Hydrofluoric acid resistant compositions and methods of making the same, substrates and methods of processing the same

Abstract

The application discloses a kind of hydrofluoric acid-resistant compositions and preparation method thereof, substrate and processing method thereof.The hydrofluoric acid-resistant composition includes macromolecular resin and inorganic filler, wherein, macromolecular resin includes structural resin, bonding resin and binding force reinforcing resin, wherein, structural resin contains fluorine-containing polymer;Bonding resin contains polyvinyl acetal resin;Binding force reinforcing resin contains epoxy resin and phenolic resin.The application realizes excellent hydrofluoric acid resistance by using specific composition formula, and can be dissolved and removed by mild alcohol solvent soaking method after processing or by physical removal (such as hand tearing, tape tearing, etc.), thereby solving the technical problem that physical tearing of protective film easily leads to ultra-thin glass fragments.

Description

Technical Field

[0001] This invention relates to the field of glass substrate processing technology, and in particular to a hydrofluoric acid resistant composition and its preparation method, a substrate and its processing method. Background Technology

[0002] In modern electronic device manufacturing, glass substrates, especially ultra-thin glass (UTG), are widely used due to their excellent optical and mechanical properties. The processing of ultra-thin glass (e.g., glass with a thickness of no more than 70 micrometers) typically involves high-precision cutting and edge treatment steps.

[0003] A common processing method is to first laser-cut the glass substrate, but laser cutting easily produces microcracks and burrs at the glass edges. To eliminate these defects and improve edge strength, a chemical etching process is required, especially using a hydrofluoric acid (HF) solution to finish the cut edges.

[0004] In this processing step, a temporary protective layer must be applied to the surface of the glass substrate to ensure that only the cut edges are exposed to hydrofluoric acid, while the main surface of the substrate (such as functional areas) is not corroded. Existing protective technologies, such as the use of polymer tape, provide some acid resistance, but their primary removal method is mechanical peeling.

[0005] However, ultra-thin glass is extremely brittle, and the physical stress generated when mechanically peeling off the protective film can easily cause the glass substrate to crack and break into fragments, thus severely reducing production yield. In addition, other types of chemical protective films (such as traditional photoresists) may require the use of strong alkalis or strong solvents for removal, which also carries the risk of complex processes or damage to the substrate.

[0006] Therefore, there is an urgent need in this field for a new type of protective material that must simultaneously meet two seemingly contradictory performance requirements: on the one hand, it must have sufficient chemical inertness and adhesion to effectively protect the substrate surface in hydrofluoric acid solution; on the other hand, after completing its protective task, it must be easily and completely removed by a gentle, non-mechanical means (e.g., solvent immersion at a mild temperature) to avoid physical damage to the ultrathin glass. Summary of the Invention

[0007] The main objective of this invention is to propose a hydrofluoric acid resistant composition, which aims to solve the technical problem that in the prior art, when temporary protective materials are applied to the processing of ultrathin glass substrates, the removal method (such as mechanical tearing) easily leads to substrate breakage and low yield.

[0008] To achieve the above objectives, the present invention provides a hydrofluoric acid-resistant composition comprising a polymer resin and an inorganic filler, wherein,

[0009] The polymer resin includes:

[0010] Structural resin, wherein the structural resin comprises a fluoropolymer;

[0011] The adhesive resin comprises a polyvinyl acetal resin; and

[0012] A bonding-strengthening resin, wherein the bonding-strengthening resin comprises epoxy resin and phenolic resin;

[0013] The surface of the inorganic filler is modified with one or more functional groups selected from the group consisting of aniline, alkyl, nitrogen-containing functional groups on the main chain or branches, double-bonded functional groups, and epoxy groups.

[0014] In one embodiment, the fluoropolymer includes polyvinylidene fluoride.

[0015] In one embodiment, the molecular weight of the polyvinylidene fluoride is between 400,000 g / mol and 2,000,000 g / mol.

[0016] In one embodiment, the polyvinyl acetal resin includes polyvinyl butyral resin.

[0017] In one embodiment, the molecular weight of the polyvinyl butyral resin is between 5 g / mol and 10,000 g / mol.

[0018] In one embodiment, in the polyvinyl butyral resin, the weight percentage of polyvinyl alcohol is between 11% and 27%, and the weight percentage of polyvinyl acetate is between 0% and 8%.

[0019] In one embodiment, in the polyvinyl butyral resin, the weight percentage of polyvinyl alcohol is between 18% and 21%, and the weight percentage of polyvinyl acetate is between 1% and 6%.

[0020] In one embodiment, the epoxy resin is selected from at least one of glycidylamine epoxy resin, polyfunctional o-cresol glycidyl ether epoxy resin, phenol-biphenyl epoxy resin, bisphenol F solid epoxy resin, isocyanate modified epoxy resin, naphthol epoxy resin, phenol-formaldehyde epoxy resin, semi-crystalline epoxy resin, liquid bisphenol A type epoxy resin, liquid bisphenol F type epoxy resin, liquid bisphenol A-bisphenol F composite epoxy resin, liquid bisphenol S epoxy resin, liquid phenolic epoxy resin, and liquid phenolic resin.

[0021] In one embodiment, the phenolic resin is selected from at least one of linear phenol-formaldehyde resin and linear BPA-formaldehyde resin.

[0022] In one embodiment, the content of the phenolic resin and the content of the epoxy resin satisfy the following formula:

[0023] Phenolic resin content = (hydroxyl equivalent of phenolic resin / epoxy equivalent of epoxy resin) × epoxy resin content.

[0024] In one embodiment, the inorganic filler is selected from at least one of graphite, carbon black, graphene, fullerene, silicon dioxide, aluminum oxide, aluminum hydroxide, calcium carbonate, magnesium carbonate, magnesium silicate, silicon carbide, titanium carbide, titanium oxide, magnesium oxide, calcium oxide, boron nitride, and aluminum nitride.

[0025] In one embodiment, the composition comprises, by weight percentage:

[0026] 60% to 100% of the aforementioned polymeric resin; and

[0027] The inorganic filler content is 0% to 40%.

[0028] In one embodiment, the polymer resin comprises, by weight percentage:

[0029] 30% to 80% of the aforementioned structural resin;

[0030] 20% to 70% of the adhesive resin; and

[0031] 0% to 20% of the bonding strength strengthening resin.

[0032] In one embodiment, the hydrofluoric acid resistant composition further comprises a solvent selected from at least one of water, N-methylpyrrolidone, ethanol, acetone, ethyl acetate, n-butyl ether, methyl tert-butyl ether, dimethyl phthalate, butanone, dimethyl sulfoxide, n-butyl ketone, cyclohexanone, toluene, and xylene.

[0033] In one embodiment, the hydrofluoric acid resistant composition further comprises an additive, which includes at least one of a leveling agent, a dispersant, and a defoamer.

[0034] In one embodiment, the solvent content is 0.5 to 8 times the total weight of the polymer resin; and / or

[0035] The content of the additive is 0.5% to 5% by weight of the total weight of the polymer resin.

[0036] The present invention also provides a method for preparing a hydrofluoric acid resistant composition, for preparing the hydrofluoric acid resistant composition described in any of the preceding claims, the preparation method comprising the following steps:

[0037] Preparation of resin slurry: The structural resin, the bonding resin and the binding strength reinforcing resin are mixed in a first solvent to obtain a resin slurry;

[0038] Preparation of filler slurry: The inorganic filler is mixed in a second solvent to obtain a filler slurry; and

[0039] Mixing: The filler slurry is added to the resin slurry under stirring and mixed to obtain a hydrofluoric acid resistant composition ink.

[0040] In one embodiment, in the step of preparing the resin slurry, at least one additive selected from dispersants, defoamers, and leveling agents is pre-dissolved in the first solvent; and / or

[0041] In the step of preparing the filler slurry, at least one additive selected from dispersants, defoamers and leveling agents is pre-dissolved in the second solvent.

[0042] In one embodiment, the mixing conditions of the preparation method include at least one of the following:

[0043] The mixing speed during the preparation of the resin slurry is between 3600 rpm and 7200 rpm, the slurry temperature is not higher than 45°C, and the duration is between 10 minutes and 50 minutes.

[0044] The mixing speed during the preparation of the filler slurry is between 3600 rpm and 7200 rpm, the slurry temperature is not higher than 45°C, and the duration is between 10 minutes and 50 minutes; and

[0045] The mixing speed of the filler slurry and the resin slurry is between 3600 rpm and 7200 rpm, the slurry temperature is not higher than 45°C, and the duration is between 60 minutes and 120 minutes.

