A high-processability high-heat-resistance thermoplastic polymer material

Abstract

The application discloses a kind of high processability high heat resistance thermoplastic high molecular materials, belong to high polymer material technical field.The material includes by diamine and diacid anhydride polycondensation and is formed by imidization soluble polyimide main chain, and polyimide molecular chain end contains reactive functional group;The material also includes additional resin system.The reactive functional group is selected from at least one in epoxy group, benzo oxazin group or acrylate group.The material presents thermoplastic in processing stage, under subsequent heating condition, end functional group and additional resin system occur crosslinking reaction, form three-dimensional network structure.The material of the application has low-temperature processability and high-temperature use stability, processing temperature ≤200 ℃, glass transition temperature is 150-240 ℃ after secondary crosslinking, thermal decomposition temperature >350 ℃, dielectric constant ≤3.0@10GHz, suitable for electronic packaging, flexible circuit board, high-frequency communication and aerospace etc.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a highly processable and heat-resistant thermoplastic polymer material based on soluble polyimide. Background Technology

[0002] Polyimide, as a representative of high-performance polymer materials, has been widely used in high-end technology fields such as aerospace, microelectronics, flexible displays, and new energy vehicles since its commercialization in the 1960s, thanks to its excellent heat resistance, mechanical strength, electrical insulation, and chemical stability. The unique molecular structure of polyimide endows it with outstanding comprehensive properties, such as a long-term operating temperature of 250-300℃, a glass transition temperature exceeding 350℃, and a thermal decomposition temperature typically above 500℃, while also possessing excellent mechanical and dielectric properties. However, traditional polyimides, such as thermosetting PI, while exhibiting excellent heat resistance, have narrow processing windows and are difficult to mold; thermoplastic PI, although thermoformable, suffers from high processing temperatures (>350℃), high melt viscosity, and demanding equipment requirements. While soluble polyimides have solved the solubility problem, most systems struggle to balance thermoplastic processability with thermosetting usability, either maintaining thermoplasticity but lacking sufficient heat resistance, or requiring high-temperature post-treatment and losing their processing advantages. While thermosetting resin systems such as epoxy and benzoxazine have relatively low processing temperatures, their heat resistance and dimensional stability are insufficient to meet the requirements of high-end electronic materials and applications in extreme environments. Existing modification methods, such as blending and copolymerization, often sacrifice one property while improving another, making it difficult to achieve a simultaneous improvement in both processability and heat resistance.

[0003] Therefore, developing a polymer material system that combines low-temperature thermoplastic processability with high-temperature stability has become an urgent technical problem to be solved in this field. Summary of the Invention

[0004] To address the problems existing in the background technology, this invention proposes a dual-functional material that achieves "first thermoplastic molding, then thermosetting crosslinking" by end-functionalizing soluble polyimide, providing an ideal material solution for high-end electronic materials, flexible circuit boards, aerospace structural components and other fields.

[0005] The purpose of this invention is to provide a highly processable and heat-resistant thermoplastic polymer material comprising a polyimide backbone formed from a diamine and a dianhydride, wherein the polymer ends contain reactive functional groups.

[0006] The further diamine is selected from any one of DDA, ODA, BAPP, and TEMB.

[0007] Further dianhydride monomers are selected from any one of ODPA, BTDA, BPDA, and PMDA.

[0008] Furthermore, the reactive functional group is any one of epoxy group, benzoxazinyl group, and acrylic group.

[0009] Furthermore, the molar ratio of diamine to dianhydride is 1:(0.95~1.05).

[0010] Furthermore, the solvent is any one of N,N-dimethylacetamide, N-methylpyrrolidone, and N,N-dimethylformamide.

[0011] Furthermore, the solid content is 10~35wt%; the reaction temperature is 25~80℃, gradually increased to 180℃ for imidization reaction; and the reaction time is 4~12 hours.

[0012] The highly processable and heat-resistant thermoplastic polymer material of this invention is manufactured using the following process. S1: The soluble polyimide is prepared by polycondensation reaction of diamine and dianhydride in a solvent. The catalyst is isoquinoline, imidazole, pyridine, etc., and the addition amount is 1%~5%.

