Electrochromic polyimide as well as preparation method and application thereof
By introducing specific trianiline-derived groups into the polyimide molecular structure, electrochromic polyimides are prepared, which solves the problems of single chromic state and long response time of existing electrochromic materials, and achieves fast and high contrast black patterning effect, broadens the scope of application.
Patent Information
- Application Number
- CN202510583836.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2025-07-11
AI Technical Summary
The tinting states of existing electrochromic materials are mostly red, green, and blue, which limits the application of optoelectronic devices and has a long response time, making patterning impossible.
The trianiline-derived groups with specific structures are used to improve the polyimide molecular structure, and electrochromic polyimide is prepared to achieve a rapid conversion from a faded state to a tinted state, which is black and can be patterned.
Fast response time (≤8s), high contrast (≥80%) and patterned black tints are achieved, broadening the application range of materials.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure belongs to the technical field of polymer materials, and particularly relates to an electrochromic polyimide, a preparation method thereof, and an application thereof. Background Art
[0002] An electrochromic material refers to a material that can produce stable and reversible phenomenon changes under the action of an applied electric field or current, and mostly exhibits reversible changes in color and transmittance in appearance; due to its unique properties, it is widely used in optoelectronic devices, smart windows, reflective glass, automobiles, military camouflage materials and other fields.
[0003] Electrochromic materials include inorganic electrochromic materials and organic electrochromic materials; among them, organic electrochromic materials are beneficial to broadening the types of materials and obtaining electrochromic materials with better performance due to the adjustable molecular structure, and further, polymers can be combined to further obtain materials with better performance and broaden the application scope of the materials. Among them, polyimide, as one of the polymer materials with excellent comprehensive properties, is widely used in the development of optoelectronic devices due to its excellent thermal stability and chemical stability, and the ease of functionalization of molecules. However, at present in the field of optoelectronic devices, the colored states of electrochromic materials are mostly electrochromic materials such as red, green, blue, etc., which limits the application of the devices. Summary of the Invention
[0004] Aiming at the deficiencies of the prior art, the purpose of the present disclosure is to provide an electrochromic polyimide, a preparation method thereof, and an application thereof. The electrochromic polyimide can undergo rapid and obvious color changes during the redox process, realize the conversion from the faded state to the colored state, and the colored state is black, with high contrast, short response time, and can realize patterning production.
[0005] To achieve this purpose, the present disclosure adopts the following technical solutions:
[0006] In the first aspect, the present disclosure provides an electrochromic polyimide having the structure shown in Formula I.
[0007]
[0008] In Formula I, Y is selected from substituted or unsubstituted Among them, Ar1 and Ar4 each independently are selected from substituted or unsubstituted C6-C12 arylene groups; Ar2, Ar3, Ar5, and Ar6 each independently are selected from substituted or unsubstituted C6-C20 aryl groups; and at least one of Ar2, Ar3, Ar5, and Ar6 has more than 6 carbon atoms; ring Ar is selected from substituted or unsubstituted cycloalkyl groups with ≥4 carbon atoms, substituted or unsubstituted aryl groups with ≥6 carbon atoms, or any one of the following; Ar7 is selected from substituted or unsubstituted C6-C12 arylene; Ar8 and Ar9 are each independently selected from substituted or unsubstituted cycloalkyl with ≥3 carbon atoms; "*" represents a connection site or a fusion site; n is selected from integers greater than 0; the substituents of the substitution include any one of D, halogen, -CN, C1-C6 straight-chain or branched alkyl, C1-C6 straight-chain or branched alkoxy, C6-C12 aryl, and C5-C12 heteroaryl.
[0009] In the present disclosure, the electrochromic polyimide adopts a specific structure, that is, a triphenylamine-derived group with a specific structure is introduced into the molecular structure of the polyimide, so that the electrochromic polyimide can realize the conversion from the faded state to the colored state, and the colored state is black, with a short response time, high contrast, and can realize patterning.
[0010] In the second aspect, the present disclosure provides a preparation method of the electrochromic polyimide according to the first aspect, and the preparation method includes the following steps:
[0011] (1) React diamine monomer H2N-Y-NH2 with dianhydride monomer to obtain polyamic acid;
[0012] (2) React the polyamic acid obtained in step (1) with an esterifying agent to obtain a precursor of the electrochromic polyimide;
[0013] (3) Perform imidization reaction on the precursor obtained in step (2) to obtain the electrochromic polyimide.