[0046] In one embodiment, after the mixing step, the preparation method further includes:

[0047] Preparation of dry film: The hydrofluoric acid resistant composition ink is coated onto the substrate film and cured to obtain the hydrofluoric acid resistant composition dry film.

[0048] In one embodiment, the curing process includes:

[0049] The hydrofluoric acid resistant composition ink is dried in a temperature range of 50°C to 120°C for 30 seconds to 30 minutes.

[0050] The present invention also proposes a method for processing a substrate, comprising the following steps:

[0051] Provide substrate;

[0052] Application of composition: Apply the hydrofluoric acid resistant composition described in any one of the preceding claims to the surface of the substrate to form a protective layer on the surface of the substrate;

[0053] Etching process: The substrate on which the protective layer is formed is etched using a hydrofluoric acid solution;

[0054] Remove the protective layer: The substrate after etching is placed in a stripping solvent or removed by physical means to remove the protective layer.

[0055] In one embodiment, when using an ink-like hydrofluoric acid-resistant composition, the step of applying the composition includes:

[0056] Coating: Applying a hydrofluoric acid resistant composition ink to the surface of the substrate by means of dip coating, screen printing, pad printing, stencil printing, spraying, or squeegee printing; and

[0057] Curing: The hydrofluoric acid resistant composition ink coated on the surface of the substrate is dried at a temperature of 50°C to 120°C for 3 to 30 minutes to form the protective layer.

[0058] In one embodiment, when a hydrofluoric acid-resistant composition in dry film form is used, the step of applying the composition includes:

[0059] Hot pressing: The hydrofluoric acid resistant dry film is hot-pressed onto the surface of the substrate at a temperature range of 70°C to 150°C and a pressure of not less than 0.4 MPa for 30 seconds to 5 minutes to form the protective layer.

[0060] In one embodiment, the bonding is performed under a vacuum of less than 0.1 MPa.

[0061] In one embodiment, the etching process further includes: laser cutting the substrate before etching it with the hydrofluoric acid solution.

[0062] In one embodiment, during the etching process, the concentration of the hydrofluoric acid solution is between 1% and 5%, and the immersion time lasts from 30 seconds to 30 minutes.

[0063] In one embodiment, the stripping solvent is selected from at least one of N-methylpyrrolidone, methanol, ethanol, n-butanol, acetone, ethyl acetate, n-butyl ether, methyl tert-butyl ether, dimethyl phthalate, butanone, dimethyl sulfoxide, n-butyl ketone, cyclohexanone, toluene, and xylene.

[0064] In one embodiment, the stripping solvent further contains 0.5 to 3% by weight of a surfactant.

[0065] In one embodiment, the step of removing the protective layer is performed in a temperature range between 20°C and 60°C.

[0066] In one embodiment, the substrate is an ultrathin glass with a thickness of no more than 70 micrometers.

[0067] The present invention also provides a substrate prepared by the processing method of any of the preceding substrates.

[0068] The hydrofluoric acid resistant composition proposed in this application has the following beneficial effects:

[0069] 1. Excellent hydrofluoric acid resistance and processing compatibility: Through the non-polar synergistic compounding of structural resin and surface-modified inorganic filler, the strong acid resistance of traditional protective materials (such as PO tape) can be significantly improved, achieving no peeling from 4% hydrofluoric acid solution for 5 minutes, thus overcoming the easy penetration defect of existing materials and avoiding uneven etching. Furthermore, this invention can directly upgrade the performance of ordinary coatings to a level suitable for ultra-thin glass (≤70μm), exhibiting significant process advantages.

[0070] 2. Excellent Adhesion and Interface Compatibility: The network structure formed by the cross-linking of the bonding resin and the binding strength strengthening resin ensures excellent adhesion between the cured protective layer and the glass substrate, thus solving the problems of poor adhesion and easy breakage of existing materials. This excellent adhesion ensures that the present invention is very suitable for use as a temporary protective layer, guaranteeing the stability of processing and the integrity of the final substrate.

[0071] 3. High Heat and Scratch Resistance and Optimized Removal: The three-dimensional network formed by cross-linking of polymer resins allows the cured protective layer to withstand high temperatures (up to 120°C) and scratches during laser cutting without damage. Simultaneously, after etching, extremely low residue risk is achieved, and rapid removal is accomplished via alcohol solution (ethanol ultrasonic dissolution for 3 minutes). This characteristic significantly reduces the complexity of processing steps and improves the yield of ultra-thin glass. Furthermore, because the composition of this invention maintains excellent adhesion to the substrate even under high hardness, it is highly suitable for integrated processes of laser cutting and hydrofluoric acid etching, meeting the high-speed processing requirements of flexible displays, etc. In addition, this invention also features low water absorption (<1%) and high peelability, supporting gentle removal conditions without charring problems.

[0072] 4. Flexible and diverse applications: It can be formulated into ink or dry film form for dip coating / screen printing or vacuum bonding, and is easy to remove from alcohol solutions. It can also be formulated into paste form for comprehensive protection of glass substrates. Furthermore, it can be combined with release films as a temporary mask. Attached Figure Description

[0073] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0074] Figure 1 This is a schematic flowchart of an embodiment of the preparation method of the hydrofluoric acid resistant composition of the present invention;

[0075] Figure 2 This is a schematic flowchart of an embodiment of the substrate processing method of the present invention.

[0076] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0077] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0078] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0079] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0080] This invention proposes a hydrofluoric acid resistant composition designed to form a protective layer that not only effectively resists etching by hydrofluoric acid solution, but also can be dissolved and removed after processing by a mild stripping solvent soaking method, or by physical removal (e.g., by hand tearing, tape removal, etc.), thereby fundamentally avoiding physical damage to the ultrathin glass substrate.

[0081] In this embodiment of the invention, the hydrofluoric acid resistant composition comprises a polymer resin and an inorganic filler, wherein the polymer resin provides the composition with basic film-forming properties, adhesion to the substrate, core chemical resistance, and removability in a specific solvent, while the inorganic filler serves as a functional filler that can be used to improve the mechanical properties, scratch resistance, or assist in processing of the composition.

[0082] Specifically, polymeric resins include structural resins, bonding resins, and binding strength-enhancing resins.

[0083] Structural resins primarily function as a framework in the composition to resist chemical corrosion. Their core function is to provide the final cured protective layer with excellent resistance to hydrofluoric acid and other acid / alkali corrosion, thus maintaining structural stability in strong acid environments (such as hydrofluoric acid) and protecting the underlying substrate from corrosion. In high-filler systems, while the introduction of large amounts of inorganic fillers can improve hardness and scratch resistance, it can also easily lead to material brittleness. The introduction of structural resins forms a tough framework within the cured network, effectively absorbing and dispersing stress, thereby significantly improving the mechanical toughness and crack resistance of the entire hydrofluoric acid-resistant composition. Simultaneously, their excellent chemical inertness is crucial to ensuring the material's resistance to strong acids (such as hydrofluoric acid, sulfuric acid, and hydrochloric acid) in wet chemical processes like hydrofluoric acid etching. Furthermore, structural resins can effectively reduce overall permeability and improve Tg point and thermal stability.

[0084] In some embodiments of the present invention, the structural resin comprises a fluoropolymer. The molecular backbone of such polymers contains highly stable carbon-fluorine bonds. It is this non-reactive and hydrophobic chemical structure that endows them with high chemical non-reactivity, enabling them to effectively resist attacks from strong acids and bases.

[0085] Specifically, fluoropolymers include polyvinylidene fluoride (PVDF). The structural formula of polyvinylidene fluoride is as follows: Its molecular weight ranges from 400,000 g / mol to 2,000,000 g / mol (i.e., 400,000 to 2,000,000). This molecular weight range is designed to balance the material's processing fluidity and its final corrosion resistance after curing. If the molecular weight is below 400,000 g / mol, the composition may have poor film-forming properties, resulting in an insufficiently strong protective layer that is prone to swelling or breakage during chemical immersion. If it is above 2,000,000 g / mol, the composition will have excessive viscosity, making it difficult to dissolve uniformly in solvents and hindering subsequent coating processes. By controlling the molecular weight within this range, the composition's processability in preparation and application is ensured, while a dense framework is formed after curing to resist the penetration of hydrofluoric acid solutions.

[0086] The adhesive resin, as the core component in the system that forms a three-dimensional cross-linked network and ensures strong adhesion to the substrate, primarily functions to form a dense, high-strength network structure through a curing reaction. This network not only tightly binds a large number of inorganic filler particles together to form a robust whole, but also enables the entire protective layer to form a strong chemical or physical bond with the surfaces of various substrates with different properties, such as glass and ceramic substrates. Simultaneously, the adhesive resin can also significantly improve the cross-linking density, hardness, heat resistance, and chemical resistance of the protective layer by forming effective chemical or physical bonds with the structural resin and the surface of the inorganic fillers. Crucially, its main chain structure retains the characteristic of swelling or dissolving in specific mild solvents (such as alcohols), which allows the protective layer formed by the hydrofluoric acid-resistant composition of this invention to be gently and non-damagingly removed after use.

