Fluorane polymer and preparation method thereof, electric etching medium, electric etching process and etched product

Abstract

The invention relates to the technical field of etching materials, and particularly provides a fluorane polymer and a preparation method thereof, an electric etching medium, an electric etching process and an etched product. The fluorane polymer comprises a fluorane unit and a polyacrylate skeleton, wherein the N site in the structural formula of the fluorane unit is connected to the R site or R'site in the structural formula of the polyacrylate skeleton. The preparation method of the fluorane polymer comprises the following steps: uniformly mixing fluorane molecules, acrylate molecules, an initiator and an organic solvent to obtain a mixed reaction system, reacting the mixed reaction system at 65-70 DEG C, eluting and concentrating to obtain the fluorane polymer. The method has the effect of improving the problem that micro-nano-scale patterns are difficult to form in the current photoetching and electric etching fields.

Description

Technical Field

[0001] The present invention relates to the technical field of etching materials, and in particular to a fluorane polymer and a preparation method thereof, an electro-etching medium, an electro-etching process and an etching product. Background Art

[0002] The photolithography process refers to forming a pattern on the surface of a silicon wafer using photoresist, and then transferring the pattern to the silicon wafer through exposure and development steps. In the traditional photolithography process, the core difficulty of micro-nano pattern processing comes from the diffraction effect of light waves. That is, when the pattern size is close to or smaller than the wavelength of the exposure light source, the diffraction of light will cause the mask pattern to be blurred on the photoresist, and the edge resolution will be significantly reduced. At the same time, the narrowing of the process window makes it very easy for slight deviations in exposure dose and focusing accuracy to cause pattern distortion. Traditional photolithography processes can generally only achieve vertical etching, that is, etching along the normal direction of the silicon wafer surface. When the photoresist has sidewall tilt or critical dimension offset due to diffraction, this vertical etching will directly "copy" these defects, resulting in the loss of control of the lateral size of the etched structure.

[0003] Electrochemical micro-nano processing has the advantages of no tool wear, no surface stress, environmental friendliness, simple operation, and low cost, and plays an irreplaceable role in micro-nano pattern processing. The key to electrochemical micro-nano processing is to limit the electrochemical reaction to the micro-nano scale. Its main working principles include anodic dissolution, cathode deposition, and electrochemically induced chemical etching. However, during the electrochemical etching process, the electric field concentration effect at the electrode edge can easily lead to differences in etching rates, causing edge collapse or "over-etching", making it difficult to achieve micro-nanoscale patterns. Summary of the Invention

[0004] The present invention aims to improve the problem that it is difficult to form micro-nanoscale patterns in the current photolithography and electrical etching fields.

[0005] To solve the above problems, as a first aspect, the present invention provides a fluoran polymer, comprising a fluoran unit and a polyacrylate backbone; wherein the structural formula of the fluoran unit is selected from any one of Formulas I to IV, and the structural formula of the polyacrylate backbone is shown in Formula V: 、 、 、 、 ; The N position in the structural formula of the fluoran unit is connected to the R position or R' position in the structural formula of the polyacrylate skeleton.

[0006] Alternatively, in Formula I to Formula V: Y is selected from any one of an O atom, a S atom and Si(CH3)2; and / or, R, R', R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 Any one selected from H, halogen, C1 to C24 alkyl, C1 to C24 substituted alkyl, hydroxy, C1 to C24 alkoxy, amino, C1 to C24 alkylamino, C6 to C24 aryl, and C7 to C24 groups containing both aromatic rings and alkanes; and / or, Z1 is selected from any one of H, C1 to C24 alkyl, C1 to C24 substituted alkyl, C1 to C24 acyl, C1 to C24 alkoxy, C6 to C24 aryl, and C7 to C24 groups containing both aromatic rings and alkanes; And / or, Ar is an aromatic ring or a substituted aromatic ring between C6 and C12.

[0007] Optionally, in Formula V, n is 1 to 25, m is 1 to 25, and p is 5 to 20.

[0008] As a second aspect, the present invention provides a method for preparing a fluoran polymer, wherein the method is used to prepare the fluoran polymer as described in the first aspect, and the method comprises: Fluoran molecules, acrylate molecules, an initiator and an organic solvent are uniformly mixed to obtain a mixed reaction system. The mixed reaction system is reacted at 65 to 70° C., and then eluted and concentrated to obtain the fluoran polymer.

[0009] Optionally, the acrylic acid ester molecule is selected from at least one of methyl methacrylate, ethyl methacrylate, ethyl acrylate, 2-propylethyl acrylate and butyl acrylate.

[0010] Optionally, the molar ratio of the fluoran molecules to the acrylate molecules is 1:(4 to 30).

[0011] As a third aspect, the present invention provides an electro-etching medium, which includes the fluoran polymer described in the first aspect, or the fluoran polymer prepared by the preparation method of the fluoran polymer described in the second aspect.

[0012] Optionally, the electro-etching medium further includes a liquid medium or a solid medium, the liquid medium includes a solvent and / or an ionic liquid, and the solid medium is a high molecular polymer.

[0013] As a fourth aspect, the present invention further provides an electro-etching process, wherein the electro-etching process is based on the electro-etching medium as described above, and the electro-etching process comprises: Pre-etching the conductive glass according to a preset pattern; Applying an electro-etching medium to the pre-etched surface of the conductive glass, and obtaining an electro-etching medium film after the solvent evaporates; The conductive glass coated with the electro-etching medium is placed in an electrolytic cell and used as a working electrode for electrolysis.

[0014] Optionally, the step of placing the conductive glass coated with the electro-etching medium in an electrolytic cell as a working electrode for electrolysis includes: the electrolytic cell being a three-electrode electrolytic cell.

[0015] As a fifth aspect, the present invention further provides an etching product, which is manufactured using the electro-etching process described in the fourth aspect.

[0016] The beneficial effects of the present invention compared to the prior art are: The present invention is to graft the fluoran unit onto the polyacrylate backbone, and through free radical polymerization, combine the fluoran and acrylate molecules so that the fluoran polymer molecules have both the polymer characteristics of polyacrylate, that is, by introducing a main chain containing a long alkyl group, it is conducive to improving the solubility of the molecule, making the fluoran polymer easy to process, and can also have the electrical response control ability of the fluoran molecule, so that it can achieve state switching while having good film-forming properties, thereby achieving solubility regulation. Then further regulate the opening and closing of the ester ring in the molecule by electrochemical means and thus achieve the change of solubility, and finally present the effect of selective etching pattern retention. Thus, on the basis of the original pattern, the original micron-scale pattern is achieved to be reduced by several times, reaching submicron or even nanometer-level patterns. Compared to the longitudinal dominant characteristics of traditional photolithography, the present invention has created a lateral expansion mechanism, realizes the production of target pattern at extremely low cost, changes the situation that traditional electrochemical etching is difficult to achieve submicron pattern, and applies electroetching to organic material system, widens the application scene of electroetching field. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG1 is a diagram of a state switching mechanism of a fluoran unit based on an electrical response in an exemplary embodiment of the present invention; Figure 2 1 is a flow chart of an electro-etching process in an exemplary embodiment of the present invention; Figure 3 is a schematic diagram of changes in an etching pattern after an electro-etching process in an exemplary embodiment of the present invention; Figure 4 Optical microscope images of the electrically etched medium film before and after voltage is applied in Example 1; Figure 5 SEM images of the electro-etched medium film before and after voltage is applied in Example 1; Figure 6The energy dispersive X-ray spectrometer (EDS) spectrum of the electro-etching process in Example 1 is shown; Figure 7 This is an SEM image of the submicron-scale pattern finally etched in Example 1; Figure 8 This is an SEM image of the nanoscale pattern finally etched in Example 1; Figure 9 This is a flow chart of an exemplary preparation process of a fluoran polymer according to Example 2; Figure 10 This is a flow chart of an exemplary preparation process of a fluoran polymer according to Example 3; Figure 11 This is a flow chart of an exemplary preparation process of a fluoran polymer according to Example 4; Figure 12 This is a flow chart of an exemplary preparation process of the fluoran polymer of Example 5; Figure 13 This is a flow chart of an exemplary preparation process of the fluoran polymer of Example 6; Figure 14 This is a flow chart of an exemplary preparation process of the fluoran polymer of Example 7; Figure 15 This is a flow chart of an exemplary preparation process of the fluoran polymer of Example 8.

