Polyimide resin composition, preparation method thereof and polyimide resin adhesive film

Abstract

The invention relates to the field of high-performance resin-based materials, in particular to a polyimide resin composition, a preparation method thereof and a polyimide resin adhesive film. The composition comprises phenylethynyl phthalic anhydride-terminated polyimide resin and a polyimide toughening agent, the use amount of the polyimide toughening agent is 5-50 parts by weight relative to 100 parts by weight of the phenylethynyl phthalic anhydride-terminated polyimide resin, the structure of the phenylethynyl phthalic anhydride-terminated polyimide resin is shown as a formula (I), and the structural formula of the phenylethynyl phthalic anhydride-terminated polyimide resin is shown as a formula (II). The structure of the polyimide flexibilizer is shown as a formula (II). According to the polyimide resin composition and the adhesive film, the problems that existing polyimide prepreg is not imidized, small molecules are released in the curing process and the process stability is poor are solved, and a composite material prepared from the polyimide resin composition is excellent in performance, few in defect, high in process stability and suitable for stable batch production. Formula (I) # imgabs0 # formula (II) # imgabs1 #

Description

Technical Field

[0001] The invention relates to the field of high-performance resin-based materials, and in particular to a polyimide resin composition and a preparation method thereof, and a polyimide resin adhesive film. Background Art

[0002] Since the 1970s, high-temperature resistant polyimide resin-based composite materials have become key basic materials for the development of important fields such as aerospace. After years of development, polyimide resin-based composite material systems with different temperature resistance levels have been formed at home and abroad, including the first generation of PMR-15, KH-308, LP-15 and BMP316 with a temperature resistance of 500°F, and the third generation of AFR-PE-4, DMBZ-15, KH-450, EC380A, BMP400 and AC732 with a temperature resistance of 800°F, all of which have been put into practical use in important equipment and played an important role in the high-performance development of equipment.

[0003] Most of the existing polyimide resins are traditional monomer in-situ polymerization PMR (reactive) type resins, which usually use low-boiling alcohol solvents to make the dianhydride monomer and alcohol undergo esterification reaction to obtain a monoacid monoester solution, and then react with the diamine monomer to generate an esteramine salt resin solution with a solid content of about 50wt% or 80wt%, which is suitable for the preparation of wet prepregs. However, the curing process of this type of esteramine salt resin solution needs to go through at least two high-temperature stages. In the first high-temperature stage, the resin viscosity is low and a large amount of solvent evaporates, which easily causes the prepreg to be poor in glue and the surface density precision is difficult to control, which ultimately leads to a decrease in product performance; in the second high-temperature stage, the resin will release small molecules during the imidization process, resulting in a high porosity of the composite material after curing, which is not conducive to the comprehensive performance of the composite material. In addition, this type of resin solution has a short storage period and poor processability and stability. The prepreg prepared by it has a short room temperature storage period and the glue content is difficult to control. The obtained composite material also has poor batch stability, low product dimensional accuracy, high quality control difficulty, low pass rate and high cost, which makes it difficult to meet the low-cost, batch and stable production needs of large-scale structural products. Therefore, in order to solve the problems of poor processability and insufficient batch stability of existing polyimide composite resin matrix, it is necessary to develop a new type of polyimide resin material. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems existing in the above-mentioned prior art and provide a polyimide resin composition and a preparation method thereof and a polyimide resin film. The polyimide resin composition and the film have excellent performance and process stability and have good application prospects in the fields of aerospace and aviation.

[0005] In order to achieve the above object, the present invention provides a polyimide resin composition, which comprises a phenylethynyl phthalic anhydride-terminated polyimide resin and a polyimide toughening agent, wherein the amount of the polyimide toughening agent is 5-50 parts by weight relative to 100 parts by weight of the phenylethynyl phthalic anhydride-terminated polyimide resin;

[0006] The structure of the phenylethynylphthalic anhydride terminated polyimide resin is shown in formula (I), and the structural unit of the polyimide toughening agent is shown in formula (II).

[0007] Formula (I)

[0008] Formula (II)

[0009] Ar1 and Ar3 are each independently selected from phenylene, One or more of, R1 is selected from a chemical bond, One or more of, R2 and R3 are each independently selected from one or more of H, C1-C3 perfluoroalkyl and C6-C10 aryl, and R4 is selected from phenylene and / or biphenylene;

[0010] Ar2 and Ar4 are each independently selected from One or more of, R5 and R6 are each independently selected from a chemical bond, R7, R8 and R9 are each independently selected from one or more of phenylene, biphenylene and C1-C6 alkylene, R 10 and R 11 Each independently selected from a chemical bond and / or a phenylene group;

[0011] n is an integer selected from 1 to 18;

[0012] The weight average molecular weight of the polyimide toughening agent is 5000-300000 g / mol.

[0013] The second aspect of the present invention provides a method for preparing the above-mentioned polyimide resin composition, which comprises contacting and reacting a phenylethynylphthalic anhydride-terminated polyimide resin and a polyimide toughening agent in the presence of a viscosity modifier to obtain the polyimide resin composition.

[0014] The third aspect of the present invention provides a polyimide resin film prepared from the polyimide resin composition.

[0015] A fourth aspect of the present invention provides a polyimide prepreg made from the polyimide resin film and fibers.

[0016] A fifth aspect of the present invention provides a polyimide composite material prepared from the polyimide prepreg.

[0017] The present invention obtains a polyimide resin composition by compounding a fully imidized low molecular weight phenylethynylphthalic anhydride end-capped polyimide resin and a high molecular weight polyimide toughening agent in a certain mass ratio, and further obtains a polyimide resin adhesive film prepared from the composition. The composition and the adhesive film have excellent performance and process stability, and are used in the preparation of prepregs to achieve uniform regulation of resin content and surface density, avoid the release of small molecules during the curing process, and also have good viscosity, draping and curing process performance, can be stored for a long time, can effectively reduce the defects of the final composite material product, improve the performance batch stability and yield rate of the composite material, reduce the manufacturing cost of the composite material, and achieve stable batch production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a comparison diagram of thermal gravimetric analysis (TGA) curves of the polyimide resin composition in Example 1 and the polyimide resin molding powder in Comparative Example 1;

[0019] Figure 2 is a melt viscosity curve of the polyimide resin composition in Example 1;

[0020] Figure 3 is a melt viscosity curve of the polyimide resin molding powder in Comparative Example 1;

[0021] Figure 4 This is a dynamic mechanical property (DMA) curve of the cured product of the polyimide resin composition in Example 1. DETAILED DESCRIPTION

[0022] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0023] In the present invention, The dashed lines in structures with dashed connecting bonds indicate the connection site and represent the connecting bond.