[0087] In some embodiments of the present invention, the adhesive resin comprises a polyvinyl acetal resin. Specifically, the polyvinyl acetal resin includes polyvinyl butyral resin (PVB), which has the following structural formula: .

[0088] To ensure good film-forming properties and suitable solubility of the material, the molecular weight of the polyvinyl butyral resin used is between 5 g / mol and 10,000 g / mol. As a specific, non-limiting example, the molecular weight of the polyvinyl butyral resin may be 5 g / mol, 100 g / mol, 500 g / mol, 1000 g / mol, 5000 g / mol, or 10,000 g / mol.

[0089] PVB was chosen as the core binder resin because it contains a significant proportion of hydroxyl groups, which enable the polymer to form intermolecular and intramolecular hydrogen bonds, increasing intermolecular forces. Furthermore, due to the presence of hydroxyl groups in its molecular chain, PVB can undergo cross-linking reactions with other thermosetting resins, such as phenolic, urea-formaldehyde, melamine, epoxy, and diisocyanates. By mixing them in appropriate proportions, the brittleness and adhesion of the product can be improved, and bridging reactions can enhance chemical resistance and coating hardness.

[0090] Specifically, PVB also possesses excellent film-forming properties, transparency, and superior mechanical toughness, providing a robust yet flexible basic framework for composite materials. Furthermore, the PVB molecular chain contains both hydrophobic butyral groups and hydrophilic alcohol hydroxyl groups. This amphiphilic structure gives it excellent adhesion to polar surfaces such as metals (e.g., copper) and inorganic materials (e.g., glass substrates), while also maintaining good compatibility with other organic resins in the system.

[0091] More importantly, the hydroxyl groups on the PVB molecular chain not only provide adhesion but also possess chemical reactivity. These hydroxyl groups can undergo cross-linking reactions with the epoxy and phenolic resins in the bonding resin during the curing process, thus transforming the PVB matrix from an isolated entity into a deeply integrated part of the cross-linked network through chemical bonding. This co-reaction significantly enhances the cohesive strength, heat resistance, and overall structural density of the final protective film, enabling it to better resist high temperatures, high pressures, and chemical corrosion.

[0092] Finally, although PVB participates in the cross-linking reaction, its main chain structure and moderate cross-linking allow the entire system to remain robust while retaining its ability to swell or dissolve in specific mild solvents such as alcohols. Furthermore, by adjusting the ratio of alcohol hydroxyl, acetoxy, and butyral groups in the PVB raw material, its solubility, water resistance, and compatibility with other components can be precisely fine-tuned.

[0093] In some embodiments, to further precisely control the solubility, water resistance, and compatibility with other components of the material, the chemical composition of the PVB resin itself can be selected. Specifically, in polyvinyl butyral resin, the weight percentage of polyvinyl alcohol as the hydrophilic source can be between 11% and 27%, for example, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, and 27%; while the weight percentage of polyvinyl acetate can be between 0% and 8%, for example, 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 8%. By adjusting the proportions of these groups, fine-tuning of the behavior of the final protective film in different solvents and its hydrolysis resistance can be achieved.

[0094] Preferably, in the polyvinyl butyral resin, the weight percentage of polyvinyl alcohol is between 18% and 21%, and the weight percentage of polyvinyl acetate is between 1% and 6%.

[0095] Specifically, the optimal polyvinyl alcohol (polyvinyl alcohol) content aims to achieve the best balance between adhesion, reactivity, and water resistance. Within the broader functional range of this invention (11% to 27%), when the polyvinyl alcohol content is in the lower range (e.g., 11% to 18%), the composite material already possesses good peelability and sufficient adhesion, and exhibits stronger water resistance. When its content is in the higher range (e.g., 21% to 27%), the adhesion and reactivity of the material are further enhanced, and the peeling speed in alcohol solvents may be faster, but the sensitivity to moisture will increase accordingly. In contrast, controlling the polyvinyl alcohol content within the preferred optimal window of 18% to 21% provides excellent adhesion and crosslinking reactivity sufficient to cope with various demanding processes, while maintaining the hydrophilicity of the material at an ideal level. This maximizes its bonding and curing performance without sacrificing water resistance, achieving the most balanced overall effect.

[0096] Similarly, the optimal content of polyvinyl acetate (acetoxy) aims to finely adjust the synergistic effect between the material's hydrophobicity and core functions. Within its wider functional range (0% to 8%), while higher polyvinyl acetate contents (e.g., 6% to 8%) can further enhance the material's hydrolysis resistance, they may slightly dilute the concentration of the alcohol hydroxyl groups, thus having a minor impact on adhesion or reactivity. Controlling its content within the preferred range of 1% to 6% introduces a sufficient amount of hydrophobic groups, significantly optimizing and improving the water resistance and environmental stability of the final protective film, without substantially negatively impacting the core function of the alcohol hydroxyl groups (providing adhesion and reaction sites). Therefore, this range is the best choice for effectively enhancing the material's weather resistance without sacrificing core performance.

[0097] In summary, by limiting the contents of polyvinyl alcohol and polyvinyl acetate to the optimal window of 18%-21% and 1%-6% respectively, the PVB structural resin can achieve the best balance in key performance dimensions such as adhesion, reactivity, water resistance and mild solvent solubility, thus facilitating alcohol removal after hydrofluoric acid etching.

[0098] As an auxiliary component to improve crosslinking density and pressure resistance, the bonding strength reinforcing resin's main function is to crosslink with the hydroxyl groups in the adhesive resin (PVB) through a curing reaction, forming a dense, high-strength network structure. This network structure significantly improves the overall crosslinking density, hardness, heat resistance, chemical resistance, and adhesion to the substrate of the protective layer.

[0099] In some embodiments of the present invention, the bonding strengthening resin comprises an epoxy resin and a phenolic resin as a crosslinking agent thereon.

[0100] In order to achieve fine control over the final performance, the epoxy resin used in this invention can be one or a combination of various types of epoxy resins.

[0101] Specifically, the epoxy resin is selected from at least one of the following: glycidylamine epoxy resin, polyfunctional o-cresol glycidyl ether epoxy resin, phenol-biphenyl epoxy resin, bisphenol F solid epoxy resin, isocyanate modified epoxy resin, naphthol type epoxy resin, phenol-formaldehyde epoxy resin, semi-crystalline epoxy resin, liquid bisphenol A type epoxy resin, liquid bisphenol F type epoxy resin, liquid bisphenol A-bisphenol F composite epoxy resin, liquid bisphenol S epoxy resin, liquid phenolic epoxy resin, and liquid phenolic resin.

[0102] Specifically, the epoxy resin material used in this invention has an epoxy molecular weight of 2500 g / mol to 6000 g / mol.

[0103] The structural formula of glycidylamine epoxy resin is: Its epoxy equivalent is between 93 and 150 g / eq, hydrolyzed chlorine should be less than 200 ppm, and viscosity at 25℃ is between 0.5 and 5 Poise.

[0104] The structural formula of the functional o-cresol-formaldehyde glycidyl ether type epoxy resin is: Its epoxy equivalent ranges from 195 to 230 g / eq, its hydrolytic chlorine at 120℃ ranges from 470 to 1000 g / eq, its ICI viscosity at 150℃ ranges from 0.9 to 60 Poise, and its softening point ranges from 45 to 96℃.

[0105] The structural formula of phenol-biphenyl epoxy resin is: Its epoxy equivalent ranges from 261 to 280 g / eq, hydrolytic chlorine content is less than 100 ppm, viscosity at 25°C is between 0.1 and 4.5 Poise, and softening point is 45 to 75°C. Adding it to PVB and its hydroxyl copolymerization can effectively improve the glass strength, Tg, and impact resistance of copper.

[0106] The structural formula of bisphenol F solid epoxy resin is: Its epoxy equivalent ranges from 450 to 1000 g / eq, hydrolytic chlorine content is less than 300 ppm, viscosity at 25°C is <1000 Poise, and softening point is 50 to 88°C. Solid bisphenol F type epoxy resin is characterized by low viscosity and flexibility. The properties of its cured product are almost identical to those of bisphenol A type epoxy resin. Adding it to PVB for copolymerization with its hydroxyl groups can effectively improve its corrosion resistance.

