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CN-122011386-A - Polyimide material and preparation method thereof

CN122011386ACN 122011386 ACN122011386 ACN 122011386ACN-122011386-A

Abstract

The invention relates to a polyimide material and a preparation method thereof, wherein the polyimide material comprises the following steps of mixing a polyamine-based monomer, a diamine monomer and a dianhydride monomer in an organic solvent, carrying out a prepolymerization reaction to obtain a polyamic acid solution, wherein the amine number in the polyamine-based monomer is more than 3, coating the polyamic acid solution on a substrate to form a film, and carrying out surface drying and then heating and curing to obtain the polyimide material with the glass transition temperature Tg of more than 350 ℃. The invention adopts polyamine monomer as core component, and forms polyimide molecular structure with super cross-linking density similar to 'fishing net' special structure through ternary polymerization reaction with diamine monomer (containing two amine groups) and dianhydride monomer, the super cross-linking density can obviously inhibit polyimide chain segment movement through triple mechanism of steric hindrance restriction, free volume compression and energy barrier lifting, thereby greatly improving the glass transition temperature of polyimide material to above 350 ℃.

Inventors

  • WANG YAO
  • XIONG SHENGWU
  • LI XIAOJUN
  • E chao
  • Ge Cuihuan
  • Li Zulan

Assignees

  • 武汉学院

Dates

Publication Date
20260512
Application Date
20260122

Claims (10)

  1. 1. The preparation method of the polyimide material is characterized by comprising the following steps of: Mixing a polyamine monomer, a diamine monomer and a dianhydride monomer in an organic solvent, and carrying out a prepolymerization reaction to obtain a polyamic acid solution, wherein the number of amine groups in the polyamine monomer is more than 3; and (3) coating the polyamic acid solution on a substrate to form a film, and heating and curing the film after surface drying to obtain the polyimide material with the glass transition temperature Tg of more than 350 ℃.
  2. 2. The method of claim 1, wherein the polyamine-based monomer comprises a triamine-based monomer or a tetramine-based monomer.
  3. 3. The method of preparing a polyimide material according to claim 2, wherein the triamine based monomers include, but are not limited to, one or more of tris (4-aminophenyl) methane, tris (4-aminophenyl) methanol, 2,4, 6-tris (4-aminophenyl) pyridine, tris (4-aminophenyl) amine, 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine; The tetramine-based monomers include, but are not limited to, one or more of 1,2,4, 5-benzenetetramine, tetrakis (4-aminophenyl) methane, 5,10,15, 20-tetrakis (4-aminophenyl) porphyrin, 4,4,4,4- [ benzene-1, 2,4, 5-tetrakistetrakis (acetylene-2, 1-diyl) ] tetraaniline, tetrakis- (4-aminophenyl) -ethylene.
  4. 4. The method for producing a polyimide material according to claim 1, wherein the diamine monomer comprises one or more of 1, 6-hexamethylenediamine, 4 '-diaminodiphenyl ether, diethyltoluenediamine, 4' -diaminodiphenylmethane, 2 '-bis (trifluoromethyl) -4,4' -diaminobiphenyl, p-phenylenediamine, m-phenylenediamine, 3 '-dimethyl-4, 4' -diaminodiphenylmethane, 2, 6-diaminotoluene, isophoronediamine, 3-dimethyl-4, 4-diaminodicyclohexylmethane, 1, 3-cyclohexanediamine, triethylenediamine, methylcyclopentylene diamine.
  5. 5. The method of producing a polyimide material according to claim 1, wherein the dianhydride monomer comprises one or more of aromatic dianhydride, alicyclic dianhydride, and functional dianhydride; The aromatic dianhydride comprises one or more of pyromellitic dianhydride, 3', 4' -biphenyl tetracarboxylic dianhydride and diphenyl ether tetracarboxylic dianhydride; The alicyclic dianhydride comprises one or more of 1,2,4, 5-cyclohexane tetracarboxylic dianhydride, cyclobutane tetracarboxylic dianhydride and 1,2,3, 4-cyclopentane tetracarboxylic dianhydride; The functional dianhydride comprises one or more of bisphenol A type diether dianhydride and hexafluorodianhydride.
  6. 6. The method of producing a polyimide material according to claim 1, wherein the molar ratio of the polyamine-based monomer, the diamine monomer and the dianhydride monomer is (0.5 to 2) 20:22.
  7. 7. The method for producing a polyimide material according to claim 1, wherein the organic solvent comprises one or more of N, N-dimethylacetamide, N-methylpyrrolidone, N-dimethylformamide and dimethylsulfoxide; the solid content of the mixed solution obtained by mixing the polyamine monomer, the diamine monomer and the dianhydride monomer in an organic solvent is 15-25%.
  8. 8. The method for preparing a polyimide material according to claim 1, wherein the pre-polymerization is carried out at 20-28 ℃ with stirring for 10-14 hours.
  9. 9. The method for preparing a polyimide material according to claim 1, wherein the surface drying is performed at 75-85 ℃ for 0.5-1.5 h; The specific process of the heating and curing comprises the steps of heating to 90-110 ℃, 140-160 ℃, 190-210 ℃ and 240-260 ℃ and maintaining the temperature of each step for 20-40 min.
  10. 10. A polyimide material produced by the production process according to any one of claims 1 to 9.