[0014] In the third aspect, the present disclosure provides a photoresist, and the photoresist includes a matrix resin, a photosensitizer, and a solvent; the matrix resin includes the electrochromic polyimide according to the first aspect or a precursor of the electrochromic polyimide.
[0015] In the fourth aspect, the present disclosure provides a patterned polyimide film, and the preparation raw materials of the patterned polyimide film include the photoresist according to the third aspect.
[0016] Compared with the prior art, the beneficial effects of the present disclosure are as follows:
[0017] The electrochromic polyimide provided by the present disclosure adopts a specific structure, that is, a triphenylamine-derived group with a specific structure is introduced into the molecular structure of the polyimide, so that the electrochromic polyimide undergoes rapid and obvious color changes during the redox process, realizes the conversion from the faded state to the colored state, and the colored state is black, with high contrast, short response time, and can realize patterning. Detailed Embodiments
[0018] In the prior art, there are few electrochromic materials with a colored state of black. For electrochromic materials with a colored state of black, the contrast is low, the response time is long, and patterning cannot be achieved. Therefore, the present disclosure provides an electrochromic material with a colored state of black, which can achieve patterning, and has a high contrast and a short response time.
[0019] The present disclosure provides an electrochromic polyimide, and the electrochromic polyimide has a structure shown in Formula I.
[0020]
[0021] In Formula I, Y is selected from substituted or unsubstituted wherein, Ar1 and Ar4 are each independently selected from substituted or unsubstituted C6-C12 arylene groups; Ar2, Ar3, Ar5, and Ar6 are each independently selected from substituted or unsubstituted C6-C20 aryl groups; and at least one of Ar2, Ar3, Ar5, and Ar6 has more than 6 carbon atoms; ring Ar is selected from substituted or unsubstituted cycloalkyl groups with ≥4 carbon atoms, substituted or unsubstituted aryl groups with ≥6 carbon atoms, or any one of the following; Ar7 is selected from substituted or unsubstituted C6-C12 arylene groups; Ar8 and Ar9 are each independently selected from substituted or unsubstituted cycloalkyl groups with ≥3 carbon atoms; "*" represents a connection site or a fusion site; n is selected from integers greater than 0; the substituents of the substitution include any one of D, halogen, -CN, C1-C6 straight-chain or branched alkyl groups, C1-C6 straight-chain or branched alkoxy groups, C6-C12 aryl groups, and C5-C12 heteroaryl groups.
[0022] In the present disclosure, the electrochromic polyimide adopts a specific structure, that is, a triphenylamine-derived group with a specific structure is introduced into the molecular structure of the polyimide, so that the electrochromic polyimide can achieve the conversion from the faded state to the colored state, and the colored state is black, the response time is short, the contrast is high, and patterning can be achieved.
[0023] In the present disclosure, the C6-C12 arylene group can be, for example, C6, C7, C8, C9, C10, C11, C12 arylene groups, etc.; exemplarily including but not limited to phenylene, biphenylene, naphthylene, etc.; if there are the same expressions below, they can represent the same meaning.
[0024] In the present disclosure, the C6-C20 aryl group can be, for example, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20 aryl groups, etc.; exemplarily including but not limited to phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, indenyl, fluorenyl, fluoranthenyl, triphenylene, pyrenyl, perylenyl, or tetraphenyl, etc.; if there are the same expressions below, they can represent the same meaning.
[0025] In the present disclosure, the cycloalkyl group having carbon atoms ≥ 4 may be, for example, a cycloalkyl group having carbon atoms 4, 5, 6, 7, 8, 9, or 10. The same expressions used below have the same meaning.
[0026] In the present disclosure, the aromatic group having a carbon number ≥ 6 may be, for example, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C22, C24, C26, C28, C30 aromatic groups, etc.; exemplary groups include, but are not limited to, phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthrenyl, indenyl, fluorenyl, fluoranthenyl, triphenylene, pyrenyl, perylenyl or tetraphenyl, etc.; if the same expression is used below, it can represent the same meaning.
[0027] In the present disclosure, the cycloalkyl group having carbon atoms ≥ 3 may be, for example, a cycloalkyl group having carbon atoms 3, 4, 5, 6, 7, 8, 9, or 10. The same expressions used below have the same meaning.
[0028] In the present disclosure, n is selected from an integer greater than 0, for example, 2, 4, 6, 8, 10, 20, 30, 40, 50, 60, 80, 100, etc.