[0024] In the present invention, The substituents R2 and R3 have multiple substitution sites on the ring, and can replace only one site or multiple sites at the same time. When multiple sites are replaced, the group selection of each substituent is independent and can be the same or different.

[0025] In one aspect, the present invention provides a polyimide resin composition, which comprises a phenylethynylphthalic anhydride-terminated polyimide resin and a polyimide toughening agent, wherein the amount of the polyimide toughening agent is 5-50 parts by weight relative to 100 parts by weight of the phenylethynylphthalic anhydride-terminated polyimide resin;

[0026] The structure of the phenylethynylphthalic anhydride terminated polyimide resin is shown in formula (I), and the structural unit of the polyimide toughening agent is shown in formula (II).

[0027] Formula (I)

[0028] Formula (II)

[0029] Ar1 and Ar3 are each independently selected from phenylene, One or more of, R1 is selected from a chemical bond, One or more of, R2 and R3 are each independently selected from one or more of H, C1-C3 perfluoroalkyl and C6-C10 aryl, and R4 is selected from phenylene and / or biphenylene;

[0030] Ar2 and Ar4 are each independently selected from One or more of, R5 and R6 are each independently selected from a chemical bond, R7, R8 and R9 are each independently selected from one or more of phenylene, biphenylene and C1-C6 alkylene, R 10 and R 11 Each independently selected from a chemical bond and / or a phenylene group;

[0031] n is an integer selected from 1 to 18;

[0032] The weight average molecular weight of the polyimide toughening agent is 5000-300000 g / mol.

[0033] According to the present invention, the above-mentioned polyimide resin composition has excellent performance and processability, which is achieved by specifically selecting the structure, molecular weight and mass ratio of its phenylethynylphthalic anhydride end-capped polyimide resin and polyimide toughening agent. By compounding the fully imidized low molecular weight phenylethynylphthalic anhydride end-capped polyimide resin and the high molecular weight polyimide toughening agent in a certain mass ratio, it is possible to avoid the problem of poor process stability caused by the incomplete imidization of the polyimide resin in the traditional method and the release of small molecules during the curing process of the prepreg, which leads to more defects in the final product, thereby improving the performance quality and batch stability of the final product, and at the same time making the composite material product finally obtained also have excellent high temperature resistance and mechanical properties. Among them, it can be understood that the polyimide toughening agent is obtained by naturally terminating the monomer through the polymerization reaction, and its terminal group is different from the end-capping group of the phenylethynylphthalic anhydride end-capped polyimide resin.

[0034] According to the present invention, in order to achieve better coordination between the phenylethynylphthalic anhydride terminated polyimide resin and the polyimide toughening agent and obtain a polyimide resin composition with better performance, preferably, the amount of the polyimide toughening agent is 10-40 parts by weight relative to 100 parts by weight of the phenylethynylphthalic anhydride terminated polyimide resin, for example, it can be 10 parts by weight, 20 parts by weight, 30 parts by weight, 40 parts by weight, and any range between these values.

[0035] According to the present invention, preferably, Ar1 and Ar3 are each independently selected from

[0036] One or more of, preferably

[0037]

[0038] One or more of .

[0039] According to the present invention, preferably, Ar2 and Ar4 are each independently selected from

[0040] One or more of, preferably

[0041] One or more of .

[0042] According to the present invention, preferably, n is selected from an integer of 1-15, preferably an integer of 1-12, for example, it can be 1, 5, 8, 9 and 12 and any range therebetween.

[0043] According to the present invention, preferably, the weight average molecular weight of the polyimide toughening agent is 10000-150000 g / mol, preferably 20000-50000 g / mol, for example, it can be 20000 g / mol, 25000 g / mol, 30000 g / mol, 35000 g / mol and 45000 g / mol and any value thereof.

[0044] According to the present invention, preferably, the molecular weight of the phenylethynylphthalic anhydride terminated polyimide resin is smaller than the molecular weight of the polyimide toughening agent.

[0045] According to the present invention, in order to adjust the viscosity of the polyimide resin composition to a suitable range to facilitate subsequent processing, and at the same time make the phenylethynylphthalic anhydride end-capped polyimide resin and the polyimide toughening agent dispersed more evenly, preferably, the polyimide resin composition further includes a viscosity regulator, and the amount of the viscosity regulator relative to 100 parts by weight of the phenylethynylphthalic anhydride end-capped polyimide resin is 10-80 parts by weight, preferably 20-60 parts by weight, for example, it can be 20 parts by weight, 40 parts by weight, 50 parts by weight, 60 parts by weight, and the like, and the range between any values ​​thereof.

[0046] According to the present invention, the viscosity modifier can be selected in a wide range. In order to obtain a better state of the polyimide resin composition and facilitate the subsequent preparation of prepregs and composite materials, preferably, the viscosity modifier is selected from one or more organic solvents, preferably chloroform, dioxane, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, γ-butyrolactone, ethyl lactate, cyclopentanone, cyclohexanone, methyl ethyl ketone, ethyl acetate and butyl acetate, preferably one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone and ethyl acetate.

[0047] The second aspect of the present invention provides a method for preparing the above-mentioned polyimide resin composition, which comprises contacting and reacting a phenylethynylphthalic anhydride-terminated polyimide resin and a polyimide toughening agent in the presence of a viscosity modifier to obtain the polyimide resin composition.

[0048] According to the present invention, the selection and dosage of the viscosity modifier, phenylethynylphthalic anhydride terminated polyimide resin and polyimide toughening agent described in the second aspect of the present invention can be selected according to the introduction in the first aspect above, which will not be repeated here.

[0049] According to the present invention, the preparation method of the polyimide resin composition is a high-temperature one-step method. In order to obtain a polyimide resin composition with better properties, the conditions of the contact reaction need to be adjusted. Preferably, the conditions of the contact reaction include: a temperature of 60-200°C and a time of 2-24h. More preferably, the conditions of the contact reaction include: a temperature of 140-160°C (for example, it can be 140°C, 145°C, 150°C and 160°C and the range between any values ​​thereof), and a time of 6-12h, for example, it can be 6h, 8h, 10h and 12h and the range between any values ​​thereof). After the above-mentioned contact reaction is completed, the obtained polyimide resin composition (with the appearance of a viscous transparent adhesive) can be divided for use.

[0050] According to the present invention, in order to obtain a phenylethynyl phthalic anhydride-terminated polyimide resin that meets the requirements for use in the preparation of a polyimide resin composition, preferably, the preparation method of the phenylethynyl phthalic anhydride-terminated polyimide resin comprises the steps of subjecting a first aromatic diamine monomer and a first aromatic dianhydride monomer to a first polymerization reaction in the presence of a first solvent, and then adding phenylethynyl phthalic anhydride to carry out a capping reaction to obtain the phenylethynyl phthalic anhydride-terminated polyimide resin.