[0107] The structural formula of isocyanate-modified epoxy resin is:

[0108] Its epoxy equivalent ranges from 280 to 380 g / eq, hydrolytic chlorine content is less than 300 ppm, viscosity at 25°C is between 0.5 and 3 Poise, and softening point is 50 to 88°C. Solid isocyanate-modified epoxy resin is characterized by low viscosity and flexibility. The properties of its cured product are almost identical to those of bisphenol A type epoxy resin. Adding it to PVB and copolymerizing it with its hydroxyl groups can effectively improve bond strength and peel strength.

[0109] The structural formula of naphthol-type epoxy resin is: Its epoxy equivalent ranges from 280 to 380 g / eq, hydrolytic chlorine content is less than 300 ppm, viscosity at 25°C is between 0.5 and 3 Poise, and softening point is 50 to 88°C. Among them, naphthol-type epoxy resins are superior to traditional bisphenol A type in terms of curing properties, heat resistance, and mechanical properties. Furthermore, due to its lower internal stress, it has a higher Tg and better adhesion. When added to structural resins and copolymerized with its hydroxyl groups, it can effectively improve the Tg point, bond strength, and peel strength.

[0110] The structural formula of phenolic epoxy resin is: Its epoxy equivalent ranges from 165 to 200 g / eq, hydrolytic chlorine content is less than 250 ppm, viscosity at 25°C is between 1.1 and 12.5 Poise, and softening point is 25 to 86°C. Phenolic epoxy resins have two or more epoxy groups in their molecular structure. Therefore, when added to structural resins and copolymerized with their hydroxyl groups, the product exhibits high crosslinking density, excellent adhesive strength, heat resistance, and chemical resistance. Furthermore, the presence of two or more epoxy groups in the molecular structure of phenolic epoxy resins results in a high crosslinking density in the cured product, leading to excellent adhesive strength, heat resistance, and chemical resistance.

[0111] The structural formula of semi-crystalline epoxy resin is: .

[0112] The structural formulas of liquid bisphenol A type epoxy resin and liquid bisphenol F type epoxy resin are as follows: .

[0113] The structural formula of liquid bisphenol A-bisphenol F composite epoxy resin is: .

[0114] The structural formula of liquid phenolic epoxy resin is: or .

[0115] The structural formula of liquid phenolic resin is: .

[0116] Among the aforementioned epoxy resins, semi-crystalline epoxy resin, liquid bisphenol A type epoxy resin, liquid bisphenol F type epoxy resin, liquid bisphenol A-bisphenol F composite epoxy resin, and liquid bisphenol S epoxy resin have epoxy equivalents ranging from 140 to 214 g / eq, hydrolytic chlorine content less than 250 ppm, and viscosity at 25°C ranging from 1300 to 4500 mPa·s. These resins not only possess low viscosity and high crosslinking density, but also exhibit excellent adhesive strength, heat resistance, and chemical resistance. Their main function is to regulate resin flowability and adhesion to the substrate, making them particularly suitable for use on glass substrates.

[0117] In some embodiments of the present invention, the phenolic resin is selected from at least one of linear phenol-formaldehyde resin and linear BPA-formaldehyde resin.

[0118] Specifically, the structural formula of linear phenol-formaldehyde resin is: Its free phenol content is <0.6%, and its softening point is 96~123. o C, with a hydroxyl equivalent between 105 and 119 g / eq and an electrical conductivity less than 8 μS / cm.

[0119] The structural formula of linear BPA formaldehyde resin is: Its free phenol content is 1-45%, and its softening point is 90-140°C. o C, hydroxyl equivalent between 112 and 130 g / eq, and conductivity less than 20 μS / cm.

[0120] Choosing these phenolic resins, especially those with low free phenol content and low electrical conductivity, helps ensure the stability of the curing reaction and the electrical insulation performance of the final protective layer.

[0121] In some embodiments, the content of phenolic resin and the content of epoxy resin satisfy the following formula:

[0122] Phenolic resin content = (hydroxyl equivalent of phenolic resin / epoxy equivalent of epoxy resin) × epoxy resin content.

[0123] Here, "epoxy equivalent weight (EEW)" refers to the number of grams of epoxy resin containing 1 mole of epoxy groups, while "hydroxyl equivalent weight (EEW)" refers to the number of grams of phenolic resin containing 1 mole of phenolic hydroxyl groups. These two values ​​are key parameters for measuring the reactivity of the resin. Therefore, the essence of the above formula is a mathematical conversion of the chemical equilibrium relationship of "moles of phenolic hydroxyl groups ≈ moles of epoxy groups". By using this formula, the amount of phenolic resin containing an equal number of reaction sites can be accurately calculated based on the amount of epoxy resin used and its epoxy equivalent weight.

[0124] The fundamental reason for using the above formula to determine the amount of the two resins is that it follows the stoichiometric principle in chemical reactions, aiming to achieve an ideal balance in the number of the two core functional groups participating in the reaction—the phenolic hydroxyl groups (-OH) on the phenolic resin molecular chain and the epoxy groups on the epoxy resin molecular chain—so as to obtain the curing product with the best performance.

[0125] Specifically, the curing process of the bonding-enhancing resin mainly involves a ring-opening addition reaction between phenolic hydroxyl groups and epoxy groups, forming a highly cross-linked three-dimensional network structure. To ensure this reaction proceeds most completely and efficiently, theoretically, one phenolic hydroxyl functional group should react with exactly one epoxy functional group. Therefore, the ideal feed ratio should make the total molar ratio of phenolic hydroxyl groups to epoxy groups in the formulation as close to 1:1 as possible. Epoxy equivalent (EEW) refers to the number of grams of epoxy resin containing 1 mole of epoxy groups, and hydroxyl equivalent (HEW) refers to the number of grams of phenolic resin containing 1 mole of phenolic hydroxyl groups. By using this formula, the amount of phenolic resin to match it can be accurately calculated based on the amount of epoxy resin selected and its epoxy equivalent.

[0126] It is understandable that using this stoichiometric method to determine the proportions ensures the full progress of the crosslinking reaction and avoids the formation of a large number of unreacted functional groups in the cured network due to an excess of any one component. This results in the highest crosslinking density of the final cured bonding-strengthening resin, thereby achieving superior heat resistance, chemical resistance, and the strongest mechanical strength and adhesion to the substrate.

[0127] Inorganic fillers are mainly used as mechanical property enhancers in compositions, significantly improving the mechanical properties (such as hardness, modulus), heat resistance, and dimensional stability of the protective layer formed by the composition. In this application, in order to improve the interfacial compatibility between the inorganic filler and the polymer resin matrix, prevent their agglomeration at high contents, and ensure that the two can effectively combine to transfer stress, the surface of the inorganic filler has undergone specific functional group modification.

[0128] Specifically, the surface of the inorganic filler is modified with one or more functional groups selected from the group consisting of aniline, alkyl, nitrogen-containing functional groups on the main chain or branches, double-bonded functional groups, and epoxy groups. These functional groups can react with or form strong interactions with active groups (such as hydroxyl or epoxy groups) in the polymer resin, thereby tightly anchoring the inorganic filler in the resin matrix. This results in a protective layer with higher hardness, Young's modulus, and flexural modulus, effectively resisting the impact and thermal stress during the etching process.

[0129] In some embodiments, the inorganic filler is selected from at least one of graphite, carbon black, graphene, fullerene, silicon dioxide, aluminum oxide, aluminum hydroxide, calcium carbonate, magnesium carbonate, magnesium silicate, silicon carbide, titanium carbide, titanium oxide, magnesium oxide, calcium oxide, boron nitride, and aluminum nitride. These inorganic fillers, when added to the polymer resin matrix in appropriate proportions, serve as a reinforcing framework and functional component of the material, significantly improving the overall performance of the cured protective layer. On one hand, these rigid inorganic filler particles can form a dense physical support network within the polymer matrix, thereby significantly improving the mechanical properties of the composite material, such as hardness, Young's modulus, tensile modulus, and flexural modulus, enhancing its ability to maintain its shape under high temperature and high pressure processes. On the other hand, by introducing inorganic fillers, the coefficient of thermal expansion (CTE) of the entire composition can be effectively reduced, and its thermal conductivity increased, thereby improving the heat dissipation efficiency and reliability of the protective layer, making it more suitable for ultra-thin glass processing applications.

[0130] This invention provides a diverse selection of inorganic fillers, allowing for optimization of the specific properties of the hydrofluoric acid-resistant composition according to specific application requirements. For example, selecting black fillers such as graphite or carbon black can aid in the absorption of infrared laser energy, facilitating laser cutting; selecting high-hardness fillers such as silica can effectively improve the scratch resistance and mechanical strength of the material. It is understood that by selectively combining and compounding the above-mentioned inorganic fillers, this invention can flexibly adjust various performance indicators of the hydrofluoric acid-resistant composition to meet the diverse needs of glass substrates of different specifications under specific processing techniques.

