Blackboard glass and preparation method thereof

Abstract

The invention provides blackboard glass and a preparation method thereof. The preparation method of the blackboard glass comprises the following steps: providing a glass substrate; arranging a protective film on the back surface of the glass substrate; the front face of the glass substrate is sequentially subjected to acid pickling, frosting and polishing, continuously-distributed concave-convex spherical points are formed on the front face of the glass substrate, and burrs are arranged on the surface of each concave-convex spherical point; wherein the glossiness of the polished glass substrate is 18 + / -5 degrees. The surface microstructure of the blackboard glass obtained by adopting the preparation method is continuous concave-convex spherical points, and the surface of each concave-convex spherical point keeps a certain burr-shaped form, so that chalk can hang powder on the surface of the glass, enough frictional resistance is provided during writing, and the chalk cannot slip during writing.

Description

Technical Field

[0001] The invention relates to the technical field of blackboard glass, and in particular to a blackboard glass and a preparation method thereof. Background Art

[0002] Anti-glare (AG) refers to a special process on the surface of mirror glass to form an uneven rough surface, creating a matte, low-reflection effect, which can reduce the interference of ambient light, improve the viewing angle and brightness of the display, and alleviate screen reflections, making the image clearer, the colors more vivid, and the colors more saturated, thereby significantly improving the display effect.

[0003] The existing AG production process mainly uses particles in the frosting liquid as a mask. During the production process, the frosting liquid is attached to the glass surface. Under the action of the particles, an uneven glass surface is obtained, and then a product with optical values ​​such as gloss and haze is obtained through chemical polishing. However, in the actual production process, after chemical polishing, the concave and convex spherical surface of the AG blackboard glass surface becomes very smooth, causing slippage when writing with chalk. In addition, the existing production process also has the following problems:

[0004] The roughness is large, which has a certain impact on the display, and the flash point value is relatively high;

[0005] The entire etching process takes a long time, has limited production capacity, and is costly;

[0006] The amount of frosting powder and polishing liquid consumed is large, the cost of treating waste acid, waste water and waste residue is high, and the environmental performance is poor. Summary of the invention

[0007] In order to overcome at least one problem in the prior art, the main purpose of the present invention is to provide a blackboard glass and a preparation method thereof. The surface micromorphology of the blackboard glass obtained by the preparation method is continuous concave and convex spherical points, and the surface of each concave and convex spherical point retains a certain burr-like shape, which is conducive to the chalk hanging on the glass surface, and there is sufficient friction resistance when writing, so that the chalk writing will not slip.

[0008] In order to achieve the above object, according to a first aspect of the present invention, a method for preparing blackboard glass is provided.

[0009] The preparation method of the blackboard glass comprises the following steps:

[0010] Providing a glass substrate;

[0011] Disposing a protective film on the back side of the glass substrate;

[0012] The front side of the glass substrate is pickled, frosted and polished in sequence to form continuously distributed concave-convex spherical points on the front side of the glass substrate, and the surface of each concave-convex spherical point has burrs; wherein the glossiness of the glass substrate after polishing is 18±5°.

[0013] Furthermore, the number of the frosting slots is 1 to 3 slots, and the frosting time of each slot is 2 to 4 minutes;

[0014] The number of grooves of the frosting is preferably 2.

[0015] Furthermore, the concentrations of the components in the frosting liquid used for frosting are: fluoride: 15-25%, acid: 5-10%, and water: 60-80%.

[0016] Furthermore, the polishing liquid used in the polishing is a hydrofluoric acid solution with a concentration of 12-17%.

[0017] Furthermore, the number of the polishing grooves is 7 to 10 grooves, and each groove takes 4 to 6 minutes;

[0018] The number of the polishing grooves is preferably 10 grooves.

[0019] Furthermore, the pickling solution used in the pickling is a hydrofluoric acid solution with a concentration of 8 to 10%;

[0020] Preferably, during the pickling and / or frosting process, the temperature of the pickling solution or frosting solution is maintained at 15-35°C.

[0021] Furthermore, the preparation method further comprises: after the pickling and the polishing, respectively, washing the front surface of the glass substrate with pure water;

[0022] Preferably, the resistivity of the pure water is ≥13 MΩ.cm.

[0023] Furthermore, the preparation method further comprises:

[0024] The polished glass substrate is subjected to CNC shaping and tempering treatments in sequence; and

[0025] Screen printing ink on the back side of the glass substrate.

