A microcrystalline glass alkaline etching solution and application thereof
By constructing a synergistic system of alkali-high-boiling-point organic solvent-sulfur-containing organosilicon compound, the problems of slow etching rate and surface inhomogeneity of microcrystalline glass are solved, achieving efficient and stable etching effect, which is suitable for the field of precision manufacturing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUHU TOKEN SCI
- Filing Date
- 2026-03-10
- Publication Date
- 2026-06-12
AI Technical Summary
Existing technologies make it difficult to achieve efficient etching of glass-ceramics without introducing fluorides. Furthermore, traditional alkaline etching solutions have slow etching rates and narrow high-temperature operating windows, resulting in defects such as surface roughness and grain shedding.
A synergistic system of alkali, high-boiling-point organic solvent, and sulfur-containing organosilicon compound was constructed. By anchoring the sulfur-containing organosilicon compound on the surface of glass-ceramics and forming a dynamic interface layer, the etching rate difference between the crystalline and amorphous phases was actively controlled, thereby improving etching uniformity and rate.
Achieving efficient, stable, and environmentally friendly microcrystalline glass etching at 130-160℃, resulting in a smooth and uniform surface, reduced roughness, and reduced grain shedding.
Smart Images
Figure CN122187378A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of etching technology, specifically relating to an alkaline etching solution for microcrystalline glass and its application. Background Technology
[0002] Glass-ceramics are high-performance materials composed of uniformly distributed microcrystalline phases and residual glass phases, possessing excellent mechanical, thermal, and chemical properties, and are widely used in precision optics and electronics. However, their multiphase structure also presents etching challenges: on the one hand, the overall high density of the material leads to a slow chemical etching rate; on the other hand, the crystalline and amorphous phases often exhibit different dissolution kinetics in the etching solution, easily inducing selective corrosion and causing defects such as surface roughness and grain shedding, which severely restricts their application in precision devices requiring high surface flatness.
[0003] Existing technologies mainly develop in two directions: one is to use an acidic fluoride etching system with hydrofluoric acid as the core. Although this system is highly efficient for etching ordinary glass, the etching rate for microcrystalline glass is still not ideal, and the selective corrosion of the two phases is prominent. It also produces problems of high toxicity, strong corrosion and environmental protection. The other is to turn to environmentally friendly alkaline etching systems, such as high-concentration sodium hydroxide solutions. However, their etching rates are generally low, and they are limited by the boiling point of the solution, resulting in a narrow operating temperature window, making it difficult to effectively accelerate the etching process by further increasing the temperature.
[0004] Therefore, there is an urgent need for a new alkaline etching technology that can achieve both high etching rate and excellent etching uniformity without introducing fluorides. Summary of the Invention
[0005] The purpose of this invention is to provide an alkaline etching solution for microcrystalline glass to solve the problems of high toxicity, serious pollution, and obvious selectivity of acidic fluoride etching systems for etching two phases of microcrystalline glass, as well as the slow etching rate and narrow high-temperature operating window of traditional strong alkaline etching solutions.
[0006] Based on the above concept, the technical solution adopted by this invention is as follows: According to a first aspect of the present invention, an alkaline etching solution for microcrystalline glass is provided, comprising: Alkali; Organic solvents; Additives; the additives are sulfur-containing organosilicon compounds; And the remaining deionized water.
[0007] In some embodiments, the alkali includes any one or more of sodium hydroxide and potassium hydroxide; The alkali accounts for 30%-65% of the total mass of the etching solution.
[0008] Furthermore, the alkali accounts for 50%-60% of the total mass of the etching solution.
[0009] Optionally, the organic solvent includes one or more of polyethylene glycol, polypropylene glycol, ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, dimethyl sulfoxide, N-methylpyrrolidone, glycerol, and sulfolane.
[0010] In some embodiments, the organic solvent accounts for 5%-30% of the total mass of the etching solution.
[0011] In some embodiments, the general structural formula of the sulfur-containing organosilicon compound is: Y-(CH2) n -Si(OR)3; Where Y is a functional group containing sulfur; n is an integer from 1 to 8; and R is methyl or ethyl.
[0012] In some embodiments, the sulfur-containing functional group includes any one of thiol (-SH), disulfide bond (-SS-), thioester group (-SC(O)R'), and other sulfur-containing groups that can be converted into thiol under alkaline conditions.
[0013] Optionally, the sulfur-containing organosilicon compound includes one or more of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, bis(3-trimethoxysilylpropyl)disulfide, and 3-thiopropyltrimethoxysilane.
[0014] In some embodiments, the sulfur-containing organosilicon compound accounts for 0.05%-5% of the total mass of the etching solution.
[0015] According to a second aspect of the present invention, an application of an alkaline etching solution is provided, the alkaline etching solution being used to etch microcrystalline glass at a temperature of 130°C to 160°C.