[0013] S2. End-capping structure design: After the polymerization reaction is completed, an end-capping agent is added so that the polyimide chain ends with reactive functional groups that can participate in secondary reactions.

[0014] S3. Design of secondary crosslinking reaction The material described in this invention undergoes a secondary heating process after initial processing, causing the terminal functional groups to crosslink with the added resin system, forming a three-dimensional network structure. By adjusting the content of the terminal functional groups and controlling the crosslinking density, processability and heat resistance are balanced. Infrared spectroscopy is used to monitor the characteristic peaks of the functional groups (such as the 915 cm⁻¹ peak of epoxy groups). -1 950cm of benzoxazine -1 The presence of ) or the determination of the content of terminal groups by titration.

[0015] The types of end-capping agents and their introduction methods are shown in the table below:

[0016] Beneficial effects Compared with the prior art, the present invention has the following beneficial effects: The highly processable and heat-resistant thermoplastic polymer material prepared by this invention exhibits excellent processing performance, with a viscosity of 2000~5000 cps and a temperature range of 100~150℃. Its heat resistance is significantly improved; using the TMA method, the glass transition temperature (Tg) after secondary crosslinking can reach over 320℃, and the thermal decomposition temperature (Td, 5%) is >400℃.

[0017] It exhibits excellent dielectric properties, with a dielectric constant (Dk) ≤ 3.0 @ 10 GHz and a dielectric loss (Df) ≤ 0.003 @ 10 GHz, making it suitable for high-frequency communication. It also demonstrates good dimensional stability; as a highly processable and heat-resistant thermoplastic polymer, its coefficient of thermal expansion can be controlled within 20~30 ppm / K, meeting the requirements for flexible circuit boards and semiconductor packaging. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] Example 1 S1. Preparation of soluble polyimide: 0.1 mol of 4,4'-diaminodiphenyl ether and 0.1 mol of 4,4'-(hexafluoroisopropene)phthalic anhydride (6FDA) were dissolved in N,N-dimethylacetamide, with a solid content of 25 wt%. The reaction was carried out at room temperature for 12 hours to generate polyamic acid. 3% isoquinoline (by mass of the total reactants) was added, and thermal imidization was performed according to the following temperature program: 80℃ for 1 hour → 120℃ for 1 hour → 180℃ for 2 hours, to obtain soluble polyimide with anhydride-terminated groups.

[0020] S2. End-capping: N,N-diglycidylaniline was added to the above SPI solution at a molar ratio of 1:10 to the end-capping agent. 2% triphenylphosphine (by mass of the end-capping agent) was added, and the reaction was carried out at 120°C for 4 hours to introduce epoxy terminal groups. After the reaction, the product was precipitated in methanol, filtered, and vacuum dried at 60°C for 24 hours.

[0021] S3. Secondary crosslinking: The modified SPI resin and bisphenol A epoxy resin were blended at a mass ratio of 100:20, and dicyandiamide curing agent was added. The mixture was hot-pressed at 100°C for 15 minutes, and then cured at 180°C for 1.5 hours to obtain the crosslinked material.

[0022] Example 2 S1. Preparation of soluble polyimide: 0.1 mol of 2,2-bis[4-(4-aminophenoxy)phenyl]propane and 0.099 mol of 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) were dissolved in N-methylpyrrolidone, with a solid content of 20 wt%. The reaction was carried out at room temperature for 10 hours to generate polyamic acid. 3% isoquinoline was added according to the total mass of the reactants, and thermal imidization was performed according to the temperature program: 80℃ for 1 hour → 120℃ for 1 hour → 180℃ for 2 hours to obtain soluble polyimide with anhydride-terminated groups.

[0023] S2. End-capping: 3-Phenyl-3,4-dihydro-2H-1,3-benzoxazine-6-amine (molar ratio of end-capping agent to SPI is 1:12) was added to the above SPI solution, and the reaction was carried out at 120°C for 6 hours to introduce benzoxazine terminal groups. After the reaction was completed, the product was precipitated in methanol, filtered, and dried under vacuum at 60°C for 24 hours.

