Frosting powder for soft light display screen glass and preparation method thereof

Abstract

The invention relates to the technical field of frosting powder preparation, and discloses frosting powder for soft light display screen glass and a preparation method thereof, and the frosting powder comprises 1-3 parts of ferric trichloride, 5-7 parts of solid citric acid, 10-14 parts of solid ammonium bifluoride, 2-4 parts of barium sulfate and 2-4 parts of solid acetylated dihydrogen phosphate. According to the frosting powder for the soft light display screen glass, a reaction system taking water and specific solid acid / salt as cores is innovatively constructed, and the use of liquid strong inorganic acid such as hydrochloric acid and hydrofluoric acid is completely abandoned, so that the serious corrosion of strong acid to production equipment is thoroughly eliminated, and the service life of the equipment is prolonged; the problems of safety risk and environmental pollution caused by acid mist volatilization and strong acid storage and transportation are completely eradicated from the source, so that the production process is safer and more environment-friendly, and ferric trichloride, solid citric acid, ammonium bifluoride, barium sulfate and acetylated dihydrogen phosphate are combined according to a specific ratio and synergistically act on the surface of the glass, so that the glass surface is more stable. According to the formula, a uniform and fine microcrystalline structure can be formed in the etching process.

Description

Technical Field

[0001] This invention relates to the field of frosting powder preparation technology, and in particular to a frosting powder for soft-light display glass and its preparation method. Background Technology

[0002] With the rapid development of display technology and the upgrading of consumption, the visual health and comfort of electronic products such as LCD screens and automotive touch screens have increasingly become a focus of attention. Traditional glossy display screens have drawbacks such as high surface reflectivity, susceptibility to glare from ambient light, and eye strain from prolonged viewing. To improve this situation, the industry typically uses a frosted glass etching process to etch the glass surface, giving it soft light and anti-glare properties, thereby achieving a softer display and eye protection.

[0003] However, existing frosting powders and processes for display glass still face several technical bottlenecks in meeting the demands of high-performance soft-light displays:

[0004] First, there are significant shortcomings in terms of environmental protection and production safety. Currently, many frosting formulas still rely on strong liquid inorganic acids such as hydrochloric acid and hydrofluoric acid as key reaction media to achieve effective glass etching. These strong acids are highly corrosive and volatile, which not only cause serious damage to production equipment and shorten its service life, but also pose significant safety risks in storage, transportation and use. At the same time, the volatilization of acid mist and the discharge of acid-containing waste liquid also burden the working environment and the ecological environment, which is not in line with the current development trend of green manufacturing.

[0005] Furthermore, the ability to coordinate and control the key optical performance of the product is weak. A high-quality soft-light display glass requires multiple optical parameters such as surface gloss, micro-roughness, and light transmittance haze to be matched within a specific precision range in order to achieve a perfect unity of "visual softness" and "tactile smoothness". Existing general-purpose frosting powder technology often focuses on improving the etching rate or a single roughness index, making it difficult to accurately and stably coordinate and control parameters such as gloss and haze, resulting in large fluctuations in product performance, low yield, and poor uniformity of display effect.

[0006] Furthermore, the process has poor adaptability and lacks versatility. Different display glass substrates (such as high-alumina glass, soda-lime glass, etc.) have different sensitivities to etching due to their different chemical compositions. Existing technologies often require the development of special frosting powders for specific glass materials. When switching glass types during production, the formula and process parameters must be readjusted. This process is cumbersome and time-consuming, and generates a large amount of debugging waste and waste liquid, which not only reduces production efficiency but also increases environmental treatment costs and material losses.

[0007] Therefore, there is an urgent need in this field to develop a new type of frosting powder and its supporting process, which can completely eliminate the use of strong acids to improve safety and environmental protection, can precisely and synergistically control multiple optical performance indicators to meet high-end display requirements, and has excellent versatility to adapt to a variety of mainstream glass substrates, thereby meeting the market's growing demand for high-performance soft-light display glass. Summary of the Invention

[0008] In view of the significant shortcomings of the existing technology in terms of environmental protection and production safety, the weak ability to coordinate control of key optical performance of products, poor process adaptability and lack of versatility, and the different sensitivity of different display glass substrates such as high-alumina glass and soda-lime glass to etching due to their different chemical compositions, this invention is proposed.

