Glass mold and preparation method thereof

Abstract

The invention relates to a glass mold and a preparation method thereof. The preparation method comprises the following steps: polishing the surface of a glass plate; plating a protective film on the first surface of the glass plate; arranging photoresist on the first surface of the glass plate, performing exposure and development to form a first pattern, and exposing the protective film; dropwise adding a protective film etching solution at the first pattern to etch the protective film, transferring the first pattern on the photoresist to the protective film, and exposing the glass plate; and dropwise adding glass etching liquid at the first pattern to etch the exposed glass plate to form a decorative pattern. The surface of the glass mold is flat, the roughness is low, and contact lenses cannot be scratched in the using process.

Description

Technical Field

[0001] The present invention relates to the technical field of glass, and particularly to a glass mold and a preparation method thereof. Background Art

[0002] Contact lenses, also known as corneal contact lenses, are lenses that are directly attached to the tear layer on the surface of the cornea and are optical lenses for correcting vision, treating, and beautifying. According to the hardness of the lens material, they are divided into soft contact lenses and hard contact lenses. According to color, they can be divided into colorless and colored contact lenses. In the production process of colored contact lenses, colored patterns need to be printed on the contact lenses, which requires a template that can hold aqueous ink. Existing templates still have some problems, such as the surface is not flat enough to scratch the contact lenses, and the cost needs to be further reduced. Summary of the Invention

[0003] To solve at least some of the above problems in the prior art, the present invention provides a preparation method of a glass mold, including the following steps:

[0004] Polish the surface of the glass plate;

[0005] Deposit a protective film on the first surface of the glass plate;

[0006] Arrange a photoresist on the first surface of the glass plate, and perform exposure and development to form a first pattern, exposing the protective film;

[0007] Drop a protective film etching solution at the first pattern to etch the protective film, transfer the first pattern on the photoresist to the protective film, and expose the glass plate; and

[0008] Drop a glass etching solution at the first pattern to etch the exposed glass plate to form a decorative pattern.

[0009] Further, the flatness of the polished glass plate is less than 10 um, and the roughness Ra < 0.1 nm.

[0010] Further, polishing the surface of the glass plate includes:

[0011] Level and polish the glass plate with a SiO2 polishing solution with a particle size of 2 um;

[0012] Rough-polish the glass plate with a SiO2 polishing solution with a particle size of 1 um;

[0013] Perform the first fine polishing on the glass plate with a SiO2 polishing solution with a particle size of 0.3 um; and

[0014] Perform the second fine polishing on the glass plate with a SiO2 polishing solution with a particle size of 0.1 um - 0.3 um.

[0015] Further, the protective film is a chromium film;

[0016] The decorative pattern is composed of a plurality of blind holes, and the depth of the blind holes is less than the thickness of the glass plate.

[0017] Further, a 5%-10% HF solution is used to etch the glass plate to form the decorative pattern, and the depth of the blind holes is 22um - 30um.

[0018] Further, during the process of etching the glass plate, it swings up and down, left and right at a frequency of 15 - 30 times / min.

[0019] Further, an anti-scratch coating is arranged on the protective film.

[0020] The present invention also provides a glass mold, including:

[0021] A glass plate, whose first surface has a decorative pattern composed of a plurality of blind holes;

[0022] A protective film, which is located on the first surface of the glass plate, and the protective film has a first pattern with the same shape as the decorative pattern.

[0023] Further, the flatness of the glass plate is less than 10um, and the surface roughness Ra < 0.1nm;

[0024] The depth of the blind holes is 22um - 30um.

[0025] Further, an anti-scratch coating is provided on the protective film, and the anti-scratch coating is an AF film.