[0016] The beneficial effects of this invention are as follows: 1. This invention constructs a high-temperature stable alkaline etching system with the synergistic effect of alkali, high-boiling-point organic solvent and sulfur-containing organosilicon compound, which improves the etching rate of microcrystalline glass without the presence of fluoride, and also broadens the operating temperature window of the etching solution, achieving efficient, stable and environmentally friendly etching at 130-160℃.
[0017] 2. This invention introduces a specific sulfur-containing organosilicon compound as an additive. Its molecules can selectively anchor on the glass phase surface of the glass-ceramic and form a dynamically controlled interface, thereby actively balancing the etching rate difference between the crystalline and amorphous phases. This solves the problem of uneven etching of multiphase materials, reduces surface roughness and reduces defects such as grain shedding, and can obtain a uniform and smooth etching morphology. Attached Figure Description
[0018] Figure 1 This is a 2D image of the microcrystalline glass surface after alkaline etching according to the present invention; Figure 2 This is a low-magnification SEM image of the microcrystalline glass surface after alkaline etching according to the present invention; Figure 3 This is a high-magnification SEM image of the microcrystalline glass surface after alkaline etching according to the present invention; Figure 4 This is a cross-sectional SEM image of the microcrystalline glass surface after alkaline etching according to the present invention. Detailed Implementation
[0019] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.
[0020] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this invention pertains. The words “a” or “one” and similar terms used in this application specification and claims do not indicate a limitation of quantity, but rather indicate the presence of at least one. “A plurality” means two or more. The words “comprising” or “including” and similar terms mean that the element or object preceding “comprising” or “including” covers the element or object listed following “comprising” or “including” and its equivalents, and does not exclude other elements or objects. The words “connected” or “linked” and similar terms are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect. The words “above” and / or “below” and similar terms are for ease of description only and are not limited to a location or spatial orientation. The singular forms “a,” “the,” and “the” used in this application specification and appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.
[0021] The technical concept of this invention includes: Firstly, addressing the bottlenecks of existing microcrystalline glass etching technologies, acidic fluoride systems, while possessing certain etching efficiency, suffer from high toxicity, heavy pollution, and inability to overcome surface roughness caused by two-phase selective corrosion. Traditional alkaline etching systems, while environmentally friendly, suffer from slow etching rates, narrow high-temperature operating windows, and limited improvement in two-phase etching uniformity. This invention focuses on achieving both high-speed and highly uniform etching without introducing fluorides.
[0022] Secondly, this solution systematically addresses the aforementioned problems by constructing a ternary synergistic system of "alkali-high-boiling-point organic solvent-sulfur-containing organosilicon compound". Its advantages are twofold: firstly, by utilizing the organic solvent to enhance the system's boiling point and thermal stability, it overcomes the high-temperature operation limitations of soda ash solution, creating conditions for accelerating the etching reaction at high temperatures; secondly, by introducing a sulfur-containing organosilicon compound as an interfacial functional additive, its molecular structure design allows it to selectively act on specific phase surfaces of the glass-ceramic during etching, actively regulating local etching kinetics through anchoring, transformation, and the formation of a dynamic interfacial layer, thereby balancing the etching rates of the two phases at the microscale.
[0023] Therefore, the present invention adopts the above-mentioned technical approach and aims to provide an overall solution for an alkaline etching solution that can take into account high etching rate, excellent etching uniformity, good high temperature stability and environmental friendliness through the synergistic design of material composition and action mechanism, so as to meet the increasing demand for high-quality surface processing of microcrystalline glass in the field of precision manufacturing.
[0024] This application provides an alkaline etching solution for microcrystalline glass, including Alkali; Organic solvents; Additives; the additives are sulfur-containing organosilicon compounds; And the remaining deionized water.
[0025] This invention constructs a high-temperature stable alkaline etching system with the synergistic effect of alkali, high-boiling-point organic solvent, and sulfur-containing organosilicon compounds. Under the premise of no fluoride, it improves the etching rate of glass-ceramics and broadens the operating temperature window of the etching solution, achieving efficient, stable, and environmentally friendly etching at 130-160℃. Furthermore, by introducing specific sulfur-containing organosilicon compounds as additives, their molecules can selectively anchor on the glass phase surface of glass-ceramics and form a dynamically regulated interface, thereby actively balancing the etching rate difference between the crystalline and amorphous phases. This solves the problem of uneven etching of multiphase materials, reduces surface roughness and defects such as grain shedding, and obtains a uniform and smooth etched morphology.
[0026] The alkaline etching solution for microcrystalline glass described in this application is used for etching microcrystalline glass at a temperature of 130°C to 160°C.
[0027] The following is in conjunction with the appendix Figures 1 to 4 This application provides a detailed description of an alkaline etching solution for microcrystalline glass.
