High-thermal-conductivity polyimide resin composition as well as preparation method and application thereof

Abstract

The invention discloses a polyimide resin composition which comprises polyamide acid, inorganic filler, a silicon-containing compound and a curing agent, wherein the silicon-containing compound is Si (H) a (R1) b (OR2) c, where a, b and c are respectively numbers > = 0, and a + b + c = 4, and c is not 0; wherein R1 and R2 are respectively and independently one or more of alkyl groups or R3 substituted alkyl groups, and R3 is a monovalent or divalent substituent group. The invention also discloses a preparation method or application of the polyimide resin composition. According to the invention, the dispersibility and interface bonding force of the inorganic filler in a resin matrix are remarkably improved, so that the obtained polyimide composition has high heat conductivity coefficient and good processing adaptability while maintaining excellent mechanical properties and heat resistance, and can be widely applied to the fields of electronic packaging, flexible printed circuit boards and the like.

Description

Technical Field

[0001] This invention relates to the field of new materials, and more particularly to a polyimide resin composition with excellent thermal conductivity, mechanical strength and processing stability, its preparation method and application. Background Technology

[0002] Polyimide (PI) resin is widely used in high-end fields such as flexible printed circuit boards (FPCBs), chip packaging, and aerospace due to its excellent high temperature resistance, mechanical properties, electrical insulation and chemical stability.

[0003] However, the thermal conductivity of pure polyimide resin is typically low (approximately 0.1–0.3 W / m•K), which limits its application as an efficient heat dissipation material in modern high-power-density electronic devices.

[0004] To improve the thermal conductivity of polyimide, existing technologies typically employ the addition of highly thermally conductive inorganic fillers (such as silica, boron nitride, and alumina). However, this method faces two major technical challenges: First, the poor compatibility between inorganic fillers and the organic polymer matrix leads to uneven dispersion of the fillers in the resin, making them prone to agglomeration. This not only affects the formation of thermal conductivity pathways but also impairs the mechanical properties of the material. Second, high filler content significantly increases the viscosity of the system, deteriorating the leveling and processability (such as coating and molding) of the composition. For example, Chinese invention patent CN1103581A discloses a polyimide composite material containing inorganic fillers. PCT application WO2009 / 110387A1, Japanese invention patents JP5650084B2 and JP5665846B2, and Korean invention patents KR101501957B1 and KR20190067600A also use thermally conductive fillers to improve the thermal conductivity of polyimide. However, these patents cannot solve the problem of filler dispersion stability.

[0005] Japanese patent JP5853704B2 and US patent US10002813B2 both add epoxy resin to polyimide to improve filler dispersibility; however, epoxy resin reduces the performance of polyimide. US patent US2015 / 0259452A1 uses a silane coupling agent to treat the filler, and Korean patent KR101446707B1 uses a core-shell structured filler with polyimide as the shell to improve compatibility. However, these patents have complex processes and offer limited improvement to the long-term storage stability and thermomechanical properties of the final composition.

[0006] Therefore, developing a thermally conductive polyimide resin composition with uniform filler dispersion, good process adaptability, and excellent comprehensive performance has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] This invention provides a polyimide composition, which has good thermal conductivity, strong interfacial bonding, high thermal conductivity, and excellent processability. Furthermore, this invention also provides a method for preparing the polyimide composition and its applications.

[0008] The first aspect of this invention is to provide a method for preparing a polyimide resin composition, comprising: Polyamic acid is generated by polycondensation of a diamine monomer used to synthesize polyimide with a tetracarboxylic acid and / or a dianhydride monomer corresponding to the tetracarboxylic acid. Inorganic fillers and silicon-containing compounds are dispersed in a solution of the polyamic acid to obtain a mixture; The curing agent is added to the mixture and mixed to obtain the polyimide resin composition.

[0009] A second aspect of the present invention is to provide a polyimide resin composition comprising the polyamic acid, the inorganic filler, the silicon-containing compound, and the curing agent; or, preferably, further comprising a solvent.

[0010] In a preferred embodiment, the polyimide resin composition is obtained by the method described above.