[0026] The present invention has at least the following beneficial effects: The surface of the glass mold of the present invention is flat, the flatness is less than 10um, and the surface roughness Ra < 0.1nm, and it will not scratch the contact lens during use; moreover, the cost of the glass is low, and the cost of the glass mold is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To further clarify the above and other advantages and features of the embodiments of the present invention, more specific descriptions of the embodiments of the present invention will be presented with reference to the accompanying drawings. It can be understood that these drawings only depict typical embodiments of the present invention and thus will not be considered as limiting its scope. In the drawings, for clarity, the same or corresponding components will be denoted by the same or similar reference numerals.

[0028] Figure 1 Shows the flow of a method for preparing a glass mold according to an embodiment of the present invention.

[0029] Figure 2 Shows a top view of a glass mold according to an embodiment of the present invention.

[0030] Figure 3 Shows a schematic structural diagram of a decorative pattern according to an embodiment of the present invention.

[0031] Figure 4 Shows a cross-sectional view of a glass mold according to an embodiment of the present invention. Detailed implementation manners

[0032] It should be noted that the components in each drawing may be exaggerated for illustration purposes and are not necessarily drawn to scale correctly.

[0033] In the present invention, each embodiment is only intended to illustrate the solution of the present invention and should not be construed as restrictive.

[0034] In the present invention, unless otherwise specified, the quantifiers "a" and "one" do not exclude the scenario of multiple elements.

[0035] It should also be noted here that in the embodiments of the present invention, for the sake of clarity and simplicity, only a part of the components or assemblies may be shown. However, those of ordinary skill in the art can understand that, under the teaching of the present invention, the required components or assemblies can be added according to the specific scenario requirements.

[0036] It should also be noted here that within the scope of the present invention, the terms "same", "equal", "equivalent", etc. do not mean that the two values are absolutely equal, but allow a certain reasonable error. That is to say, these terms also cover "substantially the same", "substantially equal", "substantially equivalent".

[0037] It should also be noted here that in the description of the present invention, the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than explicitly or implicitly indicating that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as explicitly or implicitly indicating relative importance.

[0038] In addition, the embodiments of the present invention describe the process steps in a specific order. However, this is only for the convenience of distinguishing each step and does not limit the order of each step. In different embodiments of the present invention, the order of each step can be adjusted according to the process adjustment.

[0039] The water-based ink used in the production of contact lenses has low viscosity and strong fluidity, and is easy to penetrate into micropores or scratches. In contact lens printing, a steel mold usually refers to a precision mold used to carry or transfer water-based ink, and most of its materials are stainless steel. The steel mold ground by emery has the advantages of high hardness, scratch resistance, and good durability, and has a long service life. However, there are usually some defects. The surface flatness of the steel mold is not high enough, and the roughness Ra is about 30um. It is easy to scratch the material of the contact lens, and the water-based ink is easy to penetrate into the grooves, which will cause the blank part (the part without the pupil pattern) of the contact lens to be stained with ink during use.

[0040] Therefore, a mold with a smoother surface is needed for the production of contact lenses. Glass has high hardness, high flatness after polishing, small roughness, and is wear-resistant and scratch-resistant, and can replace the steel mold. Moreover, the cost of glass is lower than that of stainless steel, and using glass can reduce costs.

[0041] Figure 1 The flowchart of a preparation method of a glass mold according to an embodiment of the present invention is shown. Figure 2 The top view of a glass mold according to an embodiment of the present invention is shown. Figure 3 The structural schematic diagram of a decorative pattern according to an embodiment of the present invention is shown.

[0042] As Figure 1 shown, a preparation method of a glass mold includes the following steps:

[0043] Step 1, optionally, cut the glass plate according to a predetermined shape and size. For example, a glass plate with a length of 150-450mm and a width of 150-450mm can be cut. The Rockwell hardness (HRC) of the glass plate is above 60, preferably above 65; the Mohs hardness of the glass plate is about 7.