[0026] In order to achieve the above objective, according to a second aspect of the present invention, a blackboard glass is provided.

[0027] The blackboard glass is prepared by the above-mentioned blackboard glass preparation method; wherein,

[0028] The front microscopic morphology of the blackboard glass is continuous concave-convex spherical points, and the surface of each concave-convex spherical point has burrs.

[0029] Furthermore, the blackboard glass has a transmittance of ≥88%, a haze of 30±10%, a DOI of 1.5±1.5, a gloss of 18±5°, a roughness Ra of 0.6±0.2 μm, a roughness RSM≤150 μm, and a pencil hardness of ≥7H.

[0030] Advantages of the present invention:

[0031] 1. The roughness is small, the flash point value is low, the display effect is improved, and the touch feel will be more delicate.

[0032] 2. When the roughness is small, a better powder coating effect is maintained by changing the microscopic morphology of the AG surface.

[0033] 3. The frosting and chemical polishing time is shortened, which greatly improves the production capacity and effect and reduces the production cost of blackboard glass.

[0034] 4. The amount of chemicals used for frosting and chemical polishing is reduced, which reduces the production cost of glass blackboards, reduces the cost of treating wastewater, waste acid and waste residue, and is more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0036] Figure 1 This is the microscopic morphology of the AG blackboard glass surface obtained by the existing process;

[0037] Figure 2 This is a surface microscopic morphology of the blackboard glass obtained in the embodiment provided by the present invention.

[0038] In the figure:

[0039] 1. Concave and convex spherical points; 2. Burrs. DETAILED DESCRIPTION

[0040] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0041] Figure 1 The microscopic morphology of the AG blackboard glass surface obtained by the existing process is shown.

[0042] Depend on Figure 1 It can be seen that the microscopic morphology of the AG blackboard glass surface is continuous concave-convex spherical points 1. After chemical polishing, the surface of each concave-convex spherical point 1 becomes very smooth, which causes slipping when writing with chalk, affecting the chalk writing experience.

[0043] The present invention adjusts the process parameters of the etching process to change the microscopic morphology of the surface of the AG blackboard glass to maintain the chalk writing effect, while improving the display effect and reducing the production cost of the blackboard glass.

[0044] DOI (Difference of Image): Indicates the molding effect.

[0045] Gloss: The higher the surface Gloss value, the better the appearance and the smoother the surface will be.

[0046] Transmittance: Indicates the amount of light that passes through glass.

[0047] Haze: Scattered light that deviates more than 2.5° from the incident light beam.

[0048] Roughness Ra: the arithmetic mean of particle height.

[0049] Roughness RSM: arithmetic mean of particle spacing.

[0050] According to a specific embodiment of the present invention, a method for preparing blackboard glass is provided.

[0051] The preparation method of blackboard glass in the present invention specifically comprises the following steps:

[0052] 1) Provide a glass substrate.

[0053] In the embodiment of the present invention, the glass substrate may be pre-processed as required, such as cutting the glass substrate into certain size specifications.

[0054] Of course, the glass substrate can also be ground and chamfered according to actual needs to remove burrs on the glass substrate; and the glass substrate can be cleaned and dried to ensure the appearance integrity of the glass substrate.

[0055] It should be noted that the pre-processing of the glass substrate is a conventional technical setting in the art and will not be elaborated in detail in the embodiments of the present invention.

[0056] 2) A protective film is provided on the back surface of the glass substrate.

[0057] In the embodiment of the present invention, in order to prevent the back side of the glass substrate from being etched, it is necessary to provide an anti-etching protective film on the back side of the glass substrate, which is mainly an acid-resistant protective film.

[0058] As some embodiments of the present invention, the protective film may be a silk-screen ink layer, the provision of which will not hinder subsequent tempering treatment, and the provision is simple and convenient for processing.

[0059] As some embodiments of the present invention, the protective film may also be a corrosion-resistant plastic film, such as a PET protective film, a PTFE plastic film, etc., to protect the back side of the glass substrate from corrosion.

[0060] In order to form continuously distributed concave-convex spherical points 1 on the front surface of the glass substrate, and each concave-convex spherical point 1 has a burr 2 on its surface, the front surface of the glass substrate needs to be etched.

[0061] In the present invention, etching of the front surface of the glass substrate mainly includes pickling, frosting and polishing.

[0062] 3) The front side of the glass substrate is pickled.