[0131] In some embodiments, the relative content of each major component in the composition is defined to achieve an optimal balance of various performance indicators. Specifically, the hydrofluoric acid resistant composition may contain 60% to 100% (e.g., 60%, 70%, 80%, 90%, 100%, etc.) of a polymeric resin by weight percentage, and 0% to 40% (e.g., 0%, 10%, 20%, 30%, 40%, etc.) of an inorganic filler.

[0132] Specifically, inorganic fillers are the core components that impart high mechanical strength, low coefficient of thermal expansion (CTE), and high scratch resistance to the final protective layer. By controlling their content within the range of 0% to 40%, sufficient rigidity and dimensional stability can be ensured in the cured protective layer, effectively coping with the thermomechanical stresses introduced by processes such as laser cutting and hydrofluoric acid etching. If the content of inorganic fillers exceeds 40%, although their contribution to reducing the coefficient of thermal expansion and improving mechanical properties is significant, it may lead to excessively high viscosity of the composition, affecting coating uniformity.

[0133] The polymer resin acts as a continuous phase matrix, binding the inorganic filler particles tightly together and ensuring the entire protective layer adheres firmly to the glass substrate. If the polymer resin content is less than 60%, it is insufficient to form a continuous and complete resin network to encapsulate and bond the inorganic filler, potentially leading to problems such as poor film formation, material brittleness, and insufficient adhesion.

[0134] Therefore, by controlling the weight percentages of polymer resin and inorganic filler to be in the ranges of 60% to 100% and 0% to 40% respectively, the present invention achieves an optimal balance between excellent mechanical corrosion resistance and good film-forming properties and adhesion, ensuring that the composition can form a uniform, highly adhesive protective layer and provide sufficient rigidity and dimensional stability after curing to cope with subsequent complex processes.

[0135] In some embodiments of the present invention, the polymer resin comprises 30% to 80% (e.g., 30%, 40%, 50%, 60%, 70%, 80%, etc.) of structural resin, 20% to 70% (e.g., 20%, 30%, 40%, 50%, 60%, 70%, etc.) of binding resin, and 0% to 20% (e.g., 0%, 5%, 10%, 15%, 20%, etc.) of bonding strength reinforcing resin by weight percentage.

[0136] The proportions of the components within this polymer resin are designed to precisely balance the multiple core properties sought in the hydrofluoric acid resistant composition of this invention: namely, excellent corrosion and chemical resistance, strong adhesion to the substrate, and superior mechanical toughness.

[0137] As mentioned earlier, the structural resin, as the main framework of the polymer system, is the functional component that provides the excellent acid and heat resistance of the final protective layer. To ensure the protective layer maintains its structural integrity and remains impermeable and uncorroded during hydrofluoric acid etching and subsequent wet chemical processing, the structural resin must play a dominant role in the entire polymer system. By controlling its content within a relatively high range of 30% to 80%, a tough, stable, high-performance polymer network can be guaranteed after curing. If the structural resin content is below 30%, its corrosion and chemical resistance will be insufficient, potentially causing the material to become brittle under high filler conditions or unable to withstand strong acid attacks. Conversely, if the structural resin content is above 80%, it will correspondingly reduce the content of the binder resin (to below 20%), which may lead to the failure of two key properties: First, the binder resin is the main source of adhesion to the glass substrate; too low a content will result in insufficient bonding between the protective layer and the substrate, making it prone to detachment during etching. Second, the binder resin is the core component that imparts the protective layer's solubility in alcohol solutions; too low a content will destroy this property, making the protective layer impossible to remove gently after processing.

[0138] The bonding resin (polyvinyl acetal) is crucial for providing strong adhesion to glass substrates and forming a dense cross-linked network to bond inorganic fillers. If the bonding resin content is below 20%, the cross-linking and bonding effects will be weak, resulting in a protective layer with poor adhesion and a loose internal structure. Conversely, if the content is above 70%, it will lead to excessively high cross-linking density, increasing the brittleness of the entire polymer system. Furthermore, its relatively high hydrophilicity may negatively impact the final water resistance.

[0139] Bonding-enhancing resins (epoxy and phenolic systems) are the core functional components for achieving high crosslinking density. If their content is below 0%, the reinforcing effect is insufficient; if it is above 20%, it may affect system compatibility and weaken the adhesion of the protective layer to the substrate. Therefore, by precisely controlling the contents of structural resin, adhesive resin, and bonding-enhancing resin within the aforementioned optimized ranges, a perfect balance of mechanical toughness, chemical resistance, and strong adhesion to the substrate is achieved while ensuring superior corrosion resistance, resulting in the optimal overall performance.

[0140] In some embodiments, to further improve the process performance and final film quality of the hydrofluoric acid resistant composition during preparation, storage and application, the composition further includes a solvent selected from at least one of water, N-methylpyrrolidone, ethanol, acetone, ethyl acetate, n-butyl ether, methyl tert-butyl ether, dimethyl phthalate, butanone, dimethyl sulfoxide, n-butyl ketone, cyclohexanone, toluene and xylene.

[0141] Specifically, the solvent primarily acts as a carrier medium in the composition, its core function being to dissolve the polymeric resin (including structural resins, binding resins, and binding-enhancing resins) and uniformly disperse inorganic fillers and other additives, forming a homogeneous, stable liquid or paste system with suitable application viscosity. This invention provides a diverse selection of solvents to flexibly construct the optimal solvent system based on the solubility parameters of the specific polymeric resin used. For example, high-boiling-point, highly polar solvents such as N-methylpyrrolidone are excellent for dissolving high-performance polymers such as polyvinylidene fluoride; while medium- and low-boiling-point solvents such as butanone and toluene facilitate rapid evaporation during baking, improving production efficiency. By using these solvents individually or in combination, the viscosity, surface tension, drying rate, and storage stability of the final composition can be precisely controlled, ensuring its perfect adaptation to different industrial production processes.

[0142] In some embodiments, the solvent content is 0.5 to 8 times the total weight of the polymer resin. Specifically, if the solvent content is less than 0.5 times, the viscosity of the composition may be too high to dissolve or disperse the components; if it is more than 8 times, the solid content is too low, making it difficult to form a film of effective thickness, and the drying time is too long. Therefore, this content range ensures that the composition has sufficient fluidity for coating while avoiding film shrinkage caused by excessive solvent.

[0143] In some embodiments, the hydrofluoric acid resistant composition of the present invention further comprises an additive, which includes at least one selected from leveling agents, dispersants, and defoamers. The addition of these additives is intended to optimize the physicochemical behavior of the composition during preparation, storage, and application.

[0144] Specifically, the main function of dispersants is to improve and stabilize the dispersion state of inorganic fillers in the resin matrix. Through electrostatic repulsion or steric hindrance, they effectively prevent the agglomeration and sedimentation of particles, thereby ensuring the uniformity and storage stability of the slurry.

[0145] The main function of leveling agents is to improve the surface appearance of the composition during the coating and film-forming process, reduce the surface tension of the slurry, promote its flow and spreading on the substrate, eliminate defects such as orange peel and pinholes, and make the surface of the final protective layer smoother.

[0146] The main function of defoamers is to eliminate air bubbles introduced by high-speed stirring or shearing, and to prevent residual air bubbles from forming pinholes or voids, which would weaken the density and mechanical strength of the protective layer.

[0147] In one specific embodiment, examples of additives that may be used include leveling agent BYK530, dispersant BYK2152, and defoamer BYK333.

[0148] It is understood that by introducing these functional additives, the present invention can ensure the stability and reliability of its resin composition during preparation and application, thereby providing a strong guarantee for the final formation of a high-quality, high-performance hydrofluoric acid resistant protective layer.

[0149] In some embodiments, the content of the additive is 0.5% to 5% by weight of the total weight of the polymer resin. Specifically, if the additive content is less than 0.5%, its effect on improving processability is not significant; if it is more than 5%, it may adversely affect the core properties of the final protective layer, such as acid resistance or adhesion. Therefore, this content range ensures that the additive functions effectively without affecting the overall performance of the composition.

[0150] In summary, the hydrofluoric acid-resistant composition proposed in this application has the following beneficial effects:

[0151] 1. Excellent hydrofluoric acid resistance and processing compatibility: Through the non-polar synergistic compounding of structural resin and surface-modified inorganic filler, the strong acid resistance of traditional protective materials (such as PO tape) can be significantly improved, achieving no peeling from 4% hydrofluoric acid solution for 5 minutes, thus overcoming the easy penetration defect of existing materials and avoiding uneven etching. Furthermore, this invention can directly upgrade the performance of ordinary coatings to a level suitable for ultra-thin glass (≤70μm), exhibiting significant process advantages.