[0011] In a preferred embodiment, the inorganic filler is selected from one or more of inorganic oxides, inorganic hydroxides, inorganic acid salts, inorganic nitrides, and inorganic carbides. For example, it may be silicon dioxide, aluminum oxide, barium oxide, vanadium oxide, cobalt oxide, nickel oxide, tungsten oxide, boron oxide, magnesium oxide, zirconium oxide, titanium dioxide, aluminum hydroxide, magnesium hydroxide, boron nitride, aluminum nitride, titanium nitride, zirconium nitride, calcium nitride, phosphorus nitride, silicon nitride, and other inorganic fillers. Magnesium, aluminum oxynitride silicon, silicon oxynitride, boron carbide, tantalum carbide, manganese carbide, cobalt carbide, nickel carbide, silicon carbide, tungsten carbide, calcium carbide, barium titanate, barium sulfate, barium carbonate, carbon nanotubes, aluminum sulfate, barium sulfate, magnesium silicate, aluminum silicate, calcium silicate, manganese silicate, diatomite, diatomite, quartz, mica, barite, attapulgite, montmorillonite, kaolinite, serpentine, feldspar, olivine, epidote, pyroxene, amphibole

[0012] In a preferred embodiment, the average particle size of the inorganic filler is preferably 0.05-60 μm, more preferably 0.1-55 μm, more preferably 0.2-50 μm, more preferably 0.3-40 μm, more preferably 0.5-35 μm, more preferably 0.8-30 μm, such as 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 5 μm, 8 μm, 10 μm, 15 μm, 20 μm, 25 μm, etc.

[0013] In a preferred embodiment, the inorganic filler may be one or more of the following: spherical, sheet-like, and rod-like shapes, more preferably spherical or sheet-like.

[0014] In a preferred embodiment, the inorganic filler is spherical, with an average particle size preferably of 0.01-5 μm, more preferably 0.03-4.5 μm, more preferably 0.05-4 μm, more preferably 0.08-3.5 μm, more preferably 0.1-3 μm, more preferably 0.3-2.5 μm, more preferably 0.5-2 μm, more preferably 0.8-1.8 μm, and more preferably 1-1.5 μm.

[0015] In a preferred embodiment, the inorganic filler is in the form of flakes, and the average particle size is preferably 0.1-15 μm, more preferably 0.3-14 μm, more preferably 0.5-13 μm, more preferably 0.8-12 μm, more preferably 1-11 μm, more preferably 2-10 μm, more preferably 3-8 μm, and more preferably 5-7 μm.

[0016] In a preferred embodiment, the silicon-containing compound is Si(H). a (R1) b (OR2) c , where a, b, and c are numbers ≥ 0, and a + b + c = 4, and c is not 0; where R1 and R2 are alkyl groups or one or more of R3-substituted alkyl groups, and R3 is a monovalent or divalent substituent.

[0017] In a preferred embodiment, a can be 0, 1, or 2, more preferably 0, 1, 2, or 3.

[0018] In a preferred embodiment, b can be 0, 1, 2, or 3; more preferably, b is not 0.

[0019] In a preferred embodiment, c can be 1, 2, 3, or 4.

[0020] In a preferred embodiment, the alkyl group may be a C1-C7 alkyl group, preferably a C1-C6 alkyl group, more preferably a C1-C5 alkyl group, and even more preferably a C1-C4 alkyl group, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, etc.

[0021] In a preferred embodiment, R3 is substituted into an alkyl group, where R3 can be a side group of the alkyl group. For example, R3 can be one or more combinations of C5-C12 aromatic rings, C3-C10 aliphatic rings, C2-C10 heterocycles, amino groups, hydroxyl groups, carboxyl groups, halogen atoms (Cl, Br, F, etc.), aldehyde groups, nitrile groups, nitro groups, sulfonic acid groups, C1-C5 alkyl acyl groups, and C1-C5 alkylamide groups.

[0022] In a preferred embodiment, R3 replaces the carbon atom of the alkyl group, meaning that R3 is located on the main chain of the alkyl group. For example, R3 can be one or more combinations of C5-C12 aromatic rings, C3-C10 aliphatic rings, C2-C10 heterocycles, -O-, -COO-, -CONH-, -CO-, -C=N-, -SO2-, -SiH2-, and -S-.