[0029] In the present disclosure, C1~C6 straight chain or branched alkyl groups may be, for example, C1, C2, C3, C4, C5, C6 straight chain or branched alkyl groups; exemplary groups include but are not limited to methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, etc.; if the same expressions are used below, they may represent the same meaning.
[0030] In the present disclosure, C1~C6 straight chain or branched alkoxy, for example, can be C1, C2, C3, C4, C5, C6 straight chain or branched alkoxy; illustratively including but not limited to methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, n-pentoxy, isopentyl, neopentyl, n-hexyloxy, etc.; if there are the same expressions below, they can represent the same meaning.
[0031] In the present disclosure, C4~C12 heteroaryl groups may be, for example, C4, C5, C6, C7, C8, C9, C10, C11, C12 heteroaryl groups, etc.; the heteroatoms therein include O, S, N, P or B, etc.; exemplary examples include but are not limited to: furyl, thienyl, pyrrolyl, pyridyl, pyrazinyl, pyridazinyl, pyrimidinyl, isoquinolyl, o-phenanthroline, benzimidazolyl, benzothiazolyl, benzoxazolyl, benzofuranyl, benzothienyl, dibenzofuranyl, dibenzothienyl, carbazolyl, etc.; if the same expressions are used below, they may represent the same meaning.
[0032] In the present disclosure, the number of substituents of the "substituted" is ≥1. When the number of substituted substituents is greater than 1, the substituents are the same or different; the substituents can be connected to any position where they can be connected in the group. The same expression hereinafter may represent the same meaning.
[0033] In some embodiments of the present disclosure, Y is selected from any one of the following structures, or any one of the following structures substituted by substituents.
[0034]
[0035] Wherein, Ar1, Ar2, Ar3, Ar4, Ar5, Ar6 are each independently selected from the same range as in Formula I; the substituted substituents are selected from the same range as in Formula I; "*" represents a connection site or a fusion site.
[0036] In some embodiments of the present disclosure, Ar1 and Ar4 are each independently selected from substituted or unsubstituted phenylene groups; Ar2, Ar3, Ar5, and Ar6 are each independently selected from substituted or unsubstituted C6-C14 aryl groups; and at least one of Ar2 and Ar3 has more than 6 carbon atoms; at least one of Ar5 and Ar6 has more than 6 carbon atoms.
[0037] In some embodiments of the present disclosure, Y is selected from any one of the following structures, or any one of the following structures substituted by substituents.
[0038]
[0039] Wherein, the substituted substituents are selected from the same range as in Formula I; "*" represents a connection site or a fusion site.
[0040] In the present disclosure, Y is selected from specific structures, which is more conducive to the conversion of the electrochromic polyimide from colorless to black; if there are fewer conjugated structures in Y, the material cannot turn black after applying voltage; if there are too many conjugated structures in Y, the material is light yellow at 0 voltage and cannot be changed from colorless to black, with low contrast.
[0041] In some embodiments of the present disclosure, the ring Ar is selected from any one of the following structures, or any one of the following structures substituted by substituents.
[0042]
[0043]
[0044] Wherein, R1 and R2 are each independently selected from any one of a single bond, O, -NH-, C1-C6 straight chain or branched alkylene, and fluorine-substituted C1-C6 straight chain or branched alkylene; the dotted line represents the fusion site; the substituted substituent is selected from the same range as Formula I.
[0045] In some embodiments of the present disclosure, the precursor of the electrochromic polyimide has a structure shown in Formula II.
[0046]
[0047] In formula II, Y and ring Ar are each independently selected from the same range as formula I; R1 and R2 are each independently selected from any one of H, a straight chain or branched alkyl group of C1 to C4, and -CH2CH(OH)CH2OOCC(CH3)=CH2; and at least one of R1 and R2 is selected from a straight chain or branched alkyl group of C1 to C4 or -CH2CH(OH)CH2OOCC(CH3)=CH2.
[0048] In the present disclosure, the straight chain or branched alkyl group of C1 to C4 may be, for example, a C1, C2, C3, or C4 straight chain or branched alkyl group; exemplary examples include, but are not limited to, a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a tert-butyl group, and the like; the same expressions below may represent the same meaning.
[0049] In the present disclosure, a precursor with a specific structure is used to reduce the carboxyl content in the main chain structure of the polyimide after imidization, thereby facilitating the improvement of the alkali resistance of the material, reducing the dissolution rate of the material in the developer, and improving the contrast of the material.