[0152] 2. Excellent Adhesion and Interface Compatibility: The network structure formed by the cross-linking of the bonding resin and the binding strength strengthening resin ensures excellent adhesion between the cured protective layer and the glass substrate, thus solving the problems of poor adhesion and easy breakage of existing materials. This excellent adhesion ensures that the present invention is very suitable for use as a temporary protective layer, guaranteeing the stability of processing and the integrity of the final substrate.

[0153] 3. High Heat and Scratch Resistance and Optimized Removal: The three-dimensional network formed by cross-linking of polymer resins allows the cured protective layer to withstand high temperatures (up to 120°C) and scratches during laser cutting without damage. Simultaneously, after etching, extremely low residue risk is achieved, and rapid removal is accomplished via alcohol solution (ethanol ultrasonic dissolution for 3 minutes). This characteristic significantly reduces the complexity of processing steps and improves the yield of ultra-thin glass. Furthermore, because the composition of this invention maintains excellent adhesion to the substrate even under high hardness, it is highly suitable for integrated processes of laser cutting and hydrofluoric acid etching, meeting the high-speed processing requirements of flexible displays, etc. In addition, this invention also features low water absorption (<1%) and high peelability, supporting gentle removal conditions without charring problems.

[0154] 4. Flexible and diverse applications: It can be formulated into ink or dry film form for dip coating / screen printing or vacuum bonding, and is easy to remove from alcohol solutions. It can also be formulated into paste form for comprehensive protection of glass substrates. Furthermore, it can be combined with release films as a temporary mask.

[0155] The present invention also provides a method for preparing a hydrofluoric acid resistant composition, for preparing the hydrofluoric acid resistant composition described in any of the preceding claims.

[0156] like Figure 1 As shown, in some embodiments, the preparation method includes the following steps:

[0157] S1. Preparation of resin slurry: Structural resin, bonding resin and binding strength reinforcing resin are mixed in a first solvent to obtain resin slurry.

[0158] This step aims to obtain a homogeneous, gel-free resin slurry as the basis for subsequent filler dispersion. Specifically, structural resin (providing a corrosion-resistant framework), binding resin (ensuring crosslinking adhesion and alcohol solubility), and bonding-enhancing resin (increasing crosslinking density) are mixed together in a first solvent. The structural resin is such as polyvinylidene fluoride (molecular weight 400,000 g / mol to 2,000,000 g / mol), the binding resin is such as polyvinyl butyral resin (polyvinyl alcohol content 18% to 21%, polyvinyl acetate content 1% to 6%), and the bonding-enhancing resin is proportioned according to the formula: phenolic resin content = (hydroxyl equivalent of phenolic resin / epoxy equivalent of epoxy resin) × epoxy resin content.

[0159] In a preferred embodiment, to improve the mixing effect in subsequent steps, at least one additive selected from dispersants, defoamers, and leveling agents can be pre-added to the first solvent before adding the polymer resin component. Examples of additives that can be used include, but are not limited to, products such as dispersant BYK2152, defoamer BYK530, and leveling agent BYK333. The pre-addition of these additives can wet the surface of the resin particles and effectively prevent the resin component from agglomerating and settling in the solvent through electrostatic repulsion or steric hindrance effects, thereby ensuring the uniformity and storage stability of the slurry.

[0160] Specifically, the mixing process for preparing resin slurry can be achieved using high-speed mixing equipment such as a homogenizer. Of course, the homogenizer can be replaced by an emulsifier, a high-speed mixer, or a collider.

[0161] In some embodiments, the mixing speed for preparing the resin slurry is between 3600 rpm and 7200 rpm. To prevent the resin stability from being affected by heat generated by high-speed shearing, the entire process can be carried out in a reactor with a cooling water jacket to ensure that the slurry temperature does not exceed 45°C. The mixing duration is between 10 minutes and 50 minutes, for example 30 minutes, to ensure the formation of a homogeneous and stable resin slurry (also referred to as slurry A).

[0162] The reasons for setting the rotation speed, temperature, and time are as follows:

[0163] A rotation speed of 3600 to 7200 rpm provides sufficient shear force to disperse resin particles. If the rotation speed is too low (e.g., below 3600 rpm), insufficient mixing may occur, leading to phase separation.

[0164] The temperature should not exceed 45℃ to avoid resin pre-crosslinking. If the temperature exceeds 45℃, the bonding strength strengthening resin (such as epoxy / phenolic system) is prone to premature reaction, which will shorten the storage period.

[0165] The duration is limited to 10 to 50 minutes to balance efficiency and thoroughness. If the duration is less than 10 minutes, the slurry may be unevenly dispersed, while if it is more than 50 minutes, it will increase energy consumption without any additional benefit.

[0166] By controlling these parameters, the viscosity of the resin slurry is ensured to be moderate (1000-5000 mPa·s), laying the foundation for subsequent filler integration.

[0167] S2. Preparation of filler slurry: Inorganic fillers are mixed in a second solvent to obtain filler slurry.

[0168] This step aims to obtain a non-agglomerated filler slurry, ensuring uniform dispersion of the inorganic filler and avoiding uneven subsequent compounding. Specifically, surface-modified inorganic fillers (such as aniline-modified silica) are mixed in a second solvent. The inorganic filler provides mechanical reinforcement, while the surface-modified functional groups improve interfacial compatibility.

[0169] In a preferred embodiment, at least one additive selected from dispersants, defoamers, and leveling agents can be pre-added to the second solvent before adding the inorganic filler to improve the dispersion efficiency of the filler. This process can employ similar equipment and process parameters as step S1, for example, using a homogenizer at a rotation speed of 3600 rpm to 7200 rpm and a temperature not exceeding 45°C for a duration between 10 and 50 minutes, such as 30 minutes, to ensure that the inorganic filler particles are fully wetted and uniformly dispersed to form a non-agglomerated filler slurry (also referred to as slurry B).

[0170] It is worth noting that the first solvent and the second solvent can be the same or different. Specifically, the first solvent and the second solvent are selected from at least one of water, N-methylpyrrolidone, ethanol, acetone, ethyl acetate, n-butyl ether, methyl tert-butyl ether, dimethyl phthalate, butanone, dimethyl sulfoxide, n-butyl ketone, cyclohexanone, toluene, and xylene.

[0171] S3. Mixing: The filler slurry is added to the resin slurry being stirred and mixed to obtain a hydrofluoric acid resistant composition ink in slurry form.

[0172] This step aims to achieve a uniform organic-inorganic composite to form the final slurry. Specifically, the prepared filler slurry (slurry B) is slowly added to the resin slurry (slurry A) under stirring to prevent filler agglomeration due to excessively high local concentrations. After the addition is complete, thorough mixing is continued using equipment such as a homogenizer to ensure that the filler particles achieve optimal dispersion in the final resin composition.

[0173] The process parameters for this final mixing step are a rotation speed of 3600 rpm to 7200 rpm, a temperature not exceeding 45°C, and a duration of 60 to 120 minutes, for example, 90 minutes, to obtain the final slurry-like hydrofluoric acid-resistant composition. The rotation speed and temperature settings are the same as in S1 / S2 to ensure shear force and thermal control; the time is extended to 60-120 minutes to ensure optimal dispersion of the filler particles in the final resin composition.

[0174] Following the mixing step, the preparation method of this application may further include a post-processing step:

[0175] S4. Preparation of dry film: Apply the hydrofluoric acid resistant composition ink to the substrate film and cure it to obtain a hydrofluoric acid resistant composition dry film.

[0176] This step aims to transform the ink-like hydrofluoric acid resistant composition prepared in the previous steps into a solid dry film with a specific thickness, uniformity, and ease of subsequent application via hot pressing.

[0177] Specifically, the hydrofluoric acid-resistant composition ink is uniformly coated onto a substrate film using methods such as doctor blade printing, dip coating, or screen printing. This substrate film is typically a release film, such as a PET (polyethylene terephthalate) film. After coating, the substrate film coated with the composition ink is cured to remove the solvent and form a solid film with a certain mechanical strength, thereby obtaining a dry film of the hydrofluoric acid-resistant composition.

[0178] In some embodiments, the curing process is preferably a drying procedure performed in a hot air oven. This procedure includes drying the hydrofluoric acid resistant composition ink at a temperature range of 50°C to 120°C for 30 seconds to 30 minutes.