[0023] The C5-C12 aromatic rings can be selected from: , , , , , , , , , , , , One or more of the following.

[0024] The C3-C10 aromatic rings can be selected from: , , , , , , , , , , , , One or more of the following.

[0025] C2-C10 heterocycles refer to aromatic or aliphatic rings in which one or more carbon atoms are replaced by heteroatoms, which can be one or more of O, N, S, Si, and P. For example, C2-C10 heterocycles can be selected from: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , wait.

[0026] In a preferred embodiment, R1 and R2 can be independently selected from methyl, ethyl, propyl, isopropyl, formyl, acetyl, propionyl, aminomethyl, halomethyl, hydroxymethyl, mercaptomethyl, carboxymethyl, β-haloethyl, β-aminoethyl, β-hydroxyethyl, β-mercaptoethyl, β-carboxyethyl, γ-halopropyl, γ-aminopropyl, γ-hydroxypropyl, γ-mercaptopropyl, γ-carboxypropyl, formylmethyl, formylethyl, acetylmethyl, acetylethyl, and so on. Formamidomethyl, formamidoethyl, acetaminomethyl, acetaminoethyl, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, glycidyl, 2,3-epoxypropoxymethyl, β-(2,3-epoxypropoxy)ethyl, γ-(2,3-epoxypropoxy)propyl, methacryloyloxymethyl, 2-(methacryloyloxy)ethyl, 3-(methacryloyloxy)propyl, acryloyloxymethyl, 2-(acryloyloxy)ethyl, 3-(acryloyloxy)propyl, etc.

[0027] However, it should be understood that the present invention Si(H) a (R1) b (OR2) c In the case where b≥2, each R1 can be the same or different.

[0028] However, it should be understood that the present invention Si(H) a (R1) b (OR2) c In the case where c≥2, each R² can be the same or different.

[0029] In a preferred embodiment, the silicon-containing compound may be selected from: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , One or more of them.

[0030] In a preferred embodiment, the diamine monomer may be one or more selected from aromatic diamines and aliphatic diamines, for example, it may be: H2N-(CH2)4-NH2, H2N-(CH2)5-NH2, H2N-(CH2)6-NH2, H2N-(CH2)7-NH2, H2N-(CH2)8-NH2, H2N-(CH2)9-NH2, H2N-(CH2) 10 -NH2, H2N-(CH2)2-NH-(CH2)2-NH2, H2N-CH2-C(CH3)2-CH2-NH2, H2N-(CH2)2-O-(CH2)2-O-( CH2)2-NH2, H2N-(CH2)2-SS-(CH2)2-NH2, H2N-(CH2)3-Si(CH3)2-O-Si(CH3)2-(CH2)3-NH2, , , , , , , , , , , , , , , , , , , , One or more of them.

[0031] In a preferred embodiment, the dianhydride monomer may be one or more selected from aromatic dianhydrides and aliphatic dianhydrides, for example, it may be: , , , , , , , , , , , , , , , , , , , , , , , , , One or more of them.

[0032] In a preferred embodiment, the curing agent is preferably an aromatic amine curing agent or an anhydride curing agent. For example, the curing agent may be selected from the above-mentioned diamine monomers or dianhydride monomers. For example, the curing agent is 4,4'-diaminodiphenyl ether or pyromellitic dianhydride.

[0033] In a preferred embodiment, the inorganic filler is present in the polyimide resin composition (without solvent) at a weight ratio of 0.01-20%, more preferably 0.05-18%, more preferably 0.1-15%, more preferably 0.5-13%, more preferably 1-10%, such as 0.02%, 0.08%, 0.3%, 0.8%, 2%, 3%, 5%, etc.

[0034] In a preferred embodiment, the silicon-containing compound is 1-10% of the weight of the inorganic filler, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%.

