Fluorescent polyimide film and preparation method thereof
阅读说明：本技术 一种荧光型聚酰亚胺薄膜及其制备方法 (Fluorescent polyimide film and preparation method thereof ) 是由 李鑫 于 2019-10-31 设计创作，主要内容包括：本发明公开了一种荧光型聚酰亚胺薄膜的制备方法,包括如下步骤：在惰性气体氛围中,向芳香型二胺溶液中第一次加入芳香型二酐反应至粘度1,加入混合溶液搅拌混匀,再第二次加入芳香型二酐调节至粘度2得到中间物料；取中间物料脱泡并涂布于基板表面,烘干,剥离薄膜,亚胺化得到荧光型聚酰亚胺薄膜,其中,混合溶液的溶质为荧光粉体、石墨烯、硅烷偶联剂。本发明还公开了一种荧光型聚酰亚胺薄膜,按照上述荧光型聚酰亚胺薄膜的制备方法制得。本发明热稳定性好,耐高低温,耐腐蚀,具有优异的力学性能,同时发光均匀。(The invention discloses a preparation method of a fluorescent polyimide film, which comprises the following steps: in an inert gas atmosphere, adding aromatic dianhydride into an aromatic diamine solution for the first time to react until the viscosity is 1, adding a mixed solution, stirring and uniformly mixing, adding aromatic dianhydride for the second time, and adjusting the viscosity to be 2 to obtain an intermediate material; and defoaming the intermediate material, coating the intermediate material on the surface of a substrate, drying, stripping the film, and imidizing to obtain the fluorescent polyimide film, wherein the solute of the mixed solution is fluorescent powder, graphene and a silane coupling agent. The invention also discloses a fluorescent polyimide film which is prepared according to the preparation method of the fluorescent polyimide film. The invention has the advantages of good thermal stability, high and low temperature resistance, corrosion resistance, excellent mechanical property and uniform luminescence.)
1. A preparation method of a fluorescent polyimide film is characterized by comprising the following steps: in an inert gas atmosphere, adding aromatic dianhydride into an aromatic diamine solution for the first time to react until the viscosity is 1, adding a mixed solution, stirring and uniformly mixing, adding aromatic dianhydride for the second time, and adjusting the viscosity to be 2 to obtain an intermediate material; and defoaming the intermediate material, coating the intermediate material on the surface of a substrate, drying, stripping the film, and imidizing to obtain the fluorescent polyimide film, wherein the solute of the mixed solution is fluorescent powder, graphene and a silane coupling agent.
2. The method for preparing a fluorescent polyimide film as claimed in claim 1, wherein the viscosity 1 is 500-1500 poise; preferably, the viscosity 2 is 2000-.
3. The method for producing a fluorescent polyimide film according to claim 1 or 2, wherein the aromatic diamine is at least one selected from the group consisting of 4,4 '-diaminodiphenyl ether, p-phenylenediamine, and 3,4' -diaminodiphenyl ether; preferably, the aromatic diamine is 4,4' -diaminodiphenyl ether; preferably, the aromatic dianhydrides are pyromellitic dianhydride and 3,3',4,4' -biphenyltetracarboxylic dianhydride; preferably, the aromatic dianhydride has a molar percentage of pyromellitic dianhydride of 70 to 90%.
4. The method for preparing a fluorescent polyimide film according to any one of claims 1 to 3, wherein the solid content of the intermediate material is 10 to 20 wt%; preferably, the solids of the intermediate materialIn the process, the content of the fluorescent powder is 11-26 wt%, the content of the graphene is 11-27 wt%, and the content of the coupling agent is 1-5 wt%; preferably, the phosphor is MgAl green powder11O19：Ce3+Green powder of MgAl11O19：Tb3+、ZnSiO4: at least one of Mn and LuAG; preferably, the particle size of the phosphor is 0.1 to 2.0. mu.m.
5. The method for preparing a fluorescent polyimide film according to any one of claims 1 to 4, wherein the molar ratio of the aromatic dianhydride to the aromatic diamine is 0.97 to 1.03: 1; preferably, the first addition of aromatic dianhydride is 95-98% of the total weight of aromatic dianhydride.
6. The method for preparing a fluorescent polyimide film according to any one of claims 1 to 5, wherein the drying temperature is 100 ℃ to 200 ℃; preferably, the drying temperature is 150-; preferably, the drying time is 5-20 min; preferably, the drying time is 5-15 min.
7. The method for preparing a fluorescent polyimide film according to any one of claims 1 to 6, wherein the imidization temperature is 200-450 ℃; preferably, the imidization temperature is 300-450 ℃; preferably, the procedure for imidization is: heating to 380 ℃ for heat preservation for 1-5min, heating to 400 ℃ for 380 ℃ for heat preservation of less than or equal to 3min, and heating to 450 ℃ for heat preservation of less than or equal to 2 min.
8. The method for preparing a fluorescent polyimide film according to any one of claims 1 to 7, wherein the fluorescent polyimide film is obtained by cooling after imidization, wherein the cooling procedure is as follows: cooling to 150 deg.C within 2min, and naturally cooling to room temperature.
9. The method for preparing a fluorescent polyimide film according to any one of claims 1 to 8, wherein the solvents of the aromatic diamine solution and the mixed solution are aprotic organic solvents; preferably, the aprotic organic solvent is at least one of N, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone; preferably, the aprotic organic solvent is N, N-dimethylacetamide.