[0050] The present disclosure also provides a method for preparing the electrochromic polyimide, the method comprising the following steps:
[0051] (1) diamine monomer H2N-Y-NH2 and dianhydride monomer reacting to obtain polyamic acid;
[0052] (2) reacting the polyamic acid obtained in step (1) with an esterifying agent to obtain a precursor of the electrochromic polyimide;
[0053] (3) subjecting the precursor obtained in step (2) to imidization reaction to obtain the electrochromic polyimide.
[0054] In the present disclosure, the reaction in step (1) is carried out in a protective atmosphere and a solvent; the protective atmosphere includes but is not limited to nitrogen; the solvent includes but is not limited to N-methylpyrrolidone (NMP); based on the total mass of the diamine monomer, dianhydride monomer and solvent being 100%, the total mass of the monomers is 10-30%; the temperature of the reaction in step (1) is room temperature, and the time is 6-18 h, for example, it can be 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, etc.
[0055] In some embodiments of the present disclosure, the molar ratio of the polyamic acid to the esterifying agent in step (2) is 1:(0.05-0.3), where the specific values in (0.05-0.3) can be, for example, 0.05, 0.06, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, 0.22, 0.24, 0.26, 0.28, 0.3, etc.
[0056] In some embodiments of the present disclosure, the esterifying agent includes at least one of glycidyl methacrylate, N,N-dimethylformamide diethyl acetal, and N,N-dimethylformamide dimethyl acetal.
[0057] In some embodiments of the present disclosure, the raw materials for the reaction in step (2) further include triphenylphosphine and 4-methoxyphenol; the molar content of triphenylphosphine is 1-4 mol% of the molar content of the esterifying agent, for example, it can be 1 mol%, 1.5 mol%, 2 mol%, 2.5 mol%, 3 mol%, 3.5 mol%, 4 mol%, etc.; the molar content of 4-methoxyphenol is 0.5-3 mol% of the molar content of the esterifying agent, for example, it can be 0.5 mol%, 0.8 mol%, 1 mol%, 1.2 mol%, 1.5 mol%, 1.8 mol%, 2 mol%, 2.2 mol%, 2.5 mol%, 2.8 mol%, 3 mol%, etc.
[0058] In some embodiments of the present disclosure, the reaction in step (2) is carried out in the presence of a protective atmosphere, the temperature of the reaction in step (2) is 90-120 °C, for example, it can be 90 °C, 95 °C, 100 °C, 105 °C, 110 °C, 115 °C, 120 °C, etc.; the time is 6-18 h, for example, it can be 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, etc.
[0059] In some embodiments of the present disclosure, the temperature of the imidization reaction in step (3) is 200 to 400 °C, for example, it can be 200 °C, 220 °C, 250 °C, 280 °C, 300 °C, 320 °C, 350 °C, 380 °C, 400 °C, etc.; the time is 0.5 to 3 h, for example, it can be 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, etc.; the imidization reaction is carried out in the presence of a protective atmosphere.
[0060] In some embodiments of the present disclosure, the weight-average molecular weight (Mw) of the electrochromic polyimide is 800,000 to 1,400,000, for example, it can be 800,000, 900,000, 1,000,000, 1,100,000, 1,200,000, 1,300,000, 1,400,000, etc.; the dispersity index is 1.3 to 1.6, for example, it can be 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, etc.
[0061] The present disclosure provides a photoresist, which includes a matrix resin, a photosensitizer and a solvent; the matrix resin includes the electrochromic polyimide or a precursor of the electrochromic polyimide.
[0062] In some embodiments of the present disclosure, the mass ratio of the matrix resin, the photosensitizer and the solvent is (10 to 20):(1 to 10):(70 to 90), wherein the specific values in (10 to 20) can be, for example, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc.; the specific values in (1 to 10) can be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.; the specific values in (70 to 90) can be, for example, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, etc.
[0063] In some embodiments of the present disclosure, the photosensitizer includes, but is not limited to, diazonaphthoquinone compounds (DNQ type photosensitizers); the solvent includes, but is not limited to, cyclopentanone; other additives can also be added to the photoresist according to actual needs.
[0064] The present disclosure provides a patterned polyimide film, and the preparation raw materials of the patterned polyimide film include the photoresist.