[0051] According to the present invention, in the preparation method of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin, the amount of each material can be selected within a wide range. In order to make the reaction proceed better, preferably, the mass ratio of the first aromatic diamine monomer, the first aromatic dianhydride monomer and the phenylethynylphthalic anhydride is 1:0.6-1.2:0.05-0.5, preferably 1:0.8-1:0.1-0.3, for example, it can be 1:0.8:0.1, 1:1:0.3, 1:0.9:0.1 and 1:0.8:0.3 and the range between any values ​​thereof.

[0052] According to the present invention, in order to make the materials more fully dispersed and contacted and improve the reaction efficiency, preferably, the mass ratio of the first aromatic diamine monomer to the first solvent is 1:2-10, preferably 1:4-8, for example, it can be 1:4, 1:5, 1:6 and 1:8 and any range between the values.

[0053] According to the present invention, in order to promote the first polymerization reaction, preferably, the conditions of the first polymerization reaction include: a temperature of 0-40°C and a time of 3-8h. More preferably, the conditions of the first polymerization reaction include: a temperature of 10-30°C (for example, it can be a range between values ​​such as 10°C, 20°C, 25°C and 30°C and any values ​​thereof), and a time of 4-6h (for example, it can be a range between values ​​such as 4h, 4.5h, 5h and 6h and any values ​​thereof).

[0054] According to the present invention, after the first polymerization reaction is completed, phenylethynylphthalic anhydride needs to be added for end-capping reaction. Preferably, the conditions of the end-capping reaction include: temperature of 0-40°C and time of 6-20h. More preferably, the conditions of the end-capping reaction include: temperature of 10-30°C (for example, it can be 10°C, 20°C, 25°C and 30°C and the range between any values ​​thereof), and time of 8-16h (for example, it can be 8h, 12h, 14h and 16h and the range between any values ​​thereof).

[0055] According to the present invention, after the end-capping reaction is completed, in order to obtain a solid phenylethynylphthalic anhydride end-capped polyimide resin, the reaction solution may be subjected to a first post-treatment, and the operation of the first post-treatment may be selected within a wide range. In order to obtain a product with higher purity and better properties, preferably, the first post-treatment includes adding a first dehydrating agent to the reaction solution, removing water at 160-190° C., distilling the first dehydrating agent at 200-250° C., and then precipitating the obtained resin solution in a first poor solvent, filtering, and drying to obtain the phenylethynylphthalic anhydride end-capped polyimide resin.

[0056] According to the present invention, preferably, the mass ratio of the first aromatic diamine monomer to the first dehydration agent is 1:0.6-1.5, preferably 1:0.8-1.3, for example, it can be 1:0.8, 1:0.9, 1:1 and 1:1.3 and any range therebetween.

[0057] According to the present invention, in order to obtain a polyimide toughening agent for use in the preparation of a polyimide resin composition, preferably, the method for preparing the polyimide toughening agent includes subjecting a second aromatic diamine monomer and a second aromatic dianhydride monomer to a second polymerization reaction in the presence of a second solvent to obtain the polyimide toughening agent.

[0058] According to the present invention, in order to obtain a better polyimide toughening agent, the amount of each material used in the preparation process can be adjusted. Preferably, the mass ratio of the second aromatic diamine monomer to the second aromatic dianhydride monomer is 1:0.6-1.2, preferably 1:0.8-1, for example, it can be 1:0.8, 1:0.9, 1:0.95 and 1:1 and any range between the values.

[0059] According to the present invention, in order to allow the various materials in the reaction to contact and react more fully, preferably, the mass ratio of the second aromatic diamine monomer to the second solvent is 1:6-15, preferably 1:8-12, for example, it can be 1:8, 1:10, 1:11 and 1:12 and any range therebetween.

[0060] According to the present invention, in order to make the second polymerization reaction proceed more smoothly, preferably, the conditions of the second polymerization reaction include: a temperature of 0-40°C and a time of 6-20h. More preferably, the conditions of the second polymerization reaction include: a temperature of 10-30°C (for example, it can be a range between values ​​such as 10°C, 20°C, 25°C and 30°C and any values ​​thereof), and a time of 8-16h (for example, it can be a range between values ​​such as 8h, 10h, 12h and 16h and any values ​​thereof).

[0061] According to the present invention, after the second polymerization reaction is completed, the reaction liquid can be subjected to a second post-treatment. Preferably, the second post-treatment comprises adding a second dehydration agent to the reaction liquid, removing water at 160-190° C., evaporating the second dehydration agent at 200-250° C., and then precipitating the obtained resin solution in a second poor solvent, filtering and drying to obtain the polyimide toughening agent.

[0062] According to the present invention, preferably, the mass ratio of the second aromatic diamine monomer to the second dehydration agent is 1:0.6-1.5, preferably 1:0.8-1.3, for example, it can be 1:0.8, 1:0.9, 1:1 and 1:1.3 and any range therebetween.

[0063] According to the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin and polyimide toughening agent, the first solvent and the second solvent can be selected in a wide range. In order to better carry out the reaction, preferably, the first solvent and the second solvent are each independently selected from one or more organic solvents, preferably chloroform, dioxane, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, γ-butyrolactone, ethyl lactate, cyclopentanone, cyclohexanone, methyl ethyl ketone, ethyl acetate and butyl acetate. One or more, more preferably N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone and ethyl acetate.

[0064] According to the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin and polyimide toughening agent, preferably, the first aromatic diamine monomer and the second aromatic diamine monomer are each independently selected from 1,4-p-phenylenediamine, 1,3-m-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,4'-bis(4'-aminophenoxy)benzene, 1,3-bis(4'-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, One or more of 1,5-bis(4-amino-2-trifluoromethylphenoxy)benzene, 4,4-bis(4-amino-2-trifluoromethylphenoxy)biphenyl, 2,6-bis(4-amino-2-trifluoromethylphenoxy)benzene, 2-phenyl-4,4'-diaminodiphenyl ether, 2,2'-bis(trifluoromethyl)-4,4'-biphenyl diamine, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether and 1,5-bis(4-amino-2-trifluoromethylphenoxy)benzene.

[0065] According to the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin and polyimide toughening agent, preferably, the first aromatic dianhydride monomer and the second aromatic dianhydride monomer are each independently selected from pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3',3,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether One or more of formic dianhydride, 2,3',3,4'-diphenyl ether formic acid dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, bisphenol A type diether dianhydride, (4-phthalic anhydride) formyloxy-4-phthalate, bis[(3,4-dianhydride)phenyl]terephthalate, p-phenylene diphthalate dianhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride, 4,4'-phenylenedioxy diphthalate tetracarboxylic dianhydride and 4,4'-(hexafluoroisopropyl) diphthalic anhydride.