10. A fluorescent polyimide film produced by the method for producing a fluorescent polyimide film according to any one of claims 1 to 9.
Technical Field
The invention relates to the technical field of polyimide films, in particular to a fluorescent polyimide film and a preparation method thereof.
Background
As a novel packaging process, the fluorescent thin film packaged LED can improve the luminous efficiency, prolong the service life of the LED, improve the luminous uniformity and the like, and has wide application prospect. However, the heat dissipation problem of the high-power LED lighting device is a difficulty in the application of the fluorescent film, and the LED chip generates a large amount of heat after long-time operation, which may cause the fluorescent film to age, even deform, and cause uneven lighting. The existing manufacturing method of the LED fluorescent film generally comprises the steps of directly mixing and uniformly stirring fluorescent powder and glue, preparing a film by spin coating, printing and other modes, drying and curing, and the like.
Disclosure of Invention
Based on the technical problems in the background art, the invention provides a fluorescent polyimide film and a preparation method thereof.
The invention provides a preparation method of a fluorescent polyimide film, which comprises the following steps: in an inert gas atmosphere, adding aromatic dianhydride into an aromatic diamine solution for the first time to react until the viscosity is 1, adding a mixed solution, stirring and uniformly mixing, adding aromatic dianhydride for the second time, and adjusting the viscosity to be 2 to obtain an intermediate material; and defoaming the intermediate material, coating the intermediate material on the surface of a substrate, drying, stripping the film, and imidizing to obtain the fluorescent polyimide film, wherein the solute of the mixed solution is fluorescent powder, graphene and a silane coupling agent.
Preferably, the viscosity 1 is 500-.
Preferably, the viscosity 2 is 2000-.
Preferably, the aromatic diamine is at least one of 4,4 '-diaminodiphenyl ether, p-phenylenediamine, and 3,4' -diaminodiphenyl ether.
Preferably, the aromatic diamine is 4,4' -diaminodiphenyl ether.
Preferably, the aromatic dianhydrides are pyromellitic dianhydride and 3,3',4,4' -biphenyltetracarboxylic dianhydride.
Preferably, the aromatic dianhydride has a molar percentage of pyromellitic dianhydride of 70 to 90%.
Preferably, the solids content of the intermediate material is from 10 to 20% by weight.
Preferably, in the solid component of the intermediate material, the content of the fluorescent powder is 11 to 26 wt%, the content of the graphene is 11 to 27 wt%, and the content of the coupling agent is 1 to 5 wt%.
Preferably, the phosphor is MgAl green powder11O19：Ce3+Green powder of MgAl11O19：Tb3+、ZnSiO4: at least one of Mn and LuAG.
Preferably, the particle size of the phosphor is 0.1 to 2.0. mu.m.
Preferably, the molar ratio of the aromatic dianhydride to the aromatic diamine is 0.97-1.03: 1.
preferably, the first addition of aromatic dianhydride is 95-98% of the total weight of aromatic dianhydride.
Preferably, the drying temperature is 100-.
Preferably, the drying temperature is 150-.
Preferably, the drying time is 5-20 min.
Preferably, the drying time is 5-15 min.
Preferably, the imidization temperature is 200-450 ℃.
Preferably, the imidization temperature is 300-450 ℃.
Preferably, the procedure for imidization is: heating to 380 ℃ for heat preservation for 1-5min, heating to 400 ℃ for 380 ℃ for heat preservation of less than or equal to 3min, and heating to 450 ℃ for heat preservation of less than or equal to 2 min.
Preferably, the procedure for imidization is: heating to 380 ℃ at the speed of 10 ℃/min, preserving the heat for 1-5min, heating to 380 ℃ at the speed of 10 ℃/min, preserving the heat for less than or equal to 3min at 400 ℃ at the speed of 380 ℃ and raising the temperature to 450 ℃ at the speed of 8 ℃/min, preserving the heat for less than or equal to 2 min.
Preferably, the fluorescent polyimide film is obtained by cooling after imidization, wherein the cooling procedure is as follows: cooling to 150 deg.C within 2min, and naturally cooling to room temperature.
Preferably, the solvent of the aromatic diamine solution and the solvent of the mixed solution are both aprotic organic solvents.
Preferably, the aprotic organic solvent is at least one of N, N-dimethylformamide, N-dimethylacetamide, and N-methyl-2-pyrrolidone.
Preferably, the aprotic organic solvent is N, N-dimethylacetamide.
The invention also discloses the fluorescent polyimide film which is prepared according to the preparation method of the fluorescent polyimide film.
In the process of preparing the intermediate material, namely the polyamide acid resin, the fluorescent powder and the graphene are added at a proper viscosity and are matched with the silane coupling agent, so that the fluorescent powder and the graphene are uniformly dispersed in the polyamide acid resin, the polyimide film uniformly emits light, and the structural stability and the mechanical property of the polyimide film are not influenced; the invention can emit blue light under the excitation of ultraviolet light; the method selects proper aromatic diamine to react with aromatic dianhydride and to be matched with graphene, so that the graphene-based fluorescent material has high mechanical property, good thermal stability and fluorescence.
Drawings
FIG. 1 shows the fluorescence detection results of the fluorescent polyimide film of the present invention.
Detailed Description
The technical solution of the present invention will be described in detail below with reference to specific examples.