High-ultraviolet photosensitive black polyimide as well as preparation method and application thereof

Abstract

The invention discloses black polyimide with high ultraviolet light sensitivity as well as a preparation method and application thereof, belongs to the technical field of functional polymer materials, and solves the problem that polyimide in the prior art cannot have excellent masking capability and ultraviolet light sensitivity at the same time. The structural formula of the polyimide is as follows: # imgabs0 #, and a structural unit A is polyaryl ether or polyaryl ketone; the structural unit B is tetraphenyl cyclopentadiene biphenyl; the structural unit C is diphenylamine or biphenol; and n is a positive integer from 1 to 50. According to the invention, reasonable molecular structure design is carried out on polyimide to prepare the intrinsic high-ultraviolet photosensitive black polyimide, so that the intrinsic high-ultraviolet photosensitive black polyimide is subjected to photoisomerization after exposure.

Description

Technical Field

[0001] The present invention relates to the technical field of functional polymer materials, and more particularly to a black polyimide with high ultraviolet sensitivity, and a preparation method and application thereof. Background Art

[0002] Black polyimide is a new type of polyimide. It is widely used in the electronics field because of its advantages such as being able to sense ultraviolet light, completely absorb visible light, effectively prevent aging of the internal circuit of the circuit board caused by external visible light, and be able to protect the internal circuit design.

[0003] With the rapid development of optoelectronic devices, demand is growing for photosensitive black polyimides that combine excellent shielding capabilities with high UV sensitivity. However, existing photosensitive black polyimides typically have a UV cutoff wavelength of around 580 nm, which results in significant absorption of UV light. This significantly reduces the effectiveness of UV exposure, resulting in weak or even no photoinduced structural transformation in the exposed area. This, in turn, leads to poor shielding capabilities and UV sensitivity.

[0004] Therefore, it is urgent to develop a polyimide with both excellent shielding ability and high UV sensitivity. Summary of the Invention

[0005] The present invention provides a black polyimide with high ultraviolet sensitivity, a preparation method and an application thereof, in order to solve the problem that the polyimide in the prior art cannot have both excellent masking ability and ultraviolet sensitivity.

[0006] In a first aspect, the present invention provides a black polyimide with high UV sensitivity, the structural formula of which is shown below: , wherein the structural unit A is a polyaryl ether or a polyaryl ketone; the structural unit B is tetraphenylcyclopentadiene biphenyl; the structural unit C is diphenylamine or biphenyldiphenol; and n is a positive integer from 1 to 50.

[0007] As a possible implementation method, the structural unit A is any one of the following groups: ; The structural unit B is any one of the following groups: ; The structural unit C is any one of the following groups: .

[0008] As a possible implementation, the number average molecular weight of the highly UV-sensitive black polyimide is 10,000-30,000; the structural unit C is connected to the photosensitive group via an alkane chain, and the molar percentage of the photosensitive group is 5%-15%.

[0009] As a possible implementation method, the structural formula is selected from any one of the following: ; .

[0010] In a second aspect, the present invention provides a method for preparing a highly UV-sensitive black polyimide as described in any possible implementation of the first aspect, comprising the following steps: under the protection of an inert gas, dissolving a diamine monomer having structural unit B and a photosensitive monomer having structural unit C in a polar organic solvent, adding an acid anhydride having structural unit A, and fully dissolving and reacting under light-proof conditions to obtain a photosensitive black polyamide solution.

[0011] As a possible implementation method, the method further includes the following steps: coating the photosensitive black polyamide solution on a substrate, performing photoetching on the surface thereof using an ultraviolet light source; and performing thermal imidization to obtain a black polyimide film with high ultraviolet sensitivity.

[0012] As a possible implementation, the acid anhydride having the structural unit A is any one of bis(3,4-dimethylphenyl)methanone and 4,4'-{[propane-2,2-diylbis(4,1-phenyl)]bis(oxy)}bis(1,2-dimethylbenzene); and / or the diamine monomer having the structural unit B is 4,4'-{3,5-bis(4'-methyl-[1,1'-biphenyl]-4-yl)cyclopentane-2 ,5-diene-1,2-diyl}diphenol, 4',4'''-(4,5-diphenylcyclopenta-3,5-diene-1,3-diyl)bis(4-methyl-1,1'-biphenyl); and / or, the photosensitive diamine monomer having the structural unit C is any one of 4,4',5,5'-tetramethyl-[1,1'-biphenyl]-3,3'-diol and bis(3,4-dimethylphenyl)amine.