[0066] In a preferred embodiment of the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin, the first aromatic diamine monomer is selected from 2,2'-bis(trifluoromethyl)-4,4'-biphenylenediamine, 3,4'-diaminodiphenyl ether, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether, 1,3-bis(4'-aminophenoxy)benzene, 2-phenyl-4,4'-diaminodiphenyl ether, 1,5-bis(4-amino-2-trifluoromethylphenoxy)benzene, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene and 2 ,6-bis(4-amino-2-trifluoromethylphenoxy)benzene; the first aromatic dianhydride monomer is selected from 2,3',3,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether carboxylic dianhydride, 2,3',3,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluoroisopropyl) diphenyl anhydride, p-phenylene trimellitic dianhydride, bis[(3,4-dianhydride)phenyl]terephthalate and 3,3',4,4'-diphenyl sulfonetetracarboxylic dianhydride.

[0067] In a preferred embodiment of the present invention, in the preparation process of the above-mentioned polyimide toughening agent, the second aromatic diamine monomer is selected from one or more of 2,2'-bis(trifluoromethyl)-4,4'-biphenyl diamine, 3,4'-diaminodiphenyl ether, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether, 1,3-bis(4'-aminophenoxy)benzene, 2-phenyl-4,4'-diaminodiphenyl ether and 1,3-m-phenylenediamine; the second aromatic dianhydride monomer is selected from one or more of 2,3',3,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether formic acid dianhydride, 2,3',3,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluoroisopropyl) diphthalic anhydride and 4,4'-phenylenedioxy diphthalic anhydride.

[0068] In a further preferred embodiment of the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin, 2,2'-bis(trifluoromethyl)-4,4'-biphenyl diamine and 3,4'-diaminodiphenyl ether are used as aromatic diamine monomers in a weight ratio of 4-9:1, and 2,3',3,4'-biphenyltetracarboxylic dianhydride and 3,3',4,4'-diphenyl ether formic acid dianhydride are used as aromatic dianhydride monomers in a weight ratio of 7-9:1. In the preparation process of the above-mentioned polyimide toughening agent, 2,2'-bis(trifluoromethyl)-4,4'-biphenyl diamine and 3,4'-diaminodiphenyl ether are used as aromatic diamine monomers in a weight ratio of 4-9:1, and 2,3',3,4'-biphenyltetracarboxylic dianhydride and 3,3',4,4'-diphenyl ether formic acid dianhydride are used as aromatic dianhydride monomers in a weight ratio of 7-9:1.

[0069] In a further preferred embodiment of the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether with a weight ratio of 4-9:1 is used as the aromatic diamine monomer, and 2,3',3,4'-benzophenonetetracarboxylic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride with a weight ratio of 1-2:1 are used as the aromatic dianhydride monomer. In the preparation process of the above-mentioned polyimide toughening agent, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether and 1,3-bis(4'-aminophenoxy)benzene with a weight ratio of 4-9:1 are used as the aromatic diamine monomer, and 2,3',3,4'-benzophenonetetracarboxylic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride with a weight ratio of 1-2:1 are used as the aromatic dianhydride monomer.

[0070] In a further preferred embodiment of the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin, 2-phenyl-4,4'-diaminodiphenyl ether is used as an aromatic diamine monomer, and 2,3',3,4'-benzophenonetetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride and 4,4'-(hexafluoroisopropyl) diphthalic anhydride in a weight ratio of 3-5:3-5:1 are used as aromatic dianhydride monomers. In the preparation process of the above-mentioned polyimide toughening agent, 2-phenyl-4,4'-diaminodiphenyl ether is used as an aromatic diamine monomer, and 4,4'-(hexafluoroisopropyl) diphthalic anhydride is used as an aromatic dianhydride monomer.

[0071] In a further preferred embodiment of the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin, 1,5-bis(4-amino-2-trifluoromethylphenoxy)benzene and 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene are used as aromatic diamine monomers in a weight ratio of 1-2:1, and p-phenylene diphthalate dianhydride and bis[(3,4-dianhydride)phenyl]terephthalate are used as aromatic dianhydride monomers in a weight ratio of 1-2:1. In the preparation process of the above-mentioned polyimide toughening agent, 1,3-bis(4'-aminophenoxy)benzene and 1,3-m-phenylenediamine are used as aromatic diamine monomers in a weight ratio of 4-9:1, and 2,3',3,4'-benzophenonetetracarboxylic dianhydride and 4,4'-phenylenedioxydiphthalic dianhydride are used as aromatic dianhydride monomers in a weight ratio of 1-2:1.

[0072] In a further preferred embodiment of the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin, 2,6-bis(4-amino-2-trifluoromethylphenoxy)benzene and 3,4'-diaminodiphenyl ether are used as aromatic diamine monomers in a weight ratio of 4-9:1, and 2,3',3,4'-biphenyltetracarboxylic dianhydride and 3,3',4,4'-diphenyl ether formic acid dianhydride are used as aromatic dianhydride monomers in a weight ratio of 7-9:1. In the preparation process of the above-mentioned polyimide toughening agent, 2,2'-bis(trifluoromethyl)-4,4'-biphenyl diamine and 3,4'-diaminodiphenyl ether are used as aromatic diamine monomers in a weight ratio of 4-9:1, and 2,3',3,4'-biphenyltetracarboxylic dianhydride and 3,3',4,4'-diphenyl ether formic acid dianhydride are used as aromatic dianhydride monomers in a weight ratio of 7-9:1.

[0073] In a further preferred embodiment of the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride terminated polyimide resin, 2,2'-bis(trifluoromethyl)-4,4'-biphenylenediamine and 3,4'-diaminodiphenyl ether are used as aromatic diamine monomers in a weight ratio of 4-9:1, and 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride and 3,3',4,4'-diphenylether formic acid dianhydride are used as aromatic dianhydride monomers in a weight ratio of 7-9:1. In the preparation process of the above-mentioned polyimide toughening agent, 2,2'-bis(trifluoromethyl)-4,4'-biphenylenediamine and 3,4'-diaminodiphenyl ether are used as aromatic diamine monomers in a weight ratio of 4-9:1, and 2,3',3,4'-biphenyltetracarboxylic dianhydride and 3,3',4,4'-diphenylether formic acid dianhydride are used as aromatic dianhydride monomers in a weight ratio of 7-9:1.

[0074] According to the present invention, in the preparation process of the above-mentioned phenylethynylphthalic anhydride-terminated polyimide resin and polyimide toughening agent, in the first post-treatment and the second post-treatment, the first dehydration agent, the second dehydration agent, the first poor solvent and the second poor solvent can be selected in a wide range. Preferably, the first dehydration agent and the second dehydration agent are each independently selected from one or more of toluene, xylene and acetic anhydride, preferably toluene and / or xylene. Preferably, the first poor solvent and the second poor solvent are each independently selected from one or more of water, methanol, ethanol and acetone, preferably water and / or ethanol. Wherein, the amount of the first poor solvent and the second poor solvent can be selected in a wide range, as long as the product can be completely precipitated, and the present invention has no special limitation on this.