[0063] In an embodiment of the present invention, the glass substrate is placed in a pickling tank for pickling, wherein the pickling liquid in the pickling tank may be a hydrofluoric acid solution with a concentration of 8-10%.

[0064] As some embodiments of the present invention, the pickling is performed in two tanks, and each pickling lasts for 20 to 40 seconds, such as 30 seconds. By performing the pickling in two tanks, the surface cleanliness of the glass substrate can be effectively ensured to avoid impurity contamination.

[0065] It should be noted that pickling can also be carried out in one tank or multiple tanks, and the number of tanks for pickling and the duration of pickling in each tank can be specifically set according to the required cleaning effect.

[0066] In an embodiment of the present invention, the temperature during the pickling process is 15-35°C.

[0067] 4) The front surface of the acid-washed glass substrate is cleaned with pure water.

[0068] In an embodiment of the present invention, the glass substrate after pickling is cleaned to remove impurities on the surface of the glass substrate.

[0069] The resistivity of the pure water used is ≥13MΩ.cm to avoid the influence of minerals in the water.

[0070] 5) The front side of the cleaned glass substrate is frosted.

[0071] In an embodiment of the present invention, the front surface of the cleaned glass substrate is frosted to form continuously distributed concave and convex spherical points 1 on the front surface of the glass substrate, turning the front surface of the glass substrate into a matte non-reflective surface, thereby reducing the reflectivity of the front surface of the glass substrate and improving the AG performance of the glass substrate.

[0072] In an embodiment of the present invention, frosting is performed using frosting powder, the main components of which are fluoride and acid, wherein the fluoride is one or more of ammonium fluoride, ammonium bifluoride, potassium bifluoride, and calcium fluoride; and the acid is one of hydrochloric acid and sulfuric acid.

[0073] In the embodiment of the present invention, the glass substrate is frosted by immersion in a frosting solution prepared from frosting powder. The concentrations of the components in the frosting solution are: fluoride: 15-25%, acid: 5-10%, and water: 60-80%.

[0074] In the embodiment of the present invention, in order to improve the frosting effect, the glass substrate is subjected to multi-groove frosting treatment, such as 2-groove frosting, and each frosting lasts for 2 to 4 minutes.

[0075] It should be noted that, in some embodiments, one tank of frosting may be performed as required, and the duration may be 4 to 8 minutes, which may be set according to actual needs.

[0076] In an embodiment of the present invention, during the frosting process, the temperature of the frosting liquid is maintained at 15-35°C.

[0077] It is worth mentioning that the surface of the glass substrate after frosting forms continuous and uniform concave and convex spherical points, and the concentration and time of pickling and frosting can be controlled to achieve different haze, gloss, DOI (brightness of image) and roughness of the glass substrate.

[0078] 6) Polishing the front side of the frosted glass substrate so that the glossiness of the front side of the glass substrate after polishing is 18±5°.

[0079] In an embodiment of the present invention, the surface of the frosted glass substrate is chemically polished so that a certain amount of burrs 2 are retained on the surface of each concave and convex spherical point 1. The burrs 2 are conducive to the chalk hanging on the glass surface, and there is sufficient friction resistance when writing, so that the chalk writing will not slip and affect the chalk writing experience.

[0080] As some embodiments of the present invention, a glass substrate is placed in a polishing tank for polishing, wherein the polishing liquid used for polishing is a hydrofluoric acid solution with a concentration of 12-17%.

[0081] As some embodiments of the present invention, in order to improve the polishing effect, polishing is performed for 7 to 10 grooves, and each polishing lasts for 4 to 6 minutes.

[0082] As a preferred embodiment of the present invention, the number of polishing grooves is 10 grooves, and each groove lasts for 4 to 6 minutes.

[0083] 7) The front side of the polished glass substrate is cleaned with pure water.

[0084] In an embodiment of the present invention, the polished glass substrate is cleaned to remove impurities on the surface of the glass substrate.

[0085] The resistivity of the pure water used is ≥13MΩ.cm to avoid the influence of minerals in the water.

[0086] 8) Perform CNC contouring on the polished glass substrate.

[0087] The polished glass substrate is subjected to CNC contouring to shape and size the glass substrate to obtain a glass substrate of the desired appearance size.

[0088] It should be noted that the CNC contour in the present invention is a commonly used processing technology and will not be described in detail.

[0089] 9) Tempering the glass substrate after CNC shaping.

[0090] The glass substrate after CNC shaping is placed in a tempering furnace for tempering treatment to form compressive stress on the surface of the glass substrate to improve the strength, impact resistance and bearing capacity of the glass.