[0018] Description of reference numerals: 1. Glass layer; 2. Conductive film; 3. Electro-etching medium film; 4. Pre-etching area; 5. Newly etched area; 6. Working electrode; 7. Counter electrode; 8. Reference electrode. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below.

[0020] Due to the growing demand for functional micro- and nanostructures in fields such as ultra-large-scale integrated circuits, micro-electromechanical systems, and precision optics, micro- and nano-machining is becoming the forefront of high-tech manufacturing.

[0021] In traditional photolithography, the core difficulty in fabricating micro- and nano-patterns stems from the diffraction effect of light waves. Specifically, when the pattern size approaches or is smaller than the wavelength of the exposure light source, light diffraction causes the mask pattern to be blurred on the photoresist, significantly reducing edge resolution. Furthermore, the narrowing process window makes it highly likely that even slight deviations in exposure dose and focus accuracy will cause pattern distortion. This limitation is further amplified by the "vertical dominance" of traditional etching processes. While conventional anisotropic etching (such as dry etching) can achieve vertical etching of high-aspect-ratio structures, its lateral dimension control is highly dependent on the accuracy of the photoresist transfer pattern, making it impossible to dynamically compensate for edge distortion or linewidth fluctuations caused by diffraction during the lithography stage. This mismatch between lithography and lateral etching can severely limit pattern fidelity and process reliability. In other words, the lack of lateral-vertical synergistic etching is a key constraint on micro- and nano-pattern fabrication.

[0022] The principle of electrochemical micro-nanomachining is to process materials by confining electrochemical reactions at the micro-nanoscale. Its core principle is to utilize electrochemical principles to induce anodic dissolution or cathodic deposition of materials in an electrolyte through electron exchange at the electrode surface, thereby achieving precise machining. Precision electrochemical machining is a top-down method based on anodic dissolution, with the workpiece acting as the anode. Micro-electroforming is a bottom-up method based on cathodic deposition, with the workpiece acting as the cathode.

[0023] The working principle of anodic dissolution is as follows: For example, using an iron-based alloy workpiece as an example, the workpiece is connected to the positive terminal of a power supply as the anode, and the forming tool is connected to the negative terminal of the power supply as the cathode. An electrolyte flows between the workpiece anode and the tool cathode. When the power is turned on, a circuit is formed, and the tool cathode continuously advances toward the workpiece, and electrolytic machining begins. During electrolytic machining, the anode (the iron-based alloy workpiece) loses electrons in an oxidation reaction, generating ferrous ions on the anode surface. These react with hydroxide ions to form a flocculent precipitate of ferrous hydroxide. This flocculent precipitate is further oxidized in the electrolyte, forming a yellow-brown precipitate of ferric hydroxide. On the cathode surface, hydrogen ions gain electrons in a reduction reaction, generating hydrogen gas. This macroscopic phenomenon manifests as continuous dissolution of the anode, no noticeable change in the cathode, and hydrogen evolution on the surface. Electrochemical corrosion of the workpiece occurs, gradually changing its structural shape. Simultaneously, the flowing electrolyte carries electrolysis products and heat away from the machining area, ensuring stable machining. Ultimately, the workpiece is machined to a shape similar to that of the forming tool, completing the electrolytic machining process.

[0024] The working principle of cathodic deposition is as follows: For example, nickel metal serves as the anode and the workpiece to be formed serves as the cathode. During the electroforming process, the anode nickel metal is oxidized into divalent nickel ions, which then enter the solution. The dissolved metal ions then reach the cathode surface through mass transfer within the electroforming solution, where they undergo a further reduction reaction to form nickel metal atoms, which are then deposited on the cathode surface. This allows the workpiece surface to be processed in combination with the pattern mask to achieve various patterns.

[0025] Therefore, current electrochemical micro-nanoprocessing utilizes redox reactions on two electrodes, mostly etching metals. The etching rate is affected by the nonlinear coupling of multiple parameters such as current density, electrolyte temperature, and pH value.

[0026] An embodiment of the present invention provides a fluoran polymer, which includes a fluoran unit and a polyacrylate backbone; wherein the structural formula of the fluoran unit is selected from any one of Formulas I to IV, and the structural formula of the polyacrylate backbone is shown in Formula V: 、 、 、 、 ; The N position in the structural formula of the fluoran unit is connected to the R position or R' position in the structural formula of the polyacrylate skeleton.

[0027] In the embodiments of the present invention, fluoran units are grafted onto a polyacrylate backbone and, through free radical polymerization, an electrically responsive fluoran polymer molecule is synthesized, thereby combining fluoran and acrylate molecules. The polyacrylate backbone has a concentrating effect, enabling high-density grafting of fluoran units. This allows the fluoran polymer molecules in the embodiments of the present invention to possess both the polymer characteristics of polyacrylates. Specifically, the introduction of a main chain containing long alkyl groups improves the solubility of the molecule, making the fluoran polymer easy to process, while also possessing the electrical response control capabilities of fluoran molecules. Furthermore, the polyacrylate backbone overcomes the difficulty of preparing films from small fluoran unit molecules.

[0028] Specifically, Figure 1 FIG. 1 is a diagram of a state switching mechanism of a fluoran unit based on an electrical response in an exemplary embodiment, Figure 1 As shown, the aromatic aniline moiety in the fluoran unit is oxidized under a positive voltage, releasing a proton. The fluoran moiety then gains a proton, opening the lactone ring, transitioning from a closed to an open state. This results in a change in polarity and, consequently, a change in solubility. The polyacrylic acid backbone exhibits a concentrating effect, enabling a high density of grafted fluoran units, thereby ensuring a large solubility change. This is achieved by the structural change (molecular ring opening) of the fluoran polymer molecules under electric field stimulation, transforming them from neutral molecules into positively charged ions. This increases the molecular polarity and, in turn, alters the solubility of the fluoran polymer in the solvent. Simultaneously, under electric field stimulation, microparticles (electrolyte ions, protons, electrons, etc.) in the electrolyte solution undergo directed diffusion. This directed diffusion gradually causes the surrounding unopened fluoran polymer molecules to open. Because this process varies with the duration of the applied current, it is possible to achieve a strategy for fabricating desired fine micro- and nanostructures by manipulating the applied current duration.