[0075] The third aspect of the present invention provides a polyimide resin film prepared from the polyimide resin composition.

[0076] The polyimide resin film can be obtained by extruding the polyimide resin composition into a film through a film forming machine at a certain temperature, and the temperature can generally be 20-150°C, preferably 50-80°C, for example, it can be 50°C, 60°C, 70°C, 75°C and 80°C or any range between the values.

[0077] The polyimide resin film of the invention has good coating properties, no small molecules are released during the curing process, a wide process window, and good processing performance. The subsequently prepared polyimide composite material has excellent high temperature resistance and mechanical properties.

[0078] A fourth aspect of the present invention provides a polyimide prepreg made from the polyimide resin film and fibers.

[0079] The polyimide prepreg can be obtained by pressing the polyimide resin film and fibers (such as carbon fibers) through a hot melt process at a certain temperature, which can usually be 20-180°C, preferably 80-100°C, for example, 80°C, 90°C, 95°C and 100°C or any range between them. In the preparation process of the polyimide prepreg, the fibers can be selected from various fibers commonly used in the art, and the amounts of the polyimide resin film and the fibers can be selected in a wide range. Preferably, the fibers are carbon fibers. More preferably, the weight ratio of the polyimide resin film to the carbon fibers is 1:0.5-1.5, preferably 1:0.8-1.2, for example, 1:0.8, 1:1, 1:1.1 and 1:1.2 or any range between them.

[0080] A fifth aspect of the present invention provides a polyimide composite material prepared from the polyimide prepreg.

[0081] Among them, the above-mentioned polyimide composite material can be obtained by curing the polyimide prepreg at a certain temperature for a period of time through an autoclave or a hot molding process. The temperature can generally be 330-400°C, preferably 350-380°C, for example, it can be 350°C, 360°C, 370°C and 380°C or any range between the values; the time can generally be 1-8h, preferably 2-4h, for example, it can be 2h, 2.5h, 3h and 4h or any range between the values.

[0082] The polyimide resin composition and polyimide resin film of the present invention solve the problems of existing polyimide prepregs not being imidized, small molecules being released during the curing process, and poor process stability. The composition and film have excellent performance and process stability, and are used in the preparation of prepregs to achieve uniform regulation of resin content and surface density, avoid small molecules being released during the curing process, and also have good viscosity, draping and curing process performance, can be stored for a long time, can effectively reduce the defects of the final composite material product, improve the performance batch stability and yield rate of the composite material, reduce the manufacturing cost of the composite material, achieve stable batch production, and the composite material finally obtained also has excellent high temperature resistance and mechanical properties, and has good application prospects.

[0083] The present invention will be described in detail below through examples.

[0084] In the following examples, the devices and operations involved are conventional devices and operations in the art, and the materials used can be obtained commercially. Among them, carbon fiber was purchased from Jiangsu Hengshen Co., Ltd., with a brand name of HF40.

[0085] Example 1

[0086] (1) Preparation of phenylethynylphthalic anhydride terminated polyimide resin

[0087] 90 parts by weight of 2,2'-bis(trifluoromethyl)-4,4'-biphenylenediamine and 10 parts by weight of 3,4'-diaminodiphenyl ether were dissolved in 700 parts by weight of N-methylpyrrolidone, 80 parts by weight of 2,3',3,4'-biphenyltetracarboxylic dianhydride and 10 parts by weight of 3,3',4,4'-diphenylethercarboxylic dianhydride were added, and the mixture was reacted at 25°C for 5 hours after dissolution, and then 20 parts by weight of phenylethynylphthalic anhydride were added and reacted at 25°C for 12 hours. 90 parts by weight of toluene were added to the reaction solution, water was removed at 160°C, toluene was evaporated at 200°C, and the obtained resin solution was precipitated in water, and a phenylethynylphthalic anhydride-terminated polyimide resin (weight average molecular weight of about 8000 g / mol) with an average degree of polymerization of 9 was obtained by filtration and drying.

[0088] (2) Preparation of polyimide toughening agent

[0089] 90 parts by weight of 2,2'-bis(trifluoromethyl)-4,4'-biphenylenediamine and 10 parts by weight of 3,4'-diaminodiphenyl ether were dissolved in 1100 parts by weight of N-methylpyrrolidone, and 90 parts by weight of 2,3',3,4'-biphenyltetracarboxylic dianhydride and 10 parts by weight of 3,3',4,4'-diphenylethercarboxylic dianhydride were added, and the mixture was reacted at 25°C for 16 hours after dissolution. 130 parts by weight of toluene were added to the reaction solution, water was removed at 180°C, toluene was evaporated at 220°C, and the obtained resin solution was precipitated in water, and a polyimide toughening agent with a weight average molecular weight of about 25000 g / mol was obtained by filtration and drying.

[0090] (3) Preparation of polyimide resin composition

[0091] 100 parts by weight of phenylethynylphthalic anhydride terminated polyimide resin and 25 parts by weight of polyimide toughening agent were added to 54 parts by weight of N,N-dimethylformamide, and stirred at 160° C. for 6 hours to obtain a polyimide resin composition having a viscous transparent adhesive appearance.

[0092] (4) Preparation of polyimide resin film

[0093] The polyimide resin composition was extruded into a film by a film forming machine at 70° C. to obtain a polyimide resin film.

[0094] (5) Preparation of polyimide prepreg

[0095] The polyimide resin film and carbon fiber with a weight ratio of 1:1.1 are pressed at 100° C. through a hot melt process to obtain a polyimide prepreg.

[0096] (6) Preparation of polyimide composite materials

[0097] The polyimide prepreg was cured at 370° C. for 2 h through an autoclave process to obtain a polyimide composite material.

[0098] Example 2

[0099] (1) Preparation of phenylethynylphthalic anhydride terminated polyimide resin

[0100] 80 parts by weight of 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether and 20 parts by weight of 1,3-bis(4'-aminophenoxy)benzene were dissolved in 600 parts by weight of N-methylpyrrolidone, 50 parts by weight of 2,3',3,4'-benzophenonetetracarboxylic dianhydride and 40 parts by weight of 3,3',4,4'-biphenyltetracarboxylic dianhydride were added, and the mixture was reacted at 20°C for 4 hours after dissolution, and then 20 parts by weight of phenylethynylphthalic anhydride was added and reacted at 30°C for 8 hours. 90 parts by weight of toluene were added to the reaction solution, water was removed at 190°C, toluene was evaporated at 220°C, and the obtained resin solution was precipitated in ethanol, and a phenylethynylphthalic anhydride-terminated polyimide resin with an average degree of polymerization of 9 (weight average molecular weight of about 8000 g / mol) was obtained by filtration and drying.