[0024] S3. Secondary crosslinking: The modified SPI resin described above is blended with bisphenol A type benzoxazine at a mass ratio of 100:30. The mixture is hot-pressed at 100°C for 15 minutes, and then cured at 220°C for 1.5 hours to obtain the crosslinked material.

[0025] Example 3 S1. Preparation of soluble polyimide: 0.1 mol of 2,2'-bis(trifluoromethyl)benzidine and 0.1 mol of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) were dissolved in N,N-dimethylformamide, with a solid content of 25 wt%. The mixture was reacted at room temperature for 12 hours to generate polyamic acid. Acetic anhydride / pyridine (molar ratio 2:1) was added for chemical imidization, and the reaction was carried out at 60°C for 4 hours to obtain a soluble polyimide with anhydride-terminated groups.

[0026] S2. End-capping: Glycidyl methacrylate was added to the above SPI solution at a molar ratio of 1:15. 1% p-toluenesulfonic acid (by mass of the end-capping agent) was added, and the mixture was reacted at 90°C for 5 hours to introduce acrylate end groups. After the reaction, the product was precipitated in ethanol, filtered, and vacuum dried at 60°C for 24 hours.

[0027] S3. Secondary crosslinking: The modified SPI resin and trimethylolpropane triacrylate were blended at a mass ratio of 100:15, and azobisisobutyronitrile (AIOBR) thermal initiator was added at an amount of 1.5% of the mass of the acrylate. The mixture was hot-pressed at 100°C for 15 minutes and then cured at 150°C for 1 hour to obtain the crosslinked material.

[0028] The properties of the polymer materials prepared in the examples are shown in the table below:

[0029] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0030] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A highly processable and heat-resistant thermoplastic polymer material, comprising a polyimide backbone formed from diamine and dianhydride, characterized in that... The polymer backbone contains reactive functional groups at its ends.

2. The highly processable and heat-resistant thermoplastic polymer material as described in claim 1, characterized in that... The diamine is selected from any one of DDA, ODA, BAPP, and TEMB.

3. The highly processable and heat-resistant thermoplastic polymer material as described in claim 1, characterized in that... The dianhydride is selected from any one of ODPA, BTDA, BPDA, and PMDA.

4. The highly processable and heat-resistant thermoplastic polymer material as described in claim 1, characterized in that... The reactive functional group is any one of epoxy group, benzoxazinyl group, and acrylic group.

5. The highly processable and heat-resistant thermoplastic polymer material as described in claim 1, characterized in that... The molar ratio of diamine to dianhydride is 1:0.95~1.

05.

6. A method for preparing the highly processable and heat-resistant thermoplastic polymeric material according to claim 1, characterized in that, Includes the following steps: S1. The preparation of soluble polyimide is carried out by polycondensation reaction of diamine and dianhydride in solvent; S2. End-capping structure design: After the polymerization reaction is completed, an end-capping agent is added to give the polyimide chain ends reactive functional groups that can participate in secondary reactions; S3. Heating to 100~200℃ causes the terminal functional groups to undergo a cross-linking reaction with the added resin system, forming a three-dimensional network structure.

7. The method for producing a highly processable and heat-resistant thermoplastic polymer material as described in claim 6, characterized in that... The solvent in step S1 is any one of N,N-dimethylacetamide, N-methylpyrrolidone, and N,N-dimethylformamide.

8. The method for producing a highly processable and heat-resistant thermoplastic polymer material as described in claim 6, characterized in that... The specific conditions for the polycondensation reaction in step S1 are: solid content of 10-35 wt%, reaction temperature of 25-80℃, and gradually increasing the temperature to 180℃ for imidization.

9. The method for producing a highly processable and heat-resistant thermoplastic polymer material as described in claim 6, characterized in that... In step S1, the polycondensation reaction time is 4 to 12 hours, and the catalyst used is isoquinoline or triethylamine. The added resin system is selected from any one of epoxy resin system, benzoxazine resin system or acrylic resin system.

10. The application of the highly processable and heat-resistant thermoplastic polymer according to any one of claims 1-5 in the fields of electronic packaging and flexible circuit boards.

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