[0035] In a preferred embodiment, the silicon-containing compound is present in the polyimide resin composition (solvent-free) at a weight ratio of 0.01-5%, preferably 0.03-4.5%, more preferably 0.05-4%, more preferably 0.08-3.5%, more preferably 0.1-3.2%, more preferably 0.5-3.0%, more preferably 1-2.5%, such as 0.02%, 0.08%, 0.3%, 0.8%, 1.2%, 1.5%, 1.8%, 2.0%, 2.1%, 2.2%, and 2.3%.

[0036] In a preferred embodiment, the polyamic acid solution has a solid content of 10-50%, more preferably 15-45%, and even more preferably 20-40%, such as 20%, 25%, 30%, and 35%.

[0037] In a preferred embodiment, the polyamic acid in the polyimide resin composition (without solvent) is ≥60% by weight, more preferably 65-99%, more preferably 70-95%, more preferably 75-93%, such as 78%, 80%, 83%, 85%, 87%, 90%.

[0038] In a preferred embodiment, the curing agent is preferably 0.1-10% by weight in the polyimide resin composition (solvent-free), more preferably 0.2-8%, more preferably 0.3-6%, more preferably 0.5-5%, more preferably 0.7-4.5%, more preferably 0.8-4%, more preferably 1-3.5%, such as 1.5%, 2%, 2.5%, 3%, etc.

[0039] In a preferred embodiment, the polycondensation reaction temperature is preferably ≤80℃, more preferably ≤60℃, and even more preferably ≤50℃.

[0040] In a preferred embodiment, the polycondensation reaction time is ≥0.5h, more preferably ≥1h, more preferably ≥2h, more preferably ≥3h, more preferably ≥4h, more preferably ≥5h, more preferably ≥6h, more preferably ≥7h, and more preferably ≥8h.

[0041] In a preferred embodiment, the polyamic acid solution may be obtained by dissolving the generated polyamic acid in a solvent, or by carrying out a polycondensation reaction in a solvent. For example, polyamic acid is reacted in a solvent to generate a polyamic acid solution.

[0042] In a preferred embodiment, the solvent may be one or more of alcohols, ethers, esters, ketones, aldehydes, phenols, alkanes, haloalkanes, heterocyclic compounds, amides, carboxylic acids, amines, and sulfoxides. For example, the solvent may be one or more of methanol, ethanol, propanol, isopropanol, glycerol, ethylene glycol, caprolactone, butyrolactone, dioxane, tetrahydrofuran, ethyl acetate, butyl acetate, diethyl ether, petroleum ether, acetone, benzene, toluene, halobenzene, benzyl chloride, N,N-dimethylformamide, dimethyl sulfoxide, carbon tetrachloride, dichloromethane, chloroform, and N-methylpyrrolidone.

[0043] In a preferred embodiment, the curing agent is added to the mixture and mixed under heating. Preferably, the heating temperature is 5-80°C, more preferably 8-70°C, and even more preferably 10-60°C, such as 20°C, 30°C, 40°C, 50°C, or 60°C.

[0044] In a preferred embodiment, a curing agent is added to the mixture and mixed for a time of ≥5 min, more preferably ≥10 min, more preferably ≥15 min, more preferably ≥20 min, more preferably ≥30 min, more preferably ≥45 min, more preferably ≥60 min, more preferably ≥75 min, and more preferably ≥90 min.

[0045] A third aspect of the present invention is to provide an application of the polyimide resin composition, which can be used to prepare polyimide films, such as polyimide films in the fields of electronic packaging and flexible printed circuit boards.

[0046] In a preferred embodiment, the polyimide resin composition is coated onto a substrate and cured to obtain the polyimide film; more preferably, the curing is carried out under heating conditions.

[0047] In a preferred embodiment, the curing is carried out at 100-300°C.

[0048] More preferably, the curing heating conditions are as follows: first, heat to 80-130℃ (e.g., 90℃, 100℃, 110℃, 120℃) and hold for 0.5-1.5h (e.g., 45-75min, e.g., 50min, 60min, 70min); then heat to 180-220℃ (e.g., 190℃, 200℃, 210℃, 220℃) and hold for 0.5-1.5h (e.g., 45-75min, e.g., 50min, 60min, 70min); then heat to 280-330℃ (e.g., 290℃, 300℃, 310℃, 320℃) and hold for 0.5-4h (e.g., 1-3.5h, e.g., 1.5h, 2h, 2.5h, 3h).