[0044] Step 2, polish the surface of the glass plate. The flatness of the polished glass plate is less than 10um, and the roughness Ra < 0.1nm. The surface of the glass plate is mechanically polished 4 times to make the surface roughness and flatness meet the requirements. First, level and polish the glass plate, and grind the thicker (higher) parts of the glass plate to make the flatness of the glass plate higher and the thickness more uniform. Polish with SiO2 polishing liquid with a particle size of 2um for 45min-1h to achieve leveling. Then, polish roughly with SiO2 polishing liquid with a particle size of 1um for 30min-40min. After that, polish finely for the first time with SiO2 polishing liquid with a particle size of 0.3um for 30min-40min. Finally, polish finely for the second time with SiO2 polishing liquid with a particle size of 0.1um-0.3um for 10min-20min.

[0045] During the processes of flattening and polishing, rough polishing, and the first fine polishing, the SiO2 particles in the SiO2 polishing liquid are polyhedral particles, such as cubes, cuboids, etc. The SiO2 particles in the SiO2 polishing liquid used for the second fine polishing are spherical, ellipsoidal, etc.

[0046] In one embodiment, a polyurethane polishing pad can be used.

[0047] After rough polishing, the roughness Ra of the glass plate is <0.1 um, and after the second fine polishing, the roughness Ra of the glass plate is <0.1 nm.

[0048] Step 3: Deposit a protective film on the first surface of the glass plate. In one embodiment, the protective film is a chromium film. Before depositing the protective film, the glass surface is ultrasonically cleaned and dried.

[0049] Step 4: Dispose a photoresist on the first surface of the glass plate and perform exposure and development to form a first pattern, exposing the protective film. The photoresist can be disposed on the first surface of the glass plate by spin coating or spraying. Multiple first patterns are formed on the glass plate, and each first pattern is the same as the decorative pattern of the contact lens. The first pattern consists of multiple round holes. The exposure can be completed using a low-precision exposure machine to copy the pattern on the mask plate to the photoresist, and a high-precision exposure machine is not required.

[0050] Step 5: Drop a protective film etching solution at the first pattern to etch the protective film, transfer the first pattern on the photoresist to the protective film, expose the glass plate, and remove the photoresist. In one embodiment, the protective film is a chromium film, and a dechroming solution is used to chemically react with the exposed chromium film layer to transfer the first pattern on the photoresist to the chromium film.

[0051] Step 6: Drop a glass etching solution at the first pattern to etch the exposed glass plate to form a decorative pattern. The decorative pattern consists of multiple blind holes, and the depth of the blind holes is less than the thickness of the glass plate. The blind holes are used to accommodate the "aqueous ink" used for colored contact lenses.

[0052] As Figure 2 and 3 shown, the etched glass plate 10 has multiple decorative patterns 11, and the apertures and depths of the multiple blind holes 111 of the decorative pattern 11 are different. The depth of the blind holes is 22 um - 30 um, meeting the accommodation requirements of the aqueous ink.

[0053] In one embodiment, a 5% - 10% HF solution is used to etch the glass plate, and the verticality of the inner wall of the formed blind holes is 80° - 90°, and the difference between the diameter of the blind hole and the diameter of the opening is about 0.5 um.

[0054] During the etching process, it is necessary to swing up and down, left and right at a frequency of 15 - 30 times per minute to achieve uniform etching, so that the inner wall of the etched blind hole is vertical, and the bottom and opening sizes of the blind hole are basically the same. One round trip of swinging left and right in the horizontal direction is counted as one time, and one round trip of swinging up and down is counted as one time.

[0055] Step 7, optionally, an anti-scratch coating is arranged on the protective film. In one embodiment, the anti-scratch coating can be an AF film.

[0056] If necessary, an AF film with anti-scratch properties and a high contact angle (110 degrees) is coated on the protective film (chromium film) of the glass plate to enhance the durability and anti-fouling ability of the product. The contact angle formed by a liquid (such as water) on the surface of the coating is 110°, indicating strong hydrophobicity (the contact angle of ordinary glass is about 30 - 50°, and the hydrophobic coating can reach 100 - 120°), which can effectively prevent fouling and fingerprint residue and is easy to clean. Moreover, when a hydrophobic AF film is coated on the surface of the glass and water-based ink is filled in the decorative pattern, it can prevent the water-based ink from remaining on the surface of the glass.