[0029] In summary, the fluoran polymer molecules in the embodiments of the present invention utilize the advantages of their polymers to enable the molecules to have excellent solubility control capabilities, and to achieve device solubility differences by electrochemically regulating the opening and closing of the ester ring in the molecule, thereby achieving a selective etching pattern retention effect. Thus, on the basis of the original pattern, the original micron-scale pattern is reduced several times to a submicron or even nanometer-scale pattern. Compared to the longitudinal dominant characteristics of traditional photolithography, the embodiments of the present invention have created a lateral expansion mechanism to achieve the production of target patterns at extremely low cost, while changing the situation where traditional electrochemical etching is difficult to achieve submicron patterns, and applying electroetching to organic material systems to broaden the application scenarios in the field of electroetching.

[0030] In some optional embodiments, in Formula I to Formula V: Y is selected from any one of an O atom, a S atom and Si(CH3)2, R, R', R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 Each of the following groups is independently selected from H, halogen, C1-C24 alkyl, C1-C24 substituted alkyl, hydroxy, C1-C24 alkoxy, amino, C1-C24 alkylamino, C6-C24 aryl, and C7-C24 groups containing both an aromatic ring and an alkane. Z1 is selected from H, C1-C24 alkyl, C1-C24 substituted alkyl, C1-C24 acyl, C1-C24 alkoxy, C6-C24 aryl, and C7-C24 groups containing both an aromatic ring and an alkane. Ar is a C6-C12 aromatic ring or a substituted aromatic ring.

[0031] It should be noted that in Formulas I to IV, R1, R2, R3, R4, R5, R6, R7, and R8 may be independent of each other or may be interconnected (such as IV-1 in Example 4).

[0032] In some optional embodiments, in Formula V, n is 1 to 25, m is 1 to 25, and p is 5 to 20.

[0033] The polyacrylate skeleton in the embodiment of the present invention has a longer main chain structure, so that multiple fluorane molecules can be grafted onto one main chain. This results in a greater change in polarity during electrochemical regulation, causing a greater difference in solubility, which is conducive to producing a better etching effect.

[0034] Another embodiment of the present invention further provides a method for preparing the above fluoran polymer, the method comprising: Fluoran molecules, acrylate molecules, initiator and organic solvent are uniformly mixed to obtain a mixed reaction system, the mixed reaction system is reacted at 65 to 70° C., and then eluted and concentrated to obtain a fluoran polymer.

[0035] In the present embodiment, fluoran molecule and acrylate molecule are carried out free radical addition reaction under the condition of heating.Wherein, initiator can be azobisisobutyronitrile, and organic solvent can be tetrahydrofuran (THF).Particularly, the mode that can adopt oil bath heating reflux promotes the sufficient reaction of fluoran molecule and acrylate molecule.After reaction is completed, can remove organic solvent by vacuum, adopt column chromatography to flush out fluoran polymer molecule then, collect the larger molecular effluent of polymerization degree, slowly add a large amount of absolute ethyl alcohol to separate out precipitation after it is concentrated, carry out suction filtration oven dry and promptly obtain fluoran polymer.

[0036] In some optional embodiments, the acrylate molecule is selected from at least one of methyl methacrylate, ethyl methacrylate, ethyl acrylate, 2-propylethyl acrylate and butyl acrylate.

[0037] In some optional embodiments, the raw materials for the fluoran molecules may include aniline, halogenated aniline, halogenated alcohol, halogenated benzene, acid anhydride, acryloyl chloride molecules, acrylate molecules, methyl reagents, etc. Related reactions include alkylation, acylation, esterification, nucleophilic addition, reduction, substitution, methylation, and amidation. The raw materials and reaction types can be appropriately selected based on the desired fluoran polymer molecules.

[0038] In some optional embodiments, the molar ratio of the fluoran molecules to the acrylate molecules is 1:(4 to 30).

[0039] In the embodiment of the present invention, by controlling the molar ratio of fluoran molecules to acrylate molecules, the number of fluoran units grafted onto the polyacrylate backbone is further regulated to obtain fluoran polymer molecules with different polymerization degrees, thereby regulating the degree of ring opening.

[0040] Yet another embodiment of the present invention provides an electro-etching medium, comprising the fluoran polymer described above, or a fluoran polymer prepared by the method for preparing a fluoran polymer described above. Alternatively, the electro-etching medium further comprises a liquid medium or a solid medium, wherein the liquid medium comprises a solvent and / or an ionic liquid, and the solid medium is a polymer.

[0041] Specifically, the solvent in the liquid medium can be selected from any combination of water, C1-C18 alcohols, C3-C24 ethers containing at least one oxygen atom, C3-C24 sulfides containing at least one sulfur atom, C2-C18 sulfoxides, C2-C18 sulfones, C3-C24 ketones, C1-C18 acids, C1-C18 sulfonic acids, C2-C18 esters, C1-C18 amides, C1-C18 alkanes, C1-C18 alkenes, C1-C18 alkynes, C1-C18 aromatic hydrocarbons, C3-C18 heterocycles containing at least one heteroatom O, S, N, or P, alkanes containing at least one halogen atom, and aromatic hydrocarbons containing at least one halogen atom.