[0065] In the present disclosure, the preparation method of the patterned polyimide film includes:
[0066] Coating the photoresist on the surface of a substrate, and obtaining the patterned polyimide film through exposure, development and post-baking; the matrix resin in the photoresist is a precursor of the electrochromic polyimide.
[0067] The numerical ranges described in this disclosure include not only the above-listed point values, but also any point values between the above numerical ranges that are not listed. Due to space limitations and for the sake of brevity, this disclosure does not exhaustively list the specific point values included in the described ranges.
[0068] The technical solutions of this disclosure will be further described below through specific embodiments. Those skilled in the art should understand that the described embodiments are only for helping to understand this disclosure and should not be regarded as specific limitations to this disclosure.
[0069] Example 1
[0070] This example provides an electrochromic polyimide with a structure of The preparation method of the electrochromic polyimide specifically includes the following steps:
[0071] (1) Mix the diamine monomer with the dianhydride monomer and NMP. The molar ratio of the diamine monomer to the dianhydride monomer is 1.1:1. Based on the total mass of the diamine monomer, dianhydride monomer, and solvent being 100%, the total mass of the diamine monomer and dianhydride monomer is 20%. React for 10 h at room temperature in the presence of nitrogen to obtain polyamic acid;
[0072] (2) Mix the polyamic acid obtained in step (1) with glycidyl methacrylate. The molar ratio of the polyamic acid to glycidyl methacrylate is 1:0.22. React for 10 h at 100 °C to obtain the precursor of the electrochromic polyimide;
[0073] (3) Subject the precursor obtained in step (2) to imidization reaction at 300 °C for 1 h to obtain the electrochromic polyimide.
[0074] Example 2
[0075] This example provides an electrochromic polyimide with a structure of The difference between the preparation method of the electrochromic polyimide in this example and that in Example 1 is only that the diamine monomer is different, that is, is replaced with an equimolar amount of All other raw materials, dosages, and preparation methods are the same as those in Example 1.
[0076] Comparative Example 1
[0077] This comparative example provides an electrochromic polyimide with a structure of The difference between the preparation method of the electrochromic polyimide in this comparative example and that in Example 1 is only that the diamine monomer is different, that is, is replaced with an equimolar amount of All other raw materials, dosages, and preparation methods are the same as those in Example 1.
[0078] Application Example
[0079] A patterned polyimide film, and its preparation method includes:
[0080] (1) Photoresist formulation: Prepare a photoresist by mixing the precursor of electrochromic polyimide provided in the examples and comparative examples, a photosensitizer (PAC320), and cyclopentanone in a mass ratio of 15:5:80.
[0081] (2) Spin-coat the photoresist onto the surface of a silicon wafer substrate at a speed of 1200 rpm, pre-bake it at 90 °C for 300 s, expose it to ultraviolet light at 365 nm for 30 s, then develop it in a 0.113% tetramethylammonium hydroxide solution for 60 s, and then perform imidization by holding it at 300 °C for 1 h to obtain the patterned polyimide film.
[0082] Performance Test
[0083] Set transparent conductive coatings (ITO conductive coatings) on the upper and lower surfaces of the patterned polyimide film; then apply voltages on both sides of the ITO conductive coatings, and record the transmittance spectrum and color change of the patterned polyimide film when the voltage gradually increases from 0 V to 2 V; wherein, the thickness of the polyimide film is 800 nm, the resolution is 3 μm, and the thickness of the ITO conductive coating is 100 nm; and record the voltage reaching the colored state, as well as the corresponding response time and optical contrast.
[0084] The specific test results are shown in Table 1.
[0085] Table 1
[0086]
[0087] As can be seen from Table 1, the electrochromic polyimide provided by the present disclosure can be patterned, and can achieve a rapid transition from the faded state to the colored state at a relatively low voltage (1 - 2 V), can achieve the effect that the colored state is black, and the contrast is higher than 80%, and the response time ≤ 8 s, and can be used in applications of displays and electronic devices.
[0088] As can be seen from Comparative Example 1, in the structure of the electrochromic polyimide, when Y is not selected from a specific structure and is a triarylamine structure substituted by an alkoxy group, the conversion from the faded state to the black colored state cannot be achieved, and the contrast is low and the response time is long.
[0089] The specific embodiments described above further elaborate on the objective, technical solution, and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included within the protection scope of the present disclosure.