[0028] Example 1 Accurately weigh 55% sodium hydroxide, 17.5% polyethylene glycol, and 2.5% 3-mercaptopropyltrimethoxysilane by weight percentage, with the remainder being deionized water. To prepare the solution, first mix the deionized water and polyethylene glycol thoroughly in an alkali-resistant container. Then, slowly add sodium hydroxide while stirring until completely dissolved. After the solution cools, add 3-mercaptopropyltrimethoxysilane dropwise. Heat the solution in an oil bath while continuously stirring to obtain a uniform and transparent etching solution at 145°C. Immerse the cleaned microcrystalline glass substrate in this etching solution and etch at a constant temperature of 145°C in an oil bath for 35 minutes. After etching, rinse with deionized water and dry with nitrogen.
[0029] Example 2 Everything else is the same as in Example 1, except that: The polyethylene glycol was replaced with an equal percentage by mass of glycerin.
[0030] Example 3 Everything else is the same as in Example 1, except that: The 3-mercaptopropyltrimethoxysilane is replaced with an equal mass percentage of bis(3-trimethoxysilylpropyl)disulfide.
[0031] Example 4 Everything else is the same as in Example 1, except that: The mass percentage of the 3-mercaptopropyltrimethoxysilane is 0.05%.
[0032] Example 5 Everything else is the same as in Example 1, except that: The mass percentage of the 3-mercaptopropyltrimethoxysilane is 5%.
[0033] Example 6 Everything else is the same as in Example 1, except that: The etching temperature is 132°C.
[0034] Example 7 Everything else is the same as in Example 1, except that: The etching temperature is 158°C.
[0035] Comparative Example 1 Everything else is the same as in Example 1, except that: No sulfur-containing organosilicon compounds were added.
[0036] Comparative Example 2 Everything else is the same as in Example 1, except that: The mass percentage of the 3-mercaptopropyltrimethoxysilane is 0.01%.
[0037] Comparative Example 3 Everything else is the same as in Example 1, except that: The mass percentage of the 3-mercaptopropyltrimethoxysilane is 10%.
[0038] Comparative Example 4 Everything else is the same as in Example 1, except that: The 3-mercaptopropyltrimethoxysilane was replaced with an equal percentage by mass of sodium gluconate.
[0039] Comparative Example 5 Everything else is the same as in Example 1, except that: The 3-mercaptopropyltrimethoxysilane is replaced with an equal percentage by mass of sodium mercaptoacetate.
[0040] The etching rate was calculated by measuring the thickness difference of the microcrystalline glass substrate before and after etching. Surface roughness Ra was measured using a contact surface profilometer or a white light interferometer. Surface roughness Rz was obtained during the same surface roughness measurement process.
[0041] Table 1 Comparison of results between the examples and comparative examples
[0042] The results of Example 1 and Comparative Example 1 show that, under identical alkaline and organic solvent conditions, the surface roughness Ra value of Comparative Example 1 without the added compound is as high as 4.80 μm, while the Ra value of Example 1 with 2.5% by mass of 3-mercaptopropyltrimethoxysilane added is significantly reduced to 2.20 μm, while the etching rates of both are essentially the same. The fundamental function of the additive in this invention is not to accelerate the dissolution of the overall silicon-oxygen network, but rather to specifically regulate the etching kinetics balance between the crystalline and amorphous phases within the glass-ceramic at the microscale. Its working principle lies in the rapid hydrolysis of the siloxane end group (-Si(OCH3)3) of the additive into silanol (-Si(OH)3) in a high-temperature, strongly alkaline environment. This silanol then undergoes a condensation reaction with the silanol groups (Si-OH) on the glass surface, forming a strong Si-O-Si covalent bond, thereby chemically anchoring the entire additive molecule to the glass surface. After anchoring, the sulfur-containing functional groups at the other end of the molecule play a role in the interfacial region. Since the amorphous phase (glass phase) surface of the glass-ceramic is usually rich in Na... + Ca 2+The network is modified with ions, while the crystal surface is dominated by a covalent [SiO4] / [AlO4] network, with thiol ions (RS) formed by the deprotonation of mercapto groups or their derivatives. - It exhibits a stronger affinity for amorphous phase surfaces, leading to the selective enrichment of additive molecules on these surfaces. This, on the one hand, increases the concentration of OH-, the main reactant in the etching solution. - On the other hand, the mass transfer resistance of ions diffusing to the surface of the amorphous phase may also be modified by chemical action to modify the local reaction microenvironment, thereby selectively slowing down the dissolution rate of the amorphous phase, which originally had a faster etching rate, so that it is synchronized with the crystalline phase, which has a slower etching rate.