[0042] Further, the ionic liquid is selected from butyltrimethylammonium bis(trifluoromethanesulfonyl)imide, tributylmethyldibutylammonium phosphate, tributylmethylammonium chloride, tributylmethylmethylammonium carbonate, triethylmethyldibutylammonium phosphate, tetraethylammonium trifluoromethanesulfonate, trioctylmethylammonium hydrogen sulfate, ethyldimethylpropylammonium bis(trifluoromethanesulfonyl)imide, diethylmethyl-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide, tetrabutylammonium heptadecafluorooctanesulfonate, tetrabutylammonium nitrite, tetrabutylammonium hydroxide, tetrabutylammonium methanesulfonate, tetrabutylammonium bis(trifluoromethanesulfonyl)imide ... Fluoromethanesulfonimide, tetrabutylammonium succinimide, tetrahexylammonium hydrogen sulfate, tetrahexylammonium iodide, tetraheptylammonium chloride, tetraheptylammonium bromide, tetra-n-butylammonium triiodide, tetrahexylammonium tetrafluoroborate, tetradodecylammonium tetrachloride, tetradodecylammonium tetrabromide, tetramethylammonium hydroxide, tetradecylammonium bromide, tetraoctylammonium chloride, methyltributylammonium methyl sulfate, methyltri(octadecyl)ammonium bromide, methyltrioctylammonium thiosalicylate, methyl-trioctylammonium bis(trifluoromethylsulfonyl)imide, 2-hydroxyethyl-trimethylammonium L-(+)-lactate, 2-hydroxy-N , N-bis(2-hydroxyethyl)-N-methylethylammonium methyl sulfate, benzyldimethyltetradecyl ammonium chloride, tetrabutylammonium benzoate, tetrabutylammonium thiophenol, choline acetate, 1-butylpyridinium bromide, 1-butyl-4-methylpyridinium hexafluorophosphate, 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide, 1-butyl-4-methylpyridinium tetrafluoroborate, 1-butyl-4-methylpyridinium iodide, 1-ethylpyridinium tetrafluoroborate, 1- (3-Cyanopropyl)pyridinium chloride, 3-methyl-1-propylpyridinium bis(trifluoromethylsulfonyl)imide, 1-butyl-2,3-dimethylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, 4-(3-butyl-1-imidazole)-1-butanesulfonate, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium dicyanamide, 1-butyl -3-Methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium hexafluoroantimonate, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium methanesulfonate, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium hydrogen sulfate, 1-butyl-3-methylimidazolium methyl sulfate, 1-butyl- 3-Methylimidazole octyl sulfate, 1-butyl-3-methylimidazole iodide, 1-butyl-3-methylimidazole hydrogen carbonate, 1-butyl-3-methylimidazole dibutyl phosphate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrachloroaluminate, 1-butyl-3-methylimidazolium toluenesulfonate, 1-butyl-3-methylimidazolium thiocyanate, 1,2,3-Trimethylimidazolium methanesulfonic acid, 1-propyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-2,3-dimethylimidazolium hexafluorophosphate, 1-ethyl-2,3-dimethylimidazolium tetrafluoroborate, 1-ethyl-2,3-dimethylimidazolium trifluoromethanesulfonate, 1-ethyl-2,3-dimethylimidazolium ethylsulfate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium L-(+)-lactate, 1-ethyl-3-methylimidazolium dibutyl phosphate, 1-ethyl-3-methylimidazolium diethyl phosphate, 1-ethyl-3-methylimidazolium imidazole dicyanamide, 1-ethyl-3-methylimidazolium dimethyl phosphate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium bis(pentafluoroethylsulfonyl)imide, 1-ethyl-3-methylimidazolium 1,1,2,2-tetrafluoroethylsulfonate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrachloroaluminate, 1-ethyl-3-methylimidazolium methyl sulfate, 1-ethyl-3-methylimidazolium methylsulfonate, 1-ethyl-3-methylimidazolium nitrate, 1-Ethyl-3-methylimidazole thiocyanate, 1-ethyl-3-methylimidazole ethyl sulfate, 1-ethyl-3-methylimidazole hydrogen sulfate, 1-ethyl-3-methylimidazole acetate, 1-ethyl-3-methylimidazolium p-toluenesulfonyl salt, 1-ethyl-3-methylimidazole bromide, 1-ethyl-3-methylimidazolium iodide, 1,3-diethoxyimidazolium hexafluorophosphate, 1,3-diethoxyimidazolium bis(trifluoromethylsulfonyl)imide, 1,2-dimethyl-3-propylimidazole tris(trifluoromethylsulfonyl)methylate, 1,2-dimethyl-3-propylimidazole bis(trifluoromethylsulfonyl)imide Amine, 1,3-dimethylimidazolium dimethylphosphine, 1,3-dimethylimidazolium methanesulfonate, 1,3-dimethylimidazolium methylsulfate, 1,3-dimethoxyimidazolium hexafluorophosphate, 1,3-dimethoxyimidazolium bis(trifluoromethylsulfonyl)imide, 1,3-dimethoxy-2-methylimidazolium hexafluorophosphate, 1,3-dimethoxy-2-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1,3-dihydroxy-2-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1,3-dihydroxyimidazolium bis(trifluoromethylsulfonyl)imide, 1-dodecyl-3-methylimidazolium iodide, 1 ,3-bis(3-cyanopropyl)imidazolium chloride, 1,3-bis(cyanomethyl)imidazolium bis(trifluoromethylsulfonyl)imide, 1,3-bis(cyanomethyl)imidazolium chloride, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-hexyl-3-methylimidazolium chloride, 1-butyl-2,3-dimethylimidazolium chloride, 1-ethyl-2,3-Dimethylimidazolium, 1-ethyl-3-methylimidazolium chloride, 1-benzyl-3-methylimidazolium chloride, 1-(3-cyanopropyl)-3-imidazolium dicyanamide, 1-(3-cyanopropyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, 1-(3-cyanopropyl)-3-methylimidazolium chloride, 1-allyl-3-methylimidazolium chloride, 1-allyl-3-methylimidazolium bromide, 1-allyl-3-methylimidazolium dicyanamide, 1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-methyl-3-propylimidazolium methyl carbonate, 1-methyl-3-propylimidazolium iodide, 1-methyl-3-vinylimidazole methyl carbonate, 1-methylimidazolium hydrogen sulfate, 1- Methylimidazolium chloride, 1-methyl-3-octylimidazolium trifluoromethanesulfonate, 1-methyl-3-octylimidazolium tetrafluoroborate, 1-methyl-3-octylimidazolium chloride, 1-decyl-3-methylimidazolium tetrafluoroborate, decylmethylimidazolium chloride, 1-hexyl-3-methylimidazolium iodide, 1-(2-hydroxyethyl)-3-methylimidazolium dicyanamide, 1-benzyl-3-methylimidazolium hexafluorophosphate, 1-benzyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium methanesulfonate, 1-butyl- 3-Methylimidazolium hydrogen sulfate, 1-butyl-3-methylimidazolium methyl sulfate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium thiocyanate, 1,2,3-trimethylimidazolium methanesulfonic acid, 1-propyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-2,3-dimethylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium diethyl phosphate, 1-ethyl-3-methylimidazolium dicyanamide, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium 1-Ethyl-3-methylimidazolium tetrachloroaluminate, 1-Ethyl-3-methylimidazolium methylsulfonate, 1-Ethyl-3-methylimidazolium thiocyanate, 1-Ethyl-3-methylimidazolium ethyl sulfate, 1-Ethyl-3-methylimidazolium hydrogen sulfate, 1-Ethyl-3-methylimidazolium acetate, 1-Ethyl-3-methylimidazolium chloride, 1-Methylimidazolium hydrogen sulfate, 1-Methylimidazolium chloride, tributylmethylphosphine dibutyl phosphate, tributylmethylphosphine methylsulfate, triethylmethylphosphine dibutyl phosphate, trihexyltetradecylphosphine bromide, trihexyltetradecylphosphine chloride, trihexyltetradecylphosphine decanoate, trihexyl(tetradecyl)phosphine dicyanamide, trihexyltetradecylphosphine bis(trifluoromethylsulfonyl)amide, trihexyltetradecylphosphine bis(2,4,4-trimethylpentyl) phosphite, 3-(triphenylphosphino)propane-1-toluenesulfonyl, 3-(triphenylphosphino)propane-1-sulfonate, tetrabutylphosphine tetrafluoroborate, tetrabutylphosphine p-toluenesulfonate, tetrabutylphosphine methanesulfonate, 1-butyl-1-methylpyrrolidine trifluoromethanesulfonate, 1-butyl-1-methylpyrrolidine dinitrile amine salt, 1-butyl-1-methylpyrrolidine hexafluorophosphate, 1-butyl-1-methylpyrrolidine bis(trifluoromethanesulfonyl)imide, 1-butyl-1-methylpyrrolidine bis(trifluoromethanesulfonyl)imide, 1-butyl-1-methylpyrrolidine tetrafluoroborate, 1-butyl-1-methylpyrrolidine chloride, 1-butyl-1-methylpyrrolidine bromide, 1-butyl-1-methylpyrrolidine Any one of pyrrolidine iodide, 1-butyl-1-methylpyrrolidine methyl carbonate, 1-ethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-ethyl-1-methylpyrrolidinium tetrafluoroborate, 1-methyl-1-ethylpyrrolidinium hexafluorophosphate, 1-methyl-1-ethylpyrrolidine bromide, triethylsulfonium bis(trifluoromethylsulfonyl)imide, cyclopropyldiphenylsulfonium tetrafluoroborate, 1-butyl-1-methylpiperidinium tetrafluoroborate, 1-butyl-1-methylpiperidinium hexafluorophosphate, 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide, 4-ethyl-4-methylmorpholinium methyl carbonate, and a C4-C60 ionic liquid containing at least one S, N, or P heteroatom.