Claims
1. An electrochromic polyimide, characterized in that, The electrochromic polyimide has the structure shown in Formula I; In formula I, Y is selected from substituted or unsubstituted wherein Ar1 and Ar4 are each independently selected from substituted or unsubstituted C6-C12 arylene groups; Ar2, Ar3, Ar5, and Ar6 are each independently selected from substituted or unsubstituted C6-C20 aryl groups; and at least one of Ar2, Ar3, Ar5, and Ar6 has more than 6 carbon atoms; Ring Ar is selected from a substituted or unsubstituted cycloalkyl group having ≥4 carbon atoms, a substituted or unsubstituted aryl group having ≥6 carbon atoms, or any one of the following; Ar7 is selected from a substituted or unsubstituted C6-C12 arylene group; Ar8 and Ar9 are each independently selected from a substituted or unsubstituted cycloalkyl group having ≥3 carbon atoms; "*" represents a connection site or a fusion site; n is selected from integers greater than 0; The substituents of the substitution include any one of D, halogen, -CN, C1-C6 straight-chain or branched alkyl, C1-C6 straight-chain or branched alkoxy, C6-C12 aryl, and C4-C12 heteroaryl.
2. The electrochromic polyimide according to claim 1, characterized in that, Y is selected from any one of the following structures, or any one of the following structures substituted by substituents; Wherein, Ar1, Ar2, Ar3, Ar4, Ar5, Ar6 are each independently selected from the same range as Formula I; the substituents of the substitution are selected from the same range as Formula I; "*" represents a connection site or a fusion site.
3. The electrochromic polyimide according to claim 1, wherein Ar1 and Ar4 are each independently selected from substituted or unsubstituted phenylene; Ar2, Ar3, Ar5, and Ar6 are each independently selected from substituted or unsubstituted C6-C14 aryl; and at least one of Ar2 and Ar3 has more than 6 carbon atoms; at least one of Ar5 and Ar6 has more than 6 carbon atoms.
4. The electrochromic polyimide according to claim 1, wherein Y is selected from any one of the following structures, or any one of the following structures substituted by substituents; Wherein, the substituents of the substitution are selected from the same range as Formula I; "*" represents a connection site or a fusion site.
5. The electrochromic polymer according to claim 1, characterized in that, The ring Ar is selected from any one of the following structures, or any one of the following structures substituted by substituents; Wherein, R1 and R2 are each independently selected from any one of a single bond, O, -NH-, C1-C6 straight-chain or branched alkylene, and fluorine-substituted C1-C6 straight-chain or branched alkylene; The dotted line represents a fusion site; the substituents of the substitution are selected from the same range as Formula I.
6. The electrochromic polymer according to claim 1, characterized in that, The precursor of the electrochromic polyimide has the structure shown in Formula II; In Formula II, Y and the ring Ar are each independently selected from the same range as Formula I; R1 and R2 are each independently selected from any one of H, C1-C4 straight-chain or branched alkyl, and -CH2CH(OH)CH2OOCC(CH3)=CH2; and at least one of R1 and R2 is selected from C1-C4 straight-chain or branched alkyl or -CH2CH(OH)CH2OOCC(CH3)=CH2.
7. A method for preparing an electrochromic polyimide according to any one of claims 1 to 6, characterized in that, The preparation method includes the following steps: (1) React a diamine monomer H2N-Y-NH2 with a dianhydride monomer to obtain a polyamic acid; (2) React the polyamic acid obtained in step (1) with an esterifying agent to obtain the precursor of the electrochromic polyimide; (3) Subject the precursor obtained in step (2) to an imidization reaction to obtain the electrochromic polyimide.
8. The preparation method according to claim 7, characterized in that, The molar ratio of the polyamic acid to the esterifying agent in step (2) is 1:(0.05-0.3).
9. The preparation method according to claim 7, characterized in that, The esterifying agent includes at least one of glycidyl methacrylate, N,N-dimethylformamide diethyl acetal, and N,N-dimethylformamide dimethyl acetal.
10. A photoresist, characterized in that, The photoresist includes a matrix resin, a photosensitizer, and a solvent; the matrix resin includes the electrochromic polyimide according to any one of claims 1-6 or the precursor of the electrochromic polyimide.
11. The photoresist according to claim 10, wherein, The mass ratio of the matrix resin, the photosensitizer, and the solvent is (10-20):(1-10):(70-90).
12. A patterned polyimide film, characterized in that, The raw materials for preparing the patterned polyimide film include the photoresist described in Claim 10 or 11.