[0013] As a possible implementation manner, the ratio of the amount of substance of the acid anhydride having the structural unit A: the diamine monomer having the structural unit B: the photosensitive diamine monomer having the structural unit C is (10-100): (1-20): (2-50); and / or the sum of the masses of the acid anhydride having the structural unit A, the diamine monomer having the structural unit B, and the photosensitive diamine monomer having the structural unit C accounts for 5%-10% of the total mass of the reaction solution; and / or the polar organic solvent is any one of N-methyl-2-pyrrolidone, N,N-dimethylformamide, N-vinyl-2-pyrrolidone, and toluene; and / or the conditions for the sufficient dissolution reaction are: placing the reaction system at -5-25°C and stirring in the dark for 12-20 hours.

[0014] As a possible implementation method, the exposure parameters of the photolithography are: the wavelength of the ultraviolet light source is 350~400nm, and the exposure time is 5~80s; the thermal imidization includes the steps of: maintaining at 30~50℃ for 30 minutes, maintaining at 50~150℃ for 30 minutes, maintaining at 150~250℃ for 30 minutes, and maintaining at 250~400℃ for 40~60 minutes under an inert gas atmosphere.

[0015] In a third aspect, the present invention provides an application of the highly UV-sensitive black polyimide described in any possible implementation of the first aspect in any field of flexible OLED display, high-end CMOS image sensor packaging, satellite solar panels, high-frequency communication antennas / shielding, and precision optical instruments.

[0016] The present invention provides a design route for a highly UV-sensitive black polyimide. By rationally designing the polyimide molecular structure, an intrinsically UV-sensitive black polyimide is prepared, which undergoes photoisomerization upon exposure. This overcomes the problems of existing photosensitive black polyimides, which suffer from poor masking ability and UV sensitivity. Furthermore, the highly UV-sensitive black polyimide provided by the present invention also exhibits excellent insulation and mechanical properties.

[0017] This invention provides a black polyimide with high UV sensitivity. This photosensitive black polyimide has a cutoff wavelength of up to 600 nm, effectively preventing photoaging of the internal structure caused by external visible light, protecting the internal structure from plagiarism. It also exhibits high sensitivity in the UV region, allowing photoisomerization in exposed areas. The molecular structure design provided in this invention is safe and easy to operate, with high raw material utilization and low energy consumption. Based on existing photolithography equipment and process technologies, it facilitates the industrial production of photosensitive black polyimide. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 Schematic diagram of a black polyimide A mask with high UV sensitivity provided by an embodiment of the present invention having a mask pattern on its surface after photolithography.

[0020] Figure 2 This is an infrared test image of the highly UV-sensitive black polyimide A provided by an embodiment of the present invention.

[0021] Figure 3The invention provides a synthetic route for the highly UV-sensitive black polyimide A.

[0022] Figure 4 The invention provides a synthetic route for the highly UV-sensitive black polyimide B.

[0023] Figure 5 The invention provides a synthetic route for common black polyimide.

[0024] Figure 6 This is a UV-visible light test chart of the highly UV-sensitive black polyimide A and ordinary black polyimide provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] In order to solve the problem that the polyimide in the prior art cannot have both excellent masking ability and ultraviolet sensitivity, the embodiments of the present invention provide a black polyimide with high ultraviolet sensitivity and a preparation method and application thereof.

[0027] The method for preparing a highly UV-sensitive black polyimide provided by an embodiment of the present invention comprises the following steps: under inert gas protection, adding a diamine monomer having structural unit B and a photosensitive diamine monomer having structural unit C to a polar organic solvent, stirring and dissolving them, and then adding an acid anhydride having structural unit A and continuing to stir. The reaction system is then placed in a water bath at -5 to 25°C and stirred in the dark for 12 to 20 hours to obtain a photosensitive black polyamide acid solution. The obtained highly UV-sensitive black polyamide acid solution is applied to a substrate by spin coating, heated to remove the solvent, and exposed to a UV light source. The substrate is then placed in an inert gas atmosphere and maintained at 30 to 50°C for 30 minutes, 50 to 150°C for 30 minutes, 150 to 250°C for 30 minutes, and 250 to 400°C for 40 to 60 minutes, performing thermal imidization in stages to produce a highly UV-sensitive black polyimide.

[0028] Wherein, in terms of the amount of substance ratio, the acid anhydride having the structural unit A: the diamine monomer having the structural unit B: the photosensitive diamine monomer having the structural unit C = (10-100): (1-20): (2-50).

[0029] The total mass of the acid anhydride having the structural unit A, the diamine monomer having the structural unit B, and the photosensitive diamine monomer having the structural unit C accounts for 5% to 10% of the total mass of the reaction solution.