[0043] Furthermore, the high molecular polymer in the solid medium can be selected from any one or more of polystyrene, polypropylene, polymethyl acrylate, polyethyl acrylate, polypropyl acrylate, polyisopropyl acrylate, polybutyl acrylate, polyisobutyl acrylate, polytert-butyl acrylate, polypentyl acrylate, polyisopentyl acrylate, polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, polyisopropyl methacrylate, polybutyl methacrylate, polyisobutyl methacrylate, polytert-butyl methacrylate, polypentyl methacrylate, polyisopentyl methacrylate, polyhexyl methacrylate, polyethylene glycol, polyvinyl alcohol, polyurethane, polyethylene, polycarbonate, polyamide, polytetrafluoroethylene, polyethylene terephthalate, polybutylene terephthalate, polyvinyl acetate, polysilicone, polyacrylonitrile, polychlorotrifluoroethylene, acrylonitrile-butadiene-styrene copolymer and polydimethylsilicate.

[0044] Figure 2 FIG. 1 is a flow chart of an electro-etching process in an exemplary embodiment. Another embodiment of the present invention further provides an electro-etching process, which is based on the electro-etching medium as described above. Figure 2 As shown, the electro-etching process includes the following steps: Step S1: Pre-etching the conductive glass according to a preset pattern. Specifically, the conductive glass is made by further coating the surface of a glass layer 1 with a conductive film 2. The conductive film 2 can be made of, for example, indium tin oxide (ITO) or tin oxide. Then, using photolithography (e.g., a laser direct write lithography machine), a preset pattern is etched onto the conductive film 2 of the conductive glass, forming a pre-etched area 4. The indium tin oxide in the patterned area is etched away, leaving only the non-conductive glass layer 1. This means that the pre-etched area 4 on the surface of the conductive glass is non-conductive, while the unetched area is conductive.

[0045] Step S2: Apply the electro-etching medium to the pre-etched surface of the conductive glass. After the solvent evaporates, an electro-etching medium film 3 is obtained. Specifically, the electro-etching medium can be applied to the pre-etched conductive glass using spin coating or doctor blade coating. The electro-etching medium further fills the pre-etched area 4 on the conductive glass surface, ultimately forming a flat surface. Because the electro-etching medium has an acrylic polymer structure, this molecule exhibits excellent film-forming properties. After the solvent evaporates, a dry film with a thickness of 180 to 200 nm is obtained.

[0046] Step S3: The conductive glass coated with the electro-etching medium is placed in an electrolytic cell and used as the working electrode 6 for electrolysis. Specifically, the electrolytic cell can be a three-electrode electrolytic cell consisting of a working electrode 6, a counter electrode 7, and a reference electrode 8. The working electrode 6 is the conductive glass mentioned above, and the material of the counter electrode 7 can be any combination of gold, silver, copper, mercury, platinum, palladium, tungsten, aluminum, zinc, zinc oxide, graphite, graphene, tungsten carbide, nickel carbide, carbon nanotubes, etc. The reference electrode 8 can be a saturated calomel electrode or a silver / silver chloride electrode. In addition, the electrolyte in the electrolytic cell can be an inorganic or organic metal salt containing a monovalent metal ion, a tetraalkyl quaternary ammonium salt, or an ionic liquid; the inorganic or organic metal salt of a monovalent metal ion is selected from any combination of Li, Na, K, Rb, Cs, Cu, or Ag salts.

[0047] Step S4: After removing the electrical stimulation, the conductive glass is taken out and then developed with acetonitrile as a developer, and finally a reduced micro-nano pattern, namely, the new etched area 5, is obtained.

[0048] Step S5: drying the conductive glass forming the new etched area 5.

[0049] Specifically, in the unpowered state, the fluoran polymer molecules in the electroetched medium have poor solubility in the electrolyte. When a positive voltage (e.g., +1.8 V) is applied, the fluoran polymer molecules undergo a transition from a closed to an open ring state under electrical stimulation, causing a change in their solubility and subsequent dissolution in the electrolyte. However, because the pre-etched region 4 of the working electrode is non-conductive, while the conductive film 2 surrounding the pre-etched region 4 is conductive, the fluoran polymer molecules in this region can only open their rings through diffusion of surrounding microparticles (electrolyte ions, protons, electrons, etc.). Consequently, the solubility of the fluoran polymer molecules in the pre-etched region 4 changes more slowly. This dissolution process varies with the duration of power application: longer power application times increase the distance the conductive particles in the electrolyte need to diffuse into the pre-etched region 4. Furthermore, this diffusion distance is affected by the proportion of flexible segments in the oligomer. Therefore, by regulating the power-on time, the degree of dissolution of the electro-etching medium film 3 is controlled, so that after the electrical stimulation is removed, a new etched area 5 of controllable size appears on the surface of the working electrode, and the size of the new etched area 5 is smaller than that of the pre-etched area 4, thereby achieving the reduction of the etched pattern. Figure 3 As shown, after the electrical etching is performed according to the above process flow, the original pre-etched area 4 can be reduced several times to achieve a sub-micron or even nanometer level pattern.

[0050] Compared to related art electroetching, which utilizes a two-electrode redox reaction, the electroetching process in the embodiments of the present invention operates within a three-electrode system. Redox reactions of the material occur only at the anode (working electrode), accompanied by the on-off cycling of the fluoran polymer molecules. Prior to electroetching, a pre-defined pattern is drawn on the working electrode using laser direct writing technology. This photolithographic pattern is then "secondarily processed" using a single electrolysis device. This allows for the creation of a further, several-fold smaller pattern by varying the solubility of the fluoran polymer molecules, eliminating the need for costly photomasks. The fluoran polymer film adheres to the electrode surface, and the close distance between the electrodes ensures a faster etching speed, reducing etching costs and making the electroetching process simpler and more efficient.

[0051] Yet another embodiment of the present invention provides an etched product, which is manufactured using the above-mentioned electro-etching process.

[0052] The present invention is described in detail below through specific embodiments: Example 1 The structural formula of the fluoran polymer in this embodiment is shown in Formula I-1, where R9, R 10 , R' is a methyl group, the fluoran unit is connected to the R of the polyacrylate skeleton, R3 and R5 are 4-butyl-N-(4-butylphenyl)-N-anilino, R5 is a methyl group, R6 is a phenyl group, R4, R6, R7, and R8 are hydrogen, Y is oxygen, Ar is a benzene ring, and Z1 is a methyl group.

[0053]

[0054] Ⅰ-1 Specifically, the preparation process of the fluoran polymer in this embodiment is as follows: First, 4-bromo-N-methylaniline (29 mmol, 1.0 eq.), sodium bicarbonate (29 mmol, 1.0 eq.), and 2-bromoethanol (73 mmol, 2.5 eq.) were stirred at room temperature. After the 4-bromo-N-methylaniline had completely reacted, the reaction mixture was extracted with deionized water, and the organic phase was collected and dried. The solvent was then removed in vacuo. Column chromatography was then performed to yield the 1-1 molecule as a white powder (25.52 mmol, 88% yield).