[0049] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: 1) Through the synergistic effect of inorganic fillers with specific particle sizes and silicon-containing compounds, the alkoxy groups in the silicon-containing compounds can react with the hydroxyl groups on the surface of the fillers, while their organic segments are compatible with the resin matrix, thereby significantly improving the dispersibility and interfacial bonding of the fillers in the resin and preventing agglomeration.

[0050] 2) Uniform dispersion of fillers helps to form a more efficient thermal conductivity network in the matrix, thus achieving a higher thermal conductivity with a lower filler content.

[0051] 3) The optimized formulation and vacuum degassing process ensure that the composition has suitable viscosity and very few internal bubbles, making it ideal for precision coating or molding.

[0052] 4) The polyimide cured product prepared by this invention not only has good thermal conductivity, but also retains the inherent high heat resistance, high strength and good electrical insulation properties of polyimide. Detailed Implementation

[0053] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following examples further illustrate the invention in detail. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0054] It should be noted that the terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or apparatuses.

[0055] Example 1: In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol ODA (4,4'-diaminodiphenyl ether) and 200 g NMP were added and stirred until dissolved. Subsequently, 0.125 mol PMDA (pyromellitic anhydride) was added in portions, and the reaction temperature was controlled below 50 °C. The reaction was carried out for 6 hours to obtain a transparent, viscous polyamic acid solution with a solid content of approximately 20%.

[0056] Add 3g of spherical silica (average particle size 1μm) and 0.2g of KH-550 to the above polyamic acid solution, and disperse at 3000 rpm for 30 minutes.

[0057] Add 0.8g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0058] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0059] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0060] Example 2: In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol ODA (4,4'-diaminodiphenyl ether) and 200 g NMP were added and stirred until dissolved. Subsequently, 0.125 mol PMDA (pyromellitic anhydride) was added in portions, and the reaction temperature was controlled below 50 °C for 6 hours to obtain a transparent, viscous polyamic acid solution.

[0061] Add 2g of boron nitride flakes (average particle size 5μm) and 0.1g of KH-550 to the above polyamic acid solution, and disperse at 3000rpm for 30 minutes.

[0062] Add 1.1g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0063] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0064] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0065] Example 3: In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol of ODA (4,4'-diaminodiphenyl ether) and 200 g of NMP were added and stirred until dissolved. Subsequently, 0.125 mol of 2,6-naphthalenedicarboxylic acid was added in portions, and the reaction temperature was controlled below 50 °C. The reaction was carried out for 6 hours to obtain a transparent, viscous polyamic acid solution.

[0066] Add 3g of spherical silica (average particle size 1μm) and 0.2g of KH-550 to the above polyamic acid solution, and disperse at 3000 rpm for 30 minutes.

[0067] Add 0.8g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0068] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0069] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0070] Example 4: In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol of ODA and 200 g of NMP were added and stirred until dissolved. Subsequently, 0.125 mol of 2,2'-bis(3,4-dicarboxylic acid) hexafluoropropane dianhydride was added in portions, and the reaction temperature was controlled below 50 °C for 6 hours to obtain a transparent, viscous polyamic acid solution.

[0071] Add 3g of spherical silica (average particle size 1μm) and 0.2g of KH-550 to the above polyamic acid solution, and disperse at 3000 rpm for 30 minutes.

[0072] Add 1g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0073] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0074] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0075] Example 5: In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol ODA (4,4'-diaminodiphenyl ether) and 200 g NMP were added and stirred until dissolved. Subsequently, 0.125 mol PMDA (pyromellitic anhydride) was added in portions, and the reaction temperature was controlled below 50 °C for 6 hours to obtain a transparent, viscous polyamic acid solution.

[0076] Add 2g of β-silicon carbide whiskers (average particle size 12μm) and 0.1g of KH-560 to the above polyamic acid solution, and disperse at 3000 rpm for 30 minutes.