[0101] (2) Preparation of polyimide toughening agent

[0102] 80 parts by weight of 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether and 20 parts by weight of 1,3-bis(4'-aminophenoxy)benzene were dissolved in 900 parts by weight of γ-butyrolactone, and 50 parts by weight of 2,3',3,4'-benzophenonetetracarboxylic dianhydride and 50 parts by weight of 3,3',4,4'-biphenyltetracarboxylic dianhydride were added, and the mixture was reacted at 20°C for 8 hours after dissolution. 90 parts by weight of toluene were added to the reaction solution, water was removed at 180°C, toluene was evaporated at 200°C, and the obtained resin solution was precipitated in ethanol, and a polyimide toughening agent with a weight average molecular weight of about 25,000 g / mol was obtained by filtration and drying.

[0103] (3) Preparation of polyimide resin composition

[0104] 100 parts by weight of phenylethynylphthalic anhydride terminated polyimide resin and 14 parts by weight of a polyimide toughening agent were added to 29 parts by weight of N,N-dimethylformamide, and stirred at 150° C. for 6 hours to obtain a polyimide resin composition having a viscous transparent adhesive appearance.

[0105] (4) Preparation of polyimide resin film

[0106] The polyimide resin composition was extruded into a film at 60° C. by a film forming machine to obtain a polyimide resin film.

[0107] (5) Preparation of polyimide prepreg

[0108] The polyimide resin film and carbon fiber in a weight ratio of 1:1 are pressed at 80° C. through a hot melt process to obtain a polyimide prepreg.

[0109] (6) Preparation of polyimide composite materials

[0110] The polyimide prepreg was cured at 370° C. for 2 h through an autoclave process to obtain a polyimide composite material.

[0111] Example 3

[0112] (1) Preparation of phenylethynylphthalic anhydride terminated polyimide resin

[0113] 100 parts by weight of 2-phenyl-4,4'-diaminodiphenyl ether was dissolved in 400 parts by weight of N-methylpyrrolidone, and 40 parts by weight of 2,3',3,4'-benzophenonetetracarboxylic dianhydride, 40 parts by weight of 2,3',3,4'-biphenyltetracarboxylic dianhydride and 10 parts by weight of 4,4'-(hexafluoroisopropyl) diphenyl anhydride were added, and the mixture was reacted at 25°C for 6 hours, and then 20 parts by weight of phenylethynyl phthalic anhydride was added and reacted at 20°C for 14 hours. 80 parts by weight of toluene was added to the reaction solution, water was removed at 160°C, toluene was evaporated at 200°C, and the obtained resin solution was precipitated in water, and the phenylethynyl phthalic anhydride-terminated polyimide resin with an average degree of polymerization of 9 (weight average molecular weight of about 8000 g / mol) was obtained by filtration and drying.

[0114] (2) Preparation of polyimide toughening agent

[0115] 100 parts by weight of 2-phenyl-4,4'-diaminodiphenyl ether was dissolved in 1000 parts by weight of N-methylpyrrolidone, and 100 parts by weight of 4,4'-(hexafluoroisopropyl)diphenyl anhydride was added, and the mixture was reacted at 25°C for 10 hours after dissolution. 100 parts by weight of xylene was added to the reaction solution, water was removed at 190°C, xylene was evaporated at 200°C, and the obtained resin solution was precipitated in water, and a polyimide toughening agent with a weight average molecular weight of about 30,000 g / mol was obtained by filtration and drying.

[0116] (3) Preparation of polyimide resin composition

[0117] 100 parts by weight of phenylethynylphthalic anhydride terminated polyimide resin and 31 parts by weight of polyimide toughening agent were added to 23 parts by weight of N,N-dimethylacetamide, and stirred at 150° C. for 6 hours to obtain a polyimide resin composition having a viscous transparent adhesive appearance.

[0118] (4) Preparation of polyimide resin film

[0119] The polyimide resin composition was extruded into a film at 60° C. by a film forming machine to obtain a polyimide resin film.

[0120] (5) Preparation of polyimide prepreg

[0121] The polyimide resin film and carbon fiber with a weight ratio of 1:1.2 are pressed at 95° C. through a hot melt process to obtain a polyimide prepreg.

[0122] (6) Preparation of polyimide composite materials

[0123] The polyimide prepreg was cured at 350° C. for 4 hours through an autoclave process to obtain a polyimide composite material.

[0124] Example 4

[0125] (1) Preparation of phenylethynylphthalic anhydride terminated polyimide resin

[0126] 60 parts by weight of 1,5-bis(4-amino-2-trifluoromethylphenoxy)benzene and 40 parts by weight of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene were dissolved in 800 parts by weight of N-methylpyrrolidone, 50 parts by weight of p-phenylene trimellitic acid dianhydride and 30 parts by weight of bis[(3,4-dianhydride)phenyl]terephthalate were added, and the mixture was reacted at 20°C for 6 hours after dissolution, and then 10 parts by weight of phenylethynylphthalic anhydride was added and reacted at 25°C for 10 hours. 100 parts by weight of toluene were added to the reaction solution, water was removed at 170°C, toluene was evaporated at 250°C, and the obtained resin solution was precipitated in water, and a phenylethynylphthalic anhydride-terminated polyimide resin (weight average molecular weight of about 10,000 g / mol) with an average degree of polymerization of 9 was obtained by filtration and drying.

[0127] (2) Preparation of polyimide toughening agent

[0128] 80 parts by weight of 1,3-bis(4'-aminophenoxy)benzene and 20 parts by weight of 1,3-m-phenylenediamine were dissolved in 1000 parts by weight of N-methylpyrrolidone, and 50 parts by weight of 2,3',3,4'-benzophenone tetracarboxylic dianhydride and 50 parts by weight of 4,4'-phenylenedioxydiphthalic dianhydride were added, and the mixture was reacted at 25°C for 14 hours after dissolution. 120 parts by weight of toluene were added to the reaction solution, water was removed at 190°C, toluene was evaporated at 210°C, and the obtained resin solution was precipitated in methanol, and a polyimide toughening agent with a weight average molecular weight of about 35,000 g / mol was obtained by filtration and drying.

[0129] (3) Preparation of polyimide resin composition

[0130] 100 parts by weight of phenylethynylphthalic anhydride terminated polyimide resin and 38 parts by weight of polyimide toughening agent were added to 25 parts by weight of N-methylpyrrolidone, and stirred at 140° C. for 8 hours to obtain a polyimide resin composition having a viscous transparent adhesive appearance.