[0055] Subsequently, 1-1 (3.28 mmol, 1.0 eq.), methacryloyl chloride (3.28 mmol, 1.0 eq.), triethylamine (4.9 mmol, 1.5 eq.), and THF (25 mL) were stirred at room temperature for 15 hours. After completion, the solvent was removed by drying. Column chromatography then yielded 1-2 as a viscous liquid (1.65 g), with a yield of 85%.

[0056] 3-Methoxyaniline (12.5 mmol, 1.0 eq.), 1-bromo-4-butylbenzene (31.3 mmol, 2.5 eq.), Pd2(dba)3 (0.13 mmol, 0.01 eq.), sodium tert-butoxide (37.5 mmol, 3.0 eq.), 2-(di-tert-butylphosphino)biphenyl (0.25 mmol, 0.02 eq.), and xylene (65 mL) were stirred in an oil bath at 120°C for 8 h under a nitrogen atmosphere. After completion of the reaction, the system was concentrated under vacuum to remove the solvent, and the product was obtained by column chromatography (yellow liquid, 10.38 mmol, 83% yield). The above product and 35 mL of HBr were placed in a round-bottom flask and stirred at 120°C for 2 days. After completion of the reaction, the organic phase was extracted with ethyl acetate and washed with saturated sodium bicarbonate. The solvent was removed by vacuum concentration, and then column chromatography was performed to obtain 1-3 molecules (green liquid, 6.44 mmol) with a yield of 62%.

[0057] Compound 1-3 (4.5 mmol, 1.0 eq.), 3-nitrophthalic anhydride (2.2 mmol, 0.5 eq.), and xylene (11 mL) were placed in a dry two-necked round-bottom flask. Niobium chloride (1.1 mmol, 0.25 eq.) was then added and stirred in an oil bath at 125°C for 8 h. After the reaction, the solvent was removed by vacuum drying. Column chromatography then yielded compound 1-4 as a blue powder (1.89 mmol, 42% yield).

[0058] Compounds 1-4 (0.55 mmol, 1.0 eq.), palladium / carbon (55% in H₂O, 10% by weight), and ethyl acetate (5 mL) were placed in a two-necked round-bottom flask. Hypophosphorous acid (109 mg, 50% by weight in water), deionized water (3 mL), and NaH₂PO₂·H₂O (5 mmol, 10.0 eq.) were added. The reaction system was then placed in an oil bath at 85°C for 7 h. Upon completion, the reaction mixture was extracted with ethyl acetate and dichloromethane, and the organic phase was collected. After vacuum concentration, the product 1-5 was purified by column chromatography to obtain a blue powder (0.30 mmol) in a 54.2% yield.

[0059] Under a nitrogen atmosphere, 1-5 (0.5 mmol, 1.0 eq.), 1-2 (0.5 mmol, 1.0 eq.), cesium carbonate (0.8 mmol, 1.6 eq.), tri-tert-butylphosphine (0.03 mmol, 0.06 eq.), palladium acetate (0.01 mmol, 0.02 eq.), and toluene (15 mL) were placed in a dry round-bottom flask. The reaction system was stirred in an oil bath at 110°C overnight. The reaction progress was monitored by thin-layer chromatography. Upon completion, the reaction system was cooled to room temperature, the solvent (toluene) was removed in vacuo, and column chromatography was performed to yield 1-6 as a light green powder (0.36 mmol) in a 71% yield.

[0060] Under a nitrogen atmosphere, 1-6 molecules (0.18 mmol, 1.0 eq.), methyl methacrylate (0.72 mmol, 4.0 eq.), azobisisobutyronitrile (0.00108 mmol, 0.006 eq.), and tetrahydrofuran (4 mL) were placed in a dry two-necked round-bottom flask. The reaction system was then stirred and refluxed in an oil bath at 65°C overnight. After completion of the reaction, the solvent (dichloromethane) was removed by vacuum evaporation, and the product was flushed out by column chromatography. The effluent containing molecules with a higher degree of polymerization was collected, concentrated, and slowly added dropwise to a large amount of anhydrous ethanol to precipitate a pale yellow flocculent precipitate. The precipitate was filtered and dried to obtain a pale yellow powder, the product fluoran polymer (0.0522 mmol), in a yield of 29%.

[0061] After testing, the solubility of the fluoran polymer in the ring-closed state in this embodiment is 2.95×10 -7 mol / L, and the solubility in the open-ring state is 3.36×10 -2 mol / L. It can be seen that the solubility of the fluoran polymer in the electrolyte in the ring-closed / ring-opened states is very different, which lays the foundation for the realization of electro-etching.

[0062] Based on the above-mentioned fluoran polymer, the electro-etching process in this embodiment includes the following steps: (1) First, a laser direct writing lithography machine is used to pre-etch the indium tin oxide conductive glass to form a pre-etched area 4 on the indium tin oxide glass, and the indium tin oxide in the pre-etched area is etched away, leaving only the non-conductive glass layer 1.

[0063] (2) 25 mg of the fluorane polymer molecules were then dispersed in 1 mL of tetrahydrofuran to obtain an electro-etching medium. 70 μL of the electro-etching medium was then applied to the surface of the indium tin oxide conductive glass by spin coating (1000 rpm, 30 s). After the solvent evaporated, an electro-etching medium film 3 with a thickness of 180 nm was obtained.

[0064] (3) Dissolve 287 mg of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) electrolyte in 10 mL of a mixed solvent of propylene carbonate and polyethylene glycol 200 (60%:40% by mass) to obtain an electrolyte. Place the electrolyte in a three-electrode electrolytic cell, wherein the indium tin oxide glass in step (2) is used as the working electrode 6, the platinum wire is used as the counter electrode 7, and the silver wire is used as the reference electrode 8. Finally, a positive voltage of 1.8 V is applied to the working electrode 6 for electroetching.

[0065] Figure 4 (a) and (b) are optical microscope images of the electro-etching medium film 3 on the conductive glass in this embodiment before and after voltage is applied, respectively. Figure 5 (a) and (b) are SEM images of the electro-etched medium film 3 before and after voltage is applied, respectively. Figure 4 and Figure 5 The pattern changes on the conductive glass surface before and after voltage application are demonstrated, proving the existence of the lateral expansion mechanism, which can not only achieve complete dissolution of the unetched area but also achieve pattern reduction in the pre-etched area 4. Figure 6 It is the energy dispersive X-ray spectrometer (EDS) spectrum of the electro-etching process, which is composed of Figure 6 It can be seen that the molecules are gradually dissolved during the electro-etching process, and the final size of the pattern is affected by factors such as the applied voltage time. Therefore, the size of the pattern is controllable and a good resolution can be maintained. Figure 7This is an SEM image of the submicron-scale pattern finally etched in this embodiment, where the resolution and line edge roughness are well maintained. Figure 8 This is the SEM image of the final nanoscale pattern etched in this embodiment, which proves that this technology can break through the limits of traditional photolithography and can achieve the effects of the most advanced photolithography equipment using mature existing photolithography equipment, thus realizing a low-cost and easy-to-operate electrical etching process for achieving sub-micro / nanoscale patterns.

[0066] Example 2 The structural formula of the fluoran polymer in this embodiment is shown in Formula II-1, where R9 is a hydrogen atom, R 10 , R' is a methyl group, the fluoran unit is connected to R in the polyacrylate skeleton, R3 is N, N-dibutyl, R5 is a methyl group, R6 is an aniline group, R4, R7, and R8 are hydrogen, Y is oxygen, and Z1 is a hydrogen atom.