[0030] The polar organic solvent is selected from any one of N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), N-vinyl-2-pyrrolidone and toluene.

[0031] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0032] Example 1

[0033] This embodiment provides an experiment for preparing black polyimide with high UV sensitivity.

[0034] 205.30 g of the diamine monomer 4'',4'''''-(4,5-diphenylcyclopenta-3,5-diene-1,3-diyl)bis([1,1':4',1''-terphenyl]-4-amine) and 110.01 g of the photosensitive diamine monomer were mixed and added to an apparatus equipped with a stirrer. The reaction system was placed in an ice-water bath at 0°C. 771.7 g of N-methylpyrrolidone (NMP) was then added and stirred until the diamine monomer was completely dissolved. 351.91 g of 5,5'-carbonylbis(isobenzofuran-1,3-dione) was added to the reaction system in three separate additions, each with a 20-min interval. The reaction was allowed to proceed under an inert atmosphere in the dark for 12 h to obtain a highly UV-sensitive black polyamic acid solution A. After filtering and defoaming, the photosensitive black polyamic acid solution A was coated onto a substrate by spin coating. The coated substrate was placed on a heating platform at 80°C for 3 h to evaporate the solvent, thereby obtaining a black polyimide film A. The photosensitive black polyimide film A was exposed to a UV light source with a wavelength of 350 nm for 10 s. Figure 1 The results shown by Figure 1 It can be seen that after exposure through the UV mask, the pattern can be clearly observed on the film.

[0035] Then, the exposed photosensitive black polyimide film A was placed in an inert gas atmosphere and kept at 50°C for 30 minutes, 100°C for 30 minutes, 250°C for 30 minutes, and 400°C for 60 minutes, and thermal imidization was performed in stages to obtain highly UV-sensitive black polyimide A. The obtained highly UV-sensitive black polyimide A was subjected to infrared testing, and the following results were obtained: Figure 2 The results shown.

[0036] The synthetic route of this embodiment is as follows Figure 3 shown.

[0037] Example 2

[0038] This embodiment provides an experiment for preparing black polyimide with high UV sensitivity.

[0039] 77.90 g of the diamine monomer 4,4'-[3,5-bis(4'-amino-[1,1'-biphenyl]-4-yl)cyclopenta-2,5-diene-1,2-diyl]diphenol and 277.03 g of the photosensitive diamine monomer were mixed and added to an apparatus equipped with a stirrer. The reaction system was placed in an ice-water bath at 5°C. Then, 1110.50 g of N,N-dimethylformamide (DMF) was added and stirred until the diamine monomer was completely dissolved. 757.70 g of 5,5'-[(propane-2,2-diylbis[4,1-phenylene])bis(oxy)]bis(isobenzofuran-1,3-dione) was added to the reaction system in three separate additions, each with a 5-minute interval. The reaction was in an inert atmosphere, shielded from light, for 15 hours to obtain a highly UV-sensitive black polyamic acid solution B. After filtering and defoaming, the photosensitive black polyamic acid solution B was coated onto a substrate by spin coating. The coated substrate was heated on a 50°C heating table for 2 hours to evaporate the solvent, resulting in a black polyimide film B. The photosensitive black polyimide film B was exposed to a 400 nm UV light source for 70 seconds. The film was then thermally imidized in stages under an inert gas atmosphere at 50°C for 30 minutes, 150°C for 30 minutes, 250°C for 30 minutes, and 400°C for 60 minutes, yielding a highly UV-sensitive black polyimide film B.

[0040] The synthetic route of this embodiment is as follows Figure 4 shown.

[0041] Example 3

[0042] This embodiment provides an experiment for preparing common black polyimide.

[0043] 17.3 g of the diamine monomer N1-(4-aminophenyl)-N1-phenylbenzene-1,4-diamine and 111.5 g of the photosensitive diamine monomer were mixed and added to a mechanically stirred apparatus. The reaction system was placed in a 20°C water bath. 1756.5 g of N,N-dimethylformamide (DMF) was then added to the apparatus and stirred until the diamine monomer was completely dissolved. Next, 108 g of 2,3,6,7-naphthalenetetracarboxylic dianhydride was added to the reaction solution in one portion. Stirring was continued under inert gas for 24 hours to produce a photosensitive black polyamide acid solution. The photosensitive black polyamide acid solution was filtered and defoamed at room temperature in the dark, then coated onto a substrate by doctor blade coating. The substrate was then placed in a forced air heating apparatus and the solvent evaporated at 60°C for 2 hours to produce a photosensitive black polyimide film. The black polyimide film was placed in an inert gas atmosphere, maintained at 80° C. for 60 minutes, 150° C. for 60 minutes, and 280° C. for 120 minutes, and heated in stages for imidization to obtain a self-supporting ordinary black polyimide.

