lattice intact regions to form the desired marking pattern.

[0042] The coloring depth of the lattice defect region is greater than that of the lattice intact region.

[0043] Since the diffusion rate of the coloring ions in the lattice defect region is greater than that in the lattice intact region, under the same salt bath temperature and salt bath time, the coloring depth of the lattice defect region will naturally be greater than that of the lattice intact region. The different coloring depths further enhance the color difference between the lattice defect region and the lattice intact region, thereby improving the recognizability of the marking pattern.

[0044] Preferably, the coloring depth of the lattice defect region is 5~30μm, and the coloring depth of the lattice intact region is less than 5μm.

[0045] By controlling the coloring depth of the lattice-completed area to below 5μm, the lattice-completed area will not produce a color change that is perceptible to the naked eye after coloring. This allows the lattice-completed area to retain the original color of the glass as much as possible, so as to avoid affecting the transmittance and transparency of the lattice-completed area, thereby meeting the optical requirements of the glass cover as a screen cover.

[0046] Example 2 In addition to the integrity of the crystal lattice network, the contact area between the glass cover and the molten bath salt also affects the diffusion rate of the coloring ions; the larger the contact area, the greater the diffusion rate.

[0047] As an optimized solution of Embodiment 1, in this embodiment, the lattice defect region has a rough surface with an uneven microstructure, and the corresponding lattice intact region has a smooth surface.

[0048] The local coloring method of the present invention increases the effective specific surface area of ​​the lattice defect region by forming a rough surface with an uneven microstructure on the lattice defect region of the glass cover plate. During ion exchange, the different contact areas between the lattice defect region and the lattice intact region and the molten bath salt further increase the color difference between the lattice defect region and the lattice intact region. In addition to increasing the color difference, the rough surface of the lattice defect region can also produce diffuse reflection of incident external light, which has a completely different visual effect from the parallel reflection formed by the smooth surface of the lattice intact region, and can further improve the recognizability of the marking pattern.

[0049] The chemical etching, laser engraving, and mechanical polishing methods described in Example 1 can all simultaneously form a rough surface with an uneven microstructure when the lattice network of the local surface layer of the cover plate is destroyed.

[0050] The greater the degree of lattice defect in the lattice defect region, the greater the diffusion rate of the coloring ions, the greater the color difference between the lattice defect region and the lattice integrity region, and the easier it is to identify the resulting marking pattern. However, the protective strength of the glass cover is also lower. Therefore, when the lattice network is damaged, it is necessary to balance the recognizability of the marking pattern and the protective strength of the glass cover.

[0051] In order to balance the recognizability of the logo pattern and the protective strength of the glass cover, preferably, the depth of the concave-convex microstructure is 10~100μm, the width is 50~200μm, and the width-to-depth ratio is 3:1~5:1.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention and not to limit them. Although the embodiments of the present invention have been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the embodiments of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for local coloring a glass cover plate, characterized in that, Includes the following steps: Step S1: Provide a glass cover containing alkali metal ions; Step S2: According to the desired marking pattern, the lattice network in a local surface layer of the glass cover is disrupted so that a lattice defect region corresponding to the marking pattern is formed in the local surface layer of the glass cover, while other surface layers where the lattice network is not disrupted form a lattice complete region. Step S3: Immerse the glass cover plate in a molten bath salt containing coloring ions, so that the coloring ions in the molten bath salt exchange with the alkali metal ions in the glass cover plate, and the concentration of coloring ions in the lattice defect region is greater than that in the lattice intact region.

2. The local coloring method according to claim 1, characterized in that, The coloring depth of the lattice defect region is greater than that of the lattice intact region.

3. The local coloring method according to claim 2, characterized in that, The coloring depth of the lattice defect region is 5~30μm, and the coloring depth of the lattice intact region is less than 5μm.

4. The local coloring method according to claim 1, characterized in that, In step S2, high-energy H+ is implanted using an ion implanter at a low temperature of 100~200℃. + He + Injected into a localized area of ​​the cover plate surface to bombard the O-type silicon-oxygen tetrahedra. 2- This causes the oxygen vacancy to detach from the lattice site and form an oxygen vacancy. The ion energy is 50~200keV, and the ion implantation dose is 10. 14 ~10 16 ions / cm2.

5. The local coloring method according to claim 1, characterized in that, In step S2, the glass cover plate is heated to 50-100°C below its glass transition temperature and held at that temperature for 30-60 minutes. Then, a local area on the surface of the cover plate is rapidly cooled by a high-speed airflow or liquid nitrogen to form a temperature gradient stress, which forces the lattice network to undergo shear deformation and generate linear dislocation defects.

6. The local coloring method according to claim 1, characterized in that, In step S2, a mask is first used to partially cover the surface of the cover plate, exposing the local area to be processed. Then, a low-concentration hydrofluoric acid solution is used to etch the local area of ​​the cover plate surface for 10 to 30 minutes, so that the silicon-oxygen tetrahedra in the local area are preferentially dissolved and a layered etched surface is formed. Finally, the mask is removed.

7. The local coloring method according to claim 1, characterized in that, In step S2, a nanosecond laser is used, and the laser beam is split into multiple parallel beams by a beam splitter to irradiate and scan a local area of ​​the cover plate surface. The power is 50~150W, the scanning speed is 50~300mm / s, and the repetition frequency is 50~200kHz, so as to utilize the thermal effect and optical breakdown effect of the laser to form parallel microcrack surfaces.

8. The local coloring method according to claim 1, characterized in that, In step S2, a high-pressure airflow is used to drive alumina or silicon carbide abrasive with a particle size of 50~200μm to impact a local area of ​​the cover plate surface, so as to tear the lattice network through mechanical impact force and form a porous three-dimensional defect area.

9. The local coloring method according to claim 1, characterized in that, The lattice defect region has a rough surface with an uneven microstructure, while the corresponding lattice intact region has a smooth surface.

10. The local coloring method according to claim 9, characterized in that, The depth of the uneven microstructure is 10~100μm, the width is 50~200μm, and the width-to-depth ratio is 3:1~5:1.

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