[0057] Figure 4 A cross-sectional view of a glass mold according to an embodiment of the present invention is shown.

[0058] As Figure 4 shown, a glass mold includes a glass plate 10 and a protective film 20. The protective film 20 is located on one side surface of the glass plate 10. In one embodiment, the protective film 20 is a chromium film. In one embodiment, the first surface of the glass plate 10 has a decorative pattern, and the protective film has a first pattern. The decorative pattern and the first pattern have the same shape and are coaxial. In one embodiment, the decorative pattern is composed of a plurality of blind holes 111, and the depth of the blind holes 111 is less than the thickness of the glass plate. The blind holes 111 are used to accommodate the "water-based ink" used for colored contact lenses. The depth of the blind holes 11 is 22um - 30um, which can meet the accommodation requirements of the water-based ink.

[0059] Optionally, an anti-scratch coating is provided on the protective film 20, and the anti-scratch coating can be an AF film.

[0060] Although some embodiments of the present invention have been described in this application document, those skilled in the art can understand that these embodiments are only shown as examples. Those skilled in the art can think of numerous variant solutions, alternative solutions, and improvement solutions under the teaching of the present invention without exceeding the scope of the present invention. The appended claims are intended to define the scope of the present invention and thereby cover the methods and structures within the scope of these claims themselves and their equivalent transformations.

Claims

1. A preparation method of a glass mold, characterized in that, The steps include: Polish the surface of the glass plate; Deposit a protective film on the first surface of the glass plate; Dispose photoresist on the first surface of the glass plate, and perform exposure and development to form a first pattern, exposing the protective film; Drop a protective film etching solution at the first pattern to etch the protective film, transfer the first pattern on the photoresist to the protective film, and expose the glass plate; And Drop a glass etching solution at the first pattern to etch the exposed glass plate to form a decorative pattern.

2. The method according to claim 1, characterized in that, The flatness of the polished glass plate is less than 10 μm, and the roughness Ra < 0.1 nm.

3. The method according to claim 1, wherein Polishing the surface of the glass plate includes: Leveling and polishing the glass plate with a SiO2 polishing solution having a particle size of 2 μm; Roughly polishing the glass plate with a SiO2 polishing solution having a particle size of 1 μm; Performing the first fine polishing on the glass plate with a SiO2 polishing solution having a particle size of 0.3 μm; and Performing the second fine polishing on the glass plate with a SiO2 polishing solution having a particle size of 0.1 μm - 0.3 μm.

4. The method according to claim 1, characterized in that The protective film is a chromium film; The decorative pattern is composed of a plurality of blind holes, and the depth of the blind holes is less than the thickness of the glass plate.

5. The method according to claim 4, characterized in that Use a 5% - 10% HF solution to etch the glass plate to form a decorative pattern, wherein the depth of the blind holes is 22 μm - 30 μm.

6. The method according to claim 5, wherein During the process of etching the glass plate, swing up and down, left and right at a frequency of 15 - 30 times / min.

7. The method according to claim 1, characterized in that It further includes disposing an anti-scratch coating on the protective film.

8. A glass mold, characterized in that, Includes: A glass plate, the first surface of which has a decorative pattern composed of a plurality of blind holes; A protective film, which is located on the first surface of the glass plate, and the protective film has a first pattern with the same shape as the decorative pattern.

9. The glass mold according to claim 8, wherein, The flatness of the glass plate is less than 10 μm, and the roughness Ra < 0.1 nm; The depth of the blind holes is 22 μm - 30 μm.

10. The glass mold according to claim 8, wherein, An anti-scratch coating is provided on the protective film, and the anti-scratch coating is an AF film.

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