[0077] Add 0.8g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0078] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0079] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0080] Example 6: In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol ODA (4,4'-diaminodiphenyl ether) and 200 g NMP were added and stirred until dissolved. Subsequently, 0.125 mol PMDA (pyromellitic anhydride) was added in portions, and the reaction temperature was controlled below 50 °C for 6 hours to obtain a transparent, viscous polyamic acid solution.

[0081] Add 3g of spherical barium titanate (average particle size 0.8μm) and 0.1g of KH-560 to the above polyamic acid solution, and disperse at 3000 rpm for 30 minutes.

[0082] Add 0.8g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0083] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0084] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0085] Example 7: In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol ODA (4,4'-diaminodiphenyl ether) and 200 g NMP were added and stirred until dissolved. Subsequently, 0.125 mol PMDA (pyromellitic anhydride) was added in portions, and the reaction temperature was controlled below 50 °C for 6 hours to obtain a transparent, viscous polyamic acid solution.

[0086] Add 3g of α-alumina flakes (average particle size 2.5μm) and 0.1g of KH-560 to the above polyamic acid solution, and disperse at 3000 rpm for 30 minutes.

[0087] Add 0.8g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0088] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0089] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0090] In SEM, the inorganic filler is seen to be uniformly distributed in the polyimide material without obvious agglomeration, indicating that the specific components of the present invention can enable the inorganic filler to be uniformly dispersed.

[0091] Example 8: In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol ODA (4,4'-diaminodiphenyl ether) and 200 g NMP were added and stirred until dissolved. Subsequently, 0.125 mol PMDA (pyromellitic anhydride) was added in portions, and the reaction temperature was controlled below 50 °C. The reaction was carried out for 6 hours to obtain a transparent, viscous polyamic acid solution with a solid content of approximately 20%.

[0092] Add 3g of spherical silica (average particle size 0.01μm) and 0.2g of KH-550 to the above polyamic acid solution, and disperse at 3000 rpm for 30 minutes.

[0093] Add 0.8g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0094] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0095] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0096] Example 9: In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol ODA (4,4'-diaminodiphenyl ether) and 200 g NMP were added and stirred until dissolved. Subsequently, 0.125 mol PMDA (pyromellitic anhydride) was added in portions, and the reaction temperature was controlled below 50 °C. The reaction was carried out for 6 hours to obtain a transparent, viscous polyamic acid solution with a solid content of approximately 20%.

[0097] Add 3g of spherical silica (average particle size 0.1mm) and 0.2g of KH-550 to the above polyamic acid solution, and disperse at 3000 rpm for 30 minutes.

[0098] Add 0.8g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0099] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0100] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0101] Comparative Example 1 In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol ODA (4,4'-diaminodiphenyl ether) and 200 g NMP were added and stirred until dissolved. Subsequently, 0.125 mol PMDA (pyromellitic anhydride) was added in portions, and the reaction temperature was controlled below 50 °C. The reaction was carried out for 6 hours to obtain a transparent, viscous polyamic acid solution with a solid content of approximately 20%.

[0102] Add 3g of spherical silica (average particle size 1μm) to the above polyamic acid solution and disperse at 3000 rpm for 30 minutes.

[0103] Add 0.8g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0104] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0105] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0106] Comparative Example 2 In a 500 mL three-necked flask equipped with a mechanical stirrer, nitrogen inlet, and drying tube, 0.125 mol ODA (4,4'-diaminodiphenyl ether) and 200 g NMP were added and stirred until dissolved. Subsequently, 0.125 mol PMDA (pyromellitic anhydride) was added in portions, and the reaction temperature was controlled below 50 °C. The reaction was carried out for 6 hours to obtain a transparent, viscous polyamic acid solution with a solid content of approximately 20%.

[0107] Add 0.8g PMDA as a curing agent and continue stirring at 50°C for 1 hour.

[0108] The mixture was transferred to a vacuum degassing device to degas, resulting in a uniform, bubble-free polyimide resin composition.

[0109] The composition was cast onto a glass plate and cured by programmed temperature increase (100℃ for 1 hour, 200℃ for 1 hour, 300℃ for 2 hours) to obtain a polyimide film.