[0043] The results of Examples 3 and 1 demonstrate that the sulfur-containing functional group Y has broad applicability and is not limited to the direct thiol form. The mechanism of action of this invention is a "precursor in-situ activation" process. In the aforementioned high-temperature alkaline etching environment, the disulfide bond (-SS-), as a chemical precursor, can break, generating in-situ active sulfur-containing species (such as sulfur radicals or thiolate ions) similar to those produced by thiosilanes. These active species are generated at the solid-liquid interface and immediately participate in the selective interaction with the glass phase surface, provided that the additive molecules are already anchored to the glass surface through siloxane end groups. Therefore, as long as the Y group in the sulfur-containing organosilicon compound used can be transformed or generate interfacially active sulfur-containing species under specific process conditions, the technical effects of this invention can be achieved.
[0044] The results of Examples 4 and 5, and Comparative Examples 2 and 3, demonstrate that the present invention can achieve fine optimization of performance by adjusting the formulation within a concentration range according to different emphases on "etching efficiency" and "surface finish". Conversely, when the additive concentration is below 0.05%, the additive is insufficient to form an effective continuous interface control layer, resulting in a weak improvement effect; when the concentration is too high, exceeding 5%, an excessively thick interface layer may lead to excessive obstruction of mass transfer, not only significantly reducing the etching rate, but also potentially causing no further improvement or even a deterioration in uniformity due to side reactions or molecular aggregation.
[0045] The results of Examples 6 and 7 demonstrate that the alkaline etching solution system provided by this invention exhibits excellent stability and effectiveness over a wide temperature range of 130°C to 160°C. Example 6, etched at a relatively low temperature of 132°C, still maintained excellent performance. Example 7, operated at a high temperature of 158°C, achieved the highest etching rate of all experiments, while maintaining a surface roughness Ra value of 2.30 μm.
[0046] The results of Example 1 and Comparative Example 4 show that Comparative Example 4, using sodium gluconate as an additive, achieved an etching rate even slightly higher than that of Example 1, but its surface roughness Ra value was at the same level as that of Comparative Example 1. The mechanism of action of sodium gluconate is to accelerate the dissolution of silicate products or alter the reaction equilibrium in the bulk solution phase through complexation. It cannot identify or differentiate between different phases in the glass-ceramic. Therefore, it cannot solve the problem of selective etching caused by the structural differences between the two phases.
[0047] The results of Example 1 and Comparative Example 5 show that the overall molecular structure of the "sulfur-containing organosilicon compound" is indispensable for achieving the effects of this invention. Comparative Example 5, using sodium mercaptoacetate, showed some improvement in roughness compared to Comparative Example 1 without any modifiers, but its effect was far from reaching the level of the embodiments of this invention. This proves that if simple sulfur-containing functional groups cannot be chemically and persistently anchored to the glass surface, their effect is short-lived, weak, and unreliable.
[0048] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. The invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.
[0049] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.
Claims
1. An alkaline etching solution for microcrystalline glass, characterized in that, include Alkali; Organic solvents; Additives; the additives are sulfur-containing organosilicon compounds; And the remaining deionized water.
2. The alkaline etching solution for microcrystalline glass according to claim 1, characterized in that, The alkali includes any one or more of sodium hydroxide and potassium hydroxide; The alkali accounts for 30%-65% of the total mass of the etching solution.
3. The alkaline etching solution for microcrystalline glass according to claim 2, characterized in that, The alkali accounts for 50%-60% of the total mass of the etching solution.
4. The alkaline etching solution for microcrystalline glass according to claim 1, characterized in that, The organic solvent includes one or more of polyethylene glycol, polypropylene glycol, ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, dimethyl sulfoxide, N-methylpyrrolidone, glycerol, and sulfolane.
5. The alkaline etching solution for microcrystalline glass according to claim 4, characterized in that, The organic solvent accounts for 5%-30% of the total mass of the etching solution.
6. The alkaline etching solution for microcrystalline glass according to claim 1, characterized in that, The general structural formula of the sulfur-containing organosilicon compound is: Y-(CH2) n -Si(OR)3; Where Y is a functional group containing sulfur; n is an integer from 1 to 8; and R is methyl or ethyl.
7. The alkaline etching solution for microcrystalline glass according to claim 6, characterized in that, The sulfur-containing functional groups include any one of the following: thiol, disulfide bond, thioester group, and other sulfur-containing groups that can be converted into thiol under alkaline conditions.
8. The alkaline etching solution for microcrystalline glass according to claim 6, characterized in that, The sulfur-containing organosilicon compounds include one or more of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, bis(3-trimethoxysilylpropyl)disulfide, and 3-thiopropyltrimethoxysilane.
9. The alkaline etching solution for microcrystalline glass according to claim 1, characterized in that, The sulfur-containing organosilicon compound accounts for 0.05%-5% of the total mass of the etching solution.
10. An application of the alkaline etching solution as described in any one of claims 1-9, characterized in that, The alkaline etching solution is used to etch microcrystalline glass at a temperature of 130°C to 160°C.