[0091] It should be noted that the tempering treatment in the present invention is a common treatment process and will not be described in detail.

[0092] 10) Screen printing ink on the back of the tempered glass substrate.

[0093] Finally, it is dried, cleaned, packed and shipped.

[0094] Figure 2 The surface microscopic morphology of the blackboard glass prepared in the embodiment of the present invention is shown, wherein the front microscopic morphology of the blackboard glass is continuous concave-convex spherical points 1, and the surface of each concave-convex spherical point 1 has burrs 2.

[0095] In order to ensure the production quality of the glass blackboard, it is necessary to inspect the prepared glass blackboard. After inspection, the blackboard glass prepared in the present invention has a glossiness of 18±5°, a roughness Ra of 0.6±0.2μm, a roughness RSM≤150μm, a DOI of 1.5±1.5, a transmittance of ≥88%, a haze of 30±10%, and a pencil hardness of ≥7H.

[0096] The surface microstructure of the AG blackboard glass prepared by the preparation method of the present invention is continuous concave-convex spherical points 1, but the surface of each concave-convex spherical point 1 is not very smooth. By controlling the concentration and time of frosting and chemical polishing, the surface of each concave-convex spherical point 1 retains a certain burr 2. This burr 2 morphology is conducive to the chalk hanging on the glass surface, and there is sufficient friction resistance when writing, so that the chalk writing will not slip, affecting the chalk writing experience.

[0097] It should be noted that the terms "comprises" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions. For example, the inclusion of a series of components is not necessarily limited to those components explicitly listed, but may include other components that are not explicitly listed or inherent to the components.

[0098] In the present invention, the directions or positional relationships indicated by the terms "upper", "lower", "bottom", "top", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction.

[0099] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0100] In addition, the descriptions of "first", "second", etc. involved in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0101] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0102] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for preparing blackboard glass, characterized in that: The following steps are involved: Providing a glass substrate; Disposing a protective film on the back side of the glass substrate; The front side of the glass substrate is pickled, frosted and polished in sequence to form continuously distributed concave-convex spherical points on the front side of the glass substrate, and the surface of each concave-convex spherical point has burrs; wherein the glossiness of the glass substrate after polishing is 18±5°.

2. The method for preparing blackboard glass according to claim 1, characterized in that: The number of the frosting slots is 1 to 3 slots, and the frosting time of each slot is 2 to 4 minutes; The number of grooves of the frosting is preferably 2.

3. The method for preparing blackboard glass according to claim 1, characterized in that: The concentrations of the components in the frosting liquid used in the frosting are: fluoride: 15-25%, acid: 5-10%, and water: 60-80%.

4. The method for preparing blackboard glass according to claim 1, characterized in that: The polishing liquid used in the polishing is a hydrofluoric acid solution with a concentration of 12-17%.

5. The method for preparing blackboard glass according to claim 1, characterized in that: The number of the polishing grooves is 7 to 10 grooves, and each groove takes 4 to 6 minutes; The number of the polishing grooves is preferably 10 grooves.

6. The method for preparing blackboard glass according to claim 1, characterized in that: The pickling solution used in the pickling is a hydrofluoric acid solution with a concentration of 8 to 10%; Preferably, during the pickling and / or frosting process, the temperature of the pickling solution or frosting solution is maintained at 15-35°C.

7. The method for preparing blackboard glass according to claim 1, characterized in that: The preparation method further comprises: after the pickling and the polishing, respectively, washing the front surface of the glass substrate with pure water; Preferably, the resistivity of the pure water is ≥13 MΩ.cm.

8. The method for preparing blackboard glass according to claim 1, characterized in that: The preparation method further comprises: The polished glass substrate is subjected to CNC shaping and tempering treatments in sequence; and Screen printing ink on the back side of the glass substrate.

9. A blackboard glass, characterized in that: It is prepared by the method for preparing blackboard glass according to any one of claims 1 to 8; wherein, The front microscopic morphology of the blackboard glass is continuous concave-convex spherical points, and the surface of each concave-convex spherical point has burrs.

10. The blackboard glass according to claim 9, characterized in that: The blackboard glass has a transmittance of ≥88%, a haze of 30±10%, a DOI of 1.5±1.5, a gloss of 18±5°, a roughness Ra of 0.6±0.2 μm, a roughness RSM≤150 μm, and a pencil hardness of ≥7H.

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