[0131] (4) Preparation of polyimide resin film

[0132] The polyimide resin composition was extruded into a film by a film forming machine at 70° C. to obtain a polyimide resin film.

[0133] (5) Preparation of polyimide prepreg

[0134] The polyimide resin film and carbon fiber in a weight ratio of 1:1 are pressed at 90° C. through a hot melt process to obtain a polyimide prepreg.

[0135] (6) Preparation of polyimide composite materials

[0136] The polyimide prepreg was cured at 380° C. for 3 h through an autoclave process to obtain a polyimide composite material.

[0137] Example 5

[0138] The method of Example 1 is different in that in step (1), 2,2'-bis(trifluoromethyl)-4,4'-biphenylenediamine is replaced by 2,6-bis(4-amino-2-trifluoromethylphenoxy)benzene.

[0139] Example 6

[0140] The method of Example 1 is different in that, in step (1), 2,3',3,4'-biphenyltetracarboxylic dianhydride is replaced by 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride.

[0141] Example 7

[0142] The method of Example 1 is different in that in step (3), the amount of the polyimide toughening agent used is 5 parts by weight.

[0143] Example 8

[0144] The method of Example 1 is different in that in step (3), the amount of the polyimide toughening agent used is 50 parts by weight.

[0145] Comparative Example 1

[0146] 50 parts by weight of 2,3',3,4'-benzophenonetetracarboxylic dianhydride and 40 parts by weight of 3,3',4,4'-biphenyltetracarboxylic dianhydride were added to 160 parts by weight of ethanol and reacted for 3 hours to obtain esterification solution A. 20 parts by weight of phenylethynylphthalic anhydride were added to 40 parts by weight of ethanol and reacted for 3 hours to obtain esterification solution B. Esterification solution A and esterification solution B were combined, 80 parts by weight of 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether and 20 parts by weight of 1,3-bis(4'-aminophenoxy)benzene were added, dissolved and reacted at 25°C for 12 hours to obtain a polyimide resin solution with a solid content of 50wt% and a viscosity of 26mPa·s. The polyimide resin solution was dried at 200°C for 2 hours to obtain a polyimide resin molding powder (weight average molecular weight of about 8000g / mol).

[0147] The polyimide resin molding powder and carbon fiber in a weight ratio of 1:1.1 are wet coated at room temperature to obtain a polyimide prepreg.

[0148] The polyimide prepreg was cured at 380° C. for 2 h through an autoclave process to obtain a polyimide composite material.

[0149] Comparative Example 2

[0150] 50 parts by weight of 2,3',3,4'-benzophenonetetracarboxylic dianhydride and 40 parts by weight of 3,3',4,4'-biphenyltetracarboxylic dianhydride were added to 160 parts by weight of methanol and reacted for 3 hours to obtain esterification solution A. 20 parts by weight of phenylethynylphthalic anhydride were added to 40 parts by weight of methanol and reacted for 3 hours to obtain esterification solution B. Esterification solution A and esterification solution B were combined, 80 parts by weight of 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether and 20 parts by weight of 1,3-bis(4'-aminophenoxy)benzene were added, dissolved and reacted at 25°C for 12 hours, methanol was evaporated at 60°C, and a polyimide resin solution with a solid content of 80wt% and a viscosity of 25mPa·s was obtained. The polyimide resin solution was dried at 200°C for 2 hours to obtain a polyimide resin molding powder (weight average molecular weight of about 8000g / mol).

[0151] The polyimide resin molding powder and carbon fiber in a weight ratio of 1:1 are wet coated at room temperature to obtain a polyimide prepreg.

[0152] The polyimide prepreg was cured at 380° C. for 2 h through an autoclave process to obtain a polyimide composite material.

[0153] Test Case

[0154] The resin materials obtained in Examples 1-8 and Comparative Examples 1-2 were tested.

[0155] Thermal weight loss: tested using the American TA Q50 series thermal analyzer, with a nitrogen flow rate of 20cm 3 / min, the heating rate is 20℃ / min, and the heating range is 50-750℃. The thermal weight loss data of the resin material after heating from 300℃ to 400℃ can be obtained from the TGA curve.

[0156] Minimum melt viscosity: Use the American TA Instruments AR2000 rheometer to test the melt viscosity of the resin material and take the minimum value. A parallel plate fixture is used for the test, and the plate diameter is 25mm. First, the resin material is pressed into a disc with a diameter of 25mm and a thickness of 1.3-1.5mm to obtain a test sample. The test temperature is controlled by the ETC (forced air heating furnace) of the rheometer. First, the rheometer is preheated to the intermediate test temperature and reset, then cooled to the starting test temperature and loaded with the sample. After the temperature stabilizes, the test is carried out in the flow mode, and the constant shear stress mode (104Pa) is selected. The temperature range of the heating test is 270-400℃, and the heating rate is 4℃ / min.

[0157] Surface density: Cut the resin material into 10cm×10cm blocks, weigh the weight m (g), and calculate the surface density = m / 100. The unit of surface density is g / cm 2 .

[0158] Comparison of thermal gravimetric analysis (TGA) curves of the polyimide resin composition in Example 1 and the polyimide resin molding powder in Comparative Example 1 Figure 1 shown.

[0159] The melt viscosity curve of the polyimide resin composition in Example 1 is as follows: Figure 2 shown.

[0160] The melt viscosity curve of the polyimide resin molding powder in Comparative Example 1 is as follows: Figure 3 shown.

[0161] The film stretching mode was adopted by the American TA Q800 series DMA instrument. During the test, the static force was 125% of the dynamic force, the dynamic force loading frequency was 1Hz, the heating rate was 5℃ / min, the heating range was 25-550℃, and the sample size of the resin material was 25.0×6.5×0.06mm 3 , the dynamic mechanical properties (DMA) curve of the cured product of the polyimide resin composition in Example 1 can be obtained, as shown in FIG. Figure 4 shown.

[0162] The results are shown in Table 1.

[0163] Table 1

[0164]

[0165]

[0166] In the preparation of prepreg and composite materials, the resin content and surface density can be uniformly regulated by using the technical solution of the present invention in Examples 1-8. No small molecules are released during the curing process. The composite materials obtained have few defects and a high yield. Figure 1 It can be seen that the thermal weight loss rates of Examples 1-8 using the technical solution of the present invention are much better than those of Comparative Examples 1-2. Figure 2 It can be seen that the minimum melt viscosity of Examples 1-8 using the technical solution of the present invention is within a good range, and has good draping and processing performance. In addition, the surface density of the film and prepreg measured in Examples 1-8 is also within a good range. Figure 4 It can also be seen that the polyimide resin material provided by the present invention has excellent mechanical properties and thermal properties.