[0067]

[0068] Ⅱ-1 The exemplary preparation process of the fluoran polymer in this embodiment is as follows Figure 9 As shown, specifically including: First, 3-nitrophthalic anhydride (60 mmol, 1.0 eq.) was added to a solution of 3-(dibutylamino)phenol (60 mmol, 1.0 eq.) in toluene (120 mL). The reaction mixture was stirred under reflux for 5 hours. The reaction was stopped, the system cooled to room temperature, and the product was concentrated by rotary evaporation. Purification by column chromatography using dichloromethane and methanol as eluents afforded 40.8 mmol of 2-1 as a dark yellow solid in a 68% yield.

[0069] To a reaction flask containing concentrated sulfuric acid (30 mL), slowly add 1-6 molecules (20 mmol, 1.0 eq.). Place the flask in an ice-water bath, then slowly add 4-methoxy-2-methyl-N-phenylaniline (20 mmol, 1.0 eq.). Stir the reaction mixture at room temperature for a period of time. Add the reaction mixture dropwise to ice water to obtain a precipitate. Filter the precipitate and wash it with cold water. Transfer the precipitate to a beaker, disperse it with water, and neutralize the dispersion with 1 mol / L sodium hydroxide. Extract with dichloromethane, dry it, and separate it by column chromatography to obtain 2-2 molecules as a yellow solid (4.6 mmol, 23% yield).

[0070] To a reaction flask containing compound 2-2 (1 mmol, 1.0 eq.) and 24 mg of palladium on carbon (10% carbon content, 55% water content) was added ethyl acetate (4 mL). To a test tube containing hypophosphorous acid (1.5 mmol, 1.5 eq.) and sodium hypophosphite monohydrate (4.5 mmol, 4.5 eq.) was added 3 mL of water and shaken to dissolve the salts. The aqueous solution was poured into the ethyl acetate phase, and the flask was placed in an oil bath preheated to 85°C. The reaction was carried out at 85°C for a period of time before cooling to room temperature. The mixture was extracted with ethyl acetate and dichloromethane, and the combined organic matter was dried and purified by column chromatography to yield 0.39 mmol of product 2-3 as a gray powder in a 39% yield.

[0071] 2-3 molecules (0.56 mmol, 1.0 eq.), triethylamine (0.85 mmol, 1.5 eq.), and dichloromethane (10 mL) were placed in a dry, two-necked round-bottom flask. The reaction system was then stirred in an ice-water bath. Simultaneously, acryloyl chloride (0.85 mmol, 1.5 eq.) and dichloromethane (10 mL) were added to a constant-pressure funnel and slowly added dropwise to the ice-water bath. After the addition was complete, the ice-water bath was removed and the mixture was stirred at room temperature overnight. Upon completion of the reaction, the reaction system was extracted three times with saturated sodium bicarbonate solution, deionized water, and saturated sodium chloride solution. The organic phase was collected, dried, and the solvent removed. The crude product was purified by column chromatography to afford 2-4 as a light gray powder (0.29 mmol) in a 52% yield.

[0072] Under a nitrogen atmosphere, 2-4 molecules (0.27 mmol, 1.0 eq.), methyl methacrylate (1.06 mmol, 4.0 eq.), azobisisobutyronitrile (0.008 mmol, 0.06 eq.), and tetrahydrofuran (4 mL) were placed in a reaction system and stirred under reflux at 65°C overnight. After completion of the reaction, the solvent was removed by vacuum column chromatography, and the smaller molecules with a lower degree of polymerization were removed by column chromatography, followed by the larger molecules with tetrahydrofuran as the eluent. The effluent was collected, concentrated, and then slowly added dropwise to a large amount of anhydrous ethanol to precipitate a light gray flocculent precipitate. Filter and dry the precipitate to obtain a light gray powder, 0.18 mmol of the fluoran polymer, in a 67% yield.

[0073] Example 3 The structural formula of the fluoran polymer in this embodiment is shown in Formula III-1:

[0074] III-1 The exemplary preparation process of the fluoran polymer in this embodiment is as follows Figure 10 As shown, specifically including: Under nitrogen, a 350 mL Schlenk tube heated in an oven was charged with 4-bromoaniline (34.9 mmol, 1.0 eq.), dichloro(pentamethylcyclopentadienyl)iridium(III) dimer (0.038 mmol, 0.1 eq.), NaOH (35 mmol, 1.0 eq.), and 60 mL of anhydrous ethanol. The resulting mixture was heated at 150°C with stirring for a period of time and then cooled to room temperature. The reaction mixture was concentrated by rotary evaporation and purified by column chromatography to obtain the corresponding solid product 3-1 (28.7 mmol, 82% yield).

[0075] Compound 3-1 (28 mmol, 1.0 eq.), sodium bicarbonate (28 mmol, 1.0 eq.), and 70 mL of 3-bromopropanol were added to a round-bottom flask. The mixture was stirred and heated to 60°C. After the reaction was complete, the organic phase was collected, washed three times with deionized water, dried, and filtered. The product was concentrated by rotary evaporation and purified by column chromatography. The corresponding light green solid, product 3-2, was obtained as a 25.7 mmol product in a 92% yield.

[0076] Subsequently, 3-2 (3.28 mmol, 1.0 eq.), methacryloyl chloride (3.28 mmol, 1.0 eq.), triethylamine (TEA, 4.9 mmol, 1.5 eq.), and THF (25 mL) were placed in an oil bath and stirred at room temperature for 15 hours. After completion, the solvent was removed by vacuum drying. Column chromatography then yielded product 3-3 as a viscous liquid (2.69 mmol, 82% yield).

[0077] To a stirred solution of 3-nitrophthalic anhydride (22 mmol, 1.0 eq.) and aluminum chloride (66 mmol, 3.0 eq.) in 50 mL of anhydrous dichloromethane at room temperature, slowly add N,N-diethylaniline (22 mmol, 1.0 eq.). The reaction is then heated to 40°C for 3 hours. The reaction is cooled to room temperature and poured into ice water. Sodium hydroxide solution is added to adjust the pH to around 7-9. A precipitate forms, which is filtered off. The filtrate is then adjusted to a pH of 3-4 and the precipitate is filtered off to yield 3-4 molecules.

[0078] Iodobenzene (4.02 mmol, 1.0 eq.), 2-chloroaniline (4.80 mmol, 1.2 eq.), palladium(II) acetate (200 μmol, 0.05 eq.), 1,1'-bis(diphenylphosphino)ferrocene (0.4 mmol, 0.1 eq.), and sodium tert-butoxide (6.0 mmol, 1.5 eq.) were mixed in toluene (5.0 mL). The reaction mixture was stirred at 110°C for 5 hours under argon. The mixture was then cooled to room temperature and 1N aqueous HCl (10 mL) was added to the reaction mixture. The organic phase was extracted from the aqueous layer with ethyl acetate, and the combined organic phases were concentrated under reduced pressure. The crude product was purified by column chromatography to obtain the compound 3-5 as a yellow oil in a 48% yield.