[0009] Therefore, the purpose of this invention is to provide a frosting powder for soft-light display glass, which aims to: completely eliminate the use of strong acids to improve safety and environmental protection; precisely and synergistically control multiple optical performance indicators to meet high-end display requirements; and possess excellent versatility to adapt to a variety of mainstream glass substrates, thereby meeting the growing market demand for high-performance soft-light display glass.

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a frosting powder for soft light display screen glass, wherein the frosting powder, by weight, comprises the following raw materials: 1-3 parts of ferric chloride, 5-7 parts of solid citric acid, 10-14 parts of solid ammonium fluoride, 2-4 parts of barium sulfate, and 2-4 parts of solid dihydrogen phosphate.

[0011] As a preferred embodiment of the present invention, the effective component content of the solid citric acid is greater than 98%;

[0012] And / or, the fineness of the barium sulfate is not less than 2000 mesh.

[0013] As a preferred embodiment of the present invention, a method for preparing frosted powder for soft-light display glass is characterized by comprising the following steps:

[0014] S1. Mix ferric chloride with water, stir to dissolve, and obtain the base solution;

[0015] S2. Solid ammonium fluoride, solid citric acid, barium sulfate and solid dihydrogen phosphate are added sequentially to the base solution and stirred continuously.

[0016] S3. The mixture obtained in step S2 is stirred and matured at a temperature of 60±3℃ and a speed of 180-200 rpm for 5-8 hours to obtain a paste-like intermediate.

[0017] S4. Continue stirring and maturing the paste-like intermediate at 50-55°C for 10-14 hours to obtain the frosting powder.

[0018] As a preferred embodiment of the present invention, in step S1, the amount of water added should be sufficient to ensure that all solid components can be uniformly dispersed in subsequent steps and ultimately form a usable frosting system.

[0019] As a preferred embodiment of the present invention, a method for treating glass using the frosting powder for the soft-light display screen is characterized by comprising the following steps:

[0020] Y1. Mix the frosting powder with water and let it mature to prepare a uniform frosting working solution;

[0021] Y2. Cool the frosting working solution and keep it at a constant temperature of 30±2℃, then place it in the circulation system;

[0022] Y3. The sand-forming working fluid is pumped into a U-shaped trough with an open top, and overflows from one side of the U-shaped trough to form a continuous and stable waterfall-like liquid curtain.

[0023] Y4. With the surface of the glass to be etched facing the liquid curtain, pass it under the liquid curtain at a constant speed of 2-4 meters per minute.

[0024] Y5. The etched glass is then cleaned, polished, and dried.

[0025] In a preferred embodiment of the present invention, in Y1, the curing is carried out at 50-55°C until the frosting working fluid system is homogeneous and stable.

[0026] As a preferred embodiment of the present invention, in Y2 and Y3, the circulation system is equipped with a stirring device, and the stirring rate is controlled at 300-350 rpm; the flow rate pumped to the U-shaped tank is controlled at 7000-9000 liters / hour.

[0027] In a preferred embodiment of the present invention, in Y4, the total travel distance of the glass to be processed through the liquid curtain is 10-14 meters.

[0028] As a preferred embodiment of the present invention, a soft-light display glass is prepared by using the method of treating the glass with frosting powder, characterized in that its surface gloss is 20±5 GU, its surface roughness Ra is 0.2-0.3 μm, and its transmittance haze is 25-35%.

[0029] Compared with the prior art, the present invention has at least the following beneficial effects:

[0030] 1. This invention innovatively constructs a reaction system with water and a specific solid acid / salt as the core, completely eliminating the use of strong liquid inorganic acids such as hydrochloric acid and hydrofluoric acid. This not only completely eliminates the serious corrosion of production equipment by strong acids and extends the equipment life, but also eliminates the safety risks and environmental pollution problems caused by acid mist volatilization and strong acid storage and transportation from the source, making the production process safer and more environmentally friendly, and in line with the requirements of sustainable development.