[0110] The polyimide films obtained in the above embodiments and comparative examples were subjected to performance tests, and the results are shown in Table 1 below.

[0111] Table 1. Performance comparison between embodiments of the present invention and comparative examples. Test Project Example 1 Example 2 Example 8 Example 9 Comparative Example 1 Comparative Example 2 Thermal conductivity (W / m·K) 0.85 1.20 0.95 1.0 0.55 0.18 Tensile strength (MPa) 152 145 148 142 125 135 Elongation at break (%) 28 25 26 26 20 35 Thermal decomposition temperature (Td5%, °C) 535 540 538 536 530 550 Dielectric constant (10 GHz) 3.1 3.3 3.2 3.2 3.2 3.0 Processability evaluation Good, no particles Good, no particles Good, no particles Good, no particles Generally, it has a slightly grainy texture. excellent It can be seen that the addition of inorganic fillers and the silicon-containing compound of this invention significantly increases the thermal conductivity, with boron nitride with a plate-like structure (Example 2) showing even better performance in constructing thermal conduction pathways. However, without the addition of the silicon-containing compound, the increase in thermal conductivity is limited, which is due to the uneven distribution of the inorganic fillers.

[0112] Comparing Examples 1 and 8-9, the products obtained under the specific particle size (0.05-60μm) of the present invention have better mechanical properties, indicating better compatibility.

[0113] Compared to pure polyimide film, the tensile strength of this invention is increased. However, without the addition of silicon-containing compounds, the tensile strength decreases, indicating that the inorganic filler and polyimide have poor compatibility without silicon-containing compounds, resulting in local defects. After adding silicon-containing compounds, the interfacial bonding between the inorganic filler and polyimide is effectively improved, thereby enhancing stress transfer efficiency.

[0114] The addition of inorganic fillers leads to a decrease in elongation at break. However, the decrease is smaller when using silicon-containing compounds, and the decrease is more significant when not using silicon-containing compounds. This indicates that silicon-containing compounds can increase the compatibility between polyimide and inorganic fillers, resulting in a more uniform distribution of inorganic fillers.

[0115] The thermal decomposition temperature of the polyimide resin in all embodiments of the present invention is higher than 530°C, thus maintaining the excellent thermal stability of polyimide.

[0116] From a processing performance perspective, inorganic fillers can reduce processing performance, especially in Comparative Example 2 where the inorganic filler is unevenly distributed and agglomerated, resulting in a grainy texture and generally poor processing performance. In this invention, when inorganic fillers are combined with silicon-containing compounds, the inorganic fillers exhibit better compatibility with polyimide, and their distribution is more uniform, thus improving processing performance.

[0117] The specific embodiments of the present invention have been described in detail above, but they are merely examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, all equivalent changes and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention.

Claims

1. A polyimide resin composition, characterized in that, It includes polyamic acid, inorganic fillers, silicon-containing compounds, and curing agents; wherein the silicon-containing compound is Si(H). a (R1) b (OR2) c , where a, b, and c are numbers ≥ 0, and a + b + c = 4, and c is not 0; where R1 and R2 are alkyl groups or one or more of R3-substituted alkyl groups, and R3 is a monovalent or divalent substituent.