Description

Polyimide material and preparation method thereof Technical Field The invention relates to the field of polyimide materials, in particular to a polyimide material and a preparation method thereof. Background Polyimide (PI) has become an indispensable core material for the microelectronics industry by virtue of its excellent high temperature resistance, low dielectric constant, high insulation and dimensional stability. Applications of PI in the microelectronics field mainly include interlayer dielectric materials as integrated circuit packages and interconnects, substrate materials for flexible displays and electronics, interface materials for high frequency communication and thermal conduction management, and the like. In the packaging and interconnection of integrated circuits, the PI film is often used as an insulating layer of a chip multilayer interconnection structure, the dielectric constant of the PI film can be as low as 3.4@1MHz, the signal crosstalk and loss can be obviously reduced, and the performance of a high-frequency circuit is improved. Meanwhile, when polyimide is used as a buffer/passivation layer in a chip packaging structure, the polyimide covers the surface of a chip, reduces warping risk caused by thermal expansion mismatch through stress buffering, and simultaneously shields alpha particle radiation and prevents soft errors. In flexible displays (e.g., OLED displays) and electronic substrate material preparation, transparent PI films replace rigid glass, supporting foldable screens, withstanding Thin Film Transistor (TFT) process temperatures >300 ℃. Meanwhile, in the OLED thin film packaging (TFE) process, PI and an inorganic film are alternately overlapped to form a flexible water-oxygen barrier layer, so that the service life of an OLED device can be remarkably prolonged. In high frequency communications and thermally conductive management substrate preparation, the low dielectric loss (Df < 0.005) characteristics of PI are adapted to millimeter wave transmissions for antenna flex circuits. Meanwhile, the modified high heat conduction PI film (such as graphene composite) is used for chip heat dissipation, and the heat conductivity can reach 20W/(m.K) (9), so that the modified high heat conduction PI film is very suitable for heat conduction interface materials in high-frequency communication and heat conduction management. The glass transition temperature (T g) is the point at which an amorphous polymer changes from a glassy state (brittle) to a highly elastic state (elastic), and is one of the very important performance indexes of PI, and currently the glass transition temperature of polyimide is generally 300 ℃ or less. Too low a T g in PI applications can significantly impair its core performance advantages, especially in high temperature, high precision or high reliability scenarios where systematic failures may be triggered. The performance impact of low glass transition temperature on PI mainly includes thermal stability and mechanical property degradation, performance defects of critical application scenarios, processing and detection challenges, etc. In terms of thermal stability and mechanical property degradation, low T g (e.g., <250 ℃) causes the material to undergo increased segmental motion under high temperature environments (e.g., above 200 ℃) and softening deformation. For example, aerospace engine components need to withstand high temperatures >250 ℃ for long periods of time, and low T g materials can cause structural instability due to creep. Meanwhile, key parts prepared from the low-T g polyimide material have poor dimensional stability, and are easy to warp or delaminate between a chip and a substrate due to thermal stress in microelectronic packaging. The polyimide material has the following main performance defects caused by the low T g in the application of the microelectronics industry: (1) The microelectronic package fails. In microelectronic packages, low T g due to polyimide materials typically results in poor reflow process compatibility. For example, chip packaging needs to undergo reflow soldering at a temperature above 260 ℃, low-T g polyimide materials lose glass state at the temperature, molecular chain segment movement is aggravated, dielectric constant (Dk) and loss factor (Df) fluctuation are increased, dielectric layer collapse, signal transmission loss is increased, circuit short-circuiting is caused, and high-frequency signal integrity is affected; (2) The flexible electronics lifetime is shortened. In the high-temperature process (such as TFT layer deposition, >300 ℃) of the flexible OLED, the substrate prepared from the low-T g polyimide material is insufficient in Cheng Nai tolerance and easy to shrink and deform, so that pixel dislocation or film stripping is caused, and the long-term reliability is seriously reduced. For example, an OLED foldable screen needs to withstand tens of thousands of bends, low T g polyimide has enhanced flexi