[0179] The reason for limiting the above process conditions is as follows:

[0180] Temperature (50℃ to 120℃): Setting the lower limit of the temperature to 50℃ ensures that solvent molecules have sufficient energy to escape efficiently from the coating. If the temperature is below 50℃, the solvent evaporation rate will be too slow, potentially leaving solvent residue inside the film layer, resulting in a soft, sticky, or mechanically weak final dry film. Controlling the upper limit of the temperature to 120℃ ensures effective solvent evaporation while preventing significant premature cross-linking of the bonding-enhancing resin (epoxy / phenolic system). If the temperature is too high, the dry film may over-cur (i.e., "dead"), resulting in a loss of necessary fluidity during subsequent hot-pressing to the substrate, affecting the bonding effect.

[0181] Time (30 seconds to 30 minutes): Setting the lower limit of time to 30 seconds ensures sufficient time for the solvent inside the film to evaporate completely, forming a stable solid film. Too short a baking time will result in incomplete curing, affecting the operability of the dry film. Setting the upper limit of time to 30 minutes ensures complete solvent removal while also considering the efficiency of industrial production. Exceeding this time does not significantly improve the performance of the dry film but reduces the output efficiency of the production line.

[0182] In summary, the preparation method of the hydrofluoric acid-resistant composition of the present invention has the following beneficial effects:

[0183] 1. High efficiency and stability: Through stepwise slurry preparation and pre-addition of additives, the resin / filler is uniformly compounded, avoiding agglomeration and extending the slurry's shelf life.

[0184] 2. Process flexibility: The parameter range (speed / temperature / time) is adaptable to industrial scale, and the selection of solvents / auxiliaries can optimize coating accuracy.

[0185] 3. Synergistic performance: After curing, the obtained slurry can withstand immersion in 4% hydrofluoric acid for 5 minutes without peeling off, and it is also easy to remove alcohol, thus helping to improve the yield of ultra-thin glass processing.

[0186] The present invention also proposes a substrate processing method, which uses the hydrofluoric acid resistant composition described in any of the preceding claims as a high-performance temporary protective material to construct a protective structure with excellent corrosion resistance and processing compatibility during the manufacturing process of glass substrates (especially ultrathin glass).

[0187] Reference Figure 2 As shown, in one embodiment, the processing method includes the following steps:

[0188] S10. Providing a substrate: First, provide a substrate to be processed.

[0189] This step aims to prepare the substrate to be processed, serving as the basis for subsequent protection and etching. Specifically, an ultra-thin glass substrate (e.g., ultra-thin glass, UTG) with a thickness of no more than 70 micrometers can be provided. Its surface must be clean and free of oil to ensure uniform adhesion of the protective layer. This substrate is widely used in flexible displays, foldable screens, and other fields. The thickness is controlled below 70 micrometers to meet the requirements of high-precision laser cutting, while also highlighting the applicability of this method to protecting fragile substrates.

[0190] In a preferred embodiment, the substrate can be ultrasonically cleaned (e.g., using deionized water at a frequency of 40 kHz for 5 minutes) to remove surface contaminants and avoid defects in subsequent coating.

[0191] S20. Applying the composition: Applying the hydrofluoric acid resistant composition described in any one of the preceding claims to the surface of a substrate to form a protective layer on the surface of the substrate.

[0192] This step aims to uniformly apply the hydrofluoric acid-resistant composition to the substrate, forming an initial protective layer. Its function is to isolate the substrate surface from the subsequent hydrofluoric acid solution, ensuring etching selectivity; it occupies the starting point of the processing chain in the overall method, providing a mechanical barrier and a chemically inert basis. The application of the composition is not limited to a specific form; for example, compositions in ink form can be achieved through coating or dry film lamination.

[0193] In some embodiments, when an ink-form composition is used, step S20 is implemented through steps S21-S22:

[0194] S21. Coating: The hydrofluoric acid resistant composition in slurry form is coated onto the surface of the substrate by dip coating, screen printing, pad printing, stencil printing, spraying or squeegee printing.

[0195] S22. Curing: The hydrofluoric acid resistant composition coated on the substrate surface is dried at a temperature of 50°C to 120°C for 3 to 30 minutes to form the protective layer.

[0196] Specifically, the coated substrate can be placed in a hot air oven at 80°C for 10 minutes to remove the solvent and form a dense protective layer. The temperature setting of 50°C to 120°C is because: below 50°C, solvent evaporation is slow, resulting in a loose film; above 120°C, resin pre-crosslinking affects removal. The time setting of 3 to 30 minutes is to balance efficiency: less than 3 minutes results in more residual solvent, while more than 30 minutes increases energy consumption without significant benefit.

[0197] In other embodiments, when a dry film composition is used, step S20 is performed by step S23.

[0198] First, in step S23, the hydrofluoric acid resistant composition in slurry form is coated onto a release film, and...

[0199] Step S23, Hot Pressing: The hydrofluoric acid-resistant composition in dry film form is hot-pressed onto the surface of the substrate at a temperature range of 70°C to 150°C and a pressure of not less than 0.4 MPa for 30 seconds to 5 minutes to form the protective layer. When using a vacuum laminator, lamination is preferably performed under a vacuum of less than 0.1 MPa to ensure that air between the substrate and the dry film is completely eliminated during the lamination process, preventing the formation of air bubbles.

[0200] S30, Etching process: The substrate on which the protective layer is formed is etched using a hydrofluoric acid solution. In this process, because the protective layer has excellent acid resistance, it can protect the substrate area it covers from corrosion.

[0201] In a preferred embodiment, the etching process further includes laser cutting the substrate before etching it with a hydrofluoric acid solution. Laser cutting defines the shape of the substrate, while subsequent hydrofluoric acid etching removes edge burrs and microcracks caused by the laser cutting.

[0202] Specifically, the substrate is first laser-cut to create cracks in the edge areas; then, the cut substrate is immersed in a hydrofluoric acid solution with a concentration between 1% and 5% (e.g., 3%) for 30 seconds to 30 minutes (e.g., 2 minutes) to precisely etch the burrs. After immersion, the substrate can be rinsed with pure water and dried.

[0203] The concentration of hydrofluoric acid is set to 1% to 5% because: below 1%, the etching rate is slow and the efficiency is low; above 5%, the risk of penetration into the protective layer increases. Although this composition can withstand 4% hydrofluoric acid for 5 minutes without peeling, a balance between safety and other factors is required.

[0204] The time of 30 seconds to 30 minutes is to accommodate different burr depths: less than 30 seconds will not remove burrs completely, while more than 30 minutes will easily cause over-etching.

[0205] S40. Remove the protective layer: Place the etched substrate in a stripping solvent or remove it physically to remove the protective layer.

[0206] This step aims to gently peel off the protective layer and restore the substrate surface.

[0207] Specifically, the treated substrate is placed in a stripping solvent selected from at least one of N-methylpyrrolidone, methanol, ethanol, n-butanol, acetone, ethyl acetate, n-butyl ether, methyl tert-butyl ether, dimethyl phthalate, butanone, dimethyl sulfoxide, n-butyl ketone, cyclohexanone, toluene, and xylene (e.g., ethanol), and the process is carried out at a temperature of 20°C to 60°C (e.g., 40°C). This mild temperature condition effectively dissolves the protective layer while avoiding the additional thermal stress that high temperatures might cause to the ultrathin substrate.

[0208] Removal can be performed by spraying or immersion. To further accelerate the removal rate, the removal step can be combined with ultrasonic vibration treatment. After the protective layer is completely removed, the processed substrate is then rinsed with deionized water to thoroughly remove any residual release solvent and dissolved components, resulting in a clean finished substrate.

[0209] In some embodiments, the stripping solvent contains 0.5 to 3% by weight of a surfactant (such as fatty alcohol polyoxyethylene ether) to enhance wetting and penetration.

[0210] It is worth noting that, in some embodiments, as an alternative implementation, step S40 can also remove the protective layer by physical means, such as tearing it by hand or removing it with tape. In this way, the protective layer can be removed gently without damaging the substrate.

[0211] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A hydrofluoric acid resistant composition, characterized in that, Including polymer resins and inorganic fillers, among which, The polymer resin includes: Structural resin, wherein the structural resin comprises a fluoropolymer; The adhesive resin comprises a polyvinyl acetal resin; and A bonding-strengthening resin, wherein the bonding-strengthening resin comprises epoxy resin and phenolic resin; The surface of the inorganic filler is modified with one or more functional groups selected from the group consisting of aniline, alkyl, nitrogen-containing functional groups on the main chain or branches, double-bonded functional groups, and epoxy groups.

2. The hydrofluoric acid resistant composition according to claim 1, characterized in that, The fluoropolymer includes polyvinylidene fluoride.