[0031] 2. This invention utilizes a specific combination of ferric chloride, solid citric acid, ammonium bifluoride, barium sulfate, and acetylated dihydrogen phosphate to synergistically act on the glass surface. This formula can form a uniform and delicate microcrystalline structure during the etching process. After subsequent polishing, the gloss of the treated glass surface can be stably controlled at 20±5 GU, the roughness (Ra) at 0.2-0.3 μm, and the transmittance haze at the ideal range of 25-35%, perfectly achieving a display effect that is soft-light, anti-glare, and has a delicate touch.

[0032] 3. The frosting powder preparation method provided by this invention is simple and the curing process is stable. More importantly, one formula can be applied to display glass substrates of various brands without the need for frequent formula adjustments due to material changes. This greatly simplifies production management, reduces downtime during production transitions and waste liquid generated during debugging, and improves overall production efficiency and environmental benefits.

[0033] 4. The present invention uses a specially designed U-shaped groove to form a waterfall-like circulating frosting liquid flow through the application method provided. This process enables the glass surface to contact the fresh solution evenly and stably during the etching process, avoiding problems such as flow marks and unevenness that may occur during static immersion or ordinary sandblasting. This ensures a high degree of consistency in the optical parameters of each piece of glass in large-scale production and a high yield rate. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the steps in the preparation method of frosting powder for soft-light display glass according to the present invention. Detailed Implementation

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0036] Example 1

[0037] A frosting powder for soft-light display screen glass is prepared from the following raw materials: 2 parts ferric chloride, 6 parts solid citric acid with an effective content of >98%, 12 parts solid ammonium fluoride, 3 parts precipitated barium sulfate with a fineness of 3000 mesh, and 3 parts solid acetylated dihydrogen phosphate.

[0038] Its preparation method includes the following steps:

[0039] In a 5mm thick PP acid-resistant stirring container, add 2 parts of ferric chloride and an appropriate amount of deionized water, and turn on the stirrer (the diameter of the impeller is about 50mm smaller than the inner diameter of the container) until completely dissolved to form a clear base liquid.

[0040] While stirring (approximately 190 rpm), add 12 parts solid ammonium fluoride, 6 parts solid citric acid, 3 parts barium sulfate, and 3 parts solid dihydrogen phosphate to the base solution in sequence. After all solids have been added, continue stirring and mixing for 30 minutes to ensure initial uniform dispersion.

[0041] Place the entire container in a 60°C constant temperature water bath and maintain a stirring speed of 190 rpm for the first stage of maturation, which lasts for 6 hours. During this time, the mixture gradually transforms into a uniform paste-like intermediate.

[0042] Subsequently, the water bath temperature was adjusted to 52℃, and stirring and maturation continued for 12 hours. During this process, the paste was further homogenized and fully matured, ultimately yielding a uniform frosting powder product that can be directly used to prepare working solutions.

[0043] Example 2

[0044] A frosting powder for soft-light display screen glass is prepared from the following raw materials: 1 part ferric chloride, 5 parts solid citric acid with an effective content of >98%, 10 parts solid ammonium fluoride, 2 parts precipitated barium sulfate with a fineness of 2500 mesh, and 2 parts solid acetylated dihydrogen phosphate.

[0045] The preparation method is the same as in Example 1, except that:

[0046] The first stage of maturation conditions are: temperature 57℃, rotation speed 185 rpm, and time 5 hours.

[0047] The second stage of maturation conditions are: temperature 50℃, time 10 hours.

[0048] Example 3

[0049] A frosting powder for soft-light display screen glass is prepared from the following raw materials: 3 parts ferric chloride, 7 parts solid citric acid with an effective content of >98%, 14 parts solid ammonium fluoride, 4 parts precipitated barium sulfate with a fineness of 4000 mesh, and 4 parts solid acetylated dihydrogen phosphate.

[0050] The preparation method is the same as in Example 1, except that:

[0051] The first stage of maturation conditions are: temperature 63℃, rotation speed 200 rpm, and time 8 hours.

[0052] The second stage of maturation conditions are: temperature 55℃, time 14 hours.

[0053] Example 4: Preparation of Soft Light Display Glass

[0054] The frosting powder prepared in Example 1 was used to treat a high-alumina glass substrate (3 mm thick, with a protective film on one side). The specific steps are as follows:

[0055] Preparation and maturation of working solution: Take 50 kg of frosting powder obtained in Example 1, mix it with 25 kg of deionized water (powder to water mass ratio 1:0.5), let it stand and mature for 5 hours at 52°C, and then gently stir it to make it completely dispersed to form a uniform and stable frosting working solution.