[0167] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A polyimide resin composition, characterized in that: The composition comprises a phenylethynylphthalic anhydride-terminated polyimide resin and a polyimide toughening agent, wherein the amount of the polyimide toughening agent is 5-50 parts by weight relative to 100 parts by weight of the phenylethynylphthalic anhydride-terminated polyimide resin; The structure of the phenylethynylphthalic anhydride terminated polyimide resin is shown in formula (I), and the structural unit of the polyimide toughening agent is shown in formula (II). Formula (I) Formula (II) Ar1 and Ar3 are each independently selected from phenylene, One or more of, R1 is selected from a chemical bond, One or more of, R2 and R3 are each independently selected from one or more of H, C1-C3 perfluoroalkyl and C6-C10 aryl, and R4 is selected from phenylene and / or biphenylene; Ar2 and Ar4 are each independently selected from One or more of, R5 and R6 are each independently selected from a chemical bond, R7, R8 and R9 are each independently selected from one or more of phenylene, biphenylene and C1-C6 alkylene, R 10 and R 11 Each independently selected from a chemical bond and / or a phenylene group; n is an integer selected from 1 to 18; The weight average molecular weight of the polyimide toughening agent is 5000-300000 g / mol.

2. The composition according to claim 1, wherein The polyimide toughening agent is used in an amount of 10-40 parts by weight relative to 100 parts by weight of the phenylethynylphthalic anhydride terminated polyimide resin; and / or, Ar1 and Ar3 are each independently selected from One or more of, preferably One or more of; and / or, Ar2 and Ar4 are each independently selected from One or more of, preferably One or more of; and / or, n is selected from an integer of 1-15, preferably an integer of 1-12; And / or, the weight average molecular weight of the polyimide toughening agent is 10000-150000 g / mol, preferably 20000-50000 g / mol; And / or, the molecular weight of the phenylethynylphthalic anhydride terminated polyimide resin is less than the molecular weight of the polyimide toughening agent.

3. The polyimide resin composition according to claim 1 or 2, wherein The composition further comprises a viscosity modifier, wherein the amount of the viscosity modifier is 10-80 parts by weight, preferably 20-60 parts by weight, relative to 100 parts by weight of the phenylethynylphthalic anhydride terminated polyimide resin; Preferably, the viscosity modifier is selected from one or more of chloroform, dioxane, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, γ-butyrolactone, ethyl lactate, cyclopentanone, cyclohexanone, methyl ethyl ketone, ethyl acetate and butyl acetate, preferably one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone and ethyl acetate.

4. A method for preparing a polyimide resin composition according to any one of claims 1 to 3, comprising contacting a phenylethynylphthalic anhydride-terminated polyimide resin and a polyimide toughening agent in the presence of a viscosity modifier to obtain a polyimide resin composition.

5. The method according to claim 4, wherein: The contact reaction conditions include: temperature of 60-200°C and time of 2-24h; Preferably, the contact reaction conditions include: temperature of 140-160° C. and time of 6-12 h.

6. The method according to claim 4 or 5, wherein: The preparation method of the phenylethynyl phthalic anhydride terminated polyimide resin comprises the steps of: performing a first polymerization reaction on a first aromatic diamine monomer and a first aromatic dianhydride monomer in the presence of a first solvent, and then adding phenylethynyl phthalic anhydride to perform a termination reaction to obtain the phenylethynyl phthalic anhydride terminated polyimide resin; Preferably, the mass ratio of the first aromatic diamine monomer, the first aromatic dianhydride monomer and the phenylethynyl phthalic anhydride is 1:0.6-1.2:0.05-0.5, preferably 1:0.8-1:0.1-0.3; Preferably, the mass ratio of the first aromatic diamine monomer to the first solvent is 1:2-10, preferably 1:4-8; Preferably, the conditions of the first polymerization reaction include: temperature of 0-40°C, time of 3-8h; More preferably, the conditions of the first polymerization reaction include: temperature of 10-30°C, time of 4-6h; Preferably, the conditions for the end-capping reaction include: temperature of 0-40°C, and time of 6-20h; more preferably, the conditions for the end-capping reaction include: temperature of 10-30°C, and time of 8-16h.

7. The method according to any one of claims 4 to 6, wherein: The preparation method of the polyimide toughening agent comprises the following steps: in the presence of a second solvent, subjecting a second aromatic diamine monomer and a second aromatic dianhydride monomer to a second polymerization reaction to obtain the polyimide toughening agent; Preferably, the mass ratio of the second aromatic diamine monomer to the second aromatic dianhydride monomer is 1:0.6-1.2, preferably 1:0.8-1; Preferably, the mass ratio of the second aromatic diamine monomer to the second solvent is 1:6-15, preferably 1:8-12; Preferably, the conditions of the second polymerization reaction include: temperature of 0-40°C, and time of 6-20h; more preferably, the conditions of the second polymerization reaction include: temperature of 10-30°C, and time of 8-16h.

8. The method according to claim 6 or 7, wherein: The first solvent and the second solvent are each independently selected from one or more of chloroform, dioxane, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, γ-butyrolactone, ethyl lactate, cyclopentanone, cyclohexanone, methyl ethyl ketone, ethyl acetate and butyl acetate, more preferably one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone and ethyl acetate; and / or, the first aromatic diamine monomer and the second aromatic diamine monomer are each independently selected from one or more of 1,4-p-phenylenediamine, 1,3-m-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,4'-bis(4'-aminophenoxy)benzene, 1,3-bis(4'-aminophenoxy)benzene, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 4,4-bis(4-amino-2-trifluoromethylphenoxy)biphenyl, 2,6-bis(4-amino-2-trifluoromethylphenoxy)benzene, 2-phenyl-4,4'-diaminodiphenyl ether, 2,2'-bis(trifluoromethyl)-4,4'-biphenyl diamine, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether and 1,5-bis(4-amino-2-trifluoromethylphenoxy)benzene; and / or, the first aromatic dianhydride monomer and the second aromatic dianhydride monomer are each independently selected from pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3',3,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether formic acid dianhydride, 2,3',3,4'-diphenyl ether formic acid dianhydride, One or more of dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, bisphenol A type diether dianhydride, (4-phthalic anhydride) formyloxy-4-phthalate, bis[(3,4-dianhydride)phenyl]terephthalate, p-phenylene diphthalate dianhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride, 4,4'-phenylenedioxy diphthalate tetracarboxylic dianhydride and 4,4'-(hexafluoroisopropyl) diphthalic anhydride.

9. A polyimide resin film prepared from the polyimide resin composition according to any one of claims 1 to 3.

10. A polyimide prepreg made from the polyimide resin film and fiber according to claim 9.

11. A polyimide composite material prepared from the polyimide prepreg according to claim 10.

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