[0079] To a solution of 3-4 molecules (11 mmol, 1.0 eq.) in 10 mL of methanesulfonic acid at room temperature, 3-5 molecules (22 mmol, 2.0 eq.) were added. The mixture was heated at 90°C for 12 hours. The reaction was cooled to room temperature and ice water was added. Extraction was performed three times with dichloromethane. The combined organic layers were then extracted with brine, dried, and filtered. After concentration, the product was purified by column chromatography. 3-6 molecules were obtained in a 67% yield.

[0080] To a reaction flask, add 3-6 molecules (1 mmol, 1.0 eq.) and palladium on carbon (30 mg, 55% in H₂O, 10% by weight) and ethyl acetate (4 mL) as solvent. To a separate reaction flask, add hypophosphorous acid (50% w / w in H₂O, 1.5 mmol) and sodium hypophosphite monohydrate (4.5 mmol). Add 3 mL of water and stir to dissolve the sodium hypophosphite. Add the aqueous solution to the ethyl acetate phase, and then place the reaction system in an oil bath preheated to 85°C. Reaction proceeds for 8 h. After cooling to room temperature, separate the layers, extract the aqueous phase with ethyl acetate and dichloromethane, and combine the organic phases, dry and concentrate over anhydrous sodium sulfate, and isolate the product by column chromatography to obtain 3-7 molecules in a 39% yield.

[0081] Under a nitrogen atmosphere, 3-7 (0.5 mmol, 1.0 eq.), 3-3 (0.5 mmol, 1.0 eq.), cesium carbonate (0.8 mmol, 1.6 eq.), tri-tert-butylphosphine (0.03 mmol, 0.06 eq.), palladium acetate (0.01 mmol, 0.02 eq.), and toluene (15 mL) were placed in a dry round-bottom flask. The reaction system was stirred in an oil bath at 110°C overnight. The reaction progress was monitored by thin-layer chromatography. Upon completion, the reaction system was cooled to room temperature, the solvent (toluene) was removed in vacuo, and column chromatography was performed to yield 3-8 as a light gray powder (0.355 mmol) in a 71% yield.

[0082] Under a nitrogen atmosphere, 3-8 molecules (0.18 mmol, 1.0 eq.), ethyl methacrylate (1.8 mmol, 10.0 eq.), azobisisobutyronitrile (0.00108 mmol, 0.006 eq.), and tetrahydrofuran (4 mL) were placed in a dry two-necked round-bottom flask. The reaction system was then stirred and refluxed in an oil bath at 65°C overnight. After completion of the reaction, the solvent (dichloromethane) was removed by vacuum evaporation, and 3-9 molecules were flushed out by column chromatography. The effluent containing molecules with a higher degree of polymerization was collected, concentrated, and slowly added dropwise to a large amount of anhydrous ethanol to precipitate a light gray flocculent precipitate. The precipitate was filtered and dried to obtain a light gray powder, the fluoran polymer, with a yield of 0.0432 mmol and a yield of 24%.

[0083] Example 4 The structural formula of the fluoran polymer in this embodiment is shown in Formula IV-1:

[0084] IV-1 The exemplary preparation process of the fluoran polymer in this embodiment is as follows Figure 11 As shown in the figure, the key raw materials and process parameters have been shown and will not be described here.

[0085] Example 5 The structural formula of the fluoran polymer in this embodiment is shown in Formula V-1:

[0086] Ⅴ-1 The exemplary preparation process of the fluoran polymer in this embodiment is as follows Figure 12 As shown in the figure, the key raw materials and process parameters have been shown and will not be described here.

[0087] Example 6 The structural formula of the fluoran polymer in this embodiment is shown in Formula VI-1:

[0088] VI-1 The exemplary preparation process of the fluoran polymer in this embodiment is as follows Figure 13 As shown in the figure, the key raw materials and process parameters have been shown and will not be described here.

[0089] Example 7 The structural formula of the fluoran polymer in this embodiment is shown in Formula VII-1:

[0090] VII-1 The exemplary preparation process of the fluoran polymer in this embodiment is as follows Figure 14 As shown in the figure, the key raw materials and process parameters have been shown and will not be described here.

[0091] Example 8 The structural formula of the fluoran polymer in this embodiment is shown in Formula VIII-1:

[0092] Ⅷ-1 The exemplary preparation process of the fluoran polymer in this embodiment is as follows Figure 15 As shown in the figure, the key raw materials and process parameters have been shown and will not be described here.

[0093] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A fluoran polymer, characterized in that The fluoran polymer comprises a fluoran unit and a polyacrylate backbone; wherein the structural formula of the fluoran unit is selected from any one of Formulas I to IV, and the structural formula of the polyacrylate backbone is shown in Formula V: 、 、 、 、 ； The N position in the structural formula of the fluoran unit is connected to the R position or R' position in the structural formula of the polyacrylate skeleton.

2. The fluoran polymer according to claim 1, wherein In Formula I to Formula V: Y is selected from any one of an O atom, a S atom and Si(CH3)2; and / or, R, R', R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 Any one selected from H, halogen, C1 to C24 alkyl, C1 to C24 substituted alkyl, hydroxy, C1 to C24 alkoxy, amino, C1 to C24 alkylamino, C6 to C24 aryl, and C7 to C24 groups containing both aromatic rings and alkanes; and / or, Z1 is selected from any one of H, C1 to C24 alkyl, C1 to C24 substituted alkyl, C1 to C24 acyl, C1 to C24 alkoxy, C6 to C24 aryl, and C7 to C24 groups containing both aromatic rings and alkanes; And / or, Ar is an aromatic ring or a substituted aromatic ring between C6 and C12.

3. The fluoran polymer according to claim 1 or 2, characterized in that In formula V, n is 1 to 25, m is 1 to 25, and p is 5 to 20.

4. A method for preparing a fluoran polymer, characterized in that: The preparation method is used to prepare the fluoran polymer according to any one of claims 1 to 3, and the preparation method comprises: Fluoran molecules, acrylate molecules, an initiator and an organic solvent are uniformly mixed to obtain a mixed reaction system. The mixed reaction system is reacted at 65 to 70° C., and then eluted and concentrated to obtain the fluoran polymer.

5. The method for preparing a fluoran polymer according to claim 4, wherein The molar ratio of the fluoran molecules to the acrylate molecules is 1:(4 to 30).

6. An electro-etching medium, characterized in that The electro-etching medium comprises the fluoran polymer according to any one of claims 1 to 3, or comprises a fluoran polymer prepared by the preparation method of the fluoran polymer according to claim 4 or 5. 7 . The electro-etching medium according to claim 6 , further comprising a liquid medium or a solid medium, wherein the liquid medium comprises a solvent and / or an ionic liquid, and the solid medium is a high molecular polymer.

8. An electro-etching process, characterized in that: The electro-etching process is based on the electro-etching medium according to claim 6 or 7, and the electro-etching process includes: Pre-etching the conductive glass according to a preset pattern; Applying an electro-etching medium to the pre-etched surface of the conductive glass, and obtaining an electro-etching medium film after the solvent evaporates; The conductive glass coated with the electro-etching medium is placed in an electrolytic cell and used as a working electrode for electrolysis.

9. The electro-etching process according to claim 8, characterized in that: The step of placing the conductive glass coated with the electro-etching medium in an electrolytic cell as a working electrode for electrolysis includes: the electrolytic cell being a three-electrode electrolytic cell.

10. An etched product, characterized in that: The etched product is made using the electro-etching process as claimed in claim 8 or 9.

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