[0056] Preparation of the circulation system: Transfer the matured frosting working solution to a specially designed acid-resistant circulation tank equipped with a stirrer. Turn on the cooling system to precisely lower the temperature of the working solution to 30±1℃ and maintain it at that temperature. Turn on the stirrer in the tank and control the speed at 320 rpm.

[0057] Waterfall etching: Start the acid-resistant pump to pump the working fluid into a top-open U-shaped trough measuring 200mm wide, 900mm long, and 150mm high at a flow rate of approximately 8000 liters per hour. One long side of the U-shaped trough is designed to be 40mm lower than the other sides, allowing the working fluid to overflow evenly and form a continuous, stable waterfall-like liquid curtain. The overflowing liquid flows back to the circulation tank, forming a closed loop.

[0058] Glass processing: The Corning glass substrate, with its unprotected side (etched side) facing upwards, is horizontally fixed on the conveyor. The glass is propelled at a constant speed of 3 meters per minute through the liquid curtain beneath the U-shaped trough, covering a total distance of approximately 12 meters. During this process, the liquid curtain makes full and uniform contact with the glass surface, resulting in an etching reaction.

[0059] Post-processing: The etched glass is immediately rinsed with plenty of water to remove residual reactants and frosting solution from the surface. It is then mechanically polished and finally dried with hot air to obtain the finished soft-light display glass.

[0060] Example 5: Preparation of Soft Light Display Glass

[0061] The frosting powder prepared in Example 2 was used to treat a soda-lime glass substrate. The application method was the same as in Example 4, with the parameters adjusted as follows:

[0062] The mixing ratio of frosting powder to water is 1:0.4.

[0063] The working fluid aging temperature is 50℃.

[0064] During etching, the glass is conveyed at a speed of 2.5 meters per minute, and the total travel distance through the liquid curtain is approximately 10 meters.

[0065] The stirring speed of the circulating tank is 300 rpm, and the pumping flow rate is 7500 liters / hour.

[0066] Example 6: Preparation of Soft Light Display Glass

[0067] The frosting powder prepared in Example 3 was used to treat the display glass substrate. The application method is the same as in Example 4, with the parameters adjusted as follows:

[0068] The mixing ratio of frosting powder to water is 1:0.6.

[0069] The working fluid aging temperature is 55℃.

[0070] During etching, the glass is conveyed at a speed of 3.5 meters per minute, and the total travel distance through the liquid curtain is approximately 14 meters.

[0071] The stirring rate of the circulating tank is 340 rpm, and the pumping flow rate is 8500 liters / hour.

[0072] Comparative Example 1: Traditional strong acid frosting process

[0073] Referring to a certain existing technology, a frosting powder formula with ammonium bifluoride, hydrofluoric acid, and hydrochloric acid as the main acid sources was used, and the glass was treated with the same conventional soaking process as in Example 4. Concentrated hydrochloric acid and hydrofluoric acid were used for aging and pH adjustment in the process.

[0074] Performance testing and effect comparison

[0075] Environmental and safety observations:

[0076] Examples 1-6: No irritating acid mist is generated during the entire preparation and production process, and the working environment has minimal odor. All raw materials used are solids or solutions, ensuring safe storage and transportation. The equipment is made of ordinary PP material and has no special corrosion protection requirements.

[0077] Comparative Example 1: The preparation and maturation stages involve the volatilization of large amounts of hydrochloric acid and hydrofluoric acid mists, requiring a powerful ventilation and exhaust gas treatment system. Production equipment necessitates high-grade corrosion-resistant materials such as Teflon, posing significant safety and environmental risks.