2. The polyimide resin composition according to claim 1, characterized in that, In the R3-substituted alkyl group, R3 is a side group of the alkyl group, and R3 is selected from one or more combinations of: C5-C12 aromatic ring, C3-C10 aliphatic ring, C2-C10 heterocyclic ring, amino group, hydroxyl group, carboxyl group, halogen atom, aldehyde group, nitrile group, nitro group, sulfonic acid group, C1-C5 alkyl acyl group, and C1-C5 alkylamide group; or; in the R3-substituted alkyl group, R3 is located on the main chain of the alkyl group, and R3 is selected from one or more combinations of: C5-C12 aromatic ring, C3-C10 aliphatic ring, C2-C10 heterocyclic ring, -O-, -COO-, -CONH-, -CO-, -C=N-, -SO2-, -SiH2-, and -S-. R1 and R2 are each independently selected from methyl, ethyl, propyl, isopropyl, formyl, acetyl, propionyl, aminomethyl, halomethyl, hydroxymethyl, mercaptomethyl, carboxymethyl, β-haloethyl, β-aminoethyl, β-hydroxyethyl, β-mercaptoethyl, β-carboxyethyl, γ-halopropyl, γ-aminopropyl, γ-hydroxypropyl, γ-mercaptopropyl, γ-carboxypropyl, formylmethyl, formylethyl, acetylmethyl, acetylethyl, formamidomethyl Formamidoethyl, acetaminomethyl, acetaminoethyl, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, glycidyl, 2,3-epoxypropoxymethyl, β-(2,3-epoxypropoxy)ethyl, γ-(2,3-epoxypropoxy)propyl, methacryloyloxymethyl, 2-(methacryloyloxy)ethyl, 3-(methacryloyloxy)propyl, acryloyloxymethyl, 2-(acryloyloxy)ethyl, 3-(acryloyloxy)propyl.

3. The polyimide resin composition according to claim 2, characterized in that, The C5-C12 aromatic rings are selected from: , , , , , , , , , , , , One or more of them; The C3-C10 aromatic rings are selected from: , , , , , , , , , , , , One or more of them; C2-C10 heterocycles are aromatic or aliphatic rings in which one or more carbon atoms are replaced by heteroatoms, which are one or more of O, N, S, Si, and P.

4. The polyimide resin composition according to any one of claims 1-3, characterized in that, The silicon-containing compound is selected from: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , One or more of them.

5. The polyimide resin composition according to claim 1, characterized in that, The inorganic filler is selected from one or more of inorganic oxides, inorganic hydroxides, inorganic acid salts, inorganic nitrides, and inorganic carbides.

6. The polyimide resin composition according to claim 6, characterized in that, The inorganic filler is selected from one or more of the following: silicon dioxide, aluminum oxide, barium oxide, vanadium oxide, cobalt oxide, nickel oxide, tungsten oxide, boron oxide, magnesium oxide, zirconium oxide, titanium dioxide, aluminum hydroxide, magnesium hydroxide, boron nitride, aluminum nitride, titanium nitride, zirconium nitride, calcium nitride, phosphorus nitride, silicon nitride, magnesium nitride, aluminum oxynitride, silicon oxynitride, boron carbide, tantalum carbide, manganese carbide, cobalt carbide, nickel carbide, silicon carbide, tungsten carbide, calcium carbide, barium titanate, barium sulfate, barium carbonate, carbon nanotubes, aluminum sulfate, barium sulfate, magnesium silicate, aluminum silicate, calcium silicate, manganese silicate, diatomaceous earth, diatomite, quartz, mica, barite, attapulgite, montmorillonite, kaolinite, serpentine, feldspar, olivine, epidote, pyroxene, and amphibole.

7. The polyimide resin composition according to claim 1, characterized in that, The inorganic filler is present in the polyimide resin composition at a weight ratio of 0.01-20%; and / or The silicon-containing compound is 1-10% of the weight of the inorganic filler, or the silicon-containing compound is 0.01-5% of the weight of the polyimide resin composition; and / or The curing agent is preferably 0.1-10% by weight in the polyimide resin composition.

8. The polyimide resin composition according to any one of claims 1, 5-7, characterized in that, The inorganic filler has an average particle size of 0.05-80 μm.

9. A method for preparing the polyimide resin composition of claim 1, characterized in that, include: The polyamic acid is generated by polycondensation of a diamine monomer used to synthesize polyimide with a tetracarboxylic acid and / or a dianhydride monomer corresponding to the tetracarboxylic acid. The inorganic filler and the silicon-containing compound are dispersed in a solution of the polyamic acid to obtain a mixture; The curing agent is added to the mixture and mixed to obtain the polyimide resin composition; The diamine monomer is selected from one or more of aromatic diamines and aliphatic diamines; the dianhydride monomer is selected from one or more of aromatic dianhydrides and aliphatic dianhydrides.

10. An application of the polyimide resin composition of claim 1, characterized in that, The polyimide resin composition can be used to prepare polyimide films.

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