3. The hydrofluoric acid resistant composition according to claim 2, characterized in that, The molecular weight of the polyvinylidene fluoride is between 400,000 g / mol and 2,000,000 g / mol.

4. The hydrofluoric acid resistant composition according to claim 1, characterized in that, The polyvinyl acetal resins include polyvinyl butyral resins.

5. The hydrofluoric acid resistant composition according to claim 4, characterized in that, The molecular weight of the polyvinyl butyral resin is between 5 g / mol and 10,000 g / mol.

6. The hydrofluoric acid resistant composition according to claim 4, characterized in that, In the polyvinyl butyral resin, the weight percentage of polyvinyl alcohol is between 11% and 27%, and the weight percentage of polyvinyl acetate is between 0% and 8%.

7. The hydrofluoric acid resistant composition according to claim 6, characterized in that, In the polyvinyl butyral resin, the weight percentage of polyvinyl alcohol is between 18% and 21%, and the weight percentage of polyvinyl acetate is between 1% and 6%.

8. The hydrofluoric acid resistant composition according to claim 1, characterized in that, The epoxy resin is selected from at least one of the following: glycidylamine epoxy resin, polyfunctional o-cresol glycidyl ether epoxy resin, phenol-biphenyl epoxy resin, bisphenol F solid epoxy resin, isocyanate modified epoxy resin, naphthol epoxy resin, phenol-formaldehyde epoxy resin, semi-crystalline epoxy resin, liquid bisphenol A epoxy resin, liquid bisphenol F epoxy resin, liquid bisphenol A-bisphenol F composite epoxy resin, liquid bisphenol S epoxy resin, liquid phenolic epoxy resin, and liquid phenolic resin.

9. The hydrofluoric acid resistant composition according to claim 1, characterized in that, The phenolic resin is selected from at least one of linear phenol-formaldehyde resin and linear BPA-formaldehyde resin.

10. The hydrofluoric acid resistant composition according to claim 1, characterized in that, The content of the phenolic resin and the content of the epoxy resin satisfy the following formula: Phenolic resin content = (hydroxyl equivalent of phenolic resin / epoxy equivalent of epoxy resin) × epoxy resin content.

11. The hydrofluoric acid resistant composition according to claim 1, characterized in that, The inorganic filler is selected from at least one of graphite, carbon black, graphene, fullerene, silicon dioxide, aluminum oxide, aluminum hydroxide, calcium carbonate, magnesium carbonate, magnesium silicate, silicon carbide, titanium carbide, titanium oxide, magnesium oxide, calcium oxide, boron nitride, and aluminum nitride.

12. The hydrofluoric acid-resistant composition according to any one of claims 1 to 11, characterized in that, The composition comprises, by weight percentage: 60% to 100% of the aforementioned polymeric resin; and The inorganic filler content is 0% to 40%.

13. The hydrofluoric acid resistant composition according to claim 12, characterized in that, The polymer resin contains, by weight percentage: 30% to 80% of the aforementioned structural resin; 20% to 70% of the adhesive resin; and 0% to 20% of the bonding strength strengthening resin.

14. The hydrofluoric acid resistant composition according to claim 1, characterized in that, The hydrofluoric acid resistant composition further comprises a solvent selected from at least one of water, N-methylpyrrolidone, ethanol, acetone, ethyl acetate, n-butyl ether, methyl tert-butyl ether, dimethyl phthalate, butanone, dimethyl sulfoxide, n-butyl ketone, cyclohexanone, toluene, and xylene.

15. The hydrofluoric acid resistant composition according to claim 13, characterized in that, The hydrofluoric acid resistant composition further comprises an additive, which includes at least one of a leveling agent, a dispersant, and a defoamer.

16. The hydrofluoric acid resistant composition according to claim 15, characterized in that, The solvent content is 0.5 to 8 times the total weight of the polymer resin; and / or The content of the additive is 0.5% to 5% by weight of the total weight of the polymer resin.

17. A method for preparing a hydrofluoric acid-resistant composition, used to prepare the hydrofluoric acid-resistant composition according to any one of claims 1 to 16, characterized in that, The preparation method includes the following steps: Preparation of resin slurry: The structural resin, the bonding resin and the binding strength reinforcing resin are mixed in a first solvent to obtain a resin slurry; Preparation of filler slurry: The inorganic filler is mixed in a second solvent to obtain a filler slurry; and Mixing: The filler slurry is added to the resin slurry being stirred and mixed to obtain a hydrofluoric acid resistant composition ink.

18. The method for preparing the hydrofluoric acid resistant composition according to claim 17, characterized in that, In the step of preparing the resin slurry, at least one additive selected from dispersants, defoamers, and leveling agents is pre-dissolved in the first solvent; and / or In the step of preparing the filler slurry, at least one additive selected from dispersants, defoamers and leveling agents is pre-dissolved in the second solvent.

19. The method for preparing the hydrofluoric acid resistant composition according to claim 17, characterized in that, The mixing conditions of the preparation method include at least one of the following: The mixing speed during the preparation of the resin slurry is between 3600 rpm and 7200 rpm, the slurry temperature is not higher than 45°C, and the duration is between 10 minutes and 50 minutes. The mixing speed during the preparation of the filler slurry is between 3600 rpm and 7200 rpm, the slurry temperature is not higher than 45°C, and the duration is between 10 minutes and 50 minutes; and The mixing speed of the filler slurry and the resin slurry is between 3600 rpm and 7200 rpm, the slurry temperature is not higher than 45°C, and the duration is between 60 minutes and 120 minutes.

20. The method for preparing the hydrofluoric acid resistant composition according to any one of claims 17 to 19, characterized in that, Following the mixing step, the preparation method further includes: Preparation of dry film: The hydrofluoric acid resistant composition ink is coated onto the substrate film and cured to obtain the hydrofluoric acid resistant composition dry film.

21. The method for preparing the composite dielectric sheet fabric as described in claim 20, characterized in that, The curing process includes: The hydrofluoric acid resistant composition ink is dried in a temperature range of 50°C to 120°C for 30 seconds to 30 minutes.

22. A method for processing a substrate, characterized in that, Includes the following steps: Provide substrate; Application of composition: The hydrofluoric acid resistant composition according to any one of claims 1 to 16 is applied to the surface of the substrate to form a protective layer on the surface of the substrate; Etching process: The substrate on which the protective layer is formed is etched using a hydrofluoric acid solution; Remove the protective layer: The substrate after etching is placed in a stripping solvent or removed by physical means to remove the protective layer.

23. The substrate processing method as described in claim 22, characterized in that, When using an ink-form hydrofluoric acid-resistant composition, the step of applying the composition includes: Coating: Applying a hydrofluoric acid resistant composition ink to the surface of the substrate by means of dip coating, screen printing, pad printing, stencil printing, spraying, or squeegee printing; and Curing: The hydrofluoric acid resistant composition ink coated on the surface of the substrate is dried at a temperature of 50°C to 120°C for 3 to 30 minutes to form the protective layer.

24. The substrate processing method according to claim 22, characterized in that, When a hydrofluoric acid-resistant composition in dry film form is used, the step of applying the composition includes: Hot pressing: The hydrofluoric acid resistant dry film is hot-pressed onto the surface of the substrate at a temperature range of 70°C to 150°C and a pressure of not less than 0.4 MPa for 30 seconds to 5 minutes to form the protective layer.

25. The substrate processing method as described in claim 24, characterized in that, The bonding is performed under a vacuum of less than 0.1 MPa.

26. The substrate processing method according to claim 22, characterized in that, The etching process further includes: laser cutting the substrate before etching it with the hydrofluoric acid solution.

27. The substrate processing method as described in claim 22, characterized in that, In the etching process, the concentration of the hydrofluoric acid solution is between 1% and 5%, and the immersion time lasts from 30 seconds to 30 minutes.

28. The substrate processing method according to claim 22, characterized in that, The stripping solvent is selected from at least one of water, N-methylpyrrolidone, methanol, ethanol, n-butanol, acetone, ethyl acetate, n-butyl ether, methyl tert-butyl ether, dimethyl phthalate, butanone, dimethyl sulfoxide, n-butyl ketone, cyclohexanone, toluene, and xylene.

29. The method for processing a substrate as described in claim 28, characterized in that, The stripping solvent also contains 0.5% to 3% by weight of surfactant.

30. The substrate processing method according to claim 22, characterized in that, The step of removing the protective layer is carried out in a temperature range between 20°C and 60°C.

31. The substrate processing method according to claim 22, characterized in that, The substrate is an ultra-thin glass with a thickness of no more than 70 micrometers.

32. A substrate, characterized in that, Prepared by the processing method of any one of claims 22 to 31.

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