[0078] The test results of the product's optical performance are shown in the table below:

[0079] sample Gloss (GU) Surface roughness Ra (μm) Haze (%) Appearance and tactile description Example 4 Product 18 0.25 28 The surface is uniform, with a fine frosted texture and a smooth feel. Example 5 Product 22 0.28 32 The surface is uniform, the soft light effect is obvious, and there is no glare. Example 6 Product 19 0.22 26 The surface is extremely uniform, the texture is delicate, and the display is soft. Comparative Example 1 Product 45 0.8 15 The surface has slight flow marks, insufficient glare suppression, and a slightly rough feel. Product target requirements 20±5 0.2-0.3 25-35 The display is soft, smooth to the touch, and glare-free.

[0080] As shown in the table above, the glass produced using the frosting powder and method provided by this invention (Examples 4-6) exhibits stable performance within the preset optimal performance range for its three key optical parameters: gloss, roughness, and haze. Furthermore, it demonstrates high consistency between batches, fully meeting the requirements of high-end soft-light displays. In contrast, the product parameters of Comparative Example 1 deviate from the target, and its uniformity is poor.

[0081] Universality verification:

[0082] Using the frosting powder from Example 1 and fixed process parameters (with only minor adjustments to the powder-to-water ratio), the glass substrate of the display screen was successfully treated. The optical parameters of the resulting products were all stably within the range of "gloss 20±5 GU, roughness 0.2-0.3 μm, haze 25-35%", demonstrating the excellent versatility of the formula of this invention and avoiding the efficiency loss and material waste caused by frequent formula changes.

[0083] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A frosting powder for soft-light display screen glass, characterized in that, The frosting powder, by weight, is prepared from the following raw materials: 1-3 parts ferric chloride, 5-7 parts solid citric acid, 10-14 parts solid ammonium fluoride, 2-4 parts barium sulfate, and 2-4 parts solid dihydrogen phosphate.

2. The frosting powder for soft-light display screen glass according to claim 1, characterized in that: The effective component content of the solid citric acid is greater than 98%; And / or, the fineness of the barium sulfate is not less than 2000 mesh.

3. A method for preparing frosted powder for soft-light display glass as described in claim 1 or 2, characterized in that, Includes the following steps: S1. Mix ferric chloride with water, stir to dissolve, and obtain the base solution; S2. Solid ammonium fluoride, solid citric acid, barium sulfate and solid dihydrogen phosphate are added sequentially to the base solution and stirred continuously. S3. The mixture obtained in step S2 is stirred and matured at a temperature of 60±3℃ and a speed of 180-200 rpm for 5-8 hours to obtain a paste-like intermediate. S4. Continue stirring and maturing the paste-like intermediate at 50-55°C for 10-14 hours to obtain the frosting powder.

4. The method for preparing frosting powder for soft-light display screen glass according to claim 3, characterized in that: In step S1, the amount of water added should be sufficient to ensure that all solid components can be uniformly dispersed in subsequent steps and ultimately form a usable frosting system.

5. A method for treating glass using the frosting powder for soft-light display glass as described in claim 1 or 2, characterized in that, Includes the following steps: Y1. Mix the frosting powder with water and let it mature to prepare a uniform frosting working solution; Y2. Cool the frosting working solution and keep it at a constant temperature of 30±2℃, then place it in the circulation system; Y3. The sand-forming working fluid is pumped into a U-shaped trough with an open top, and overflows from one side of the U-shaped trough to form a continuous and stable waterfall-like liquid curtain. Y4. With the surface of the glass to be etched facing the liquid curtain, pass it under the liquid curtain at a constant speed of 2-4 meters per minute. Y5. The etched glass is then cleaned, polished, and dried.

6. The method for treating glass with frosting powder according to claim 5, characterized in that: In Y1, the curing is carried out at 50-55℃ until the frosting working fluid system is homogeneous and stable.

7. The method for treating glass with frosting powder according to claim 6, characterized in that: In Y2 and Y3, the circulation system is equipped with a stirring device, and the stirring rate is controlled at 300-350 revolutions per minute; The flow rate pumped into the U-shaped channel is controlled at 7000-9000 liters / hour.

8. The method for treating glass with frosting powder according to claim 7, characterized in that: In Y4, the total travel distance of the glass to be processed through the liquid curtain is 10-14 meters.

9. A soft-light display glass manufactured by the method according to any one of claims 5 to 8, characterized in that, Its surface gloss is 20±5 GU, surface roughness Ra is 0.2-0.3 μm, and transmittance haze is 25-35%.

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