[0044] The synthetic route of this embodiment is as follows Figure 5 shown.

[0045] The high UV-sensitive black polyimide A and ordinary black polyimide prepared in Example 1 were subjected to UV-visible light testing, and the results were as follows: Figure 6 The results shown by Figure 6 It can be seen that the absorbance of the highly UV-sensitive black polyimide A in the UV region is more than 40% higher than that of the ordinary photosensitive black polyimide.

[0046] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0047] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A black polyimide with high UV sensitivity, characterized in that: The structural formula is shown below: ； Wherein, the structural unit A is polyaryl ether or polyaryl ketone; the structural unit B is tetraphenylcyclopentadienylbiphenyl; the structural unit C is diphenylamine or biphenyldiphenol; and n is a positive integer from 1 to 50.

2. The highly UV-sensitive black polyimide according to claim 1, characterized in that: The structural unit A is any one of the following groups: ； The structural unit B is any one of the following groups: ； The structural unit C is any one of the following groups: 。 3. The black polyimide with high UV sensitivity according to claim 1, characterized in that: The number average molecular weight of the highly UV-sensitive black polyimide is 10,000 to 30,000; The structural unit C is connected to the photosensitive group via an alkane chain, and the molar percentage of the photosensitive group is 5% to 15%.

4. The black polyimide with high UV sensitivity according to claim 1, characterized in that: Its structural formula is selected from any one of the following: ； 。 5. A method for preparing the highly UV-sensitive black polyimide according to any one of claims 1 to 4, characterized in that: The following steps are involved: Under the protection of inert gas, a diamine monomer having structural unit B and a photosensitive monomer having structural unit C are dissolved in a polar organic solvent, an acid anhydride having structural unit A is added, and the mixture is fully dissolved and reacted under light-proof conditions to obtain a photosensitive black polyamide solution.

6. The preparation method according to claim 5, characterized in that The method also includes the following steps: coating the photosensitive black polyamide solution on a substrate, performing photoetching on the surface of the substrate using an ultraviolet light source, and performing thermal imidization to obtain a black polyimide film with high ultraviolet sensitivity.

7. The preparation method according to claim 5, characterized in that The acid anhydride having the structural unit A is any one of bis(3,4-dimethylphenyl)ketone and 4,4'-{[propane-2,2-diylbis(4,1-phenyl)]bis(oxy)}bis(1,2-dimethylbenzene); And / or, the diamine monomer having the structural unit B is any one of 4,4'-{3,5-bis(4'-methyl-[1,1'-biphenyl]-4-yl)cyclopenta-2,5-diene-1,2-diyl}diphenol and 4',4'''-(4,5-diphenylcyclopenta-3,5-diene-1,3-diyl)bis(4-methyl-1,1'-biphenyl); And / or, the photosensitive diamine monomer having the structural unit C is any one of 4,4',5,5'-tetramethyl-[1,1'-biphenyl]-3,3'-diol and bis(3,4-dimethylphenyl)amine.

8. The preparation method according to claim 5, characterized in that In terms of the ratio of the amount of substance, the acid anhydride having the structural unit A: the diamine monomer having the structural unit B: the photosensitive diamine monomer having the structural unit C = (10-100): (1-20): (2-50); and / or, the sum of the mass of the acid anhydride having structural unit A, the diamine monomer having structural unit B, and the photosensitive diamine monomer having structural unit C accounts for 5% to 10% of the total mass of the reaction solution; And / or, the polar organic solvent is any one of N-methyl-2-pyrrolidone, N,N-dimethylformamide, N-vinyl-2-pyrrolidone, and toluene; And / or, the conditions for the sufficient dissolution reaction are: placing the reaction system at -5 to 25° C. and stirring in the dark for 12 to 20 hours.

9. The preparation method according to claim 6, characterized in that The exposure parameters of the photolithography are: the wavelength of the ultraviolet light source is 350-400 nm, and the exposure time is 5-80 s; The thermal imidization comprises the steps of: maintaining at 30-50° C. for 30 minutes, maintaining at 50-150° C. for 30 minutes, maintaining at 150-250° C. for 30 minutes, and maintaining at 250-400° C. for 40-60 minutes under an inert gas atmosphere.

10. Use of the highly UV-sensitive black polyimide according to any one of claims 1 to 4 in any field of flexible OLED display, high-end CMOS image sensor packaging, satellite solar panels, high-frequency communication antennas / shielding, and precision optical instruments.

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